DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
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.
The following is a quotation of the appropriate paragraphs of pre-AIA 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 –
(b) the invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country, more than one year prior to the date of application for patent in the United States.
Claim(s) 8-11, 14, 15, and 17 is/are rejected under pre-AIA 35 U.S.C. 102(b) as being anticipated by US 7142349 (herein Yang).
Regarding claim 8, Yang teaches A method of forming a MEMS device, the method comprising:
etching a first cavity and a second cavity (openings 430, Fig. 4C) in a topmost dielectric layer of a first substrate (dielectric layer 420 is deposited on substrate 405, Col. 9, Line 31), a portion of the topmost dielectric layer being disposed between the first cavity and the second cavity (FIG. 4C illustrates the patterning and etching of dielectric layer 420 to form openings 430, Col. 9, Lines 54-55);
forming a first protrusion on a floor of the first cavity, and a second protrusion on a floor of the second cavity (In FIG. 4F, the dielectric layer 420 is removed to expose the landing posts 460, Col. 10, Lines 41-42),
wherein each of the first protrusion and the second protrusion have a low surface energy relative to the surface energy of a material of the topmost dielectric layer (conductive layer 440 is formed using polysilicon, Col. 10, Line 22; dielectric layer 420 is a silicone oxide, Col. 9, Line 32; Note that it is known in the art that polysilicon has a lower surface energy than silicon oxide, comparatively);
bonding a second substrate (substrate 470, Fig. 5G) to the first substrate (Wafer bonding techniques are used in some embodiments, to form a hermetic seal between layer 476 and substrate 405, Col. 10, Line 66-Col. 11, Line 1); and
after bonding the second substrate to the first substrate, patterning the second substrate to form a first movable element at least partially suspended above the first cavity (Col. 11, Lines 17-29 teach etching process of substrate 470),
wherein the first protrusion is in a path of movement of the first movable element when the first movable element is deflected in a first direction (Fig. 3A shows moveable structure 320 moving in a path in which landing posts 314 are located).
Regarding claim 9, Yang teaches wherein after bonding the second substrate to the first substrate, patterning the second substrate to form a second movable element at least partially suspended above the second cavity, wherein the second protrusion is in a path of movement of the second movable element when the second movable element is deflected in the first direction (Col. 11, Lines 17-29 teach etching process of substrate 470; Fig. 4H teaches two portions of mirror 480 on each side of hinge 486, each having landing posts 460 within their moving path when rotating about hinge 486).
Regarding claim 10, Yang teaches wherein the first substrate further comprises: a plurality of stacked dielectric layers beneath the topmost dielectric layer, the plurality of stacked dielectric layers having a plurality of interconnect layers formed therein (electrodes 410 are coupled to the surface of substrate 405. Preferably, the electrodes are made of a multilayer stack of deposited titanium nitride, aluminum, and titanium nitride layers. In some embodiments, the electrodes 410 are distributed in an array pattern and coupled to addressing and control circuitry, Col. 8, Lines 30-35).
Regarding claim 11, Yang teaches wherein forming the first protrusion on the floor of the first cavity comprises: patterning the floor of the first cavity to form a protrusion extending therefrom (FIG. 4C illustrates the patterning and etching of dielectric layer 420 to form openings 430, Col. 9, Lines 54-55); and depositing a first conductive film over a top surface and sidewalls of the protrusion, the first conductive film being electrically coupled to a first contact on the floor of the first cavity (a generally conformal liner layer commonly used in contact hole/via plug formation processes is deposited prior to the deposition of electrically conductive layer 440. Merely by way of example, the conformal liner layer may be formed as a TiN, Col. 10, Lines 14-18; Note that TiN is conductive, and would connect with electrodes 410).
Regarding claim 14, Yang teaches wherein the second protrusion on the floor of the second cavity is electrically coupled to a second contact on the floor of the second cavity (Figs. 4A-4C teach electrodes 410c, 410d connected to openings 430 and thus conformal liner layer of electrodes 462 discussed in Col. 10, Lines 14-18).
Regarding claim 15, Yang teaches A method of forming a MEMS device, the method comprising:
forming a cavity in a substrate (openings 430, Col. 9, Line 55);
forming a protrusion that extends from a floor of the cavity (landing post 460, Col. 10, Line 42, Fig. 4F), the protrusion comprising:
a dielectric layer (dielectric layer 420); and
a conductive film over sidewalls and a top surface of the dielectric layer (conformal liner layer commonly used in contact hole/via plug formation processes is deposited, conformal liner layer may be formed as a TiN, Col. 10, Lines 14-18),
wherein a first material of the conductive film has a low surface energy relative to the surface energy of a second material of the dielectric layer (conformal liner layer may be formed as a TiN, Col. 10, Line 18; dielectric layer 420 is a silicone oxide, Col. 9, Line 32; Note that it is known in the art that TiN has a lower surface energy than silicon oxide, comparatively); and
positioning a movable element above the cavity such that the movable element is configured to contact the protrusion when the movable element is deflected vertically downwards into the cavity (Fig. 4H teaches two portions of mirror 480 on each side of hinge 486, each having landing posts 460 within their moving path when rotating about hinge 486, equivalent to the contact made in Fig. 2A).
Regarding claim 17, Yang teaches wherein the conductive film comprises TiN (conformal liner layer may be formed as a TiN, Col. 10, Line 18).
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 pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 pre-AIA 35 U.S.C. 103(a) 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 12 and 18 is/are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Yang in view of US 6376048 (herein Takeishi).
Regarding claim 12, Yang does not teach, “wherein forming the first protrusion on the floor of the first cavity further comprises depositing a second conductive film over the first conductive film, wherein the first conductive film comprises TiN, and the second conductive film comprises AlCu.” However, Yang teaches a layer of TiN (Col. 10, Line 18) and also states a combination of layers may be possible. Takeishi teaches AlCu as a conductive film. It would have been obvious to one of ordinary skill in the art to simply substitute the second layer of Yang with AlCu taught by Takeishi because both function as conductive films. The above findings satisfies the Graham factual inquiries stated in MPEP 2143 B regarding simple substitution of one known element for another to obtain predictable results.
Regarding claim 18, Yang does not teach, “wherein the conductive film comprises amorphous carbon.” However, Takeishi teaches amorphous carbon as a conductive film (Col. 6, Line 24). It would be obvious to one of ordinary skill in the art to simply substitute the TiN layer of Yang with amorphous carbon taught by Takeishi because both function as conductive films. The above findings satisfies the Graham factual inquiries stated in MPEP 2143 B regarding simple substitution of one known element for another to obtain predictable results.
Claims 19-20 is/are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Yang in view of US 5869916 (herein Suzuki).
Regarding claim 19, Yang does not teach, “wherein the movable element comprises a membrane, a cantilever beam, or a comb structure.” However, Suzuki teaches it is known in the art to provide a comb shaped and cantilevered movable electrode (Col. 5, Lines 67, Fig. 2A), the shape which may be implements into the mirror of Yang. It would have been obvious to one of ordinary skill in the art to simply substitute the shape of Suzuki into the mirror shape of Yang to provide equivalent movable structure. The above findings satisfies the Graham factual inquiries stated in MPEP 2143 B regarding simple substitution of one known element for another to obtain predictable results.
Regarding claim 20, Yang does not teach, “wherein the protrusion is configured to be switchably coupled to a ground potential node or a potential voltage node.” However, Suzuki teaches it is known in the art to provide a switch to switch between potential voltage and reference/ground (Cool. 15, Lines 6-19). It would have been obvious to one of ordinary skill in the art before the time of filing to incorporate the switch of Suzuki into the protrusions 460, 462 of Yang. One would have been motivated to do so for at least the purpose of controlling potential prior to and during contact (Suzuki, Col. 3, Lines 39-42).
Allowable Subject Matter
Claims 1-7 are allowed.
Regarding claim 1 and dependents there, the prior art does not teach, “patterning a second substrate to form a series of interdigitated fingers, wherein each of the series of interdigitated fingers is fixed at one end and is free at another end; mounting the second substrate atop the first substrate, wherein free ends of the series of interdigitated fingers extend over the cavity; forming a plurality of protrusions extending from a floor of the cavity, wherein a first interdigitated finger of the series of interdigitated fingers will contact a first protrusion of the plurality of protrusions when the series of interdigitated fingers are deflected downwards towards the floor of the cavity; electrically coupling the first protrusion of the plurality of protrusions to the series of interdigitated fingers; and electrically coupling a second protrusion of the plurality of protrusions to a potential voltage node that provides a voltage of an opposite polarity to that of a voltage on the series of interdigitated fingers.” MEMS with interdigitated fingers are known in the art and taught by Suzuki. Further, Yang teaches an equivalent protrusion that contacts movable electrodes. However, even if combining Suzuki and Yang, neither would teach the specific electrical configuration.
Claims 13 and 16 objected to as being dependent upon a rejected base claim, but would have been allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The prior art does not appear to teach specific contact angle of the protrusion claimed.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Non-Patent Literature titled, “Correlation of surface roughness and surface energy of silicon-based materials with their priming reactivity” (herein Bodner) is cited to show inherent surface energy qualities of polysilicon and silicon oxide.
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/WALTER L LINDSAY JR/Supervisory Patent Examiner, Art Unit 2852
/PHILIP T FADUL/Examiner, Art Unit 2852