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 .
DETAILED ACTION
Claim Rejections - 35 USC § 102
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.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 9-13 are rejected under 35 U.S.C. 102 (a)(1) as being anticipated by Liu (US 20070281497).
Regarding claim 9. Fig 2H of Liu discloses A contact structure, comprising:
a conductive feature 107 [0031] embedded in a first dielectric layer 105 ([0031]: ‘dielectric material’);
a first etch stop layer (ESL) 110 over the conductive feature and the first dielectric layer;
a second ESL 116 over the first ESL;
a second dielectric layer 118 [0041] over the second ESL; and
a contact via 126 [0043] extending through the second dielectric layer, the second ESL, and the first ESL to couple to the conductive feature (Fig 2H),
wherein the first ESL comprises aluminum nitride or silicon carbonitride ([0032]: ‘nitrogen doped silicon carbide’ which is SiCN),
wherein the second ESL comprises aluminum oxide or silicon oxycarbide ([0039]: ‘oxygen doped silicon carbide’, which is SiOC).
Regarding claim 10. Liu discloses The contact structure of claim 9, wherein the conductive feature comprises copper [0031].
Regarding claim 11. Liu discloses The contact structure of claim 9, further comprising:
a middle ESL 111 [0036] sandwiched between the first ESL and the second ESL (Fig 2H).
Regarding claim 12. Liu discloses The contact structure of claim 11, wherein the middle ESL comprises silicon oxycarbide ([0036]: ‘oxygen doped silicon carbide’, which is SiOC).
Regarding claim 13. Liu discloses The contact structure of claim 9, wherein top surfaces of the conductive feature and the first dielectric layer are coplanar (Fig 2H: the top surfaces of 107 and 105 are coplanar along the bottom surface of 110).
Claims 15-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tung (US 10468297).
Regarding claim 15. Tung discloses A method, comprising:
receiving a workpiece comprising a conductive feature 330 (col 3, line 9-10) embedded in a first dielectric layer 328 (Fig 4, col 5, line 10);
depositing a first etch stop layer (ESL) 362 (col 3, line 22) over the workpiece such that the first ESL is in direct contact with top surfaces of the conductive feature and the first dielectric layer (Fig 4);
depositing a second ESL 366 (col 4, line 12) over the first ESL (Fig 5);
depositing a second dielectric layer 368 (col 5, line 2) over the second ESL (Fig 7);
forming an opening 372 through the second dielectric layer, the second ESL and the first ESL to expose the conductive feature (Fig 13); and
forming a contact via 384 in the opening (Fig 16, col 7, line 41),
wherein the first ESL comprises metal oxide (col 3, line 24-25).
Regarding claim 16. Tung discloses The method of claim 15, wherein the conductive feature comprises tungsten (W) (col 10, line 19).
Regarding claim 17. Tung discloses The method of claim 15, wherein the first ESL comprises aluminum oxide (col 3, line 34).
Regarding claim 18. Tung discloses The method of claim 15, wherein the second ESL comprises metal nitride or metal oxide (col 4, line 28: aluminum oxide).
Regarding claim 19. Tung discloses The method of claim 18, wherein when the second ESL comprises metal oxide (col 4, line 28), an oxygen content in the second ESL and greater than an oxygen content in the first ESL (362 is aluminum oxynitride whereas 366 is aluminum oxide. the oxygen content in aluminum oxide is inherently greater than the oxygen content in aluminum oxynitride).
Regarding claim 20. Tung discloses The method of claim 15, wherein the second ESL comprises aluminum nitride (col 4, line 28).
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.
Claims 1-5 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Tung (US 10468297) in view of Ngo (US 6383925).
Regarding claim 1. Tung discloses A method, comprising:
receiving a workpiece 300A comprising a conductive feature 330 (col 3, line 9-10) embedded in a first dielectric layer 328 (Fig 4, col 5, line 10);
depositing a first etch stop layer (ESL) 362 (col 3, line 22) over the workpiece (Fig 4);
depositing a second ESL 366 (col 4, line 12) over the first ESL (Fig 5);
depositing a second dielectric layer 368 (col 5, line 2) over the second ESL (Fig 7);
forming an opening 372 through the second dielectric layer, the second ESL and the first ESL to expose the conductive feature (Fig 13); and
forming a contact via 384 in the opening (Fig 16, col 7, line 41),
wherein the first ESL comprises aluminum nitride (col 4, line 17; col 4, line 28; col 4, line 33-35: 362 is metal nitride including common metallic component as the 366) and or silicon carbonitride,
wherein the second ESL comprises aluminum oxide (col 4, line 25) or silicon oxycarbide.
But Tung does not explicitly disclose treating the workpiece with a nitrogen-containing plasma (However, Tung discloses the metal oxide based first ESL layer 362 is formed by either Chemical Vapor Deposition (CVD) or Atomic Layer Deposition (ALD) (col 3, line 44-46). In the applicant’s field of endeavor and based on semiconductor fabrication processes, a surface treatment is essential prior to forming a metal oxide (e.g., AlO, AlOC, AlON) etch stop layer on conductive metal surface using ALD or (CVD). This treatment, often a hydrogen plasma exposure, nitrogen-based plasma, or a cleaning step, is required to remove native oxide or contaminants, ensuring proper adhesion and preventing further oxidation of the underlying metal during the subsequent oxygen-containing dielectric deposition. For example, Ngo discloses treating a surface of a copper (Cu) or Cu alloy layer with a plasma containing nitrogen and ammonia (col 3, line 3-5).
Thus, 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 Ngo’s treating process within the Tung’s method for the purpose of enhancing surface energy, ensuring high-quality, reliable, and uniform deposition of dielectric or metallic ESL structure.
Regarding claim 2. Tung in view of Ngo discloses The method of claim 1, wherein the conductive feature comprises copper (Cu) (col 10, line 19).
Regarding claim 3. Tung in view of Ngo discloses The method of claim 1, Ngo discloses wherein the nitrogen-containing plasma comprises ammonia plasma and nitrogen plasma (col 3, line 5).
Regarding claim 4. Tung in view of Ngo discloses The method of claim 1, Tung discloses further comprising:
before the depositing of the second ESL, depositing a middle ESL 364 over the first ESL (Fig 5).
Regarding claim 5. Tung in view of Ngo discloses The method of claim 4, Tung discloses wherein a composition of the middle ESL is different from either a composition of the first ESL or the second ESL (col 3, line 67: 364 is silicon oxide or silicon carbide whereas first ESL 362 is aluminum nitride and second ESL 366 is aluminum oxide. Thus, having different composition).
Regarding claim 7. Tung in view of Ngo discloses The method of claim 4, Tung discloses wherein the depositing of the middle ESL comprises use of tetramethylsilane, silane, trimethylsilane, carbon dioxide, xenon, oxygen, or a combination thereof (col 3, line 63 – col 4 line 4: 364 is made of silicon oxide using CVD, PVD. Thus, essentially including silane and oxygen).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Tung (US 10468297) in view of Ngo (US 6383925), and further in view of Liu (US 20070281497).
Regarding claim 6. Tung in view of Ngo discloses The method of claim 4. But Tung in view of Ngo does not disclose wherein the middle ESL comprises oxygen-doped silicon carbide.
However, Liu discloses the middle ESL 111 comprises oxygen-doped silicon carbide [0036].
Thus, 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 method of Tung in view of Ngo to have the Liu’s method for the purpose of providing enhanced dielectric performance, enhanced mechanical strength and enhancing oxidation resistance in electronic devices.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Tung (US 10468297) in view of Ngo (US 6383925), and further in view of Lin (US 20180366369).
Regarding claim 8. Tung in view of Ngo discloses The method of claim 1, Tung discloses wherein the first ESL comprises a bottom surface closer to the conductive feature and a top surface away from the conductive feature (Fig 4).
But Tung in view of Ngo does not disclose wherein a nitrogen content at the bottom surface is greater than a nitrogen content at the top surface.
However, Fig 1 of Lin discloses ESL 140 [0013] a nitrogen content at the bottom surface 142 is greater than a nitrogen content at the top surface 144 ([0016]: ‘a nitrogen content of the first portion 142 is greater than a nitrogen content of the second portion 144’).
Thus, 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 Tung in view of Ngo’s method to have the Lin’s method of forming ESL structure for the purpose of providing enhanced adhesion to conductive via with greater nitrogen content and enhanced adhesion to second dielectric layer with lower nitrogen content [0016].
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Liu (US 20070281497) in view of Lin (US 20180366369).
Regarding claim 14. Liu discloses The contact structure of claim 9,
wherein the first ESL comprises a bottom surface closer to the conductive feature and a top surface away from the conductive feature (Fig 2H).
But Liu does not disclose wherein a nitrogen content at the bottom surface is greater than a nitrogen content at the top surface.
However, Fig 1 of Lin discloses ESL 140 [0013] a nitrogen content at the bottom surface 142 is greater than a nitrogen content at the top surface 144 ([0016]: ‘a nitrogen content of the first portion 142 is greater than a nitrogen content of the second portion 144’).
Thus, 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 Liu’s device structure to have the Lin’s ESL structure for the purpose of providing enhanced adhesion to conductive via with greater nitrogen content and enhanced adhesion to second dielectric layer with lower nitrogen content [0016].
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Changhyun Yi whose telephone number is (571)270-7799. The examiner can normally be reached Monday-Friday: 8A-4P.
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, Davienne Monbleau can be reached on 571-272-1945. 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.
/Changhyun Yi/Primary Examiner, Art Unit 2812