DETAILED ACTION
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
2. Applicant's election without traverse of claims 1-15 in the reply filed on 2/12/2026 is acknowledged.
3. Claims 16-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected group.
4. Applicant cancelled claims 16-20; and added claims 21-25.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(B) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
2. Claims 1-7 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding the limitations, "the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the bottom portion of the trench” (Claim 1, Lines 20-22), it is unclear how the first dielectric layer can have a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the same bottom portion of the trench. Because the first dielectric layer is deposited on the same location, the deposition rate on the bottom surface of the trench is expected to be the same such that the above limitations are unclear. Claims 2-7 depend from claim 1 and inherit its deficiencies. Examiner is reading this limitation, “the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the bottom portion of the trench”, as “the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the top portion of the trench”.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Hsueh et al. (US 2021/0111176) (hereafter Hsueh), in view of Lee et al. (US 2020/0176259) (hereafter Lee259), in further view of Harada et al. (US 2018/0308681) (hereafter Harada).
Regarding claim 1, Hsueh discloses a method, comprising:
forming a first semiconductor fin (leftmost 64 in Fig. 12B, paragraph 0023) and a second semiconductor fin (rightmost 64 in Fig. 12B, paragraph 0023) over a substrate 50 (Fig. 12B, paragraph 0022);
forming a gate structure 97 (Fig. 12A, paragraph 0035) over the substrate 50 (Fig. 12A) and crossing the first (leftmost 64 in Fig. 12A) and second semiconductor fins (rightmost 64 in Fig. 12A);
forming a first source/drain epitaxy structure (leftmost 80 in Fig. 12B, paragraph 0031) over the first semiconductor fin (leftmost 64 in Fig. 12B) and a second source/drain epitaxy structure (rightmost 80 in Fig. 12B, paragraph 0018) over the second semiconductor fin (rightmost 64 in Fig. 12B), respectively;
forming an interlayer dielectric (ILD) layer 90 (Fig. 12B, paragraph 0035) over the first (leftmost 80 in Fig. 12B) and second source/drain epitaxy structures (rightmost 80 in Fig. 12B);
etching (see Figs. 14A and 14B, paragraph 0049) the gate structure 97 (Fig. 14A) and the ILD layer 90 (Fig. 14B) to form a trench 141 (Figs. 14A and 14B, paragraph 0049), the trench 141 (Fig. 14B) being between the first (leftmost 80 in Fig. 14B) and second source/drain epitaxy structures (rightmost 80 in Fig. 14B), wherein in a cross-sectional view perpendicular to a lengthwise direction (stacking direction in Fig. 14b) of the first (leftmost 64 in Fig. 14B) and second semiconductor fins (rightmost 64 in Fig. 14B), the trench 141 (Fig. 14B) comprises a top portion (141 between 124 in Fig. 14B) and a bottom portion (141 between 90 in Fig. 14B) separated by a neck portion (141 between 122 in Fig. 14B), the neck portion (141 between 122 in Fig. 14B) having a maximal width (vertical length of 141 between 122 in Fig. 14B) less than a maximal width (vertical length of 141 between 124 in Fig. 14B) of the top portion (141 between 124 in Fig. 14B) and a maximal width (vertical length of 141 between 90 in Fig. 14B) of the bottom portion (141 between 90 in Fig. 14B);
depositing a first dielectric layer (bottom layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) in the trench 141 (Fig. 14B); and
the first dielectric layer (bottom layer of 140 in Fig. 15B) has a deposition rate on the surfaces of the bottom portion of the trench 141 (Fig. 14B) same as (see Fig. 15B and paragraph 0054, wherein the first dielectric layer is deposited on the same location such that the deposition rate on the bottom surface of the trench is same) on the surfaces of the bottom portion of the trench.
Hsueh does not disclose performing a first surface treatment to modify surfaces of the top portion and the bottom portion of the trench to NH-terminated;
performing a second surface treatment to modify the surfaces of the top portion of the trench to N-terminated, while leaving the surfaces of the bottom portion of the trench being NH-terminated; and
wherein the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the bottom portion of the trench.
Lee259 discloses performing a first surface treatment (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) to modify surfaces of the top portion and the bottom portion of the trench 141 (Fig. 32, paragraph 0053) to NH-terminated;
performing a second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) to modify the surfaces of the top portion of the trench 141 (Fig. 32) to N-terminated, while leaving the surfaces of the bottom portion of the trench being NH-terminated.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include performing a first surface treatment to modify surfaces of the top portion and the bottom portion of the trench to NH-terminated; performing a second surface treatment to modify the surfaces of the top portion of the trench to N-terminated, while leaving the surfaces of the bottom portion of the trench being NH-terminated, as taught by Lee259, since the precursor (Lee259, paragraph 0053) reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053). In addition, since the H.sub.2 gas (Lee259, paragraph 0053) functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141 (Lee259, Fig. 32, paragraph 0053).
Hsueh and Lee259 do not disclose the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the top portion of the trench.
Harada discloses the first dielectric layer (“SiN” in Fig. 6B) has a higher deposition rate (see paragraph 0110, wherein “the film thickness (deposition rate) of the SiN film formed on the lower portion of the trench is thicker (larger) than the film thickness (deposition rate) of the SiN film formed on the upper portion of the trench”) on the surfaces of the bottom portion of the trench (“TRENCH” in Fig. 6B) than on the surfaces of the top portion of the trench (“TRENCH” in Fig. 6B).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Lee259 to include the first dielectric layer has a higher deposition rate on the surfaces of the bottom portion of the trench than on the surfaces of the top portion of the trench, as taught by Harada, since it is possible (Harada, paragraph 0038) to realize a bottom-up film formation in which the filling of the SiN film gradually proceeds from the lower portion to the upper portion of the trench, and it is possible to fill the trench of the pattern with the SiN film in without a gap.
Regarding claim 2, Hsueh in view of Lee259 and Harada discloses the method of claim 1, however Hsueh does not disclose the first surface treatment comprises supplying a first nitrogen containing gas and a hydrogen containing gas over the substrate, and the second surface treatment comprises supplying a second nitrogen containing gas over the substrate without using hydrogen containing gas.
Lee259 discloses the first surface treatment (see Fig. 32, paragraph 0053) comprises supplying (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) a first nitrogen containing gas and a hydrogen containing gas over the substrate 50 (Fig. 32, paragraph 0013), and the second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) comprises supplying a second nitrogen containing gas over the substrate 50 (Fig. 32) without using hydrogen containing gas.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include the first surface treatment comprises supplying a first nitrogen containing gas and a hydrogen containing gas over the substrate, and the second surface treatment comprises supplying a second nitrogen containing gas over the substrate without using hydrogen containing gas, as taught by Lee259, since the precursor (Lee259, paragraph 0053) reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053). In addition, since the H.sub.2 gas (Lee259, paragraph 0053) functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141 (Lee259, Fig. 32, paragraph 0053).
Regarding claim 3, Hsueh in view of Lee259 and Harada discloses the method of claim 2, however Hsueh does not disclose supplying the second nitrogen containing gas is controlled such that the second nitrogen containing gas does not reach the bottom portion of the trench.
Lee259 discloses supplying the second nitrogen containing gas (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) is controlled such that the second nitrogen containing gas does not reach (see Fig. 34, wherein 142 is formed on the bottom of the trench; and see paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process” such that N.sub.2 gas does not reach the bottom portion of the trench) the bottom portion of the trench 141 (Fig. 32, paragraph 0053).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include supplying the second nitrogen containing gas is controlled such that the second nitrogen containing gas does not reach the bottom portion of the trench, as taught by Lee259, since the first N.sub.2 gas (Lee259, paragraph 0053) is used to remove the unreacted materials on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053) through a purge process.
Regarding claim 4, Hsueh in view of Lee259 and Harada discloses the method of claim 2, however Hsueh does not disclose the first surface treatment is performed under a first pressure and the second surface treatment is performed under a second pressure greater than the first pressure.
Lee259 discloses the first surface treatment (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) is performed under a first pressure (see paragraph 0060, wherein “about 15 T”) and the second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) is performed under a second pressure (see paragraph 0057, wherein “about 22.5 T”) greater than the first pressure (see paragraph 0060, wherein “about 15 T”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include the first surface treatment is performed under a first pressure and the second surface treatment is performed under a second pressure greater than the first pressure, as taught by Lee259, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 5, Hsueh in view of Lee259 and Harada discloses the method of claim 2, however Hsueh does not disclose a duration of the first surface treatment is longer than a duration of the second surface treatment.
Lee259 discloses a duration (see paragraph 0056, wherein “about 30 seconds”) of the first surface treatment (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) is longer than a duration (see paragraph 0056, wherein “about 0.1 seconds”) of the second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include a duration of the first surface treatment is longer than a duration of the second surface treatment, as taught by Lee259, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Lee259 and Harada as applied to claim 1 above, and further in view of Chen et al. (US 2021/0166978) (hereafter Chen978).
Regarding claim 6, Hsueh further discloses the method of claim 1, further comprising depositing a second dielectric layer (top layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) over the first dielectric layer (bottom layer of 140 in Fig. 15B) and overfilling the trench 141 (Fig. 14B), wherein the second dielectric layer (top layer of 140 in Fig. 15B, paragraph 0054) and the first dielectric layer (bottom layer of 140 in Fig. 15B, paragraph 0054) are made of a same material.
Hsueh, Lee259, and Harada do not disclose while the second dielectric layer has a higher hydrogen atomic concentration than the first dielectric layer.
Chen978 discloses while the second dielectric layer 242 (Fig. 20A, paragraph 0056) has a higher hydrogen atomic concentration (see paragraph 0056, wherein “a concentration of carbon, oxygen, nitrogen, silicon, fluorine, or hydrogen in the silicon-containing precursor of the flowable dielectric material 244 is less than that in the flowable dielectric material 242”) than the first dielectric layer 244 (Fig. 20A, paragraph 0056) .
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Lee259 and Harada to include the second dielectric layer has a higher hydrogen atomic concentration than the first dielectric layer, as taught by Chen978, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Lee259 and Harada as applied to claim 1 above, and further in view of Su et al. (US 2020/0043794) (hereafter Su).
Regarding claim 7, Hsueh in view of Lee259 and Harada discloses the method of claim 1, however Hsueh, Lee259, and Harada do not disclose the neck portion of the trench is substantially level with a widest portion of the first source/drain epitaxy structure.
Su discloses the neck portion (middle portion of T3 in Fig. 8A) of the trench T3 (Fig. 8A, paragraph 0061) is substantially level with a widest portion of the first source/drain epitaxy structure 16 (Fig. 8A, paragraph 0061).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Lee259 and Harada to include the neck portion of the trench is substantially level with a widest portion of the first source/drain epitaxy structure, as taught by Su, since a change in size is generally recognized as being within the level of ordinary skill in the art In re Rose, 105 USPQ 237 (CCPA 1955). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claims 8-11, 13, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Hsueh et al. (US 2021/0111176) (hereafter Hsueh), in view of Su et al. (US 2020/0043794) (hereafter Su), in further view of Lee et al. (US 2020/0176259) (hereafter Lee259), in another further view of Liaw et al. (US 2016/0020210) (hereafter Liaw).
Regarding claim 8, Hsueh discloses a method, comprising:
forming a first semiconductor fin (leftmost 64 in Fig. 12B, paragraph 0023) and a second semiconductor fin (rightmost 64 in Fig. 12B, paragraph 0023) over a substrate 50 (Fig. 12B, paragraph 0022);
forming a gate structure 97 (Fig. 12A, paragraph 0035) over the substrate 50 (Fig. 12A) and crossing the first (leftmost 64 in Fig. 12A) and second semiconductor fins (rightmost 64 in Fig. 12A);
forming a first source/drain epitaxy structure (leftmost 80 in Fig. 12B, paragraph 0031) over the first semiconductor fin (leftmost 64 in Fig. 12B) and a second source/drain epitaxy structure (rightmost 80 in Fig. 12B, paragraph 0018) over the second semiconductor fin (rightmost 64 in Fig. 12B), respectively;
forming an interlayer dielectric (ILD) layer 90 (Fig. 12B, paragraph 0035) over the first (leftmost 80 in Fig. 12B) and second source/drain epitaxy structures (rightmost 80 in Fig. 12B);
etching (see Figs. 14A and 14B, paragraph 0049) the gate structure 97 (Fig. 14A) to form a trench 141 (Figs. 14A and 14B, paragraph 0049) that breaks the gate structure 97 (Fig. 14A) into discontinuous first (left 97 in Fig. 14A) and second gate structures (right 97 in Fig. 14A);
depositing a first dielectric layer (bottom layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) along surfaces of the trench 141 (Fig. 14B), the trench comprising a top portion (top portion of 141 in Fig. 15B) and a bottom portion (bottom portion of 141 in Fig. 15B) below the top portion (top portion of 141 in Fig. 15B); and
depositing a second dielectric layer (top layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) over the first dielectric layer (bottom layer of 140 in Fig. 15B) and overfilling the trench 141 (Fig. 14B).
Hsueh does not disclose the trench has a bowling-shape cross-sectional profile.
Su discloses the trench (T3 in Fig. 8B, paragraph 0061, wherein “bowling shaped”) has a bowling-shape cross-sectional profile.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include the trench has a bowling-shape cross-sectional profile, as taught by Su, since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp, in the instant case choosing bowling shaped from the shapes listed in Su (e.g. bowling shaped, vase shaped, or the like); if this leads to the anticipated success, in the instant case providing a method of forming trench for dielectric layer, it is likely the product not of innovation but of ordinary skill. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007).
Hsueh and Su do not disclose depositing the first dielectric layer comprises:
performing a surface modification process such that surfaces of the top portion of the trench and surfaces of the bottom portion of the trench have different termination species; and
performing a first deposition cycle by sequentially supplying a first precursor and a second precursor into the trench, wherein the surface modification process and the first deposition cycle are repeatedly performed until the trench has a V-shape cross-sectional profile.
Lee259 discloses depositing the first dielectric layer 142 (Fig. 34, paragraph 0053) comprises:
performing a surface modification process (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) such that surfaces of the top portion of the trench 141 (Fig. 32, paragraph 0053) and surfaces of the bottom portion of the trench 141 (Fig. 32) have different termination species; and
performing a first deposition cycle by sequentially supplying a first precursor (“precursor comprising diiodosilane, an N.sub.2 gas and an H.sub.2 gas” in paragraph 0053) and a second precursor (“The precursor reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141” in paragraph 0053) into the trench 141 (Fig. 32), wherein the surface modification process and the first deposition cycle (“The bulk PEALD process is applied to the FinFETs repeatedly until the first dielectric layer 142 is formed” in paragraph 0059) are repeatedly performed.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su to include depositing the first dielectric layer comprises: performing a surface modification process such that surfaces of the top portion of the trench and surfaces of the bottom portion of the trench have different termination species; and performing a first deposition cycle by sequentially supplying a first precursor and a second precursor into the trench, wherein the surface modification process and the first deposition cycle are repeatedly performed, as taught by Lee259, since the precursor (Lee259, paragraph 0053) reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053). In addition, since the H.sub.2 gas (Lee259, paragraph 0053) functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141 (Lee259, Fig. 32, paragraph 0053).
Hsueh, Su, and Lee259 do not disclose the trench has a V-shape cross-sectional profile.
Liaw discloses the trench 222 (Fig. 4C, paragraph 0031, wherein “V-shaped trench”) has a V-shape cross-sectional profile.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su and Lee259 to include the trench has a V-shape cross-sectional profile, as taught by Liaw, since such a modification would have involved a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular configuration of the claimed invention was significant. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Regarding claim 9, Hsueh in view of Su, Lee259, and Liaw discloses the method of claim 8, however Hsueh and Su do not disclose the surface modification process comprises: performing a first surface treatment by supplying N2 gas and H2 gas with plasma treatment; and performing a second surface treatment by supplying N2 gas with plasma treatment, wherein the first surface treatment is performed under a lower pressure than the second surface treatment, such that the surfaces of the top portion of the trench has more N- termination species than the surfaces of the bottom portion of the trench.
Lee259 discloses the surface modification process comprises: performing a first surface treatment (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) by supplying N2 gas and H2 gas with plasma treatment; and performing a second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) by supplying N2 gas with plasma treatment, wherein the first surface treatment is performed under a lower pressure (see paragraph 0060, wherein “about 15 T”; and see paragraph 0057, wherein “about 22.5 T”) than the second surface treatment, such that the surfaces (see paragraph 0053) of the top portion of the trench has more N- termination species than the surfaces of the bottom portion of the trench.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su to include the surface modification process comprises: performing a first surface treatment by supplying N2 gas and H2 gas with plasma treatment; and performing a second surface treatment by supplying N2 gas with plasma treatment, wherein the first surface treatment is performed under a lower pressure than the second surface treatment, such that the surfaces of the top portion of the trench has more N- termination species than the surfaces of the bottom portion of the trench, as taught by Lee259, since the precursor (Lee259, paragraph 0053) reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053). In addition, since the H.sub.2 gas (Lee259, paragraph 0053) functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141 (Lee259, Fig. 32, paragraph 0053).
Regarding claim 10, Hsueh in view of Su, Lee259, and Liaw discloses the method of claim 9, however Hsueh and Su do not disclose the first surface treatment is performed for a longer duration than the second surface treatment.
Lee259 discloses the first surface treatment (see Fig. 32, paragraph 0053, wherein “In the third step, the RF source is turned on and a N.sub.2 plasma treatment (the first N.sub.2 gas) is applied to the sidewalls of trench 141” and “During the third step, after the RF source has been turned on, the H.sub.2 gas functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141”) is performed for a longer duration (see paragraph 0056, wherein “about 30 seconds”; and see paragraph 0056, wherein “about 0.1 seconds”) than the second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su to include the first surface treatment is performed for a longer duration than the second surface treatment, as taught by Lee259, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 11, Hsueh in view of Su, Lee259, and Liaw discloses the method of claim 9, however Hsueh and Su do not disclose the second surface treatment is performed without using H2 gas.
Lee259 discloses the second surface treatment (see Fig. 32, paragraph 0053, wherein “In the fourth step, the first N.sub.2 gas is used to remove the unreacted materials on the sidewalls of trench 141 through a purge process”) is performed without using H2 gas.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su to include the second surface treatment is performed without using H2 gas, as taught by Lee259, since the precursor (Lee259, paragraph 0053) reacts with the N.sub.2 plasma to form a silicon nitride layer on the sidewalls of trench 141 (Lee259, Fig. 32, paragraph 0053). In addition, since the H.sub.2 gas (Lee259, paragraph 0053) functions as an H.sub.2 plasma treatment to cure the damages on the sidewalls of the trench 141 (Lee259, Fig. 32, paragraph 0053).
Regarding claim 13, Hsueh further discloses the method of claim 12, wherein the second dielectric layer (top layer of 140 in Fig. 15B, paragraph 0054, wherein “ALD”) has a uniform deposition rate at the bottom portion of the trench 141 (Fig. 14B) and at the top portion of the trench 141 (Fig. 14B).
Regarding claim 14, Hsueh further discloses the method of claim 8, wherein the first (bottom layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) and second dielectric layers (top layer of 140 in Fig. 15B) are made of a same material.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Su, Lee259, and Liaw as applied to claim 9 above, and further in view of Harada et al. (US 2018/0308681) (hereafter Harada).
Regarding claim 12, Hsueh in view of Su, Lee259, and Liaw discloses the method of claim 9, however Hsueh, Su, Lee259, and Liaw do not disclose the first dielectric layer has a higher deposition rate at the bottom portion of the trench than at the top portion of the trench.
Harada discloses the first dielectric layer (“SiN” in Fig. 6B) has a higher deposition rate (see paragraph 0110, wherein “the film thickness (deposition rate) of the SiN film formed on the lower portion of the trench is thicker (larger) than the film thickness (deposition rate) of the SiN film formed on the upper portion of the trench”) at the bottom portion of the trench (“TRENCH” in Fig. 6B) than at the top portion of the trench (“TRENCH” in Fig. 6B).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su, Lee259, and Liaw to include the first dielectric layer has a higher deposition rate at the bottom portion of the trench than at the top portion of the trench, as taught by Harada, since it is possible (Harada, paragraph 0038) to realize a bottom-up film formation in which the filling of the SiN film gradually proceeds from the lower portion to the upper portion of the trench, and it is possible to fill the trench of the pattern with the SiN film in without a gap.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Su, Lee259, and Liaw as applied to claim 8 above, and further in view of Kwak et al. (US 2018/0090493) (hereafter Kwak).
Regarding claim 15, Hsueh further discloses the method of claim 8, wherein the first dielectric layer (bottom layer of 140 in Fig. 15B, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) is free of void.
Hsueh, Su, Lee259, and Liaw do not disclose a void is formed in the second dielectric layer.
Kwak discloses a void 162g (Fig. 7C, paragraph 0090) is formed in the second dielectric layer 162 (Fig. 7C, paragraph 0090).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Su, Lee259, and Liaw to include a void is formed in the second dielectric layer, as taught by Kwak, since the semiconductor device (Kwak, paragraph 0068) can have enhanced reliability.
Claims 21 and 25 are rejected under 35 U.S.C. 103 as being unpatentable over Hsueh et al. (US 2021/0111176) (hereafter Hsueh), in view of Chen et al. (US 2021/0166978) (hereafter Chen978).
Regarding claim 21, Hsueh discloses a method, comprising:
forming a first semiconductor fin (leftmost 64 in Fig. 14A, paragraph 0023) and a second semiconductor fin (rightmost 64 in Fig. 14A, paragraph 0023) over a substrate 50 (Fig. 14A, paragraph 0022);
forming a first gate structure (left 97 in Fig. 14A, paragraph 0035) and a second gate structure (right 97 in Fig. 14A, paragraph 0035) over the substrate and crossing the first (leftmost 64 in Fig. 14A) and second semiconductor fins (rightmost 64 in Fig. 14A);
forming a first source/drain epitaxy structure (leftmost 80 in Fig. 14A, paragraph 0031) over the first semiconductor fin (leftmost 64 in Fig. 14A) and a second source/drain epitaxy structure (rightmost 80 in Fig. 14A, paragraph 0031) over the second semiconductor fin ((rightmost 64 in Fig. 14A), respectively; and
forming an isolation structure 140 (Fig. 15A, paragraph 0054) having opposite sides respectively interfacing a longitudinal end of the first gate structure (left 97 in Fig. 15A) and a longitudinal end of the second gate structure (right 97 in Fig. 15A), wherein the isolation structure 140 (Fig. 15A) comprises: a first portion (bottom layer of 140 in Fig. 15A; paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”); and
a second portion (top layer of 140 in Fig. 15A) over the first portion (bottom layer of 140 in Fig. 15A), wherein in a cross-sectional view, the first portion (bottom layer of 140 in Fig. 15A) cups an underside of the second portion (top layer of 140 in Fig. 15A).
Hsueh does not disclose the second portion has a higher hydrogen atomic concentration than the first portion.
Chen978 discloses the second portion 242 (Fig. 20A, paragraph 0056) has a higher hydrogen atomic concentration (see paragraph 0056, wherein “a concentration of carbon, oxygen, nitrogen, silicon, fluorine, or hydrogen in the silicon-containing precursor of the flowable dielectric material 244 is less than that in the flowable dielectric material 242”) than the first portion 244 (Fig. 20A, paragraph 0056).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh to include the second portion has a higher hydrogen atomic concentration than the first portion, as taught by Chen978, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 25, Hsueh further discloses the method of claim 21, wherein the first portion (bottom layer of 140 in Fig. 15A, paragraph 0054, wherein “the dielectric material may include multiple materials or multiple layers”) of the isolation structure 140 (Fig. 15A) and the second portion (top layer of 140 in Fig. 15A) of the isolation structure 140 (Fig. 15A) are made of a same material.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Chen978 as applied to claim 21 above, and further in view of Su et al. (US 2020/0043794) (hereafter Su), another further in view of Lee et al. (US 2020/0027991) (hereafter Lee991).
Regarding claim 22, Hsueh in view of Chen978 discloses the method of claim 21, however Hsueh and Chen978 do not disclose the isolation structure has a bowling-shape cross-sectional profile, while the second portion of the isolation structure has a triangular cross-sectional profile.
Su discloses the isolation structure 28a (Fig. 10A, paragraph 0063; and see paragraph 0061, wherein “bowling shaped”) has a bowling-shape cross-sectional profile.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Chen978 to include the isolation structure has a bowling-shape cross-sectional profile, while the second portion of the isolation structure has a triangular cross-sectional profile, as taught by Su, since a person of ordinary skill has good reason to pursue the known options within his or her technical grasp, in the instant case choosing bowling shaped from the shapes listed in Su (e.g. bowling shaped, vase shaped, or the like); if this leads to the anticipated success, in the instant case providing a method of forming trench for dielectric layer, it is likely the product not of innovation but of ordinary skill. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007).
Hsueh, Chen978, and Su do not disclose the second portion of the isolation structure has a triangular cross-sectional profile.
Lee991 discloses the second portion of the isolation structure 902 (Fig. 9, paragraph 0044) has a triangular cross-sectional profile.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Chen978 and Su to include the second portion of the isolation structure has a triangular cross-sectional profile, as taught by Lee991, since such a modification would have involved a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular configuration of the claimed invention was significant. In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Chen978 as applied to claim 21 above, and further in view of Su et al. (US 2020/0043794) (hereafter Su).
Regarding claim 24, Hsueh in view of Chen978 discloses the method of claim 21, however Hsueh and Chen978 do not disclose a first lateral thickness of the first portion of the isolation structure below a widest portion of the first source/drain epitaxy structure is greater than a second lateral thickness of the first portion of the isolation structure above a widest portion of the first source/drain epitaxy structure.
Su discloses a first lateral thickness (horizontal length of lower portion of 28a in Fig. 10A) of the first portion of the isolation structure 28a (Fig. 10A, paragraph 0063) below a widest portion of the first source/drain epitaxy structure 16 (Fig. 10A, paragraph 0076) is greater than a second lateral thickness (horizontal length of upper portion of 28a in Fig. 10A) of the first portion of the isolation structure 28a (Fig. 10A) above a widest portion of the first source/drain epitaxy structure 16 (Fig. 10A).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Chen978 to include a first lateral thickness of the first portion of the isolation structure below a widest portion of the first source/drain epitaxy structure is greater than a second lateral thickness of the first portion of the isolation structure above a widest portion of the first source/drain epitaxy structure, as taught by Su, since a change in size is generally recognized as being within the level of ordinary skill in the art In re Rose, 105 USPQ 237 (CCPA 1955). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Hsueh, in view of Chen978 as applied to claim 21 above, and further in view of Chen et al. (US 2021/0098594) (hereafter Chen594).
Regarding claim 23, Hsueh in view of Chen978 discloses the method of claim 21, however Hsueh and Chen978 do not disclose in a top view, the first portion covers at least four sides of the second portion.
Chen594 disclose in a top view (see Fig. 6M), the first portion 222 (Fig. 6M, paragraph 0037) covers (see Fig. 6M, wherein 222 covers inner sides of 220) at least four sides of the second portion 220 (Fig. 6M, paragraph 0037).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Hsueh in view of Chen978 to include in a top view, the first portion covers at least four sides of the second portion, as taught by Chen594, since the dielectric layer 220 (Chen594, Fig. 6M, paragraph 0038) serves as a barrier for preventing oxygen atoms from diffusing into the HKMG structure 210 (Chen594, Fig. 6M, paragraph 0038).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LAMONT B KOO whose telephone number is (571)272-0984. The examiner can normally be reached 7:00 AM - 3:30 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Steven Gauthier can be reached on (571)270-0373. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/L.B.K/Examiner, Art Unit 2813
/STEVEN B GAUTHIER/Supervisory Patent Examiner, Art Unit 2813