DETAILED ACTION
Response to Arguments
Applicant's arguments filed with respect to claims 14-20 have been fully considered but they are not persuasive.
Applicant argues on pages 8-9 that Park is silent as to explicitly teaching “forming second openings in the material stack, the second openings extending in a second direction perpendicular to the first direction” as recited in claim 14. Applicant argues that storage node contact plug 55 is not formed to be perpendicular to the first direction.
Examiner respectfully disagrees. The claim specifies that “removing portions of a material stack to form lines of the material stack extending in a first direction” at lines 4-5 of claim 14. Therefore, the first direction is into-out of the page of fig. 3 of the instant application, which is the left-right direction of fig. 4C of Park. Therefore, the claimed second opening being perpendicular to the first direction is met by Park since the opening for storage node contact plug 55 is vertical, which is perpendicular to the left right direction of fig. 4C of Park and also into-out of the page of fig. 5B of Park.
The rejection of claim 14 is being maintained.
With respect to claim 18 the limitations with respect to opposing first sides of the channel material and opposing second sides of the channel material, Examiner takes the position that left and right sides of each channel meet these limitations since there is no positive recitation of what the structure is. The claims merely gives an element a name but does not recite how they are on opposite sides of the channel with respect to a specific direction or the number of gates.
Rejection of claims 14-20 are being maintained.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim(s) 14, and 16-20 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Park et al. (US PGPub 2011/0073925; hereinafter “Park”).
Re claim 14: Park teaches (e.g. figs. 4C-4F, 5B) a method of forming a semiconductor device, comprising: forming one or more transistors (memory cell transistors; e.g. paragraph 27), comprising: removing portions (middle trench 49 of fig. 4C; e.g. paragraph 76; hereinafter “1O”) of a material stack (103, 46A, 102, 101B, 101A; hereinafter “MS”) to form lines (portion of MS under 47A; hereinafter “L”) of the material stack (MS) extending in a first direction (left-right direction of fig. 4C; hereinafter “1D”), the material stack (MS) comprising one or more conductive materials (metal bit lines 103; e.g. paragraph 24), a dielectric material (dielectric pattern 46A; e.g. paragraph 75), and a channel material (active pillars 101B; e.g. paragraph 76) and the lines (L) separated from one another by first openings (49); forming another conductive material (middle 51 of fig. 4D; hereinafter “ACM”) in the first openings (49); removing a portion (etchback process to recess ACM; e.g. paragraph 77; hereinafter “R”) of the another conductive material (ACM) in the first openings (49); forming second openings (opening for 55; e.g. paragraph 80; hereinafter “2O”) in the material stack (MS), the second openings (2O) extending in a second direction (opening for 55 extends in the vertical direction; hereinafter “2D”) perpendicular to the first direction (1D); forming an additional conductive material (55; e.g. paragraph 80) in the second openings (2O); and forming another dielectric material (54) in the first openings (1O) adjacent to the another conductive material (ACM).
Re claim 16: Park teaches the method of claim 14, wherein forming an additional conductive material (ACM) in the second openings (2O) comprises forming tungsten, titanium, tungsten nitride, or titanium nitride (TiN; e.g. paragraph 77) in the second openings (2O).
Re claim 17: Park teaches the method of claim 14, wherein forming another conductive material (ACM) in the first openings (1O) and forming an additional conductive material in the second openings (2O) comprises forming the another conductive material (51 is split into two 104) and the additional conductive material surrounding the channel material (101B).
Re claim 18: Park teaches the method of claim 17, wherein forming the another conductive material (104) and the additional conductive material (ACM) surrounding the channel material (101B) comprises forming active control gates on opposing first sides of the channel material (101B) and threshold voltage control gates on opposing second sides of the channel material (101B).
Re claim 19: Park teaches the method of claim 14, further comprising forming an additional dielectric material (50) on sidewalls of the material stack (MS) before forming the another conductive material (51/ACM) in the first openings (1O).
Re claim 20: Park teaches the method of claim 19, further comprising removing a portion of the additional dielectric material (50) so that a top surface of the another conductive material (51/ACM) is substantially coplanar with a top surface of the additional dielectric material (104).
Claim Rejections - 35 USC § 103
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.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Park as applied to claim 14 above.
Re claim 15: Park teaches substantially the entire method of claim 14, except explicitly teaching forming another conductive material (51) in the first openings comprises forming an n+ doped polysilicon material or a p+ doped polysilicon material in the first openings.
Park teaches the material of 51 can be a metal such as TiN/W. Doped polysilicon is a known alternative material used for conductive structures.
It would have been obvious to one of ordinary skills in the art at the time of effective filing, absent unexpected results, to use a known material which is cheaper to use in the device of Park such that it can be produced to save manufacturing costs.
Allowable Subject Matter
Claims 1, 3-8 are allowed.
The following is an examiner' s statement of reasons for allowance: Allowable subject matter has been indicated because the closest prior art references of record, Park et al. (US PGPub 2011/0073925) and Myung et al. (US PGPub 2014/0061745), either alone or in combination, fails to teach or fairly suggest the feature directed to for formation of the threshold voltage control gates which states “forming first openings in the material stack, wherein the first openings extend through the dielectric material, the second conductive material, the channel material, and the third conductive material, and expose a top surface of the first conductive material; forming a first dielectric material on sidewalls of the material stack in the first openings; forming a fourth conductive material in the first openings to fill the first openings; removing a portion of the fourth conductive material to form recesses; forming second openings in the material stack; forming a fifth conductive material in the second openings to fill the second openings; and forming a second dielectric material in the recesses”.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
THIS ACTION IS MADE FINAL. 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 JESSE Y MIYOSHI whose telephone number is (571)270-1629. The examiner can normally be reached M-F, 8:30AM-5:00PM.
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/JESSE Y MIYOSHI/
Primary Examiner, Art Unit 2898