Prosecution Insights
Last updated: April 19, 2026
Application No. 18/994,222

METAL INTERCONNECTION LINE AND MANUFACTURING METHOD THEREFOR

Non-Final OA §103
Filed
Jan 14, 2025
Examiner
CHEN, DAVID Z
Art Unit
2815
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
Cansemi Technology Inc.
OA Round
1 (Non-Final)
44%
Grant Probability
Moderate
1-2
OA Rounds
3y 9m
To Grant
94%
With Interview

Examiner Intelligence

Grants 44% of resolved cases
44%
Career Allow Rate
299 granted / 675 resolved
-23.7% vs TC avg
Strong +49% interview lift
Without
With
+49.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
63 currently pending
Career history
738
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
47.4%
+7.4% vs TC avg
§102
26.4%
-13.6% vs TC avg
§112
24.4%
-15.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 675 resolved cases

Office Action

§103
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . 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. Specification The title of the invention is broad and not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1-5, 10-11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 6,472,329 B1 to Goto et al. (“Goto”) in view of CN 110867389 A to Li et al. (“Li”), U.S. Patent Application Publication No. 2021/0119128 A1 to Zhang (“Zhang”), JP-2010045204-A to Kobayashi (“Kobayashi”), and JP-2008144195-A to Ohashi (“Ohashi”). As to claim 1, although Goto discloses a method of manufacturing a metal interconnection line, comprising: providing a wafer (18) on which a metal layer (22) is formed, the metal layer (22) comprising an aluminum (Al) layer (12); performing a main etch process (Step 1) on the Al layer (12) using a chlorine-containing gas, thereby removing a partial thickness of the Al layer (12) and producing aluminum chloride (AlCl3); performing a gradient over etch (OE) process (Column 6, lines 51-58, Step 2, final step) on a remainder of the Al layer (12) using the chlorine-containing gas and a fluorine-containing gas, thereby removing an undesired part of the remainder of the Al layer (12) and forming an Al interconnection line (12), wherein in the gradient OE process (Column 6, lines 51-58, Step 2, final step), a proportion of the fluorine-containing gas is increased stepwise to exchange the AlCl3 for aluminum fluoride (AlF3) (See Fig. 3, Fig. 5, Column 1, lines 5-60, Column 2, lines 52-60, Column 4, lines 43-67, Column 5, Column 6, Column 7, Column 8, Column 9, Column 10, lines 1-62) (Notes: the limitation “producing aluminum chloride (AlCl3) is met by providing the same chlorine-containing gas recited in claim 2 and evidenced by Page 4 of Li. Further, the proportion of the fluorine-containing gas is increased from 20 sccm to 200 sccm after the chlorine-containing gas at least decreases from 100/70 sccm to 50/40 sccm and/or to 0 sccm in sequential steps/orders. Lastly, the limitation “to exchange the AlCl3 for aluminum fluoride (AlF3)” is met by applying the same fluoride-containing gas recited in claim 3 and evidenced by ¶ 0169 of Zhang), Goto does not further disclose and soaking the wafer in an ammonium fluoride (NH4F) solution to remove the AlF3. However, Kobayasi does disclose and soaking the wafer in an ammonium fluoride (NH4F) solution to remove a natural oxide (See Page 1-Page 4) and Ohashi discloses the ammonium fluoride (NH4F) solution to remove the AlF3 (See Page 3). In view of the teachings of Kobayashi and Ohashi, 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 teaching of Goto to have and soaking the wafer in an ammonium fluoride (NH4 F) solution to remove the AlF3 because the ammonium fluoride removing the AlF3 provides a purer Al interconnection line while also improving the flatness to obtain a high-performance device (See Kobayashi Page 3 and Ohashi Page 3). As to claim 2, Goto further discloses wherein the chlorine-containing gas comprises boron trichloride (BCl3) and chlorine (Cl2) (See Column 6, lines 4-10). As to claim 3, Goto further discloses wherein the fluorine-containing gas comprises carbon tetrafluoride (CF4) and/or trifluoromethane (CHF3) (See Column 6, lines 51-58, Column 7, lines 51-67, Column 8, lines 16-36). As to claim 4, Goto in view of Kobayashi further discloses wherein before the main etch process (Step 1) is performed on the Al layer (12) using the chlorine-containing gas, the method of manufacturing the metal interconnection line further comprising: forming an anti-reflective layer (10) on the metal layer (22); forming a photoresist layer (20) on the anti-reflective layer (10); patterning the photoresist layer (20) by performing a photolithography process; and with the patterned photoresist layer (20) serving as a mask (20), etching the anti-reflective layer (10) and a natural alumina (Al2O3) layer on a surface of the Al layer (12) (See Fig. 5, Goto Column 5, lines 1-8, Column 7, lines 40-50, Column 7, lines 37-56, and Kobayashi Page 1), where the natural alumina is “naturally” formed, especially in an oxidizing environment and is etched selectively before the Al layer below thereof. As to claim 5, Goto in view of Kobayashi further discloses wherein after the gradient OE process (Column 6, lines 51-58, Step 2, final step) is performed on the remainder of the Al layer (12) using the chlorine-containing gas and the fluorine-containing gas, and before the wafer (18) is soaked in the NH4F solution, the method of manufacturing the metal interconnection line further comprising: removing the patterned photoresist layer (See Goto Column 2, lines 52-60). As to claim 10, Goto further discloses wherein the metal layer (22) further comprises a titanium (Ti)/titanium nitride (TiN) layer (14) formed between the wafer (18) and the Al layer (12) and a TiN layer (10) formed on the Al layer (12), wherein the TIN layer (10) is etched before the main etch process (Step 1) is performed on the Al layer (12) using the chlorine-containing gas, and the Ti/TiN layer (14) is etched after the gradient OE process (Column 6, lines 51-58, Step 2, final step) is performed on the remainder of the Al layer (12) using the chlorine-containing gas and the fluorine-containing gas (See Column 7, lines 41-50, Column 8, lines 37-67, Column 9, Column 10, lines 1-62). As to claim 11, it would have been obvious in view of Goto and Zhang to have wherein the photoresist layer (20/6) has a thickness of 3 μm to 6 μm, and wherein the patterned photoresist layer (20/6) has a minimum line width and pitch both of 1 μm and a height-to-width aspect ratio of 4:1 because the dimensions of the photoresist layer are adjusted in view of the overall device dimensions including the channel length and the required structure to cover and pattern the metal line. Further, the applicant also has not established the critical nature of the “a thickness of 3 μm to 6 μm” and “a minimum line width and pitch both of 1 μm and a height-to-width aspect ratio of 4:1”. “The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims….In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range.” In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir.1990). Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was made to have various ranges. It would also have been obvious to one of ordinary skill in the art at the time the invention was made to discover the optimum or workable ranges by routine experimentations to obtain optimized photoresist dimensions in light of design requirements and constrains. See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious). As to claim 13, Goto discloses a metal interconnection line made in accordance with the method of manufacturing the metal interconnection line of claim 1 (See Fig. 3, Fig. 5). Claim(s) 8 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 6,472,329 B1 to Goto et al. (“Goto”), CN 110867389 A to Li et al. (“Li”), U.S. Patent Application Publication No. 2021/0119128 A1 to Zhang (“Zhang”), JP-2010045204-A to Kobayashi (“Kobayashi”), and JP-2008144195-A to Ohashi (“Ohashi”) as applied to claim 1 above, and further in view of U.S. Patent Application Publication No. 2009/0032091 A1 to Huang et al. (“Huang”). The teachings of Goto, Li, Zhang, Kobayashi, and Ohashi have been discussed above. As to claim 8, Goto in view of Kobayashi and Huang further discloses wherein after the wafer (18/100) is soaked in the NH4F solution, the method of manufacturing the metal interconnection line further comprising: washing the wafer (18/100) with deionized water (See Huang ¶ 0026, ¶ 0031) such that impurities and dust are washed away. Claim(s) 9 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent No. 6,472,329 B1 to Goto et al. (“Goto”), CN 110867389 A to Li et al. (“Li”), U.S. Patent Application Publication No. 2021/0119128 A1 to Zhang (“Zhang”), JP-2010045204-A to Kobayashi (“Kobayashi”), JP-2008144195-A to Ohashi (“Ohashi”), and U.S. Patent Application Publication No. 2009/0032091 A1 to Huang et al. (“Huang”) as applied to claim 8 above, and further in view of U.S. Patent Application Publication No. 2025/0126923 A1 to Meng et al. (“Meng”). The teachings of Goto, Li, Zhang, Kobayashi, Ohashi, and Huang have been discussed above. As to claim 9, Goto in view of Kobayashi, Huang, and Meng further discloses wherein after the wafer (18/100) is washed with deionized water, the method of manufacturing the metal interconnection line further comprising: drying the wafer (18/100) with indolepropionic acid (IPA) such that the indolepropionic acid (IPA) serves as an additive to improve the uniformity of chemical reaction (See Meng ¶ 0097, ¶ 0098). Allowable Subject Matter Claims 6-7 and 12 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to DAVID CHEN whose telephone number is (571)270-7438. The examiner can normally be reached M-F 12-6. 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, JOSHUA BENITEZ can be reached at (571) 270-1435. 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. /DAVID CHEN/Primary Examiner, Art Unit 2815
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Prosecution Timeline

Jan 14, 2025
Application Filed
Mar 05, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
44%
Grant Probability
94%
With Interview (+49.2%)
3y 9m
Median Time to Grant
Low
PTA Risk
Based on 675 resolved cases by this examiner. Grant probability derived from career allow rate.

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