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 .
Election/Restrictions
Applicant’s election without traverse of Invention I in the reply filed on 2/3/2026 is acknowledged.
Claims 11-13 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Invention II, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 2/3/2026.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the “sixth encapsulation layer coating the fifth layer” (e.g. claim 10) must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claims 1-6 and 9-10 are objected to because of the following informalities:
Claim 1 recites “a first layer in a phase change material”, which ought to be phrased as “a first layer which is a phase change material”, or something to similar effect; “interposed between the first and second layers, in a material having a density higher than that of the material of the second layer” which ought to be phrased as “interposed between the first layer and the second insulating layer, in a material having a density higher than that of the material of the second insulating layer” or something to similar effect.
Claim 2 recites “the second layer is in silicon carbide or in silicon carbonitride” which ought to be phrased as “the second insulating layer is silicon carbide or silicon carbonitride”.
Claim 3 recites “the third layer is in silicon carbide, in silicon nitride, in silicon carbonitride, in germanium nitride, in carbon nitride or in carbon” which ought to be phrased as “the third insulating layer is silicon carbide, silicon nitride, silicon carbonitride, germanium nitride, carbon nitride or carbon”.
Claim 4 recites “the third layer is in the same material as the second layer” which ought to be phrased as “the third insulating layer is the same material as the second insulating layer”, or something to similar effect.
Claim 5 recites “wherein the second and third layers are in silicon carbide” which ought to be phrased as “wherein the second and third insulating layers are silicon carbide”.
Claim 6 recites “wherein the second and third layers are in silicon nitride” which ought to be phrased as “wherein the second and third insulating layers are silicon nitride”
Claim 9 recites “side faces of the first, second and third layers and a fifth encapsulation layer coating the fourth layer and having a lower density than that of the fourth layer” which ought to be phrased as “side faces of the first layer and the second and third insulating layers, and a fifth encapsulation layer coating the fourth encapsulation layer and having a lower density than that of the fourth encapsulation layer”.
Claim 10 recites “a sixth encapsulation layer coating the fifth layer and having a density higher than that of the fifth layer” which ought to be phrased as “a sixth encapsulation layer coating the fifth encapsulation layer and having a density higher than that of the fifth encapsulation layer”.
Appropriate correction is required.
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.
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.
Claims 1-2 and 4-5 are rejected under 35 U.S.C. 103 as being unpatentable over US patent publication US 20220149274 A1 (Lin et al hereinafter Lin).
Regarding claim 1, Lin discloses a phase change memory cell (the cell of FIG. 1G ¶ [0004]) comprising: - a first layer (FIG. 1G, variable resistance layer 212 is a phase change material ¶ [0024-0026]) in a phase change material; - a heating element (FIG. 1G, bottom electrode 206 functions as a heating element under layer 212 ¶ [0014]) located under the first layer; - a second insulating layer (FIG. 1G, lower half of first dielectric layer 202 coats a side of electrode 206 ¶ [0013]) coating a side of the heating element; and - a third insulating layer (FIG. 1G, upper half of first dielectric layer 202 is between the lower half of layer 204 and layer 212 ¶ [0013]) interposed between the first and second layers.
Lin does not explicitly disclose that the third insulating layer is in a material having a density higher than that of the material of the second layer, differentiation between densities of sub-layers of dielectric layer 202 not being discussed in the disclosure of Lin. However, a person of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to try having the density of the upper half of dielectric layer 202 greater than the density of the lower half of dielectric layer 202 in view of manufacturing tolerances limiting the precision and uniformity of the density of dielectric layer 202. Even if the average density of the upper half of dielectric layer 202 is only a small amount (e.g. an amount of difference caused due to limitations of manufacturing precision) greater than the average density of the lower half of dielectric layer 202, such disparity would be sufficient to satisfy the limitation “the third insulating layer is in a material having a density higher than that of the material of the second layer” as it is currently claimed. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to have the third insulating layer is in a material having a density higher than that of the material of the second layer, in order to provide a phase change memory cell device manufactured by methods known in the art.
Regarding claim 2, Lin discloses the limitations of claim 1 as detailed above, and further discloses that the second layer is in silicon carbide or in silicon carbonitride (lower half of first dielectric layer 202 is formed of silicon carbide ¶ [0013]).
Regarding claim 4, Lin discloses the limitations of claim 1 as detailed above, and further discloses that the third layer is in the same material as the second layer (lower and upper halves of first dielectric layer 202 are formed of silicon carbide ¶ [0013]).
Regarding claim 5, Lin discloses the limitations of claim 4 as detailed above, and further discloses that the second and third layers are in silicon carbide (lower and upper halves of first dielectric layer 202 are formed of silicon carbide ¶ [0013]).
Claims 1, 3, 6-9 are rejected under 35 U.S.C. 103 as being unpatentable over US patent publications US 20140124726 A1 (Oh) in view of US 20210174840 A1 (Kaushik et al hereinafter Kaushik).
Regarding claim 1, Oh discloses a phase change memory cell (the cell of FIG. 2A ¶ [0051]) comprising: - a first layer (FIG. 2A, phase-change layer 172 is a phase change material ¶ [0073]) in a phase change material; - a heating element (FIG. 2A, lower electrode 158 may be used as a heating element ¶ [0074, 0092]) located under the first layer; - a second insulating layer (FIG. 2A, gap-filling mold layer 148 coats a side of lower electrode 158 ¶ [0076]) coating a side of the heating element; and - a third insulating layer (FIG. 2A, second spacer 146 is between mold layer 148 and phase-change layer 172 ¶ [0080]) interposed between the first and second layers.
Oh does not explicitly teach that the third insulating layer is in a material having a density higher than that of the material of the second layer, relative densities of layers 146 and 148 not being elements of particular importance to the disclosure of their invention. Oh does teach that layers 146 and 148 may both be formed of silicon nitride (¶ [0076, 0080]).
Further, Kaushik discloses a memory device (see Abstract) and teaches that the method of depositing silicon nitride layers affects the density of the layers, noting the ALD and CVD depositions may provide different silicon nitride layers of distinct densities (¶ [0047]), it being known in the art that an ALD process results in a higher density than a CVD process when forming silicon nitride layers. Oh also teaches that silicon nitride layers in their device may be formed both by ALD and CVD processes (Oh ¶ [0099]).
Oh and Kaushik both pertain to the field of memory devices, placing them in the same field of endeavor as the claimed invention. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to form second spacer 146 using an ALD process so that the spacer can be precisely formed as a liner in trench 142 (FIG. 3C, ¶ [0091]), and to form gap-filling mold layer 148 using a CVD process to fill the remainder of trench 142 (FIG. 3E, ¶ [0095]) efficiently. By doing so, the third insulating layer is in a material having a density higher than that of the material of the second layer.
Regarding claim 3, Oh in view of Kaushik discloses the limitations of claim 1 as detailed above, and they further disclose that the third layer is in silicon carbide, in silicon nitride, in silicon carbonitride, in germanium nitride, in carbon nitride or in carbon (second spacer 146 is formed of silicon nitride Oh ¶ [0080]).
Regarding claim 6, Oh in view of Kaushik discloses the limitations of claim 1 as detailed above, and they further disclose that the second and third layers are in silicon nitride (second spacer 146 and gap filling mold 148 may both be formed of silicon nitride Oh ¶ [0076, 0080]).
Regarding claim 7, Oh in view of Kaushik discloses the limitations of claim 1 as detailed above, and they further disclose a first conduction electrode (FIG. 2A, contact plug 134 is located under and in contact with the lower face of heating electrode 158 opposite phase-change layer 172 ¶ [0075]) located under and in contact with one face of the heating element opposite the first layer and a second conduction electrode (FIG. 2A, upper electrode 182 is located on and in contact with an upper face of phase-change layer 172 opposite heating electrode 158 ¶ [0075]) located on and in contact with one face of the first layer opposite the heating element.
Regarding claim 8, Oh in view of Kaushik discloses the limitations of claim 1 as detailed above, and they further disclose that the heating element is L-shaped (as can be seen in the A1-A2 cross section of FIG. 2A, heating electrode 158 is L-shaped).
Regarding claim 9, Oh in view of Kaushik discloses the limitations of claim 1 as detailed above, and they further disclose a stack comprising a fourth encapsulation layer (FIG. 2A, protection layer 162, which can be seen in the B1-B2 cross section to coat side faces of heating electrode 158, second spacer 146, and gap-filling mold layer 148 after referencing the cross-sectional designations of FIG. 1B ¶ [0099]) coating the side faces of the first, second and third layers and a fifth encapsulation layer (FIG. 2A, second mold layer 164 coats protection layer 162 ¶ [0099]) coating the fourth layer and having a lower density than that of the fourth layer (protection layer 162 is formed of silicon nitride by ALD and second mold layer 164 is formed of silicon nitride by CVD, which as discussed regarding claim 1 leads to the fifth encapsulation/second mold layer 164 having lower density than fourth encapsulation/protection layer 162 since the ALD process that formed layer 162 produces a higher density silicon nitride than the CVD process that forms layer 164).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Oh in view of Kaushik as applied to claim 9 above, and further in view of US patent publications US 20210265426 A1 (Nakamura) and US 20170369743 A1 (Siebert et al hereinafter Siebert).
Oh in view of Kaushik discloses the limitations of claim 9 as detailed above, and they further disclose a sixth encapsulation layer (FIG. 2A, second interlayered insulating layer 190 coats second mold layer 164 ¶ [0110]) coating the fifth layer.
Oh in view of Kaushik does not explicitly state the sixth encapsulation layer having a density higher than that of the fifth layer; second interlayered insulating layer 190 is suggested to be formed of an insulating material, suggesting silicon dioxide (Oh ¶ [0110]), while second mold layer 164 is formed of silicon nitride that is formed by a CVD process (Oh ¶ [0099]).
However, Nakamura discloses a memory device (storage device 1 of FIG. 6A ¶ [0079]) wherein an interlayer insulation layer (FIG. 6A, interlayer insulating film 31) may be interchangeably formed of silicon dioxide and SiO (¶ [0080]). Additionally, Siebert teaches that SiO may have a density of 2.648 g/cm^3, which exceeds the density of silicon nitride when it is formed by CVD processes.
Oh, Kaushik, Nakamura, and Siebert all pertain to the field of semiconductor devices, placing them in the same field of endeavor as the claimed invention. Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to modify the device of Ok in view of Kaushik further in view of Nakamura by using SiO as the material of the sixth encapsulation, as it has been demonstrated to be a known and interchangeable alternative in the art, and may be found beneficial in view of consideration of materials costs and changing market conditions. Having done so, the sixth encapsulation layer having a density higher than that of the fifth layer.
Cited Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: US patent publications US 20230270024 A1, US 20230240160 A1, US 20220399492 A1, US 20170250222 A1, and US 20110031462 A1.
Conclusion
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/E.R.C./Examiner, Art Unit 2813
/STEVEN B GAUTHIER/Supervisory Patent Examiner, Art Unit 2813