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 .
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 1-8 and 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Fitzgerald (USPGPub 2003/0215990) in view of Figuet et al. (USPGPub 2007/0051975).
Regarding claims 1 and 6, Fitzgerald teaches that it is known to form SiGe layers [0026] on the surface of a silicon substrate [0015] wherein the layers may be graded (see items 218A and 218B of Fig. 2) and the impurity gradient, which may relate to Ge (claim 65) may increase up to what may be referred to as a “final content” wherein the layers may be relaxed [0023] wherein the layers may be deposited using a gas mixture of GeCl4 and SiH2Cl2 [0025] during what may be referred to as a “first stage and a second stage” wherein deposition preferably occurs at 850C [0027] wherein the grade rate may be 10% Ge per micron of thickness [0026] wherein the growth rate may be greater than 0.1 microns per minute throughout the process [0027]. Fitzgerald fails to each wherein the grade rate is within the range claimed. However, Fitzgerald teaches that the impurity gradient and its profile directly affects device performance [0011]. Therefore, in the absence of criticality of the specific grade rate of the current claims, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the grade rate and gradient profile of the invention of Fitzgerald in order to control the properties and performance of the devices formed by Fitzgerald. Discovery of optimum value of result effective variable in known process is ordinarily within skill of art. In re Boesch, CCPA 1980, 617 F.2d 272, 205 USPQ215.
The teachings of Fitzgerald are as shown above. Fitzgerald fails to teach that growth rates vary from a first stage to a second stage in the manner claimed. However, Figuet teaches that it is known to be desirable to deposit SiGe materials at a first higher rate in order to allow for faster deposition amounts that are less smooth followed by later growing at a slower growth rate which deposits materials less at a peak area and more in valleys of the already deposited surface thereby effectively smoothing the overall deposition [0048]. Therefore, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to deposit the SiGe coating of Fitzgerald in two stages (a higher growth rate stage followed by lower grow rate stage) in order to effectively deposit significant amounts of SiGe while providing them with a smooth surface as guided by Figuet. The teachings of Fitzgerald in view of Figuet are as shown above. Fitzgerald in view of Figuet fails to teach wherein the exact growth rate range of the second stage as claimed. However, as acknowledged above, Figuet generally teaches a smoothing effect value to providing a reduced growth rate. Therefore, in the absence of criticality of the specific second stage growth rate of the current claims, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the growth rate of the second stage or growth rate reduced stage of Fitzgerald in view of Figuet in order to control the level of smoothness of the invention of Fitzgerald in view of Figuet. Discovery of optimum value of result effective variable in known process is ordinarily within skill of art. In re Boesch, CCPA 1980, 617 F.2d 272, 205 USPQ215.
Regarding claim 2, the teachings of Fitzgerald in view of Figuet are as shown above. Figuet does not speak as to when one would start a second stage. However, as described above one applying the teachings of Figuet would reasonably apply them at any time during the manufacturing process wherein using slower growth rates earlier would slow overall growth but provide a more smoothed surface while using slower growth rates later would speed the overall growth but result in a less smooth product. Therefore based on this logical understanding and in the absence of criticality of the specific fraction of final germanium content to be reached that is claimed, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to start the second stage of slower growth in the invention of Fitzgerald in view of Figuet at any time realizing that production smoothness versus thickness produced time is being optimized.
Regarding claim 3, Fitzgerald teaches content ratios of Ge that would read upon the current claims as shown by the impurity gradients in Fig. 2.
Regarding claim 4, Fitzgerald teaches depositing layers via CVD [0026].
Regarding claim 5, Fitzgerald reasonably implies the use of silicon single crystal wafers when referencing monocrystalline Si substrates [0006] for semiconductor fabrication [0002]. One of ordinary skill in the art would reasonably envisage wafers.
Regarding claim 7, Fitzgerald teaches a first growth step less than 0.5 microns per minute which reads upon the claimed range [0027].
Regarding claim 8, Fitzgerald teaches the use of a second exposure step at “less than about 0.2 micron per minute”, which reads upon the claimed range (claim 55).
Regarding claim 10, the teachings of Fitzgerald in view of Figuet are as shown above. Fitzgerald in view of Figuet teaches wherein the substrate is made of silicon and can be a wafer but does not explicitly state that the wafer is a single crystal silicon wafer. However, the examiner is taking Official Notice to inform the applicant that single crystal silicon substrates are commonly used when references to silicon wafers are mentioned in this field of endeavor and are were well known to be used at the time of invention. Therefore, if it were not already implied that this is what is taking place in the prior art, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to use a single crystal silicon wafer as the silicon wafer substrate of Fitzgerald in view of Figuet based upon the known prevalent use of such substrates in this particular field of endeavor by those of ordinary skill in the art.
Regarding claim 11, Fitzgerald teaches that his method may provide TDD of less than 105/cm2 which would read upon the claimed range [0051].
Allowable Subject Matter
Claim 9 is 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.
The following is a statement of reasons for the indication of allowable subject matter: it is not known in the prior art to deposit a strain relaxed graded buffer layer of silicon germanium on a surface of a substrate, the surface comprising silicon and the buffer layer comprising an increasing content of germanium up to a final content, the method comprising: conducting GeCl4 and SiH2Cl2 during a first stage and a second stage over the surface of the substrate at a deposition temperature of not less than 800C growing the buffer layer with a grade rate that is less than 10 % Ge /micron and growing the buffer layer with a growth rate that is not less than 0.1 microns /min during the first stage, and that is less than 0.1 microns /min during the second stage wherein the final content is 25% Ge and the first stage ends when a content of 8% Ge has been reached as in claim 9.
The most pertinent prior art (previously cited as Fitzgerald et al) teaches that it is known to deposit buffer layers as generally claimed in claim 1. However, while the prior art teaches first and second stages of deposition there is no teaching as to the formation of a product with a final Ge% content of 25% and wherein the first stage would end at 8% which would correspond to a particular profile gradient of Ge present in the final product that is not described in the prior art, and no motivation would be provided to obtain.
Response to Arguments
The applicant first argues that Fitzgerald teaches a two-step coating process that does not equate to the currently claimed process because the prior art grows a first SiGe layer followed by an Si layer. However, this does not cover all embodiments of Fitzgerald. Fitzgerald explicitly teaches that the strained layer which has a growth rate less than the SiGe layer may be Si, Ge or SiGe [0033-0034].
Secondly the applicant argues that the prior art process does not modulate growth within a single buffer layer. However, the entire structure of the prior art would be considered the buffer layer and as such the growth rate is regulated within what may be referred to as the singular buffer layer. It appears as though the applicant may be attempting to argue that because the process of Fitzgerald is not continuous then maybe one singular continuous layer is not formed. However, the wording of the claim does not actually claim this structure or methodology.
Finally, the applicant argues that the optimization rationale is not applicable because first, the general conditions of the prior art are not present because the methodology of the prior art is not applied to a single graded buffer layer. However, as described above this is inaccurate. Second, the applicant states that the claimed parameters represent a non-obvious relationship between nucleation dislocation loops and glide of existing loops. However, these terms are not claimed and the parameters actually claimed are representative of other parameters wherein it is not a requirement of the prior art that they perform the modifications of the current claims for the same reasons. The reason or motivation to modify the reference may often suggest what the inventor has done, but for a different purpose or to solve a different problem. It is not necessary that the prior art suggest the combination to achieve the same advantage or result discovered by applicant. See, e.g., In re Kahn, 441 F.3d 977, 987, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006). Third the applicant argues that the growth rates are critical as they provide an “optimal growth rate”. This statement at face value generally indicates an optimization took place and that the data provided does not show criticality. A showing of criticality would generally be expected to provide a new and unexpected results arising from the conditions rather than an improved or “optimal” one.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 ANDREW J BOWMAN whose telephone number is (571)270-5342. The examiner can normally be reached Mon-Sat 5:00AM-11:00AM.
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/ANDREW J BOWMAN/Examiner, Art Unit 1717
/Dah-Wei D. Yuan/Supervisory Patent Examiner, Art Unit 1717
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