Ex parte Jonker

Board of Patent Appeals and Interferences

Feb 19, 1998

08083231 (B.P.A.I. Feb. 19, 1998)

Application for patent filed June 29, 1993. 1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today
(1) was not written for publication in a law journal and
(2) is not binding precedent of the Board.
Paper No. 13
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte BEREND T. JONKER
_____________
Appeal No. 95-3335
Application 08/083,2311
______________
ON BRIEF
_______________
Before THOMAS, HAIRSTON and LEE, Administrative Patent Judges.
LEE, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from the
final rejection of claims 1-6 and 25-26. Claims 7-24 and 27-28
have been objected to as being dependent from a rejected claim.
Reference relied on by the Examiner
IBM Technical Disclosure Bulletin, "Imaging Magnetic Domains on
Ferromagnetic Thin Films on III-V Compounds by Tunneling
Luminescence Microscopy," vol. 33, no. 11, pp. 469-472, 1991.
("IBM Disclosure")
Appeal No. 95-3335
Application 08/083,231
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The Rejection on Appeal
Claims 1-6 and 25-26 stand finally rejected under 35 U.S.C.
§ 103 as being unpatentable over the IBM Disclosure.
The Invention
The invention is directed to light emitting semiconductor
devices and processes which use spin-polarized carriers to
produce circularly polarized light.
Claims 1 and 25 are the only independent claims. They are
reproduced below:
1. A device for producing polarized optical emission,
comprising:
a semiconducting heterostructure, further comprising at
least one doped semiconducting layer;
a contact having a net magnetic moment, in electrical
contact with a region of said semiconducting heterostructure;
a contact electrically connected to a different region of
said semiconducting heterostructure.
25. A method for producing circularly polarized optical
emission, comprising the step of applying a bias across a
semiconducting heterostructure through a magnetic contact having
a net magnetic moment, thereby injecting spin polarized carriers
into said semiconducting heterostructure for recombination to
produce circularly polarized light.
Opinion
Our opinion is based solely on the arguments raised by the
appellant in his brief. We do not address and offer no opinion
Appeal No. 95-3335
Application 08/083,231
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on arguments which could have been raised but were not set forth
in the brief.
We sustain the rejection of claims 1-6 and 25-26 as being
unpatentable over the IBM Disclosure.
The appellant has grouped all rejected claims 1-6 and 25-26
together for single treatment (Br. at 3). We discuss claim 1.
Initially, the appellant makes several arguments (Br. at 4):
(1) the claimed first contact serves as the source of primary
electrons whereas the magnetic thin film in the IBM Disclosure is
merely a source of secondary electrons; (2) in the appellant’s
invention it is the primary electrons which are recombined with
holes, not secondary electrons as in the case of the IBM
Disclosure; and (3) the magnetic thin film in the IBM Disclosure
does not have a net magnetic moment. The examiner correctly
rejected all three of these arguments.
It is true that in the invention described in the IBM
Disclosure, the primary source of electrons is the tunneling
electron microscope and the primary electrons create a cascade of
spin-polarized secondary electrons in the magnetic thin film
which in turn are recombined with holes in the semiconductor
substrate. See IBM Disclosure at page 469. The examiner
correctly points out that nothing in the appellant’s claims
Appeal No. 95-3335
Application 08/083,231
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requires either (a) that the contact having a net magnetic moment
be a source of primary electrons as opposed to secondary
electrons, or (b) that the circularly polarized light be
generated by recombination of primary electrons, as opposed to
secondary electrons, with holes. The appellant has pointed to
nothing in the claims to support his argument based on a
distinction between primary electrons and secondary electrons.
It is the claims which define the subject matter sought to
be patented. It is improper to read features into the claims
from the specification, where they are not required to make sense
of the claims. See, e.g., In re Priest, 582 F.2d 33, 37,
199 USPQ 11, 15 (CCPA 1978). The claims are simply too broad and
not commensurate in scope with the appellant’s arguments.
We also agree with the examiner that the entire magnetic
thin film need not have a net magnetic moment in order to meet
the requirement of the claims. It is sufficient that the local
area of the magnetic thin film which serves as a source or
location of carrier injection underneath the electron microscope
has a net magnetic moment. As claimed, the contact having the
net magnetic moment need only be in electrical contact with a
region of the semiconductor substrate, not the entire surface
thereof. The area on the magnetic film providing the carrier
Appeal No. 95-3335
Application 08/083,231
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injection is such a contact. It is not helpful to the appellant
that the net magnetic moment in the electrical contact region can
be balanced out by magnetic moments elsewhere if all the magnetic
moments are added together. Moreover, the appellant has not
challenged or rebutted the examiner’s finding that the IBM
Disclosure describes techniques applicable to any ferromagnetic
film, "including the more common situation where different
regions of the film have magnetic moments that do not add up to
zero, as in a refrigerator magnet" (answer at 3, lines 14-16).
In the appeal brief on page 4, lines 13-14, the appellant
argues that the IBM Disclosure does not suggest to "directly
provide optical emission which is circularly polarized to a
significant degree." By "directly," the appellant means "e.g.,
without additional optical elements such as the polarizer 6 [in
the IBM Disclosure]," as is indicated also on page 4 of the
appeal brief. But the examiner is correct that the polarizer 6
in the IBM Disclosure is a part of the detector elements used to
analyze the emitted light and not a part of the elements for
producing the circularly polarized light. See IBM Disclosure
at p. 470, lines 5-7. Accordingly, the appellant’s argument is
rejected.
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The appellant further argues that the IBM Disclosure does
not suggest the production of "useful quantities" of circularly
polarized light, since it suggests only injection of small
quantities of electrons into small areas where a magnetic moment
may or may not exist. However, the examiner is also correct that
the claims do not require any particular quantity of light to be
emitted and that the amount of light emitted in the device of the
IBM Disclosure is sufficiently useful for the purpose disclosed.
The appellant’s argument is without merit.
The IBM Disclosure does not expressly disclose a second
contact contacting another region of the semiconductor substrate.
However, the examiner gave many plausible reasons why it would
have been obvious to one with ordinary skill in the art to
recognize that such a second contact should be provided. Among
the reasons given by the examiner are: (1) the second contact
would set up an electric field inside the substrate to draw the
electron flow in the proper direction; and (2) the second contact
would provide a discharge path for the electrons which are
accumulating in the substrate. See the examiner’s discussion in
the answer from page 4, line 15, to page 5, line 2. These
reasons are rational and plausible. Therefore, the burden has
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Application 08/083,231
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shifted to the appellant to rebut the reasoning set forth by the
examiner.
The appellant argues (Br. at 5, lines 8-10) that "the
provision of an additional contact for applying a bias (and a
current) to the semiconductor could only be for the purpose of
increasing optical emissions over an increased area." That,
however, does not account for or otherwise nullify the examiner’s
stated reasons on why it would have been obvious to one with
ordinary skill in the art to provide the second contact. Thus,
the argument is not helpful to the appellant.
The appellant further argues that increased optical
emissions would interfere with and probably prevent the resolving
of particular domains of the thin film. But appellant’s argument
does not take the place of evidence, and there is no declaration
evidence in this record tending to show that the addition of a
second electrode in the device according to the IBM Disclosure
would render that device inoperative or unuseful. Note that even
the appellant uses the speculative term "probably" in his
argument. We conclude that the appellant has not established
that the presence of a second electrode in the device of the IBM
Disclosure would cause significant or substantial interference
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Application 08/083,231
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such that one with ordinary skill in the art would not see fit to
provide the second electrode.
Finally, the appellant argues that there is nothing in the
IBM Disclosure which suggests a solution to the problem addressed
by the appellant or the benefits of producing circularly
polarized light without additional optical elements. However, in
an obviousness determination, the prior art need not suggest
solving the same problem set forth by appellant. In re Dillon,
919 F.2d 688, 692-93, 16 USPQ2d 1897, 1901 (Fed. Cir. 1990) (in
banc) (overruling in part In re Wright, 848 F.2d 1216, 1220, 6
USPQ2d 1959, 1962 (Fed. Cir. 1988)), cert. denied, 500 U.S. 904
(1991). Moreover, the device of the IBM Disclosure does produce
circularly polarized light without using a quarter wave plate
like that shown in prior art Figure 1 of the appellant’s
specification. The appellant’s arguments are unpersuasive.
Additionally, note also that the advantages and/or problems with
which the appellant is concerned are not recited in the claims.
In our view, the appellant has not sufficiently rebutted the
examiner’s reasons for providing a second electrode on the
semiconductor substrate.
For all of the foregoing reasons, we sustain the rejection
of claims 1-6 and 25-26.
Appeal No. 95-3335
Application 08/083,231
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Conclusion
The rejection of claims 1-6 and 25-26 under 35 U.S.C. § 103
as being unpatentable over the IBM Disclosure is affirmed.
No time period for taking any subsequent action in
connection with this appeal may be extended under
37 CFR § 1.136(a).
AFFIRMED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
KENNETH W. HAIRSTON )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
JAMESON LEE )
Administrative Patent Judge )
Appeal No. 95-3335
Application 08/083,231
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Associate Counsel (Patents)
Code 3008.2
Naval Research Laboratory
Washington, DC 20375-5325