DETAILED ACTION
Table of Contents
I. Notice of Pre-AIA or AIA Status 3
II. Claim Rejections - 35 USC § 103 3
A. Claims 11, 12, 15-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US 2017/0365513 (“Yang”) in view of US 2024/0006180 (“Pan”) and as evidenced by US 2025/0022751 (“Lee”). 3
III. Response to Arguments 18
IV. Pertinent Prior Art 19
Conclusion 19
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I. 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 .
II. Claim Rejections - 35 USC § 103
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 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 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.
A. Claims 11, 12, 15-18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over US 2017/0365513 (“Yang”) in view of US 2024/0006180 (“Pan”) and as evidenced by US 2025/0022751 (“Lee”).
Claim 11 reads,
11. (Currently Amended) A method of forming a structure on a substrate, comprising:
[1a] forming a nucleation layer within an opening comprising
[1b] a first tier opening formed in a first tier layer and a second tier opening formed in a second tier layer, the substrate comprising the first tier layer and the second tier layer over the first tier layer;
[2a] partially exposing the nucleation layer to a radical treatment, to form a passivation layer, wherein the passivation layer tapers and terminates at or near a pinch point of the opening,
[2b] wherein a portion of the nucleation layer near a bottom of the first tier opening is un-covered by the passivation layer; and
[3] filling the opening with a tungsten fill layer by a pulse chemical vapor deposition (CVD), the substrate having an internal stress less than 200 MPa,
[4a] wherein the tungsten fill layer is formed by a plurality of treatment cycles, each treatment cycle including:
[4b] pulsing a first gas at the substrate for a pulse time duration while concurrently flowing a second gas over the substrate; and
[4c] purging the first gas and the second gas by flowing a purge gas over the substrate for a purge time duration.
Yang is drawn to tungsten filling of a variety of kinds of openings including vertical openings used in NAND and VNAND devices (Yang: ¶¶ 23, 27, 28, 65, 66, 74), particularly openings have a constriction, 109, 151 (Yang: Figs. 1C, 1D, 5; ¶¶ 26, 27). With regard to claim 11, Yang discloses, generally in Fig. 1C, 3, and 5,
11. (Currently Amended) A method of forming a structure on a substrate, comprising:
[1a] forming a nucleation layer 504 within an opening [shown but not labeled in either of Figs. 1C and 5] [2nd step in Fig. 5 (¶ 67) and step 301 in Fig. 3 (¶ 44)] comprising
[1b] a first tier opening formed in a first tier layer [portion of opening in Fig. 1C below the “constriction 109”] and a second tier opening formed in a second tier layer [portion of opening in Fig. 1C above the “constriction 109”] [¶ 26],
[1c] the substrate comprising the first tier layer and the second tier layer over the first tier layer [as shown in Fig. 1C];
[2a] partially exposing the nucleation layer 504 to a radical treatment, to form a passivation layer 506, wherein the passivation layer tapers and terminates at or near a pinch point [“constriction 109” in Fig. 1C; “constriction 151” in Figs. 1G and 5 (¶¶ 27, 28, 67)] of the opening [third step in sequence in Fig. 5; step 201 in Fig. 3 (¶¶ 44, 40, 47, 49)],
[2b] wherein a portion of the nucleation layer 504 near a bottom of the first tier opening is un-covered by the passivation layer 506 [because the passivation layer ends at the constriction 151 in Fig. 5 and therefore at constriction 109 in Fig. 1C; see explanation below]; and
[3] filling the opening with a tungsten fill layer 510 by a … chemical vapor deposition (CVD), the substrate [fourth and fifth steps in the sequence in Fig. 5 (¶ 67); steps 203 and 205 in Fig. 3 (¶¶ 44, 41-43); see explanation below] …
[4a] wherein the tungsten fill layer 508/510 is formed by a plurality of treatment cycles [4th and 5th steps in sequence in Fig. 5 (¶¶ 67-69); steps 203 and 205 in Fig. 3 (¶¶ 41-43)], each treatment cycle including:
[4b]-[4b] … [not taught] …
With regard to features [2a]-[2b] of claim 11, Yang discloses that the inhibition process of remote-plasma-generated, nitrogen-radial exposure of the nucleation layer 504 produces a tungsten nitride (WN) passivation layer 506 that terminates within the constriction 151, as shown in the third through fifth steps in the sequence shown in Fig. 5, as follows:
Next, the structure is exposed to an inhibition chemistry to selectively inhibit portions 506 of the structure 500. … Inhibition can involve for example, exposure to a direct (in-situ) plasma generated from a gas such as N2, H2, forming gas, NH3, O2, CH4, etc. Other methods of exposing the feature to inhibition species are described above.
(Yang: ¶ 67; emphasis added)
Yang further discloses that the inhibition species may be a nitrogen radical formed by a remote plasma generator:
[0006] In some embodiments, the metal is tungsten. In some embodiments, selectively inhibiting nucleation on a conformal layer of tungsten is a remote plasma process. In some embodiments, the remote plasma process involves exposing the feature to nitrogen radicals.
[0047] According to various embodiments, selective inhibition can involve exposure to activated species that passivate the feature surfaces. For example, in certain embodiments, a tungsten (W) surface can be passivated by exposure to a nitrogen-based or hydrogen-based plasma. In some embodiments, inhibition can involve a chemical reaction between activated species and the feature surface to form a thin layer of a compound material such as tungsten nitride (WN) or tungsten carbide (WC). … In some embodiments, one or more gases may be fed into a remote plasma generator, with activated species formed in the remote plasma generator fed into a chamber in which the substrate sits. … Activated species can include atomic species, radical species, and ionic species. In certain embodiments, exposure to a remotely-generated plasma includes exposure to radical and atomized species, with substantially no ionic species present in the plasma such that the inhibition process is not ion-mediated. …
14. The method of claim 12, wherein selectively inhibiting tungsten nucleation on the conformal layer of tungsten comprises exposing the layer to nitrogen radicals.
(Yang: ¶¶ 6, 47, claim 14; emphasis added)
Further with regard feature [2a], specifically limitation, “wherein the passivation layer tapers and terminates at or near a pinch point”, as noted above the third through fifth frames of Fig. 5 show that the tungsten nitride (WN) passivation layer 506 that terminates within the constriction 151, as shown in the third through fifth steps in the sequence shown in Fig. 5.
While Yang does not show that the tungsten nitride (WN) passivation layer 506 is tapered, Yang suggests that it can be inherently tapered by controlling the nitrogen radical inhibition conditions in a “mass transport limited regime”, i.e. diffusion limited, thereby having the greatest concentration of the nitrogen radical species near the opening and gradually decreasing the into the opening. In other words, the thickness of the WN passivation layer 506 decreases as a function of depth into the opening due to the decrease in the concentration of nitrogen radicals as a function of depth into the opening. In this regard, Yang states in this regard,
[0054] In some embodiments, selective inhibition can be achieved by performing operation 203 in a mass transport limited regime. In this regime, the inhibition rate inside the feature is limited by amounts of and/or relative compositions of different inhibition material components (e.g., an initial inhibition species, activated inhibition species, and recombined inhibition species) that diffuse into the feature. In certain examples, inhibition rates depend on various components' concentrations at different locations inside the feature.
[0055] Mass transport limiting conditions may be characterized, in part, by overall inhibition concentration variations. In certain embodiments, a concentration is less inside the feature than near its opening resulting in a higher inhibition rate near the opening than inside. This in turn leads to selective inhibition near the feature opening. Mass transport limiting process conditions may be achieved by supplying limited amounts of inhibition species into the processing chamber (e.g., use low inhibition gas flow rates relative to the cavity profile and dimensions), while maintaining relative high inhibition rates near the feature opening to consume some activated species as they diffuse into the feature. In certain embodiment, a concentration gradient is substantial, which may be caused relatively high inhibition kinetics and relatively low inhibition supply. …
[0056] In addition to the overall inhibition concentration variations inside features, selective inhibition may be influenced by relative concentrations of different inhibition species throughout the feature. These relative concentrations in turn can depend on relative dynamics of dissociation and recombination processes of the inhibition species. As described above, an initial inhibition material, such as molecular nitrogen, can be passed through a remote plasma generator and/or subjected to an in-situ plasma to generate activated species (e.g., atomic nitrogen, nitrogen ions). However, activated species may … and/or react with W, WN, TiN, or other feature surfaces along their diffusion paths. As such, different parts of the feature may be exposed to different concentrations of different inhibition materials, e.g., an initial inhibition gas, activated inhibition species, and recombined inhibition species. This provides additional opportunities for controlling selective inhibition. … Furthermore, specific process conditions may result in activated species being present at higher concentrations near features' openings than inside the features. For example, some activated species may be consumed (e.g., reacted with feature surface materials and/or adsorbed on the surface) and/or recombined while diffusing deeper into the features, especially in small high aspect ratio features. …
[0057] Flow rates of the inhibition gas can depend on a size of the chamber, reaction rates, and other parameters. A flow rate can be selected in such a way that more inhibition material is concentrated near the opening than inside the feature. In certain embodiments, these flow rates cause mass-transport limited selective inhibition. …
(Yang: ¶¶ 54-57; emphasis added)
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use mass-transport limited conditions for the nitrogen radical inhibition of the tungsten nucleation layer 504 that forms the WN passivation layer 506 because Yang explicitly suggestions this (supra).
As explained in paragraphs [0054]-[0057], the result of using said mass-transport limited conditions results in a “activated species [e.g. plasma-generated N radicals] being present at higher concentrations near features' openings than inside the features” (¶ 56), i.e. a substantial “concentration gradient” (¶ 55) of nitrogen radicals is formed from the opening into the pinch point that results in “more inhibition material [i.e. WN passivation material 506] … concentrated near the opening than inside the feature” (¶ 57). Because more WN 506 forms at/near the opening than into the opening, the thickness of WN 506 tapers from the opening into the opening. And because the WN passivation layer 506 ends within the pinch point, farthest from the opening, the “the passivation layer 506 tapers and terminates at or near a pinch point”, as required by feature [2a] of claim 11.
Additional evidence comes from Lee. Lee shares a common assigned and a common inventor with Yang, specifically Anand Chandrashekar. Paragraphs [0121]-[0124] of Lee are either verbatim or essentially the same as paragraphs [0054]-[0057] of Yang (supra). Fig. 2 of Lee shows that the conformal nucleation layer 212 (formed in step 220), which may be tungsten, when treated with, e.g., nitrogen radicals, forms a “metal nitride”, e.g. WN (¶ 55), passivation layer 214 that is tapered (step 230), being thickest at the opening and decreasing in thickness away from the opening. Said metal nitride layer 214 inhibits the tungsten fill layer 216 from depositing thereon as shown in step 240 (Lee: ¶¶ 52-56). The formation of the metal nitride inhibition layer 214 is explained in the section entitled “Inhibition of Metal Nucleation” at paragraphs [0113]-[0125] of Lee, again, paragraphs [0121]-[0124] being the either verbatim or essentially the same as paragraphs [0054]-[0057] of Yang (supra).
Based on the foregoing, the burden of proof is shifted to Applicant to prove the contrary, i.e. that the WN passivation layer 506 of Yang formed in the vertically-oriented openings shown in Fig. 1C of Yang is somehow not tapered. (See MPEP 2112(I)-(V).)
With regard to features [3] and [4a] of claim 11,
[3] filling the opening with a tungsten fill layer 510 by a … chemical vapor deposition (CVD), the substrate [fourth and fifth steps in the sequence in Fig. 5 (¶ 67); steps 203 and 205 in Fig. 3 (¶¶ 44, 41-43); see explanation below] …
[4a] wherein the tungsten fill layer is formed by a plurality of treatment cycles, each treatment cycle including:
Generally, with regard to the formation of the tungsten fill layers shown in Figs. 1C and 5 (i.e. 510) Yang states,
[0041] Once the feature is selectively inhibited, the method can continue at block 203 with selective deposition of tungsten according to the inhibition profile. Block 203 may involve one or more chemical vapor deposition (CVD) and/or atomic layer deposition (ALD) processes, including thermal, plasma-enhanced CVD and/or ALD processes. The deposition is selective in that the tungsten preferentially grows on the lesser- and non-inhibited portions of the feature. In some embodiments, block 203 involves selectively depositing tungsten in a bottom or interior portion of the feature until a constriction [109] is reached or passed.
(Yang: ¶ 41; emphasis added)
As applied to Fig. 1C, the bottom of the openings are preferentially filled with tungsten upwardly until the constriction 109 is reached because of the WN passivation layer formed in the top portion of the opening and in the constriction 109, by the nitrogen-radical inhibition process of the nucleation layer.
With regard to all of the features of claim 11, so far discussed above, while the process shown in Fig. 5 is in the context of a horizontally-oriented opening with a constriction 151, with regard to the vertically-oriented openings with a constriction 109 shown in Fig. 1C, Yang states that “[a]s described further below, methods described herein allow void-free fill as depicted in FIG. 1C” (¶ 26, last sentence). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use the process described in association with Fig. 5 to fill the openings in Figs. 1C with tungsten, because the opening in Fig. 1C also includes a “constriction 109” (Yang: ¶ 26) for which the “nucleation inhibition” process (Yang: title) was developed, in order to allowing void-free tungsten filling despite the constriction 109, 151 (Yang: ¶¶ 26-27).
As such, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to form the nucleation layer 504 in the vertically-oriented openings of Fig. 5, in the vertically-oriented openings in Fig. 1C with the constrictions 109 in Fig. 1C, as well as the subsequently performed nucleation inhibition to form the passivation layer 506 that would end in the upper portion of the opening in Fig. 1C “at or near the pinch point 109”, as shown in Fig. 5—as required by features [2a]-[2b]—and, then, perform the tungsten filling that forms the void-free tungsten fill 510 in the vertically-oriented openings in Fig. 1C—as required by features [3] and [4a]-[4c]—in order to form the void-free tungsten fill shown in Fig. 1C, because Yang explicitly suggests using the processes disclosed therein below (Yang: ¶ 26) to form the void-free tungsten fill, such as the process described in association with the horizontally-oriented opening including a constriction 151.
With regard to features [3] and [4b]-[4c] of claim 11,
[3] filling the opening with a tungsten fill layer by a pulse chemical vapor deposition (CVD), the substrate having an internal stress less than 200 MPa,
[4b] pulsing a first gas at the substrate for a pulse time duration while concurrently flowing a second gas over the substrate; and
[4c] purging the first gas and the second gas by flowing a purge gas over the substrate for a purge time duration.
As stated in paragraph [0041] of Yang, the selectively-deposited portion 508 of the tungsten fill 508/510 can be formed by ALD, which inherently includes alternating pulses of a tungsten reactant and reductant.
Yang does not, however, provide the details of either of the ALD of the selectively-deposited portion 508 of the tungsten fill and only scant details of the CVD deposition of the remaining bulk fill in step 205, which may include tungsten hexafluoride (WF6) and hydrogen (H2) (Yang: ¶ 42) and does not consequently disclose that the CVD process that may be used to perform the bulk tungsten fill (Yang: ¶ 41, supra), is pulsed CVD, as required by feature [3], having the pulsed CVD process steps required by features [4b]-[4c].
Pan, like Yang, is directed to tungsten filling of openings having constrictions found in manufacturing NAND and VNAND devices (Pan: ¶¶ 45-46). (Compare Figs. 3A-3D of Pan with Figs. 1E-1G of Yang.) Also like Yang, Pan uses nitrogen-radical inhibition to form a passivation layer of WN that prevents tungsten deposition on the nitrogen-radical inhibited part of the opening, thereby allowing selective tungsten deposition on the non-treated portion of the opening.
With regard to with regard to claims 11, 12, and 15, Pan teaches, generally in Figs. 4, 6, and 7A-7B,
11. (Currently Amended) A method of forming a structure on a substrate [abstract; ¶ 4, comprising:
[1a] forming a nucleation layer 753 within an opening 751 … [steps 750, 755, 760 in Fig. 7B; Pan: ¶¶ 71-72]
[1b] … [not taught] …
[2a] partially exposing the nucleation layer 753 to a radical treatment, to form a passivation layer 756 [Pan: ¶ 73; e.g. WN, as in Yang] …
[2b] wherein a portion of the nucleation layer 753 near a bottom of the … opening 751 is un-covered by the passivation layer 756 [as shown in step 765 in Fig. 7B; Pan: ¶ 73]; and
[3] filling the opening 751 with a tungsten fill layer 754 by a pulse chemical vapor deposition of the substrate [steps 770, 775 in Fig. 7B; Pan: ¶ 75; i.e. “bulk tungsten layer” at step 406 or both “first portion of bulk tungsten layer” at step 404 and “bulk tungsten layer” at step 406 in Fig. 4; Pan: ¶ 68: “a pulsed CVD process as shown in FIG. 6 is performed to initiate and complete operations 404 and 406” (emphasis added)] … having an internal stress less than 200 MPa [see discussion below],
[4a] wherein the tungsten fill layer is formed by a plurality of treatment cycles [Pan: ¶ 68 : “in some embodiments, after operation 402, a pulsed CVD process as shown in FIG. 6 is performed to initiate and complete operations 404 and 406”], each treatment cycle including:
[4b] pulsing a first gas [WF6] at the substrate for a pulse time duration while concurrently flowing a second gas [H2/Ar] over the substrate [Pan: ¶ 64; Fig. 6]; and
[4c] purging the first gas [WF6] and the second gas [H2/Ar] by flowing a purge gas [H2/Ar] over the substrate for a purge time duration [Pan: ¶ 64; Fig. 6].
12. (Original) The method of claim 11, wherein
[1] the first gas is tungsten hexafluoride [Pan: ¶ 64; Fig. 6],
[2] the second gas is a mixture of hydrogen gas and Argon [Pan: ¶ 64; Fig. 6], and
[3] the purge gas is a mixture of hydrogen gas and Argon [Pan: ¶ 64; Fig. 6].
15. (Original) The method of claim 11, wherein
[1] the pulse time duration is between about 0.3 seconds and about 2 seconds [i.e. 0.5 to 2 seconds (Pan: ¶ 65)] and
[2] the purge time duration is between about 0.5 seconds and about 5 seconds [i.e. 1 to 4 seconds (Pan: ¶ 65)].
Although, the subsequent steps shown at frames 770 and 775 in Fig. 7B of Pan of the remaining portion of the bulk W fill 754 are formed by ALD (steps 707-718 in Fig. 7A), Pan states that the remaining W fill deposition process step 406 may be either of ALD and pulsed CVD:
[0068] Once the B or B(Si) layer is converted, growth of the bulk tungsten layer is continued in an operation 406. In some embodiments, this can involve a continuation of the pulsed CVD process. Thus, in some embodiments, after operation 402, a pulsed CVD process as shown in FIG. 6 is performed to initiate and complete operations 404 and 406. In other embodiments, operation 406 can involve ALD deposition of bulk tungsten using H2 a reducing agent.
(Pan: ¶ 68; emphasis added)
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use pulsed CVD shown in Fig. 6 of Pan to form the remaining bulk W fill 754 shown in Fig. 7B—after the inhibition process to form the WN passivation layer 756—because Pan explicitly states that the bulk W fill can be either ALD or pulse CVD (Pan: ¶ 68, supra). Moreover, one having ordinary skill in the art would readily appreciate that the opening 751 would be subject to pinching off using pulsed CVD, just as with ALD, without the formation of the passivating WN layer.
In addition, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to use the process of Pan for tungsten filling of the openings in Fig. 1C of Yang because Yang is silent as to the details of the ALD or CVD process such that one having ordinary skill in the art would use known processes for tungsten filling suitable for the same purpose of filling openings used in making NAND devices that may have a constriction, such as the process disclosed in Pan.
Finally with further regard to feature [3] of claim 11,
[3] depositing a tungsten fill layer into the opening of the substrate having an internal stress less than 200 MPa,
Pan does not state what the internal stress of the tungsten fill is that is formed by the process disclosed therein. However, it is held, absent evidence to the contrary that the tungsten fill layer formed using the pulsed CVD process for steps 404 and 406 in Fig. 4 of Pan that is used to fill the openings in Fig. 1C of Yang, inherently has “an internal stress less than 200 MPa” because the conditions used to form the bulk fill are the same as used in the Instant Application that are indicated, therein, to achieve the claimed internal stress.
In this regard, the Instant Application indicates that it is the pressure and temperature, stating in this regard,
[0065] Activity 308 represents forming the tungsten gap fill 428 in the opening 405 as shown in FIG. 4E using a pulse chemical vapor deposition (“pulse CVD”). Reducing the pressure and increasing the temperature have been found to improve the stress formed in a tungsten gap fill. However, simply increasing the temperature and reducing the pressure have diminishing returns. For example, low pressures, such as a vacuum condition, impact the quality of the gap fill and interferes with chucking the substrate 400 to the substrate support assembly 220. Some temperatures may degrade or adversely impact other features formed on the substrate 400. Additionally, some temperatures promote degradation of components of the processing system 200, resulting in increased maintenance costs. The pulse CVD process shown as activity 308 includes processing the substrate 400 at low pressures at moderate to high temperatures to leverage their stress reduction benefits. However, the pulse CVD 308 results in improved tungsten gap fill and lower stresses than can be achieved by only adjusting the temperature and pressure parameters.
[0066] The pulse CVD process, represented by 308, includes cyclically pulsing a first gas over a pulse time duration while a second gas concurrently flows into the processing region 221 and then purging the first and second gases from the processing region 221 with a purge gas over a purge time duration. The first gas and the second gas are supplied into the processing region 221 by the deposition gas source 240. The pressure within the processing volume 215 is between about 0.7 Torr and about 15 Torr, such as 1 Torr, 1.5 Torr, 2 Torr, 2.5 Torr, 3 Torr, 3.5 Torr, 4 Torr, 4.5 Torr, 5 Torr, 5.5 Torr, 6 Torr, 6.5 Torr, 7 Torr, 7.5 Torr, 8 Torr, 8.5 Torr, 9 Torr, 9.5 Torr, 10 Torr, 10.5 Torr, 11 Torr, 11.5 Torr, 12 Torr, 12.5 Torr, 13 Torr, 13.5 Torr, 14 Torr, 14.5 Torr. The temperature within the processing region 221 may be between 400° C. and 500° C. and the heat may be supplied by the heater 229, first heater 263, and/or second heater 264.
(Instant Specification: ¶¶ 65-66; emphasis added)
Similarly, the conditions used in Pan include pressures e.g. 10 Torr (¶ 67) and temperatures as high as 445 ℃, e.g. 250 ℃ to 445 ℃ (Pan: ¶ 70), which overlaps 45% of the range of 400 ℃ to 500 ℃ disclosed in the Instant Application (supra). Moreover, Pan also uses pulsed WF6 with continuous flow of H2 and Argon for each of the second gas and the purge gas (Pan: Fig. 6). In addition, Pan uses WF6 pulse and H2/Ar purge times that fall entirely within the claimed ranges (claim 15, supra; Pan: ¶ 65). Thus, to the extent that the first, second, and purge gases and/or pulse time contribute to the stress reduction, Pan also teaches these pulsed CVD tungsten gapfill parameters.
Based on the foregoing, the burden of proof is shifted to Applicant to prove the contrary, i.e. that the tungsten gapfill formed by the pulsed CVD process of Pan for steps 404 and 406 does not result in a tungsten gapfill having “an internal stress less than 200 MPa”. (See MPEP 2112(I)-(V).)
This is all of the limitations of claims 11, 12, and 15.
With regard to claim 16, Yang further discloses,
16. (Currently Amended) The method of claim 11, further comprising: wherein the passivation layer is formed within the opening [i.e. the WN passivation layer 506 of Yang formed in the vertically-oriented openings shown in Fig. 1C of Yang (supra)] by injecting an activated nitrogen species [i.e. nitrogen radicals, as explained above] from a radical generator 1206 attached to a lid of a processing chamber 1218 into a processing region of the processing chamber 1218 [Yang: ¶¶ 81-82].
This is consistent with Pan, which also uses a remote plasma generator to form a plasma-activated nitrogen species with which the tungsten nucleation layer 753 to form the WN passivation layer 756 in step 765 in Fig. 7B (Pan: ¶ 73).
Claim 17 reads,
17. (Currently Amended) A method of forming a structure on a substrate, comprising:
[1a] forming a nucleation layer within an opening comprising
[1b] a first tier opening formed in a first tier layer and a second tier opening formed in a second tier layer, the substrate comprising the first tier layer and the second tier layer over the first tier layer,
[1c] wherein a first portion of the nucleation layer is deposited in the opening of the substrate and a second portion of the nucleation layer is deposited on a field of the substrate;
[2a] forming a passivation layer, wherein the passivation layer tapers and terminates at or near a pinch point of the opening, by partially exposing the nucleation layer in the second tier opening to a radical treatment,
[2b] wherein the passivation layer prevents tungsten deposition on the second portion of the nucleation layer; and
[3] filling the opening with a tungsten fill layer by a pulse chemical vapor deposition (CVD),
[4a] wherein the tungsten fill layer is formed by a plurality of treatment cycles, each treatment cycle including:
[4b] pulsing a first gas at the substrate for a pulse time duration while concurrently flowing a second gas over the substrate; and
[4c] purging the first gas and the second gas by flowing a purge gas over the substrate for a purge time duration.
With regard to claim 17, Yang discloses,
17. (Currently Amended) A method of forming a structure on a substrate, comprising:
[1a] forming a nucleation layer within an opening [i.e. the nucleation layer 504 of Fig. 5 of Yang formed in the openings in Fig. 1C of Yang (supra)] comprising
[1b] a first tier opening formed in a first tier layer [portion of opening in Fig. 1C below the “constriction 109”] and a second tier opening formed in a second tier layer [portion of opening in Fig. 1C above the “constriction 109”] [¶ 26],
[1c] the substrate comprising the first tier layer and the second tier layer over the first tier layer [as shown in Fig. 1C];
[1d] wherein a first portion of the nucleation layer 504 is deposited in the opening of the substrate and a second portion of the nucleation layer is deposited on a field of the substrate [as shown in Figs. 1C and 5];
[2a] forming a passivation layer [i.e. WN passivation layer 506 of Fig. 5 of Yang formed in the openings in Fig. 1C of Yang (supra)] , wherein the passivation layer tapers and terminates at or near a pinch point 109 of the opening [as explained in detail under claim 1], by partially exposing the nucleation layer 504 in the second tier opening [portion of opening in Fig. 1C above the “constriction 109”] to a radical treatment [i.e. N radical treatment (supra)],
[2b] wherein the passivation layer 506 prevents tungsten deposition on the second portion of the nucleation layer 506 [as shown in the 4th step in the sequence shown in Fig. 5 of Yang and as explained above under claim 11]; and
[3] filling the opening with a tungsten fill layer [i.e. W fill 508/510 of Fig. 5 forming the W fill shown in Fig. 1C] by a … chemical vapor deposition (CVD) [fourth and fifth steps in the sequence in Fig. 5 (¶ 67); steps 203 and 205 in Fig. 3 (¶¶ 44, 41-43); supra],
[4a] wherein the tungsten fill layer 508/510 is formed by a plurality of treatment cycles, each treatment cycle including:
[4b]-[4c] … [not taught] …
With regard to features [3] and [4b]-[4c] of claim 17,
[4b] pulsing a first gas at the substrate for a pulse time duration while concurrently flowing a second gas over the substrate; and
[4c] purging the first gas and the second gas by flowing a purge gas over the substrate for a purge time duration.
As explained under claim 11, above, the limitations of features [4b]-[4c] are not disclosed in Yang, but these features are obvious in view of Pan for the reasons explained under features [3] and [4b]-[4c] of claim 11.
This is all of the limitations of claim 17.
Claim 18 reads,
18. (Original) The method of claim 17, wherein
[1] the first gas is tungsten hexafluoride,
[2] the second gas is a mixture of hydrogen gas and Argon, and
[3] the purge gas is a mixture of hydrogen gas and Argon.
See discussion under claim 12, which applied equally here.
Claim 20 reads,
20. (Original) The method of claim 17, wherein the tungsten fill layer has a stress between 0 MPa and 200 MPa.
See discussion under feature [3] of claim 11, which applies equally here.
III. Response to Arguments
Applicant’s arguments filed 06/09/2026 have been fully considered but they are not persuasive.
Consistent with Examiner’s statement in the Interview Summary mailed 06/03/2026, a more thorough review of Yang shows that the tapering of the WN passivation layer 506 of Fig. 5 formed in the opening of Fig. 1C is inherently tapered, as explained in detail above. An additional evidenciary reference US 2025/0022751 (“Lee”) is added to the rejection, which Applicant has not yet had the opportunity to address.
IV. Pertinent Prior Art
US 2024/0222128 (“Zhao”) is cited for teaching essentially the same information as taught in Lee (supra), i.e. that an N-radical inhibition treatment results in a graded, i.e. tapered, inhibiting layer 406, formed in an opening. See Figs. 4B-4C and paragraph [0073].
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERIK KIELIN whose telephone number is (571)272-1693. The examiner can normally be reached Mon-Fri: 10:00 AM-7:00 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, Wael Fahmy can be reached on 571-272-1705. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Signed,
/ERIK KIELIN/
Primary Examiner, Art Unit 2814
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