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 17/849,755 filed on June 27 2022 in which claims 1 to 20 are pending.
Drawings
The drawings submitted on June 27 2022 have been reviewed and accepted 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).
Claim Objections
Claims 1, 15 and 18 are objected to because of the following informalities:
The following limitation “low thermal conductivity” (LTC) and “high thermal conductivity” (HTC) needs to be defined so the office know how to interpret “Low” and “High” and avoid any 112 rejections later in the prosecution. The level or threshold of high and low should be defined for example “low thermal conductivity” compared to a portion of the bottom electrode that has “high thermal conductivity”.
. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The term “substantially” in claims 2, 7, 13, 16 and 19 is a relative term which renders the claim indefinite. The term “substantially” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention.
In a semiconductor device all the layers are substantially aligned and the following limitation does not further define a structural limitation in the claim. Office interprets the limitations “substantially aligned” as “aligned” in each of the claims 2, 7, 13, 16 and 19.
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.
Claim 1, 2, 5, 7-9, 11-15, 16, 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Manfrini et al. (US 2020/0136038 A1; hereinafter “Manfrini”).
Regarding claim 1, Manfrini teaches in Figures 1A-13 and related text e.g. A selector structure (118; Fig.1A and Fig.6; ¶ 0036):
A bottom electrode (114, Fig.1A; ¶ 0036) includes a bottom low thermal conductive (LTC; ¶0019) metal and a first bottom high thermal conductivity (HTC) metal (different claimed invention; 128; ¶ 0023);
a first switching film (selector element; ¶ 0036) on the bottom electrode (114) and having an electrical resistivity switchable by an electric field (505 is a PRAM device that can be used as selector element; ¶ 0036); and
a first top electrode (116, Fig.1A; ¶ 0046) on the first switching film (122/124; ¶ 0045) and including a first top low thermal conductivity (LTC) metal (¶ 0046) and a first top high thermal conductivity (HTC) metal (different claimed invention 126; Fig.1A).
Manfrini does not explicitly teach (HTC) in each of the bottom electrode and upper electrode.
However, Manfrini teaches a thermal conductivity (128) of the upper electrode (116, Fig.1A) and a thermal conductivity (126) of the lower electrode (114, Fig.1A) and the thermal conductivity of the filament can be highly conductive with respect to the dielectric layers (122 and 120, Fig.1A).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to recognize to have high thermal conductive metal of the bottom electrode and top electrode in selector structure of Manfrini to have a selector device to have a reduced threshold voltage (¶ 0036).
Regarding claim 2, Manfrini teaches first top HTC metal (128, Fig.1A) is substantially aligned with the first bottom HTC metal (126, Fig.1A) in a thickness direction (Fig.1A).
Regarding claim 5, Manfrini teaches herein the first top LTC metal is located on opposing sides of the first top HTC metal (128 is located on the opposing side of 116; Fig.1A), and the bottom LTC metal is located on opposing sides of the first bottom HTC metal (126 is located on the opposing side of 114; Fig.1A).
Regarding claim 7, Manfrini teaches wherein a width of the first top electrode and a width of the bottom electrode are substantially the same as a width of the first switching film (width of the first top electrode 116, 118 and 114; Fig.1A).
Regarding claim 8, Manfrini teaches wherein the first switching film has a thickness in a range from about 5nm to about 50 nm (0 nm; ¶ 0020).
Regarding claim 9, Manfrini teaches wherein each of the first top electrode and the bottom electrode each has a thickness in a range from about l nm to about 500nm (each metal layer can have thickness of 15nm to 30 nm; ¶ 0021).
Regarding claim 11, Manfrini does not explicitly teach wherein a ratio of a contact area of the first top LTC metal to a contact area of the first top HTC metal, and a ratio of a contact area of the bottom LTC metal to a contact area of the first bottom HTC metal are each in a range of about 1:1 to about 10,000:1.
Manfrini teaches the thickness of each dielectric layer (122, 124; Fig.1A; ¶ 0021) and metal layer (114, 116; Fig.1A; ¶ 0021).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to be able to calculate a ratio of a contact area of the first top LTC metal to a contact area of the first top HTC metal, and a ratio of a contact area of the bottom LTC metal to a contact area of the first bottom HTC metal are each in a range of about 1:1 to about 10,000:1 since it has been held that where the general conditions of a claim are disclosed in the prior art (thickness of each layer, material of each layer and ratio of contact can be calculated 126 and 128), discovering the optimum or working ranges involves only routine skill in the art. See MPEP § 2144.05.
Regarding claim 12, Manfrini teaches wherein a shape of the selector structure comprises a circular cylinder (502, Fig.5A) and a square cylinder (cross section view; 112, Fig. 5B).
Regarding claim 13, Manfrini teaches a first selector including the bottom electrode (114, Fig.5B), the first switching film (118, Fig.5A; formed on the left side), and the first top electrode (116, Fig.5A); and
a second selector (502, Fig.5A; selector formed a second memory) including the bottom electrode (114), a second switching film (120) on the bottom electrode (114), and a second top electrode (116) on the second switching film (124), wherein the second top electrode comprises a second top HTC metal (128, Fig.1A) and a second top LTC metal (128), and the bottom electrode (114) further comprises a second bottom HTC metal (126) that is substantially aligned with the second top HTC (128) metal in the thickness direction (thickness direction; 126 and 1128 are aligned).
Regarding claim 15, Manfrini teaches in Figures 1A-13 and related text e.g. a memory cell (Fig.5A), comprising:
a resistive element (504, Fig.5B; ¶ 0036); and
a selector structure (118; Fig.1A and Fig.6; ¶ 0036) electrically coupled to the resistive element (504);
a bottom electrode (114, Fig.1A; ¶ 0036) includes a bottom low thermal conductive (LTC; ¶0019) metal and a first bottom high thermal conductivity (HTC) metal (different claimed invention; 128; ¶ 0023);
a first switching film (selector element; ¶ 0036) on the bottom electrode (114) and having an electrical resistivity switchable by an electric field (505 is a PRAM device that can be used as selector element; ¶ 0036); and
a first top electrode (116, Fig.1A; ¶ 0046) on the first switching film (122/124; ¶ 0045) and including a first top low thermal conductivity (LTC) metal (¶ 0046) and a first top high thermal conductivity (HTC) metal (different claimed invention 126; Fig.1A).
Manfrini does not explicitly teach (HTC) in each of the bottom electrode and upper electrode.
However, Manfrini teaches a thermal conductivity (128) of the upper electrode (116, Fig.1A) and a thermal conductivity (126) of the lower electrode (114, Fig.1A) and the thermal conductivity of the filament can be highly conductive with respect to the dielectric layers (122 and 120, Fig.1A).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to recognize to have high thermal conductive metal of the bottom electrode and top electrode in selector structure of Manfrini to have a selector device to have a reduced threshold voltage (¶ 0036).
Regarding claim 16, Manfrini teaches first top HTC metal (128, Fig.1A) is substantially aligned with the first bottom HTC metal (126, Fig.1A) in a thickness direction (Fig.1A).
Regarding claim 18, Manfrini teaches in Figures 1A-13 and related text e.g. a memory array (Fig.5A);
a plurality of word lines (WL1-WLm; ¶ 0034);
a plurality of bit lines (BL1-BLn, ¶ 0034) extending perpendicularly to the plurality of word lines (WL1- WLm);
a plurality of memory cells (502) located at intersections of plurality of word lines (WL) and plurality of bit lines (BL), respectively, wherein a first memory cell (502) of the plurality of memory cells comprises (502):
a first resistive element (504); and
a first selector of the selector structure (118; Fig.1A and Fig.6; ¶ 0036), wherein the first selector (118) is electrically coupled to the first resistive element (504, Fig.5A) and comprises:
a bottom electrode (114, Fig.1A; ¶ 0036) includes a bottom low thermal conductive (LTC; ¶0019) metal and a bottom high thermal conductivity (HTC) metal (different claimed invention; 128; ¶ 0023);
a first switching film (selector element; ¶ 0036) on the bottom electrode (114) and having an electrical resistivity switchable by an electric field (505 is a PRAM device that can be used as selector element; ¶ 0036); and
a first top electrode (116, Fig.1A; ¶ 0046) on the first switching film (122/124; ¶ 0045) and including a first top low thermal conductivity (LTC) metal (¶ 0046) and a first top high thermal conductivity (HTC) metal (different claimed invention 126; Fig.1A).
Manfrini does not explicitly teach (HTC) in each of the bottom electrode and upper electrode.
However, Manfrini teaches a thermal conductivity (128) of the upper electrode (116, Fig.1A) and a thermal conductivity (126) of the lower electrode (114, Fig.1A) and the thermal conductivity of the filament can be highly conductive with respect to the dielectric layers (122 and 120, Fig.1A).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the invention, to recognize to have high thermal conductive metal of the bottom electrode and top electrode in selector structure of Manfrini to have a selector device to have a reduced threshold voltage (¶ 0036).
Regarding claim 19, Manfrini teaches a second memory cell of the plurality of memory cells comprises: a second resistive element (502, Fig.5A-5D); and a second selector of the selector structure (second 118), wherein the second selector (118) is electrically coupled to the second resistive element and comprises:
the bottom electrode (114);
a second switching film on the bottom electrode (second 118; Fig.5A-5D); and
a second top electrode (116, Fig.5A) on the second switching film (122/124/120), wherein the second top electrode (116) comprises a second top HTC metal (128) and the bottom electrode (114) further comprises a second bottom HTC metal (126) that is substantially aligned with the second top HTC metal (128) in the thickness direction (thickness direction of the 118).
Regarding claim 20, Manfrini teaches wherein a word line of the plurality of word lines is coupled to the bottom electrode (WL, Fig.5A), a first bit line of the plurality of bit lines (BL1-BLn; Fig.5A; ¶ 0034) is coupled to the first top electrode (116) of the first memory cell (first memory cell), and a second bit line (BL) of the plurality of bit lines is coupled to the second top electrode (116) of the second memory cell (504).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Manfrini et al. (US 2020/0136038 A1; hereinafter “Manfrini”) as applied to claim 1 above, and further in view of Park (US 2018/0159030 A1; hereinafter “Park”).
Regarding claim 6, Manfrini does not teach wherein the first switching film comprises an ovonic threshold switching (OTS) film including at least one of selenium, tellurium or germanium.
However, Park teaches the first switching film comprises an ovonic threshold switching (OTS) film including at least one of selenium, tellurium or germanium (106, ¶ 0026).
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 first switching film comprises an ovonic threshold switching (OTS) film including at least one of selenium, tellurium or germanium in the device of Manfrini as taught by Park in the device of Manfrini 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.
Allowable Subject Matter
Claims 3, 4, 10, 14 and 17 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.
Claim 3 is objected to since the prior art does not teach the following limitation: “…each of the first top HTC metal and the first bottom HTC metal comprises a proximal end and a distal end, and a width of the distal end is greater than a width of the proximal end.”
Claim 4 is objected to since the prior art does not teach the following limitation: “…the first top HTC metal is located in a central region of the first top electrode, and the first bottom HTC metal is located in a central region of the bottom electrode.”
Claim 10 is objected to since the prior art does not teach the following limitation: “…a ratio of a thermal conductivity of the first top LTC metal to a thermal conductivity of the first top HTC metal, and a ratio of a thermal conductivity of the bottom LTC metal to a thermal conductivity of the first bottom HTC metal are each in a range of about 1:10 to about 1:10,000.”
Claim 14 is objected to since the prior art does not teach the following limitation “wherein the bottom electrode further comprises an HTC coupling line connecting the first bottom HTC metal to the second bottom HTC metal” with the rest of the limitations of claim 13 and 1.
Claim 17 is objected to since the prior art does not teach the following limitation “each of the top HTC metal and the bottom HTC metal comprises a proximal end and a distal end, and a width of the distal end is greater than a width of the proximal end.”
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Mounir S Amer whose telephone number is (571)270-3683. The examiner can normally be reached Monday-Friday 9:00-5:30.
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/Mounir S Amer/Primary Examiner, Art Unit 2818