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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 5/20/2026 has been entered.
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 following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 uses the term “selective stop”. It is unclear to one having ordinary skill in the art what the term requires (does it require an etch?) as it is not a term of art nor explicitly defined in the specification. For the purpose of this Office action, “selective stop as interpreted as “removal step”.
Claims 2-11 depend form claim 1 and are, therefore, also rejected.
Claim Rejections - 35 USC § 102
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 2, 7, 8, and 10 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Karpov et al. (US 8,026,173 B2).
Regarding claim 1, Karpov discloses a method of forming a phase change memory array, the method comprising:
depositing a first dielectric layer (18 in Fig. 2);
depositing a second dielectric layer (24) connected to the first dielectric layer, wherein the second dielectric layer is different than the first dielectric layer;
depositing a heating material (26 in Fig. 3);
performing a first removal step to remove excess heating material above the second dielectric layer (see Fig. 4; it is noted that the portion of the removal which removes the heating material may be considered the first removal step), wherein the first selective stop has a first removal rate for the heating material (greater than zero) and a second removal rate of the second dielectric layer (zero), and wherein the first removal rate is higher than the second removal rate (greater than zero is greater than zero); and
performing a second removal step (see Fig. 4; it is noted that the portion of the removal which removes the second dielectric material may be considered the second removal step) to remove the second dielectric layer, wherein the second selective stop has a third removal rate for the second dielectric layer (greater than zero) and a fourth removal rate for the first dielectric layer (zero), and wherein the third removal rate is higher than the fourth removal rate (greater than zero is greater than zero).
Regarding claim 2, Karpov discloses the method of claim 1, as discussed above.
Karpov further discloses wherein the first removal step and the second removal step use different chemical slurries (Col. 2, Line 36).
Regarding claim 7, Karpov discloses the method of claim 1, as discussed above.
Karpov further discloses wherein: the first removal step stops after a first polish time (i.e., what time it takes to remove the heater material) and the second removal step stops after a second polish time (i.e., whatever time it takes to remove the second dielectric); the first polish time is determined based on a height of the excess heating material and a material of a first chemical slurry (as these two factors determine how long it takes to remove the heater material); and the second polish time is determined based on a height of the second dielectric layer and a material of a second chemical slurry (as these two factors determine how long it takes to remove the second dielectric material).
Regarding claim 8, Karpov discloses the method of claim 1, as discussed above.
Karpov further discloses patterning one or more openings in the first dielectric layer and the second dielectric layer; wherein the depositing the heating material includes depositing the heating material in the one or more openings (see Fig. 1).
Regarding claim 10, Karpov discloses the method of claim 1, as discussed above.
Karpov further discloses performing a third removal step to remove a portion of the first dielectric layer and a portion of the heating material (Karpov discloses that that layer 18 acts as an etch stop, therefore a portion of the first dielectric layer 18 is removed as well as a portion of the heater that was below the second dielectric layer; the removal of these portions may be considered a third removal step).
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov as applied to claim 1 above, and further in view of Barnes (US 2010/0286014 A1).
Regarding claim 3, Karpov discloses the method of claim 1, as discussed above.
Karpov does not disclose that the removal steps use chemical mechanical polishing with slurries specific to the particular material.
Barnes, in the same field of endeavor, discloses using chemical mechanical polishing with slurries specific to the particular material.
There was a benefit to this in that it allows for precisely tuning the removal step and thereby limit undesired material removal of other layers. It would have been obvious to one having ordinary skill in the art before the Application's effective filing date to use chemical mechanical polishing with slurries specific to the particular material in the method of Karpov for this benefit.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov in view of Barnes as applied to claim 3 above, and further in view of Frye (US 2018/0291309 A1).
Regarding claim 4, Karpov in view of Barnes discloses the method of claim 3, as discussed above.
Karpov does not disclose using a silica-based solution for a slurry. However, silica based slurries and the corresponding function was known in the art (¶ 0018 of Frye). 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 slurry of silica as taught by Frye for slurry of Karpov and the results of the substitution would have been predictable. (see MPEP § 2143(I)(B)).
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov in view of Barnes as applied to claim 3 above, and further in view of Das et al. (US 2020/0181535 A1).
Regarding claim 5, Karpov in view of Barnes discloses the method of claim 3, as discussed above.
Karpov does not disclose using a CeO2 for a slurry. However, CeO2 based slurries and the corresponding function was known in the art (¶ 0022 of Das). 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 slurry of CeO2 as taught by Das for slurry of Karpov and the results of the substitution would have been predictable. (see MPEP § 2143(I)(B)).
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov as applied to claim 1 above, and further in view of Turovets (US 2019/0027386 A1)
Regarding claim 6, Karpov discloses the method of claim 1, as discussed above.
Karpov does not disclose measuring a height of the second dielectric layer and calculating a polish time based on this height.
Turovets, in the same field of endeavor, discloses measuring the heights of layers remaining in a CMP process and calculating polish times based on the measurements (¶ 0072). There was a benefit to such a methodology in that it allows for a more precise control of the etching process. It would have been obvious to one having ordinary skill in the art before the Application's effective filing date to, after performing the first selective stop, measure a height of the second dielectric layer; and calculate a polish time for the second selective stop based on the height of the second dielectric layer of Karpov for this benefit.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov as applied to claim 8 above, and further in view of Park (US 2010/0127234 A1)
Regarding claim 9, Karpov discloses the method of claim 8, as discussed above.
Karpov does not disclose forming dummy areas as claimed.
Park, in the same field of endeavor, discloses using dummy active regions (¶ 0027). There was a benefit to using dummy active regions in that it allows for uniform distribution of components when active components are not required to be uniformly distributed, which allows for a more even and planar surface.
It would have been obvious to one having ordinary skill in the art before the Application's effective filing date for the one or more openings to comprise a first opening and a second opening; the first opening is patterned in a phase change memory area and the second opening is patterned in a dummy area of the phase change memory array; and no openings are patterned in a non-phase change memory area of the phase change memory array for this benefit.
Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Karpov as applied to claim 1 above, and further in view of Shen et al. (US 2012/0104339 A1).
Regarding claim 11, Karpov discloses the method of claim 1, as discussed above.
Karpov does not disclose using SiO--2 or SiN for the dielectric layers. However, SiO--2 or SiN based dielectric layers and the corresponding function was known in the art (¶ 0017 of Shen). 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 SiO--2 or SiN based dielectric layers as taught by Shen for the dielectric layers of Karpov and the results of the substitution would have been predictable. (see MPEP § 2143(I)(B)).
Response to Arguments
Applicant's arguments filed 5/13/2026 have been fully considered but they are not persuasive.
Applicant argues that “’selective stop’ is clearly defined”. This argument is not persuasive as the portion of the Specification cited by Application does not provide a clear definition of ‘selective stop’, but merely a possible example (“may be the selective removal”; emphasis added). As this is not a clear definition, one having ordinary skill in the art would not be appraised as to what other processes may be considered a ‘selective stop’.
Applicant argues that the first and second removal steps of Karpov are “a single CMP step”. This argument is not persuasive because, as discussed in the rejection above, the portion of the removal which removes the heating material may be considered the first removal step and the portion of the removal which removes the second dielectric material may be considered the second removal step.
Conclusion
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
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