Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Acknowledgement
This office action is in response to the communication filed on 12/15/2025.
Claims 1, 8, and 12-29 are currently pending in the present application. Claim 12 has been amended, claims 2-7 and 9-11 have been canceled, and new claims 21-29 have been added. Claims 1 and 8 have been withdrawn from consideration.
Response to Arguments
Applicant’s arguments with respect to claim(s) 12-29 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 12, 14-17, 19, 23, 26 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Sato et al. (US 20150076589 A1; hereinafter “Sato”).
In re claim 12, Sato discloses in figs. 1-6, a method of forming a super junction device (¶18), the method comprising:
forming an N-type material 12 on a substrate 10 (fig. 2; ¶19);
etching a trench 62 in the N-type material 12, wherein the trench extends from a top surface of the N-type material 12 down to at least a top surface of the substrate 10 to form a first N-type region and a second N-type region (fig. 2; ¶47; a first n- type region 12 between the left and the middle trenches 62 and a second n- type region 12 between the right and the middle trenches 62);
forming a P-type liner 64 in the trench 62 (fig. 4; ¶49); and
filling the trench 62 with a passive fill material 66 (fig. 5; ¶50),
wherein the passive fill material 66 comprises a void or seam 70 inside the passive fill material (¶50, 53-54).
In re claim 14, Sato discloses in figs. 1-6, the method of claim 12, wherein the trench 62 is filled with the passive fill material 66 without one or more grow-etch cycles (¶51-54).
In re claim 15, Sato discloses in figs. 1-6, the method of claim 12, wherein the passive fill material 66 comprises undoped silicon (e.g., non-doped single-crystal silicon; ¶50).
In re claim 16, Sato discloses in figs. 1-6, the method of claim 12, wherein the trench 62 is filled with the passive fill material 66 at a temperature greater than or about 900° C (¶51; “The first semiconductor films 64 and the second semiconductor films 66 are formed by, for example, CVD. CVD conditions include that, for example, source gas is dichlorosilane (DCS:SiH.sub.2Cl.sub.2) and hydrochloric acid (HCl), a temperature is 950.degree. C. to 1100.degree. C.”).
In re claim 17, Sato discloses in figs. 1-6, the method of claim 12, further comprising planarizing a top surface of the device after filling the trench 62 with the passive fill material 66 to remove excess passive fill material (¶55).
In re claim 19, Sato discloses in figs. 1-6, the method of claim 12, wherein the P-type liner 64 is grown on sidewalls of the trench as a P-doped epitaxial silicon liner (¶49).
In re claim 23, Sato discloses in figs. 1-6, the method of claim 12, wherein the method further comprises:
forming a first contact region 10 that comprises a drain of a super junction transistor (¶20);
forming a second contact region 42 that comprises a gate of the super junction transistor (¶40, 57); and
forming a third contact region 34 that comprises a source of the super junction transistor (¶39).
In re claim 26, Sato discloses in figs. 1-6, the method of claim 12, wherein a doping concentration of the P-type liner is higher than a doping concentration of the second N-type region (¶34, 18; second N-type region 12 is an n- type semiconductor layer and P-type liner 24 is a P type semiconductor layer).
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, 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.
Claim(s) 13, 27 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sato, as applied to claim 12 above.
In re claim 13, Sato discloses in figs. 1-6, the method of claim 12.
Sato does not expressly disclose wherein the trench is filled with the passive fill material in less than 15 minutes. However, Sato further discloses in fig. 6, the second semiconductor films 66 are formed under a condition (condition b) of a comparatively high film growth rate and poor coverage in FIG. 5. By this means, it is possible to intentionally form voids, control shapes of the voids, increase the film growth rates and improve productivity (¶53-54). Therefore, Sato recognized that the trench is filled with the passive fill material with a high speed epitaxy process.
It would therefore have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to experiment from Sato’s teachings and arrived at the claimed time of 15 minutes, as Sato teaches by this means, it is possible to intentionally form voids, control shapes of the voids, increase the film growth rates and improve productivity. In addition, the shapes of the voids can be controlled by not only controlling the epitaxial growth condition but also controlling shapes of trenches, or controlling the shapes of the trenches and controlling the epitaxial growth condition in combination (¶54).
MPEP §2144.05-II (A) states "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.).
Furthermore, MPEP §2144.05-II (B) describes that it is considered to be prima facie obvious when there is a motivation to optimize result-effective variables, i.e., a variable which achieves a recognized result.
In re Claim 27, Sato discloses the method of claim 12.
Sato further discloses in the embodiment shown in figs. 9-10, a location of the void with respect to the neighboring void and within the passive fill material controls stress at the void end portion and the stress at the void end portion can be made sufficiently little stress to such a degree that a defect such as dislocation is not produced (¶72-74). Therefore, Sato recognized that controlling the location of the void with the passive fill material is a result-effective variable.
It would therefore have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the location of the void relative to the top and bottom of the passive fill material and make a void or seam is a least 1 µm from a bottom of the passive fill material, and the void or seam is at least 1 µm from a top of the passive fill material to control the stress at the void end portion to such a degree that a defect such as dislocation is not produced (¶72-74 of Sato).
One would have been motivated to do so as Chang recognizes that optimization of the location of the void is a known result effective variable as explained above.
MPEP §2144.05-II (A) states "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.).
Furthermore, MPEP §2144.05-II (B) describes that it is considered to be prima facie obvious when there is a motivation to optimize result-effective variables, i.e., a variable which achieves a recognized result.
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sato as applied to claim 12 above, and further in view of Tan et al. (US 20240038853 A1; hereinafter “Tan”).
In re Claim 18, Sato discloses the method of claim 12 outlined above. Sato does not expressly disclose wherein the trench is etched below the top surface of the substrate.
In the same field of endeavor, Tan discloses a method of forming a high voltage device (figs. 2-21) wherein a trench T is etched below a top surface of a substrate 1 (fig. 11; ¶0124).
It 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 to employ the teachings of Tan into the method of Sato to form a device with high breakdown voltage and low on-resistance (¶0005 of Tan).
Claim(s) 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sato as applied to claim 12 above and further in view of Tokano et al. (US 20060197152 A1; hereinafter “Tokano”).
In re Claim 20, Sato discloses the method of claim 12. Sato does not expressly disclose wherein a doping concentration of the N-type material is between about 1e14 dopants/cm3 and about 1e16 dopants/cm3, and a doping concentration of the P-type liner is greater than about 8 times the doping concentration of the N-type material.
In the same field of endeavor, Tokano discloses a method of forming a super junction device (figs. 10-12), wherein a doping concentration of a P-type liner 19 (i.e., p; shown in fig. 10) is higher than a doping concentration of the second N-type region 67 (i.e., n-; shown in fig. 10) (¶0074-0078). Tokano further discloses a doping concentration of the P-type liner 19 is between 1015 /cm3 to 1016 /cm3 and the doping concentration of the second N-type region 67 is lower than 1015 /cm3 to 1016 /cm3.
It 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 from the teachings of Tokano and arrive at the claimed concentration ratio (i.e., about 8 times higher doing concentration in the liner) in Sato’s super junction device so that the break of the charge balance can be made much smaller (¶0076 of Tokano).
Claim(s) 21, 24, 25, 28-29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sato as applied to claim 12 above, and further in view of Yang et al. (US 20150061007 A1; hereinafter “Yang”).
In re Claim 21, Sato discloses the method of claim 12. Sato does not expressly disclose wherein a height of the P-type liner is greater than or about 40 µm.
In the same field of endeavor, Yang discloses a method of forming a super junction device (figs. 8-19), wherein a height of the P-type liner 1200 is in a range of 30 µm to 40 µm (¶20), which overlaps the claimed range of greater than or about 40 µm.
It 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 from the teachings of Yang and arrive at the claimed height of the P-type liner in Sato’s super junction device to further enhance device performance (¶2-3 of Yang).
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). “[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See MPEP § 2144.05, Obviousness of Ranges
Referring to MPEP § 2144.05, “…the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results over the prior art range.” (See also MPEP § 716.02 for a discussion of criticality and unexpected results.)
In re Claim 24, Sato discloses the method of claim 12.
Sato further discloses the p-type semiconductor layers and the n-type semiconductor layers which are alternately arranged form a pseudo and nearly non-doped region, so that it is possible to achieve higher breakdown voltage (¶36).
Sato does not expressly disclose wherein the super junction transistor has a breakdown voltage of greater than or about 650 V.
In the same field of endeavor, Yang discloses a method of forming a super junction device (figs. 8-19), wherein the super junction transistor has a breakdown voltage of greater than or about 650 V (e.g., approximately 800 V; ¶16).
It 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 from the teachings of Yang and arrive at the claimed breakdown voltage in Sato’s super junction device to meet the demand of high breakdown voltage devices (¶1-3, 16 of Yang).
In re Claim 25, Sato discloses the method of claim 12. Sato does not expressly disclose wherein a width of the trench is less than or about 2 µm.
In the same field of endeavor, Yang discloses a method of forming a super junction device (figs. 8-19), wherein a width of the trench is less than or about 2 µm (¶20).
It 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 from the teachings of Yang and arrive at the claimed trench width in Sato’s super junction device to further enhance device performance (¶2-3 of Yang).
In re Claim 28, Sato discloses the method of claim 12. Sato does not expressly disclose wherein an aspect ratio of an area occupied by the P-type liner and the passive fill material is greater than or about 20.
In the same field of endeavor, Yang discloses a method of forming a super junction device (figs. 8-19), wherein an aspect ratio of an area occupied by the P-type liner 1200, 1400 (¶31) and the passive fill material 1300 is the trenches ranging from approximately 10:1 to approximately 50:1 (¶20), which overlaps the claimed range of greater than or about 20.
It 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 from the teachings of Yang and arrive at the claimed aspect ratio in Sato’s super junction device to further enhance device performance (¶2-3 of Yang).
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). “[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See MPEP § 2144.05, Obviousness of Ranges
Referring to MPEP § 2144.05, “…the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results over the prior art range.” (See also MPEP § 716.02 for a discussion of criticality and unexpected results.)
In re Claim 29, Sato discloses the method of claim 12. Sato does not expressly disclose wherein an aspect ratio of an area occupied by the P-type liner and the passive fill material is greater than or about 40.
In the same field of endeavor, Yang discloses a method of forming a super junction device (figs. 8-19), wherein an aspect ratio of an area occupied by the P-type liner 1200, 1400 (¶31) and the passive fill material 1300 is the trenches ranging from approximately 10:1 to approximately 50:1 (¶20), which overlaps the claimed range of greater than or about 20.
It 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 from the teachings of Yang and arrive at the claimed aspect ratio in Sato’s super junction device to further enhance device performance (¶2-3 of Yang).
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). “[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See MPEP § 2144.05, Obviousness of Ranges
Referring to MPEP § 2144.05, “…the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results over the prior art range.” (See also MPEP § 716.02 for a discussion of criticality and unexpected results.)
Claim(s) 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sato as applied to claim 12 above, and further in view of Fuchs et al. (US 20220028727 A1; hereinafter “Fuchs”).
In re Claim 22, Sato discloses the method of claim 12. Sato does not expressly disclose wherein a width of the P-type liner is less than or about 200 nm.
In the same field of endeavor, Fuchs discloses a method of forming a super junction device (figs. 5-6, 10), wherein a width of a pre-filler side wall layer liner 520 is a range from 100 nm to 500 nm (¶48), which overlaps the claimed range of less than or about 200 nm.
It 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 from the teachings of Fuchs and arrive at the claimed width for the P-type liner in Sato’s super junction device to achieve a well-controlled process of trench formation and filling of the trench for the super junction device and reduce defect formation (¶2-5 of Fuchs).
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). “[A] prior art reference that discloses a range encompassing a somewhat narrower claimed range is sufficient to establish a prima facie case of obviousness." In re Peterson, 315 F.3d 1325, 1330, 65 USPQ2d 1379, 1382-83 (Fed. Cir. 2003). See MPEP § 2144.05, Obviousness of Ranges
Referring to MPEP § 2144.05, “…the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results over the prior art range.” (See also MPEP § 716.02 for a discussion of criticality and unexpected results.)
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NILUFA RAHIM whose telephone number is (571)272-8926. The examiner can normally be reached M-F 9am-5:30pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Yara J. Green can be reached at (571) 270-3035. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/NILUFA RAHIM/ Primary Examiner, Art Unit 2893