Ex Parte Schulze et al

Patent Trial and Appeal Board

Dec 13, 2017

11232735 (P.T.A.B. Dec. 13, 2017)

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
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/232,735 09/22/2005 Hans-Joachim Schulze 1012-1105 / 2004P53410 8002
us
57579 7590 12/15/2017
MURPHY, BILAK & HOMILLER/INFINEON TECHNOLOGIES
1255 Crescent Green
Suite 200
CARY, NC 27518
EXAMINER
LUKE, DANIEL M
ART UNIT PAPER NUMBER
2813
NOTIFICATION DATE DELIVERY MODE
12/15/2017 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):
official@mbhiplaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HANS-JOACHIM SCHULZE, ANTON MAUDER,
HELMUT STRACK, and HOLGER SCHULZE1
Appeal 2016-004830
Application 11/232,735
Technology Center 2800
Before RICHARD E. SCHAFER, LINDA M. GAUDETTE, and
DEBORAH KATZ, Administrative Patent Judges.
KATZ, Administrative Patent Judge.
DECISION ON APPEAL
1 The real party-in-interest is reported to be INFINEON TECHNOLOGIES
AG. (App. Br. 2.)
Appeal 2016-004830
Application 11/232,735
Appellants seek our review, under 35 U.S.C. § 134(a), of the
Examiner’s decision to reject claims 1, 2, 7—9, 11—16, 18—22, 26, and 27.
(App. Br. 1.) We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM.
The Examiner made the following rejections under pre-AIA 35 U.S.C.
§ 103(a):
Claims References Final Office
Action Citation
1,2, 11, 12, 18, 19,
26, and 27
Nishizawa2 2-5
7, 14, and 15 Nishizawa and Matsunaga3 5-6
8 and 9 Nishizawa, Matsunaga, and
Fi4
6-7
13 Nishizawa and Mogami5 7
15, 16, 20, and 21 Nishizawa and Hu6 7-8
22 Nishizawa, Hu, and Usui7 8
Appellants do not argue for the separate patentability of the claims
that depend on claim 1. Accordingly, these claims stand or fall with claim 1,
which is our focus. See 37 C.F.R. § 41.37(c)(l)(iv). We discuss
independent claims 26 and 27 separately.
Claim 1
Appellants claim methods of fabricating a doped zone in a
semiconductor. Specifically, Appellants claim a method of introducing
dopants into both sides of a semiconductor body by implanting them into a
2 U.S. Patent 4,596,605, issued June 24, 1986.
3U.S. Patent 6,583,018 Bl, issued June 24, 2003.
4 U.S. Patent 5,633,174, issued May 27, 1997.
5 U.S. Patent 5,571,735, issued November 5, 1996
6 U.S. Patent 6,100,189, issued August 8, 2000.
7 U.S. Patent 5,943,601, issued August 24, 1999.
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Application 11/232,735
layer of the semiconductor with irradiation and then heating the
semiconductor body to activate the dopant particles and avoid diffusion.
Appellants’ currently pending claim 1 recites:
A method for fabricating a doped semiconductor zone in
a semiconductor body comprising:
implanting dopant particles to one side of the
semiconductor body;
irradiating the semiconductor body via the one side with
further particles at least in the region containing the dopant
particles;
carrying out a thermal treatment by means of which the
semiconductor body is heated, at least in the region containing
the dopant particles, to a predetermined temperature in order to
activate the implanted dopant particles and in order to largely
avoid diffusion of the implanted dopant particles, said
temperature being less than 450°C;
wherein the further particles are protons and wherein the
proton dose is 1 - 1015 cm'2 or less; and
selecting the implantation energy for implanting the
dopant particles and the irradiation energy for irradiating the
further particles such that the further particles penetrate more
deeply into the semiconductor body proceeding from the one
side than the dopant particles.
(App. Br. 13, Claims App’x (emphasis added).)
Previously, Appellants presented claims that are substantially similar
to currently pending claim 1, except that the prior claims recited a
temperature of less than 500° C instead of the currently claimed temperature
of less than 450° C. The Board affirmed the Examiner’s rejection of those
claims as being obvious under 35 U.S.C. § 103(a) over Nishizawa. (See
Decision in Appeal No. 2012-005172, mailed June 23, 2014.)
The current rejection is also based on Nishizawa, which teaches a
method for fabricating a doped semiconductor zone in a semiconductor
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Application 11/232,735
body. (Final Act. 2, citing Nishizawa 3:47—51 and Fig. 5A and B.) In the
current rejection, the Examiner determined that it would have been obvious
to one of ordinary skill in the art at the time of the invention to use a
temperature of 450° C because discovering the optimum or workable
temperature range would have involved only routine skill, as held in In re
Alter, 220 F.2d 454, 455 (C.C.P.A. 1955). (See Final Act. 4.)
Appellants acknowledge that Nishizawa teaches using an annealing
temperature range of 500° C to 1200° C. (App. Br. 6; see Nishizawa 2:43—
45 (“a third step of annealing the semiconductor layer at a relatively low
temperature like a temperature in a range of 500° C.-12000 C”).) Appellants
argue that despite this teaching, the claimed temperature does not overlap
with the temperature range taught in Nishizawa and, therefore, the holding
of Alter does not apply. (App. Br. 6—7.) Appellants misapprehend the
holding of Alter as requiring an overlap between a claimed range and the
range taught in the prior art. Under the facts of Alter, claims to a method of
making phenol using 25—70% sulphuric acid at between 40° and 80° were
held to be obvious over art teaching 10% sulphuric acid at 100° C. Thus, the
facts of Alter demonstrate that no overlap is necessary and we are not
persuaded by Appellants’ argument.
Appellants also argue that the Examiner failed to demonstrate the
extent of overlap was known to be a "result-effective variable.” (App. Br.
6—7.) We are not persuaded by this argument. Nishizawa teaches that
temperature is a result effective variable because it teaches that low
annealing temperatures prevent the reallocation of lattice defects caused by
high temperatures. (Ans. 2, citing Nishizawa at 6:54—56.)
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Application 11/232,735
Appellants argue further that the claimed method is not obvious over
the method taught in Nishizawa because it differs in kind not degree from
the method of Nishizawa. (Reply Br. 2.) According to Appellants, the
claimed method avoids diffusion of implanted dopant particles, while the
method taught in Nishizawa does not. We are not persuaded by this
argument because the effect Appellants cite is the result of the claimed
difference in temperature. Appellants do not direct us to any differences
between the claimed method and Nishizawa’s method other than the
annealing temperature. Because the Examiner finds that the claimed
temperature could have been optimized by routine skill, the results of such
optimization would not lead to a patentable difference over Nishizawa.
Appellants argue further that the Examiner erred in basing the
rejection on the lack of criticality of the claimed temperature. (See App. Br.
7—8.) According to Appellants, criticality is only an issue when a claimed
range overlaps with a range taught in the prior art. (See id,, citing Titanium
Metals Corp. of America v. Banner, 778 F.2d 775 (Fed. Cir. 1985), and In re
Woodruff 919 F.2d 1575 (Fed. Cir. 1990).)
Again, Appellants misapprehend the law. In consideration of the facts
of Alter, which presented no overlap in claimed and previously taught
ranges, the court explained that
[njjormally, it is to be expected that a change in temperature, or in
concentration, or in both, would be an unpatentable modification.
Under some circumstances, however, changes such as these may
impart patentability to a process if the particular ranges claimed
produce a new and unexpected result which is different in kind and
not merely in degree from the results of the prior art. . . . Such ranges
axe termed ‘critical’ ranges, and the applicant has the burden of
proving such criticality.
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Application 11/232,735
Alter, 220 F.2d at 456. Appellants admit that “the criticality of a claimed
range is not at stake in the present appeal.” (App. Br. 7 (emphasis omitted),)
Accordingly, the Examiner did not err in citing the lack of criticality as the
basis for the rejection.8
Appellants argue that modifying the method taught in Nishizawa to
anneal at less than 450° C would frustrate the purpose of Nishizawa. (App.
Br. 8—11.) According to Appellants, Nishizav/a increases the annealing
temperature to achieve its stated goal of deeper doped regions with
annealing temperature that are not so high as to cause undesired effects.
(App. Br. 8—10, citing Nishizawa 7:1—11 and 12:1—25.) Appellants assert
that if the substrate in Nishizawa is annealed at less than 450°C, the depth of
the implanted region would not extend deeper into the substrate. (App. Br.
10.)
Appellants do not direct us to evidence in support of their argument
about the effects of a lower annealing temperature. Accordingly, w^e are not
persuaded that a lower temperature would necessarily be contrary to the
purpose of Nishizawa. Indeed, Appellants’ own claimed method “largely
avoid[s] diffusion of the implanted dopant particle” at the lower temperature
range of less than 450° C. (See App. Br, 13, Claims App’x, claim 1.)
Because Nishizawa demonstrates the relationship between annealing
temperature and diffusion depth, wherein a lower temperature would reduce
8 Appellants argue that their Specification teaches a minimum temperature
range of from 350° C to 450° C, not 400° C to 700° C, as the Examiner
found. (App. Br. 8, citing, e.g., Spec. 141.) This is harmless error because
the Examiner’s rejection is based what would have been obvious over the
teachings of the prior art, not the disclosures in the Specification.
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Application 11/232,735
the depth of the diffusion, but not eliminate it, and teaches that annealing
temperatures should be as low as possible (see Ans. 7; see Nishizawa
abstract), we are persuaded that one of ordinary skill in the art would have
considered it obvious to optimize the annealing temperature when
fabricating a doped semiconductor zone as taught in Nishizawa.
Claims 26 and 27
The method steps of claims 26 and 27 are substantially identical to the
steps of claim 1, expect that claims 26 and 27 include the phrase:
producing hydrogen-induced donors in the region into which the
protons penetrate by carrying out the thermal treatment at the
predetermined temperature in a range between 350°C and 450°C.
(App. Br. 16 and 17, Claims App’x.)
Appellants argue that the Examiner erred by not giving any weight to
the added phrase and determining that “producing hydrogen-induced donors
in the region into which the protons penetrate” simply expresses the result of
the process step “carrying out the thermal treatment at the predetermined
temperature in a range between 350°C and 450°C.” (Final Act. 5.)
According to Appellants, this phrase distinguishes the claimed method over
Nishizawa because at the temperature Nishizawa teaches implanted H or He
are dissipated into the surrounding atmosphere. (App. Br. 11, citing
Nishizawa 7:1^4 and 12:19-22.)
We are not persuaded by Appellants’ argument. The phrase added to
claims 26 and 27 recites a result of carrying out thermal treatment at 350° C
to 450° C — producing hydrogen-induced donors in the region into which the
protons penetrate. Because it would have been obvious to optimize the
method of Nishizawa using routine skill to choose a thermal treatment of
less than 450° C, the added phrase merely recites the result of the method
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Application 11/232,735
steps already recited. This is clear from the wording of the phrase, wherein
“by carrying out” the thermal treatment at the recited temperature, the result
of producing hydrogen-induced donors as recited occurs.
Accordingly, we are not persuaded that the Examiner erred in
rejecting claims 26 and 27.
Conclusion
Upon consideration of the record and for the reasons given, the
rejections of claims 1, 2, 7—9, 11—16, 18—22, 26, and 27 under 35 U.S.C.
§ 103(a) are sustained.
Therefore, we affirm the decision of the Examiner.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136.
AFFIRMED
8