CTNF 18/345,303 CTNF 91751 DETAILED ACTION Notice of Pre-AIA or AIA Status 07-03-aia AIA 15-10-aia The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA. Election/Restrictions Applicant’s election without traverse of invention group I and species A in the reply filed on 4/27/2026 is acknowledged. Claims 18-20 have been canceled. Claims 21-23 are added. Claims 6-8, 15 have been withdrawn from consideration. Claim Rejections - 35 USC § 112 07-30-02 AIA 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. 07-34-01 Claims 13-14, 16-17, 21-23 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 13 recites “forming a source/drain region on a side of the gate stack” in line 3. The phrase “on a side of the gate stack” implies that the gate stack must be formed before the source/drain region. According to Figs. 4-6 of the specification of the instant application, the dummy gate stack 38 satisfies this limitation, not the replacement gate stack 64 in Fig. 9. However, subsequent steps such as “depositing a dielectric hard mask over the gate stack” (line 8 of claim 13) implies that the gate stack must the replacement gate stack (as shown in Fig. 10 of the instant application). So it is unclear whether the Applicant is attempting to claim the dummy gate stack or the replacement gate stack with the step “forming a gate stack…” in line 2. For the purpose of examination, it is interpreted that the gate stack is the replacement gate stack. The order of the formation steps implied in lines 2-3 of the claim is therefore treated as automatically satisfied. Claim 21 recites “forming a source/drain region adjacent to the gate region”. This is indefinite for the same reason as claim 13. Claim Rejections - 35 USC § 103 07-20-aia AIA 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. 07-21-aia AIA Claim s 1-2, 4-5, 9-11 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (10062784 B1) in view of Wang et al. (US 2007/0066060 A1) . Regarding claim 1 , Lee teaches a method ( method in Fig. 18 as illustrated in Figs. 15-17 of Lee ) comprising: forming a dielectric layer ( ILD 82 in Fig. 16 of Lee ) over a conductive feature ( replacement gate stack 64 or lower conductive plug 78 in Fig. 16 of Lee ); etching the dielectric layer to form an opening ( 83 / 84 in Fig. 16 of Lee ), wherein the conductive feature is exposed through the opening ( as shown in Fig. 16 of Lee ); forming a liner ( 90 in Fig. 17 ) in the opening, wherein the tungsten liner contacts sidewalls of the dielectric layer ( as shown in Fig. 17 of Lee ); depositing a tungsten layer ( 92 , as described in column 9 lines 4-5 of Lee ) to fill the opening; and planarizing the tungsten layer ( as described in column 9 lines 1-2 of Lee ), wherein portions of the tungsten layer and the tungsten liner in the opening form a contact plug ( 86 / 88 ). But Lee does not teach that the liner is a tungsten liner ( the term “tungsten liner” is interpreted to include any alloy, compound,… with tungsten as one of the elements of that alloy, compound ). Wang teaches a method ( Fig. 1-4 ) of forming a tungsten contact structure ( 170a-190a in Fig. 4 ). The method comprises: forming an opening ( 160 in Fig. 1 ) in a dielectric layer ( 150 ); forming a tungsten liner layer ( 170 ) on the bottom and sidewalls of the opening; depositing a tungsten nucleation layer ( 180 ) on the tungsten liner layer; depositing a bulk tungsten layer ( 190 in Fig. 3 ) on the tungsten nucleation layer; performing a planarization step to remove portions of the liner, nucleation layer, and the bulk layer over the dielectric layer ( see Fig. 4 and [0023] of Wang ) in order to form the tungsten contact structure. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the liner and tungsten layer of Lee as disclosed by Wang, i.e. using tungsten-containing barrier liner instead of titanium nitride and including a tungsten nucleation layer before the bulk tungsten layer, in order to improve the contact resistance of the contact plug ( as discussed in [0004] of Wang ). Regarding claim 2 , Lee in view of Wang teaches all limitations of the method of claim 1, and also teaches wherein the depositing the tungsten layer comprises: depositing a tungsten nucleation layer ( tungsten seed layer 180 in Fig. 1 of Wang ) on the tungsten liner; and depositing a bulk tungsten layer ( tungsten 190 in Fig. 3 of Wang ) on the tungsten nucleation layer. Regarding claim 4 , Lee in view of Wang teaches all limitations of the method of claim 2, and also teaches wherein the depositing the tungsten nucleation layer is performed using a precursor comprising tungsten fluoride ( as described in [0017] of Wang ). Regarding claim 5 , Lee in view of Wang teaches all limitations of the method of claim 2, and also teaches wherein the depositing the bulk tungsten layer is performed using a precursor comprising tungsten fluoride ( as described in [0022] of Wang ). Regarding claim 9 , Lee in view of Wang teaches all limitations of the method of claim 1, and also teaches wherein the tungsten liner and the tungsten layer are free from titanium therein ( as taught in Wang above, these tungsten layers do not have titanium ). Regarding claim 10 , Lee in view of Wang teaches all limitations of the method of claim 1, and also teaches wherein the contact plug comprises a source/drain contact plug ( 86 in Fig. 17 of Lee is a source/drain contact plug ). Regarding claim 11 , Lee in view of Wang teaches all limitations of the method of claim 1, and also teaches wherein the contact plug comprises a gate contact plug ( 88 in Fig. 17 of Lee is a gate contact plug ) . 07-21-aia AIA Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Wang, as applied to claim 2, and further in view of Chandrashekar et al. (US 2013/0302980 A1) . Regarding claim 3 , Lee in view of Wang teaches all limitations of the method of claim 2, but does not teach wherein the depositing the tungsten nucleation layer is performed using a precursor comprising tungsten chloride. Chandrashekar teaches a method of forming a tungsten nucleation layer ( 2302 in Fig. 23 of Chandrashekar ) followed by a bulk deposition using WF 6 or WCl 6 ( [0154] of Chandrashekar ). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the tungsten nucleation layer using WCl 6 instead of WF 6 , as according to Chandrashekar. Because WCl 6 is a solid at room temperature, it might be preferred for ease of delivery and high deposition rates . 07-21-aia AIA Claim s 1, 12 are rejected under 35 U.S.C. 103 as being unpatentable over Lai et al. (US 2015/0179512 A1) in view of Bhowmik et al. (US 2003/0062626 A1) . Regarding claim 1 , Lee teaches a method ( 100 in Fig. 1 as illustrated in Figs. 2-6 of Lee ) comprising: forming a dielectric layer ( ILD 310 in Fig. 3 of Lai ) over a conductive feature ( 214 ); etching the dielectric layer to form an opening ( 320 in Fig. 3 ), wherein the conductive feature is exposed through the opening ( as shown in Fig. 3 of Lai ); forming a liner ( pre-silicide layer 405 in Fig. 4 ) in the opening, wherein the liner contacts sidewalls of the dielectric layer ( as shown in Fig. 4 ); depositing a tungsten layer ( W fill layer 420 ) to fill the opening; and planarizing the tungsten layer ( as described in [0019] of Lai ), wherein portions of the tungsten layer and the tungsten liner in the opening form a contact plug ( structure of 405 - 420 as shown in Fig. 5 of Lai ). But Lai does not teach that the liner is a tungsten liner ( [0046] of the published specification indicated that the tungsten liner includes silicon as deposited. Thus, the term “tungsten liner” is interpreted as a material that include any alloy, compound of tungsten ). Bhowmik teaches a method of forming a tungsten contact plug ( 10 in Fig. 4 of Bhowmik ) which comprises: forming a WSi layer ( 12 in Fig. 4 ) and a second tungsten film ( 13 ) using sputtering ( see [0028] of Bhowmik ); forming bulk W ( 14 ) using CVD process ( [0029] of Bhowmik ). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the contact plug of Lai as according to Bhowmik in order to obtain a high quality and more reliable contact plug structure ( the problem with Ti/TiN below the W plug is shown in Fig. 2 of Bhowmik and discussed in [0008]-[0009] of Bhowmik ). As incorporated, bulk W layer 14 of Bhowmik is analogous to the bulk W layer 420 of Lai; WSi layer 12 and W layer 13 of Bhowmik replace layers 405 and 410 of Lai. Regarding claim 12 , Lai in view of Bhowmik teaches all limitations of the method of claim 1, and also teaches wherein the tungsten liner comprises substantially pure tungsten ( [0046] of the published specification indicated that the tungsten liner includes silicon as deposited. Thus, the WSi layer 12 of Bhowmik satisfies the requirement of substantially pure tungsten ) . 07-21-aia AIA Claim s 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (10062784 B1) in view of Bhowmik et al. (US 2003/0062626 A1) . Regarding claim 13 , Lee teaches a method ( method in Fig. 18 as illustrated in Figs. 12A-17 of Lee ) comprising: forming a gate stack ( 64 in Fig. 12A ) on a semiconductor region ( 24 ); forming a source/drain region ( 42 ) on a side of the gate stack ( please see interpretation in 112b rejection above ); depositing a contact etch stop layer ( 47 in Fig. 12A ) over the source/drain region; depositing an inter-layer dielectric ( 46 in Fig. 12A ) over the contact etch stop layer; etching the inter-layer dielectric and the contact etch stop layer to form a source/drain contact opening ( opening of the S/D contact plug 78 in Fig. 15 ); forming a dielectric hard mask ( 66 in Fig. 15 ) over the gate stack; etching the dielectric hard mask to form a gate contact opening ( 84 in Fig. 16 ); and forming a contact plug ( 88 in Fig. 17 ) in one of the source/drain contact opening and the gate contact opening, wherein the forming the contact plug comprises: depositing a liner ( 90 in Fig. 17 ); and depositing a bulk tungsten layer ( 92 in Fig. 17 ) over the liner. But Lee does not teach that the liner is a tungsten liner deposited through physical vapor deposition; and the bulk tungsten layer is deposited through chemical vapor deposition. Bhowmik teaches a method of forming a tungsten contact plug ( 10 in Fig. 4 of Bhowmik ) which comprises: forming a WSi layer ( 12 in Fig. 4 ) and a second tungsten film ( 13 ) using sputtering ( see [0028] of Bhowmik ); forming bulk W ( 14 ) using CVD process ( [0029] of Bhowmik ). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the contact plug of Lee as according to Bhowmik in order to obtain a high quality and more reliable contact plug structure ( the problem with Ti/TiN below the W plug is shown in Fig. 2 of Bhowmik and discussed in [0008]-[0009] of Bhowmik ). As incorporated, bulk W layer 14 of Bhowmik is analogous to the bulk W layer 92 of Lee; barrier layer 15 , including WSi layer 12 and W layer 13 , of Bhowmik replace layer 90 of Lee. Regarding claim 14 , Lee in view of Bhowmik teaches all limitations of the method of claim 13, and also teaches wherein the tungsten liner is deposited as a substantially pure tungsten layer ( [0046] of the published specification indicated that the tungsten liner includes silicon as deposited. Thus, the WSi layer 12 of Bhowmik satisfies the requirement of substantially pure tungsten ) . 07-21-aia AIA Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Bhowmik, as applied to claim 2, and further in view of Wang . Regarding claim 16 , Lee in view of Bhowmik teaches all limitations of the method of claim 13 but does not teach the method further comprising depositing a nucleation layer over the tungsten liner using a fluorine-containing process gas, wherein the bulk tungsten layer is deposited on the nucleation layer. Wang teaches a method ( Fig. 1-4 ) of forming a tungsten contact structure ( 170a-190a in Fig. 4 ). The method comprises: forming an opening ( 160 in Fig. 1 ) in a dielectric layer ( 150 ); forming a barrier layer ( 170 ) on the bottom and sidewalls of the opening; depositing a tungsten nucleation layer ( 180 ) on the tungsten liner layer using CVD process with WF 6 as reactant gas ( see [0021] of Wang ); depositing a bulk tungsten layer ( 190 in Fig. 3 ) on the tungsten nucleation layer; performing a planarization step to remove portions of the liner, nucleation layer, and the bulk layer over the dielectric layer ( see Fig. 4 and [0023] of Wang ) in order to form the tungsten contact structure. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have added a nucleation tungsten layer of Wang before the bulk tungsten layer, in order to improve the formation of the bulk W layer . 07-21-aia AIA Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Bhowmik, as applied to claim 2, and further in view of Chandrashekar . Regarding claim 17 , Lee in view of Bhowmik teaches all limitations of the method of claim 13 but does not teach the method further comprising depositing a nucleation layer over the tungsten liner using a chlorine-containing process gas, wherein the bulk tungsten layer is deposited on the nucleation layer ( as taught in Wang above ). Chandrashekar teaches a method of forming a tungsten nucleation layer ( 2302 in Fig. 23 of Chandrashekar ) followed by a bulk deposition using WCl 6 ( [0154] of Chandrashekar discloses both WF 6 and WCl 6 as reactant, however, WCl 6 might be preferred for ease of delivery and high deposition rates ). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the tungsten nucleation layer before forming the bulk W layer, as according to Chandrashekar in order to improve the formation of the bulk W layer. Because WCl 6 is a solid at room temperature, it might be preferred for ease of delivery and high deposition rates . 07-21-aia AIA Claim s 21-23 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Bhowmik . Regarding claim 21 , Lee teaches a method ( method in Fig. 18 as illustrated in Figs. 1-17 of Lee ) comprising: forming a transistor ( transistor in Fig. 17 ) comprising: forming a gate stack ( 46 in Fig. 17 ) on a semiconductor region ( 52 ); and forming a source/drain region ( 42 ) adjacent to the gate region; and forming a contact plug ( 86 / 88 ) in a dielectric layer ( 82 ), wherein the contact plug is over and electrically coupled to one of the gate stack and the source/drain region ( as shown in Fig. 17 ), and wherein the contact plug is in physical contact with the dielectric layer ( as shown in Fig. 17 of Lee ). But Lee does not teach wherein an entirety of the contact plug is formed of tungsten (( [0046] of the published specification indicated that the tungsten liner includes silicon as deposited. So the limitation is interpreted that the entire contact plug can be formed of materials that comprises of tungsten, such as W alloy ). Bhowmik teaches a method of forming a tungsten contact plug ( 10 in Fig. 4 of Bhowmik ) which comprises: forming a first tungsten layer ( WSi layer 12 in Fig. 4 ) and a second tungsten film ( 13 ) using sputtering ( see [0028] of Bhowmik ); forming a third W layer ( bulk W layer 14 ) using CVD process ( [0029] of Bhowmik ). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the contact plug of Lee as according to Bhowmik in order to obtain a high quality and more reliable contact plug structure ( the problem with Ti/TiN below the W plug is shown in Fig. 2 of Bhowmik and discussed in [0008]-[0009] of Bhowmik ). As incorporated, bulk W layer 14 of Bhowmik is analogous to the bulk W layer 92 of Lee; barrier layer 15 , including WSi layer 12 and W layer 13 , of Bhowmik replace layer 90 of Lee. The layers 12-14 of Bhowmik are made of tungsten materials. Regarding claim 22 , Lee in view of Bhowmik teaches all limitations of the method of claim 21, and also teaches wherein the method comprises: depositing a first tungsten layer ( WSi layer 12 of Bhowmik ); depositing a second tungsten layer ( W layer 13 of Bhowmik ) over the first tungsten layer; and depositing a third tungsten layer ( bulk W layer 14 of Bhowmik ) over the second tungsten layer, wherein the first tungsten layer, the second tungsten layer, and the third tungsten layer are deposited using different deposition methods ( as taught in [0028]-[0029] of Bhowmik above ). Regarding claim 23 , Lee in view of Bhowmik teaches all limitations of the method of claim 22, and also teaches wherein the second tungsten layer is deposited using fluorine-free process gases ( layer 13 of Bhowmik is deposited using sputtering, so it uses some inert process gas such as nitrogen to create the plasma for the sputtering process. Consequently, it does not use any fluorine process gas such as WCl 6 . ). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to TUAN A HOANG whose telephone number is (571)270-0406. The examiner can normally be reached Monday-Friday 8-9am, 10am-6pm EST. 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, Jessica Manno can be reached at (571) 272-2339. 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. /Tuan A Hoang/ Primary Examiner, Art Unit 2898 Application/Control Number: 18/345,303 Page 2 Art Unit: 2898 Application/Control Number: 18/345,303 Page 3 Art Unit: 2898 Application/Control Number: 18/345,303 Page 4 Art Unit: 2898 Application/Control Number: 18/345,303 Page 5 Art Unit: 2898 Application/Control Number: 18/345,303 Page 6 Art Unit: 2898 Application/Control Number: 18/345,303 Page 7 Art Unit: 2898 Application/Control Number: 18/345,303 Page 8 Art Unit: 2898 Application/Control Number: 18/345,303 Page 9 Art Unit: 2898 Application/Control Number: 18/345,303 Page 10 Art Unit: 2898 Application/Control Number: 18/345,303 Page 11 Art Unit: 2898 Application/Control Number: 18/345,303 Page 12 Art Unit: 2898 Application/Control Number: 18/345,303 Page 13 Art Unit: 2898 Application/Control Number: 18/345,303 Page 14 Art Unit: 2898
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