Prosecution Insights
Last updated: April 18, 2026
Application No. 18/344,194

LOW DRIFT PHASE CHANGE MATERIAL COMPOSITE MATRIX

Non-Final OA §102§103
Filed
Jun 29, 2023
Examiner
DULKA, JOHN P
Art Unit
2817
Tech Center
2800 — Semiconductors & Electrical Systems
Assignee
International Business Machines Corporation
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
96%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
688 granted / 825 resolved
+15.4% vs TC avg
Moderate +12% lift
Without
With
+12.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
28 currently pending
Career history
853
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
37.3%
-2.7% vs TC avg
§102
32.2%
-7.8% vs TC avg
§112
21.7%
-18.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 825 resolved cases

Office Action

§102 §103
CTNF 18/344,194 CTNF 85910 DETAILED ACTION 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. 07-06 AIA 15-10-15 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. Domestic Benefit No claim to an application for domestic benefit. Foreign Priority No claim to an application for foreign priority. Information Disclosure Statements The three information disclosure statements submitted respectively on 06/29/2023, 09/13/2024 and 02/04/2026 were filed before first Office action. The submissions are in compliance with the provisions of 37 CFR 1.97. Accordingly, the three information disclosure statements have been considered. Claim Rejections - 35 USC § 102 07-07-aia AIA 07-07 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 – 07-08-aia AIA (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. 07-15 AIA Claim s 1-4, 10 and 13 are rejected under 35 U.S.C. 102( a)(1 ) as being anticipated by US 2008/0165569 A1 to Chen et al. (“Chen”) . PNG media_image1.png 492 644 media_image1.png Greyscale Regarding claim 1 , Chen teaches in Figure 3, paragraphs 0023-0029 of a phase change memory device 300 comprising: a composite phase change material 330 layer comprising a mixture of a dispersed phase of a projection material of a first resistivity 334, and a matrix of a phase-change material 332 of a second resistivity or third resistivity dependent on phase, wherein the first resistivity of the projection material has a resistance that is greater than the second resistance for the phase change material, and is less than the third resistance of the phase change material; Chen in Figure 3, paragraphs 0023-0029 shows that the PCM material has two phases a " higher resistivity amorphous phase while the remainder of the PCM remains in a lower resistivity crystalline phase." Furthermore, Chen teaches that "The resistor material is in the form of discrete resistor clusters 334 that are dispersed throughout the PCM . Moreover, the resistor material forming the resistor clusters has a lower resistivity than the PCM when the PCM is in its substantially amorphous phase . " a first electrode 310; and a second electrode 320 on opposing faces of the composite phase change material layer 330, wherein the projection material forms a percolated conducting path from the first electrode to the second electrode. Chen in Figure 3, paragraph 0028 shows two black lines which illustrate the path (= percolated conducting path) of the read current through the memory cell 300. The paths percolate the amorphous phase, which is the high resistivity phase of the PCM material, is such that a conductive path is formed via the resistor cluster 334 with lower resistance compared to the amorphous phase. Regarding claims 2 and 10 , Chen describes in Figure 3, paragraphs 0023-0029 that the amorphous phase has the highest resistivity (= third resistivity) and the crystalline phase a lower resistivity (= second resistivity). Further, Chen in paragraph 0004 describes that the resistivity between these two phases of the PCM increases by 6 orders in magnitude (i.e. > 20 times). Regarding claims 3 and 4 , Chen describes in paragraph 0033 that metal nitrides, e.g. titanium or tantalum nitrides, are used for the resistor cluster (= projection material). Regarding claim 13 , Chen shows in Figure 9 and paragraphs 0040-0041 (a plurality) of composite PCM layers alternating stacked with PCM layers . 07-15 AIA Claim s 16-20 are rejected under 35 U.S.C. 102( a)(1 ) as being anticipated by US 2008/0165569 A1 to Chen et al. (“Chen”) with support provided by US 2022/0093853 A1 to Syed et al. (“Syed”) . Regarding independent claim 16 , Chen teaches a method for reducing drift effects (the limitations, “reducing drift effects” appears to necessarily happen because all the method limitations in the body of the claim are taught by Chen and thereby necessarily causing the intended-use of “reducing drift effects.” Further Syed, in paragraphs 0006-0010--- states that a projected phase change memory based on metal nitrides projection materials reduce drift effects. Therefore, Chen’s paragraph 0033 will necessarily reduce the drift effects) in a phase change memory device (refer to claim 1 rejection supra ) comprising: forming a composite phase change material layer comprising a mixture of a dispersed phase of a projection material of a first resistivity, and a matrix of a phase-change material of a second resistivity or third resistivity dependent on phase, wherein the first resistivity of the projection material has a resistance that is greater than the second resistance for the phase change material, and is less than the third resistance of the phase change material (refer to claim 1 rejection supra ); forming a first electrode and a second electrode on opposing faces of the composite phase change material layer (refer to claim 1 rejection supra ); and applying a current (see background and also paragraph 0025 and Figure 3: there is a current applied across the electrodes) across the first and second electrode, wherein the projection material forms a percolated conducting path from the first electrode to the second electrode through a phase change region of the composite phase change material layer at one of the first and second electrode, wherein the projection material forms a percolated conducting path from the first electrode to the second electrode (refer to claim 1 rejection supra ). Regarding claim 17 , Chen teaches in paragraphs 0034-0036 of co-sputtering for the formation of the composite material. Regarding claims 18 and 20 , refer respectively to claim rejections 2 and 10 supra . Regarding claim 19 , refer to claim 3 rejection supra . 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. 07-20-02-aia AIA 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. 07-21-aia AIA Claim s 5-9 are rejected under 35 U.S.C. 103 as being unpatentable over US 2008/0165569 A1 to Chen et al. (“Chen”) . Chen teaches all limitations of claim 1 from which claims 5-9 depend. Regarding claims 5- 9, Chen in paragraph 0033 describes that "Suitable resistor material may therefore comprise a myriad of metallic and semiconductor materials . Such materials will preferably be commonly used in semiconductor processing for ease of manufacture and will not interdiffuse into the PCM and cause the PCM properties to be degraded." As the application is silent about a distinct benefit of the different materials of claims 5-9, the problem solved is less ambitious and denotes finding alternative resist cluster materials that meet the requirements according to Chen’s explanation in paragraph 0033 "the resistivity of the resistor material will be lower than that of the PCM in its amorphous phase ( and, optionally, higher than the PCM in its crystalline phase). GST in its amorphous phase typically has a resistivity of about one K[Omega]-cm, depending on how the GST is deposited and whether the GST is doped." It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to solve the problem of which exact material meets the requirements as explained in Chen’s paragraph 0033 . 07-21-aia AIA Claim s 11 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over US 2008/0165569 A1 to Chen et al. (“Chen”) in view of US 2022/0209105 A1 to Brew et al. (“Brew”) . Chen teaches all limitations of claims 1, 2 and 10 from which claim 11 depends. Regarding claim 11 , it is obvious to one of ordinary skill in the art before the effective filing date of the claimed invention given Cheng’s Figure 3 and paragraphs 0008, 0028 that the percolation path follows the crystalline PCM phase (lowest resistivity) and follows along the resistor cluster phase if the PCM is in the amorphous phase. The claimed feature "5 times or more" with respect to resistivity appears to be arbitrary given the arguments supra with respect to claims 5-9 in view of Chen’s paragraph 0033 and especially when Chen is viewed in light of Brew’s paragraph 0036-0037 comments on resistivity and material thereby making it an obvious choice to utilize a liner material, which exhibits a reasonable difference between the states of the PCM device. Chen teaches all limitations of claim 1 from which claim 14 depends. Regarding claim 14 , Chen does not teach of the listed additives in the phase change material. The problem encountered by Chen is the need to further control the resistivity of the phase change material/layer as suggested by Brew in paragraph 0027. Brew in Figure 1A, paragraph 0027 remedies this problem by introducing phase separated dopant material 114 in order to increase resistivity. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to recognize that combining Brew’s phase separated dopant material with Chen’s invention would have been beneficial as explained by Brew in paragraph 0027 in order to increase resistivity in the phase change layer . Allowable Subject Matter 12-151-08 AIA 07-43 12-51-08 Claim 12 is 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. Claim 12 contains allowable subject matter, because the closest art of record, singularly or in combination, fails to disclose of suggest, in combination with the other elements of claim 12, wherein the matrix of the phase-change material includes alternating layers of the phase change material with layers of conductive material. Specifically, Chen’s Figures 8 and 9, paragraphs 0039-0041 does not anticipate, teach or render obvious that the PCM matrix comprises alternating layers of conductive material and PCM layers in order to improve an internal thermal barrier (paragraph 0059 of the present application). Claim 15 contains allowable subject matter , because the closest art of record, singularly or in combination, fails to disclose of suggest, in combination with the other elements of claim 15, a phase change memory device comprising: a composite phase change material layer comprising a mixture of a dispersed phase of a projection material of a first resistivity, and a matrix of a phase-change material of a second resistivity or third resistivity dependent on phase, wherein the first resistivity of the projection material has a resistance that is greater than the second resistance for the phase change material, and is less than the third resistance of the phase change material; a projection material layer in direct contact with a backside surface of the composite phase change material layer; a backside electrode in direct contact with the projection material layer at the backside surface of the composite phase change material layer; and a top electrode on an opposing face of the composite phase change material layer that is opposite the face of the composite phase change material layer that is in direct contact with the projection material layer, wherein the projection material forms a percolated conducting path from the first electrode to the second electrode. Chen’s Figure 3 does not teach of an additional projection material layer between the backside electrode and the composite phase change material layer. Brew in Figure 2, paragraph 0041; Syed in Figure 3B, paragraph 0047; US 2022/0165948 A1 in Figure 1, paragraph 0054: teach such a projection liner material layer between an electrode and phase change material layer, however it would be impermissible hindsight to add these layers to Chen because Chen teaches a very specific resistivity and conducting path that would appear to not benefit from the added projection liner layer. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN P DULKA whose telephone number is (571)270-7398. The examiner can normally be reached Monday-Friday, 9am-5pm, 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, ELISEO RAMOS-FELICIANO can be reached at (571)272-7925. 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. 28 March 2026 /John P. Dulka/Primary Examiner, Art Unit 2817 Application/Control Number: 18/344,194 Page 2 Art Unit: 2817 Application/Control Number: 18/344,194 Page 4 Art Unit: 2817 Application/Control Number: 18/344,194 Page 5 Art Unit: 2817 Application/Control Number: 18/344,194 Page 6 Art Unit: 2817 Application/Control Number: 18/344,194 Page 7 Art Unit: 2817 Application/Control Number: 18/344,194 Page 8 Art Unit: 2817 Application/Control Number: 18/344,194 Page 9 Art Unit: 2817 Application/Control Number: 18/344,194 Page 10 Art Unit: 2817 Application/Control Number: 18/344,194 Page 11 Art Unit: 2817
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Prosecution Timeline

Jun 29, 2023
Application Filed
Mar 28, 2026
Non-Final Rejection — §102, §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
83%
Grant Probability
96%
With Interview (+12.4%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 825 resolved cases by this examiner. Grant probability derived from career allow rate.

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