Ex Parte Huttner et al

Board of Patent Appeals and Interferences

Mar 25, 2005

09313424 (B.P.A.I. Mar. 25, 2005)

The opinion in support of the decision being entered today was not written for publication and
is not binding precedent of the Board.
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte THOMAS HUTTNER, HELMUT WURZER,
and REINHARD MAHNKOPF
____________
Appeal No. 2005-0518
Application No. 09/313,424
____________
HEARD: March 9, 2005
____________
Before OWENS, KRATZ, and TIMM, Administrative Patent Judges.
TIMM, Administrative Patent Judge.
DECISION ON APPEAL
Claims 1-6 and 16-25 are pending in the Application. Claims 1-6 have been withdrawn
from consideration. Claims 7-15 have been cancelled. Claim 22 has been deemed allowable if
written in independent form. Claims 16-21 and 23-25 stand rejected and are subject to this
appeal (Brief, p. 2). We have jurisdiction over the appeal pursuant to 35 U.S.C. § 134.
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Application No. 09/313,424
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1A rejection of claim 18 under 35 U.S.C. § 112, ¶ 2 has been withdrawn by the Examiner (Advisory Action
mailed November 18, 2003).
INTRODUCTION
The only remaining rejection is a rejection maintained under 35 U.S.C. § 103(a).1 As
evidence of obviousness, the Examiner relies upon the following two prior art references:
Hsu 5,468,657 Nov. 21, 1995
Sato et al. 6,121,117 Sep. 19, 2000
(filed July 20, 1998)
The specific rejection is as follows: Claims 16-21 and 23-25 stand rejected under 35
U.S.C. § 103(a) as being unpatentable over Hsu in view of Sato. (Answer, pp. 3-6).
Claim 16, the only independent claim, is illustrative of the invention on appeal:
16. A method of fabricating a semiconductor configuration, which comprises the
following steps:
fabricating a semiconductor structure having a base layer, an insulation layer, a
monocrystalline silicon layer, and an interface between the insulation layer and the
monocrystalline silicon layer;
placing a passivating substance X into the monocrystalline silicon layer, during or after
the fabrication of the semiconductor structure; and
heat-treating the semiconductor structure with the passivating substance X for causing
the passivating substance X in the monocrystalline silicon layer to diffuse both to the interface
and to a surface of the monocrystalline silicon layer opposite to the interface.
For the reasons presented in the Brief, particularly the reasons presented on pages 14 and
15, we reverse. We add the following primarily for emphasis.
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Application No. 09/313,424
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OPINION
Claim 16 requires a step of placing a passivating substance X into the monocrystalline
silicon layer of a semiconductor structure additionally having a base layer and an insulation
layer. The placement can be done, according to the specification, by ion-implanting a substance
such as nitrogen into the layer (specification, p.13, ll. 10-12). The claim also requires a step of
heat treating for causing the passivating substance X placed into the monocrystalline silicon
layer to diffuse not only to the interface between the monocrystalline silicon layer and the
insulation layer, but also to the surface of the monocrystalline silicon layer opposite to the
interface. In other words, the passivating substance X must diffuse towards both the upper and
lower surfaces of the monocrystalline silicon layer.
The Examiner relies upon Hsu as describing a nitrogen ion implantation step meeting or
rendering obvious the step of placing a passivating substance X into the monocrystalline layer.
Hsu, however, describes implanting nitrogen ions into the insulating layer (middle layer 59 as
shown in Fig. 4), not in the monocrystalline silicon layer 42. Even if some of the ions were to
come to rest in the monocrystalline layer, it appears that they would come to rest very near the
interface with the insulation layer (Hsu, Fig. 2). The Examiner does not provide any reasonable
basis to believe that those ions traverse the entire thickness of the monocrystalline silicon layer
42 to reach the top surface during the heat treatment step in accordance with the diffusion
requirement of claim 16. Sato is not relied upon in a manner which cures this deficiency in the
rejection.
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Not only is there no adequate finding with regard to the diffusion requirement of the
claim, the burden shift called for by the Examiner is also not adequately supported. The
Examiner indicates that the depth of ion implantation in the process of Hsu “is a function
Gaussian distribution [sic] which is dependent on implant energy, ion density, and anneal
temperature” and then attempts to shift the burden to Appellants to show that Hsu does not teach
the placing step (Answer, pp. 7-8). In a case where it is reasonable to believe that a property
relied upon for patentability is inherently present in the prior art, it is reasonable to shift the
burden to Appellants to show, in fact, that property does not reside in the prior art. In re Best,
562 F.2d 1252, 1255, 195 USPQ 430, 432-33 (CCPA 1977). Such a finding of inherency is not
reasonable here because evidence of the Gaussian distribution is present in Hsu itself. Hsu
describes the Gaussian distribution of the ions in the process as shown in Figure 2 and explains
that “[t]he nitrogen ions come to rest in an [sic] Gaussian distribution pattern within the buffed
silicon dioxide layer 59.” (Hsu, col. 7, ll. 29-33 (emphasis added)). Hsu specifically states that
the ions reside in the silicon dioxide layer 59 (col. 7, ll. 29-33). It is inappropriate under the
circumstances of this case to shift the burden to Appellants. While it is possible that a small
number of ions might come to rest outside the silicon dioxide layer 59, such as in the portion of
layer 42 closest to the silicon dioxide layer, inherency cannot be based on probabilities and
possibilities, it must be necessarily present. Akamai Technologies Inc. v. Cable & Wireless
Internet Services Inc., 344 F.3d 1186, 1192, 68 USPQ2d 1186, 1190 (Fed. Cir. 2003); In re
Oelrich, 666 F.2d 578, 581, 212 USPQ 323, 326 (CCPA 1981).
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We also note that there is no reason, suggestion, or motivation in the prior art to place the
nitrogen ions of Hsu into the monocrystalline layer. Hsu specifically desires to place all the ions
in the silicon dioxide layer and no teaching in Sato or elsewhere has been relied upon which
provides a reason, suggestion, or motivation to modify the location of the nitrogen ion
placement.
We conclude that the Examiner has failed to establish a prima facie case of obviousness
with respect to the subject matter of claims 16-21 and 23-25.
CONCLUSION
To summarize, the decision of the Examiner to reject claims 16-21 and 23-25 under 35
U.S.C. § 103(a) is reversed.
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Application No. 09/313,424
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REVERSED
TERRY J. OWENS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
PETER F. KRATZ ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
CATHERINE TIMM )
Administrative Patent Judge )
CT/tdl
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Application No. 09/313,424
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