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 .
This Office action is in response to Amendments filed 9/30/2025.
Claim Rejections - 35 USC § 102
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.
Claim(s) 1, 2, and 8 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Song et al. (US 2019/0140021 A1).
Regarding claim 1, Song discloses a memory device (Fig. 16A), comprising:
a substrate (102);
a bottom electrode (120) disposed over the substrate;
a top electrode (140) disposed over the bottom electrode; and
a phase change layer (130) disposed between the top electrode and bottom electrode, wherein the phase change layer comprises a GeSbTe material that contains a Ge content of about 1-20 at%, an Sb content of about 30-55 at%, and a Te content of about 40-55 at% (“Ge1Sb4Te7”, ¶ 0058; the Examiner notes that 58.3% is considered to fall within the range of “about 40-55 at%”).
Regarding claim 2, Song discloses that the phase change layer comprises the multilayer structure (¶ 0058).
Regarding claim 8, Song further discloses a barrier electrode (170, ¶ 0028) disposed on the phase change layer; and
a selector layer (150, ¶ 0042) disposed between the barrier electrode and the top electrode
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 (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.
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.
Claim(s) 3-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song et al. (US 2019/0140021 A1) as applied to claim 1, above.
Regarding claim 3, Song does not explicitly set forth an example as claimed.
However, Song discloses that the phase change layer may be a superlattice comprising a repetition of different GST compositions (¶ 0058). Selecting a repeating structure comprising alternating layers of GST124 and GST147 (two of the compounds explicitly listed by Song) would therefore have been obvious to one having ordinary skill in the art to use a superlattice structure with alternating layers of equal thickness of GST124 and GST147 as it amounts to choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success (see MPEP 2143).
In the resulting configuration, germanium content of the phase change layer will vary from about 5 to about 15 at% between the layers of GST124 and GST147 in a thickness direction extending between the bottom electrode and the top electrode.
Regarding claim 4, Song does not explicitly set forth an example as claimed.
However, Song discloses that the phase change layer may be a superlattice comprising a repetition of different GST compositions (¶ 0058). Selecting a repeating structure comprising alternating layers of GST124 and GST147 (two of the compounds explicitly listed by Song) would therefore have been obvious to one having ordinary skill in the art to use a superlattice structure with alternating layers of equal thickness of GST124 and GST147 as it amounts to choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success (see MPEP 2143).
In the resulting configuration, the phase change layer comprises first sublayers (i.e., the topmost layer and every third layer from the topmost layer which alternates composition between GST124 and GST147) and second sublayers (the layers directly beneath the first sublayers) alternatively stacked, the topmost layer is a first sublayer in contact with the top electrode layer, and Ge contents of the first sublayers of the phase change layer are discontinuously changed in a thickness direction.
Regarding claim 5, Song does not explicitly set forth an example as claimed.
However, Song discloses that the phase change layer may be a superlattice comprising a repetition of different GST compositions (¶ 0058). Selecting a repeating structure comprising alternating layers of GST124 and GST147 (two of the compounds explicitly listed by Song) would therefore have been obvious to one having ordinary skill in the art to use a superlattice structure with alternating layers of equal thickness of GST124 and GST147 as it amounts to choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success (see MPEP 2143).
In the resulting configuration, the germanium content of the phase change layer is discontinuously changed in a thickness direction extending between the bottom electrode and the top electrode (it changes as it alternates between GST124 and GST147).
Regarding claim 6, Song does not explicitly set forth an example as claimed.
However, Song discloses that the phase change layer may be a superlattice comprising a repetition of different GST compositions (¶ 0058). Selecting a repeating structure comprising alternating layers of GST124 and GST147 (two of the compounds explicitly listed by Song) would therefore have been obvious to one having ordinary skill in the art to use a superlattice structure with alternating layers of equal thickness of GST124 and GST147 as it amounts to choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success (see MPEP 2143).
In the resulting configuration, the phase change layer comprises second sublayers (i.e., the topmost layer and every third layer from the topmost layer which alternates composition between GST124 and GST147) and first sublayers (the layers directly beneath the second sublayers) alternatively stacked, the topmost layer is a second sublayer in contact with the top electrode layer, and Ge contents of the first sublayers of the phase change layer are discontinuously changed in a thickness direction.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song et al. (US 2019/0140021 A1) as applied to claim 1, above, and further in view of Takeuchi et al. (US 2022/0407001 A1) and Cheng (US 2023/0099931 A1).
Regarding claim 7, Song discloses using alternating layers of GST and chalcogenide materials comprising two elements such as antimony and tellurium (¶ 0058). Song differs from the claimed invention by the substitution of GST467 and Sb2Te3 with other GST and chalcogenide compositions. However, GST 467 and Sb2Te3 and their corresponding functions were known in the art (¶ 0018 of Takeuchi and ¶ 0018 of Cheng). As such, it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to have substituted the known compounds of GST467 and Sb2Te3 as taught by Takeuchi and Cheng for the superlattice layer compositions of Song in equal thickness and the results of the substitution would have been predictable. (see MPEP § 2143(I)(B)).
In the resulting configuration, the phase change layer comprises Ge4Sb6Te7 and Sb2Te3 in a ratio of 10:1 to 1:10.
Claim(s) 9-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song et al. (US 2019/0140021 A1) in view of Takeuchi et al. (US 2022/0407001 A1) and Cheng (US 2023/0099931 A1).
Regarding claim 9, Song discloses a memory device (Fig. 16A), comprising:
a lower interconnect structure (110) over a substrate (102);
a bottom electrode (120) disposed over the lower interconnect structure;
a top electrode (140) disposed over the bottom electrode;
a phase change layer (130) disposed between the top electrode and bottom electrode, wherein the phase change layer comprises a GeSbTe material and a SbTe based material (¶ 0058); and
an upper interconnect structure (170) over the top electrode.
Song discloses using alternating layers of GST and chalcogenide materials comprising two elements such as antimony and tellurium (¶ 0058). Song differs from the claimed invention by the substitution of GST467 and Sb2Te3 with other GST and chalcogenide compositions. However, GST 467 and Sb2Te3 and their corresponding functions were known in the art (¶ 0018 of Takeuchi and ¶ 0018 of Cheng). As such, it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to have substituted the known compounds of GST467 and Sb2Te3 as taught by Takeuchi and Cheng for the superlattice layer compositions of Song in equal thickness and the results of the substitution would have been predictable. (see MPEP § 2143(I)(B)).
In the resulting configuration, the phase change layer comprises Ge4Sb6Te7 and Sb2Te3 in a ratio of 5:1 to 1:5 and when in that ratio the phase change layer contains a Ge content of about 1-20 at%, an Sb content of about 30-55 at%, and a Te content of about 40-55 at%.
Regarding claim 10, in the resulting configuration, the Ge content of the phase change layer is discontinuously changed in a thickness direction extending between the bottom electrode and the top electrode (discontinuously changed between the sublayers).
Regarding claim 11, in the resulting configuration, the phase change layer first sublayers (i.e., the topmost layer and every third layer from the topmost layer which alternates composition between GST124 and GST147) and second sublayers (the layers directly beneath the first sublayers) alternately stacked, and Ge contents of the first sublayers of the phase change layer are discontinuously changed towards the thickness direction.
Regarding claim 12, in the resulting configuration, the phase change layer comprises first sublayers (the GST467 layers) and second sublayers (the Sb2Te3 layers) alternately stacked.
Regarding claim 13, the first sublayers and the second sublayers comprise different materials (see rejection of claim 12, above).
Regarding claim 14, each of the first sublayers and the second sublayers comprise GST467, Sb2Te3, or a combination of both (see rejection of claim 9, above).
Regarding claim 15, in the resulting configuration, the phase change layer comprises a multilayer structure (see rejection of claim 9, above).
Regarding claim 16, Song further discloses doping the phase change layer with a dopant including nitrogen (¶ 0058).
Response to Arguments
Applicant's arguments filed 9/30/2025 have been fully considered but they are not persuasive.
Regarding claim 1, Applicant argues that GST147 is outside of the ranges for Ge, Sb, and Te in claim 1. This argument is not persuasive as GST147 is within the claimed range as Applicant uses the approximate terminology of “about”.
Regarding claim 9, Applicant argues that the combination of references does not disclose the newly added limitations. This argument is not persuasive as the combination of references does disclose the newly added limitations.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER A CULBERT whose telephone number is (571)272-4893. The examiner can normally be reached M-F 9-5.
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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.
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/CHRISTOPHER A CULBERT/ Examiner, Art Unit 2815