Ex Parte Fuller et al

Patent Trial and Appeal Board

Feb 22, 2018

13899278 (P.T.A.B. Feb. 22, 2018)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O.Box 1450
Alexandria, Virginia 22313-1450
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APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/899,278 05/21/2013 Scott Edward Fuller F588US 8209
121028 7590 02/26/2018
SrTieinhera Rr Asisinoiates; PP
EXAMINER
PO BOX 164140
Austin, TX 78716-4140
ABRAHAM, IBRAHIME A
ART UNIT PAPER NUMBER
1756
NOTIFICATION DATE DELIVERY MODE
02/26/2018 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
patents @ scheinbergip.com
eofficeaction @ appcoll.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte SCOTT EDWARD FULLER, BRIAN ROBERTS ROUTH JR.,
and MICHAEL MORIARTY
Appeal 2017-010462
Application 13/899,278
Technology Center 1700
Before RAE LYNN P. GUEST, JULIA HEANEY, and
JEFFREY R. SNAY, Administrative Patent Judges.
SNAY, Administrative Patent Judge.
DECISION ON APPEAL1
Appellants2 appeal under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 1-5, 7-16, 18, 21, and 22. We have jurisdiction
pursuant to 35 U.S.C. § 6(b).
We reverse.
1 We cite to the substitute Specification (“Spec.”) filed August 16, 2013;
Final Office Action (“Final Act.”) dated September 27, 2016; Appellants’
Appeal Brief (“App. Br.”) dated March 9, 2017; Examiner’s Answer
(“Ans.”) dated June 6, 2017; and Appellants’ Reply Brief (“Reply Br.”)
dated August 6, 2017.
2 Appellants identify FEI Company as the real party in interest. App. Br. 3.
Appeal 2017-010462
Application 13/899,278
BACKGROUND
The invention relates preparation of a sample lamella for transmission
electron microscopy (TEM) inspection. Spec. ^ 2. According to Appellants’
Specification, critical pattern dimensions in a semiconductor manufacturing
process can be monitored by TEM inspection of a thin (e.g., less than 100
nm thick) lamella that is milled from an area of interest on a semiconductor
substrate. Id. at^ffl 5-7. Appellants’ process for forming a lamella includes
operating an ion beam to mill in a line raster pattern, such that each
subsequent cut removes less material than the previous cut. Id. at 66. The
final line raster is operated to make the opposing lamella faces orthogonal to
the wafer surface. Id. Consequently, the milled lamella includes a shelf or
ledge section which slopes away from a thinned observation window such
that, in cross-section, the window and ledge portions take the form of an
inverted Y. Id. at 26, 56, 66, Figs. 6A, 6B. Claim 1—the sole
independent claim on appeal—reads as follows:
1. A method of forming a lamella having an observation
face for transmission electron microscope observation of a
feature of interest in the observation face, comprising:
directing a charged particle beam toward a work piece in
the vacuum chamber of a charged particle beam system to
induce deposition from a precursor gas of a protective layer
above the feature of interest, the ratio of the sputtering rate of
the work piece and the sputtering rate of the protective layer
being within a ratio of 1.5 to 1 and a ratio of 1:1, the work piece
comprising silicon;
directing a focused ion beam toward the sample to mill
one or more fiducials near the feature of interest;
directing the focused ion beam to mill cavities on both
sides of the region of interest to form a lamella;
from each side of the lamella, directing the focused ion
beam to mill progressively closer to the observation face from
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Application 13/899,278
the cavity, successively milling to remove less material from the
lamella as the beam approaches the region of interest to
provide a bottom surface of the lamella that slopes away from
the observation face, the ions in the focused ion beam having a
first landing energy;
after milling progressively closer to the observation face
from the cavity, milling to remove material separating the
cavities to leave tabs supporting the cavity;
after milling to remove material separating the cavities,
directing an ion beam toward the observation face, the ion beam
having a second landing energy, lower than the first landing
energy.
App. Br. 17 (Claims Appendix) (emphasis added to highlight the key
recitation in dispute).
REJECTIONS
I. Claims 1-5, 7-16, 21, and 22 stand rejected under 35 U.S.C. § 103(a)
as unpatentable over Blackwood,3 Wanzenboeck,4 and Tsai.5
II. Claims 1-5, 7-16, 21, and 22 stand rejected under 35 U.S.C. § 103(a)
as unpatentable over Blackwood, Hahnel,6 Wanzenboeck, and Tsai.
III. Claim 18 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Blackwood, Wanzenboeck, Tsai, and Wells.7
IV. Claim 18 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Blackwood, Hahnel, Wanzenboeck, Tsai, and Wells.
3 US 2010/0300873 Al, published December 2, 2010 (“Blackwood”).
4 US 2010/0276601 Al, published November 4, 2010 (Wanzenboeck”).
5 US 6,080,991, issued June 27, 2000 (“Tsai”).
6 Hahnel, A. et al., Nano-beam electron diffraction evaluation of strain
behavior in nano-scale patterned strained silicon-on-insulator, Phys. Status
Solidi, C 8, No. 4, 1319-24 (2011).
7 US 2009/0218488 Al, published September 3, 2009 (“Wells”).
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Application 13/899,278
DISCUSSION
A dispositive issue in this case is whether the Examiner reversibly
erred in finding that Tsai teaches forming a lamella having a bottom surface
that slopes away from an observation face. Compare Final Act. ^ 14 (“Tsai
teaches a method of forming a lamella ... to provide a bottom surface of the
lamella that slopes away from the observation face.”), with App. Br. 12
(“Applicants respectfully disagree that Tsai teaches a method of forming a
lamella ... to provide a bottom surface that slopes away from the
observation face.”), and Reply Br. 7 (“The cited prior art does not teach
forming a bottom surface of the lamella that slopes away from the
observation face.”).
Blackwood discloses using a focused ion beam to mill a lamella
having a thinned observation window that is suitable for TEM inspection.
Blackwood ^ 67. By decreasing scan speed of the beam as the beam is
stepped closer to the window face, the milling depth increases, resulting in a
milled trench that slopes toward the observation window. Id. 78, Fig. 19C.
The Examiner acknowledges that Blackwood teaches forming a
bottom lamella surface that slopes toward, rather than away from, the
observation face. Ans. 16 (“Blackwood teaches sloping in the opposite
direction as claimed.”). However, the Examiner finds that Tsai teaches
“forming a lamella by successive etching steps wherein less material is
removed from the lamella as the beam approaches the region of interest to
provide a bottom surface of the lamella that slopes away from the
observation face.” Final Act ^ 14. The Examiner relies on Tsai’s Figures 3
and 4 and the corresponding discussion at column 1, line 62, through column
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2, line 30. Final Act. 14, 35. There, Tsai refers to a conventional milling
process in which “[a] slanted surface 410 of the TEM observable wall is
automatically formed due to FIB milling.”8 Tsai 2:17-19. Such a slanted
TEM observable wall is depicted in Tsai’s Figure 4, labeled as prior art,
which we reproduce below:
FIB FIB
Norma! tine Norms! tine
FIG. 4 (PRIOR ART)
Figure 4 is a schematic drawing of a cross-sectional view of a TEM
test slice. Tsai 2:15-16.
In light of the foregoing disclosure in Tsai, the Examiner finds that
one of ordinary skill in the art would have had a reason to substitute Tsai’s
milling operation as a known “functionally equivalent” milling method.
Final Act. 14, 35. See also, Ans. 16 (“One of ordinary skill in the art
would certainly be able to select from one of these known methods to form a
suitable lamella with predictable expectations of successfully forming
lamella suitable for TEM viewing.”).
One problem with the Examiner’s reasoning is that, even if one were
to adopt Tsai’s so-called conventional milling technique in Blackwood’s
window milling process, the result would have been a sloping observation
8 FIB refers to a focused ion beam. Tsai 1:3 3-34.
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Application 13/899,278
face—surface 410 in Tsai’s Figure 4—rather than a surface that “slopes
away from the observation face” as is called for in claim 1. See Tsai 2:24—
25 (“[T]he TEM observable wall is gradually wider from the top to the
bottom.”). The Examiner fails to identify evidence in Tsai, or elsewhere in
the record, of successively milling to remove less material from the lamella
as the beam approaches the region of interest, so as to form both an
observation face and a bottom surface that slopes away from the observation
face. The Examiner, therefore, fails to set forth a factual basis which is
sufficient to support a determination that it would have been obvious to
modify Blackwood’s milling process in a manner that would have produced
a lamella having a bottom surface that slopes away from an observation face.
Because each of Rejections I-IV is premised on the same erroneous
finding that Tsai teaches forming a lamella having bottom surface that slopes
away from an observation face, these Rejections are not sustained.
DECISION
The Examiner’s decision rejecting claims 1-5, 7-16, 18, 21, and 22 is
reversed.
REVERSED
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