DETAILED ACTION
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 .
Status of the Application
This Office Action is in response to Applicant’s application 18/327,432 filed on January 12, 2026 in which claims 1 to 37 are pending. Claims 1-17 are canceled. Claims 21-27 are new claims.
Drawings
The drawings submitted on June 01 2023 have been reviewed and accepted by the Examiner.
Information Disclosure Statement
The Information Disclosure Statement (IDS), filed on March 28 2024, August 15 2024, and January 13 2024 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosed therein has been considered by the Examiner.
Notation
References to patents will be in the form of (C:L) where C is the column number and L is the line number. References to pre-grant patent publications will be to the paragraph number in the form of (¶ XXXX).
Election/Restrictions
Applicant’s election without traverse of claims 18-20 in the reply filed on January 12, 2026 is acknowledged. Claims 1-17 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Claims 1-17 are canceled.
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, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
Claims 18 and 21-26 are rejected under 35 U.S.C. 103 as being unpatentable over Slovin et al. (US 10,461,253 B1; hereinafter “Slovin”) in view of Wu (US 2019/0165264 A1; hereinafter “Wu”).
Regarding claim 18, Slovin teaches in Figures 1A-9B a method of fabricating a phase change material (PCM) switch (510, Fig.5A; Col. 10; Ln. 25-30) comprising:
forming a first electrode (544; Fig.5A; Col. 10; Ln. 25-30) laterally surrounded by a first dielectric layer (542; Fig.5A; Col.10; Ln. 20-25);
forming a phase change material layer (512; Fig.5A; Col.10; Ln. 25-30) over an upper surface of the first dielectric material layer (342); and
forming a second electrode (554; Fig.5A; Col.10; Ln. 34-35) and a third electrode (554, Fig.5A; Col.10; Ln. 34-35) contacting the phase change material layer (812), wherein a signal pathway extends across the phase change material layer (812) between the second electrode and the third electrode along a first direction (X-axis; Fig.5).
Slovin does not explicitly teach forming an ovonic threshold switching (OTS) layer over the first electrode and laterally surround by the first dielectric material layer; forming a phase change material layer over an upper surface of the OTS layer; and the OTS layer extends below the phase change material layer along a second direction that is transverse to the first direction.
However, Wu teaches forming an ovonic threshold switching (OTS) layer (160’; Fig.5; ¶ 0027) over the first electrode (110, Fig.5; ¶ 0027) and laterally surround by the first dielectric material layer (150’; ¶ 0024); forming a phase change material layer (130’; Fig.5;¶ 0022) over an upper surface of the OTS layer (160’); and the OTS layer extends below the phase change (130’) material layer along a second direction (second direction could be the Y-axis; Fig.5) that is transverse to the first direction (x-axis; Fig.5).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to have an ovonic threshold switching (OTS) layer over the first electrode and laterally surround by the first dielectric material layer; forming a phase change material layer over an upper surface of the OTS layer; and the OTS layer extends below the phase change material layer along a second direction that is transverse to the first direction in the device of the Slovin as taught by Wu for the purpose of having a selector to reduce leakage current (¶ 0027).
Regarding claim 21, Slovin as modified by Wu teaches the OTS layer comprises at least one of a selenium-containing compound, a tellurium-containing compound, or a germanium-containing compound (Wu;160; Fig.5; ¶ 0027).
Regarding claim 22, Slovin as modified by Wu teaches the phase change material layer comprises at least one of a germanium telluride compound, an antimony telluride compound, a germanium antimony telluride compound, a germanium antimony compound, an indium germanium telluride compound, an aluminum selenium telluride compound, an indium selenium telluride compound, or an aluminum indium selenium telluride compound (Wu; 130; Fig. 5; ¶0032).
Regarding claim 23, Slovin does not explicitly teach wherein the OTS layer is composed of a material having a higher melting temperature than a melting temperature of a material of the phase change material layer.
However, Wu teaches that the material of the OTS layer can be formed from germanium containing compound (130; ¶ 0027) and phase change material can be formed from chalcogenide alloy (¶ 0032).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to have the OTS layer is composed of a material having a higher melting temperature than a melting temperature of a material of the phase change material layer in the device of Slovin as taught by Wu since it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended use as a matter of obvious design choice. MPEP § 2144.07.
Regarding claim 24, Slovin does not teach a thickness of the OTS layer is greater than 100 nm.
However, Wu teaches a thickness of the OTS layer is between 0.5 nm to about 50 nm (¶ 0040).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to have a a thickness of the OTS layer is greater than 100 nm, in the device of the Slovin as taught by Wu since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. See MPEP § 2144.05.
Regarding claim 25, Slovin as modified by Wu teaches a second dielectric material layer (Slovin; 358; Fig.3A; Col.5; Ln. 60-62) over the first dielectric material layer (342), the phase change material layer (322), the OTS layer, and the second and third electrodes (354).
Regarding claim 26, Slovin as modified by Wu teaches a first pair of electrical contacts (356/556, Fig.3A; Col.5; Ln. 60-62) extending through the second dielectric material layer (358/558) and contacting the second electrode and the third electrode (354; Fig.3A/554; Fig.5A).
Allowable Subject Matter
Claims 27-37 are allowed.
Claims 19 and 20 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.
The following is a statement of reasons for the indication of allowable subject matter:
Claim 19 is allowed because the prior art does not teach the following limitation “…. forming a trench in the first dielectric material layer; depositing a continuous electrode layer over the upper surface of the first dielectric material layer and within the trench; and performing a planarization process to remove portions of the continuous electrode layer from over the upper surface of the first dielectric material layer to provide a first electrode laterally surrounded by the first dielectric material layer, and wherein forming the OTS layer comprises: performing a recess etch to vertically recess the upper surface of the first electrode relative to the upper surface of the first dielectric material layer; depositing a continuous OTS layer over the upper surface of the first dielectric material layer and over the upper surface of the first electrode; and performing a planarization process to remove portions of the continuous OTS layer from over the upper surface of the first dielectric material layer to provide an OTS layer over the upper surface of the first electrode.”
Claim 20 is allowed because the prior art does not teach the following limitation “…. depositing a continuous electrode layer over the upper surface of a lower dielectric material layer; depositing a continuous OTS layer over the upper surface of the continuous electrode layer; etching the continuous OTS layer and the continuous electrode layer through a patterned mask to provide a discrete first electrode over the upper surface of the lower dielectric material layer and a discrete OTS layer over the upper surface of the first electrode; forming an upper dielectric material layer over the upper surface of the lower dielectric material layer, over the sides of the first electrode, and over the sides and upper surface of the OTS layer; and performing a planarization process to remove the upper dielectric material layer from over the upper surface of the OTS layer to provide the first electrode and the OTS layer embedded within the first dielectric material layer comprising the lower dielectric material layer and the upper dielectric material layer.”
Claim 27 is allowed because the prior art does not teach the following limitation “…. etching the continuous OTS layer and the continuous electrode layer through a patterned mask to provide a discrete first electrode over the upper surface of the lower dielectric material layer and a discrete OTS layer over an upper surface of the first electrode; forming an upper dielectric material layer over the upper surface of the lower dielectric material layer, over side surfaces of the first electrode, and over side surfaces and an upper surface of the OTS layer; performing a planarization process to remove the upper dielectric material layer from over the upper surface of the OTS layer; forming a phase change material layer over the upper surface of the OTS layer; and forming a second electrode and a third electrode contacting the phase change material layer.”
The prior art references on record do not teach the exact order of the steps of forming in claim 27.
The following is a statement of reasons for the indication of allowable subject matter: Claim 32 is allowed because the prior art does not teach the following limitation “…. forming one or more electrical contacts extending through the dielectric material layer, the OTS layer and contacting the first electrode” with the rest of the limitations of claim 32.
Slovin teaches in Figures 1A-9B a method of fabricating a phase change material (PCM) switch (31, Fig.3A; Col. 5; Ln. 55-60) comprising:
forming a first electrode (344; Fig.3A; Col. 5; Ln. 55-60);
forming a phase change material layer (512; Fig.5A; Col.10; Ln. 25-30);
forming a second electrode (554; Fig.5A; Col.10; Ln. 34-35) and a third electrode (554, Fig.5A; Col.10; Ln. 34-35) contacting the phase change material layer (812),
forming a dielectric material layer (542; Col.5; Ln. 20-25) over the second electrodes (554), the third electrode (554), and the phase change material layer (522); and
forming one or more electrical contacts (556, Fig.3A; Col.5; Ln. 60-62) extending through the dielectric material layer (556; Fig.5A) and contacting the second and third electrode (556).
Wu teaches forming an ovonic threshold switching (OTS) layer (160’; Fig.5; ¶ 0027) over the first electrode (110, Fig.5; ¶ 0027); forming a phase change material layer (130’; Fig.5;¶ 0022) over an upper surface of the OTS layer (160’); and
However, none of the prior art teaches the above limitation of claim 32.
Conclusion
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/Mounir S Amer/Primary Examiner, Art Unit 2818