U.S. patent application number 10/872902 was filed with the patent office on 2005-02-03 for method for the production of iii-v laser components.
Invention is credited to Dadgar, Armin, Jurgensen, Holger, Krost, Alois.
Application Number | 20050025909 10/872902 |
Document ID | / |
Family ID | 26010857 |
Filed Date | 2005-02-03 |
United States Patent
Application |
20050025909 |
Kind Code |
A1 |
Jurgensen, Holger ; et
al. |
February 3, 2005 |
Method for the production of III-V laser components
Abstract
The invention relates to a method for the production of III-V
laser components, whereby a III-V semiconductor layer is deposited
on a silicon substrate in a process chamber of a reactor from a
gaseous starting material. According to the invention, an
economical method for the production of qualitatively high-grade
laser may be achieved whereby, firstly, an Al-containing buffer
layer is deposited on the Si substrate, in particular a Si(III)
substrate, on which the III-V semiconductor layer, in particular,
GaN is then deposited such that the lattice plane thereof runs
parallel to the cleavage direction of the substrate, whereby, on
cleaving the substrate plane-parallel layer, cleavage surfaces are
formed.
Inventors: |
Jurgensen, Holger; (Aachen,
DE) ; Krost, Alois; (Berlin, DE) ; Dadgar,
Armin; (Berlin, DE) |
Correspondence
Address: |
ST. ONGE STEWARD JOHNSTON & REENS, LLC
986 BEDFORD STREET
STAMFORD
CT
06905-5619
US
|
Family ID: |
26010857 |
Appl. No.: |
10/872902 |
Filed: |
June 21, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10872902 |
Jun 21, 2004 |
|
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PCT/EP02/12799 |
Nov 15, 2002 |
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Current U.S.
Class: |
428/21 ;
257/E21.127 |
Current CPC
Class: |
H01S 5/021 20130101;
H01L 21/02458 20130101; H01L 21/0254 20130101; H01L 21/02433
20130101; H01S 5/32341 20130101; H01L 21/02381 20130101 |
Class at
Publication: |
428/021 |
International
Class: |
A41G 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2001 |
DE |
101 63 714.4 |
Feb 19, 2002 |
DE |
102 06 750.3 |
Claims
1. Method for producing III-V laser components, in which a III-V
semiconductor layer is deposited on a silicon substrate, in
particular an Si(111) substrate, from gaseous starting substances
in a process chamber of a reactor, wherein first of all an
Al-containing buffer layer is deposited on the Si substrate, then
the III-V semiconductor layer, in particular a GAN layer, and if
appropriate further active layers, are deposited on the buffer
layer, in such a manner that the lattice plane thereof runs
parallel to the cleavage direction of the substrate, plane-parallel
layer fracture surfaces then being produced by cleaving the
substrate in the cleavage direction, and components in which the
layer fracture surfaces form the laser facets subsequently being
fabricated.
2. Method according to claim 1, characterized in that the buffer
layer consists of AIN or AIN with the addition of one or more
further elements from group III or V.
3. Method according to claim 1, characterized in that the buffer
layer is a III-V semiconductor layer and is between 20 and 100 nm
thick.
Description
[0001] This application is a continuation of pending International
Patent Application No. PCT/EP02/12799 filed Nov. 15, 2002 which
designates the United States and claims priority of pending German
Patent Application Nos. 101 63 714.4 filed Dec. 21, 2001 and 102 06
750.3 filed Feb. 19, 2002.
[0002] The invention relates to a method for producing III-V laser
components, in which a III-V semiconductor layer, for example
gallium nitride, is deposited on a silicon substrate from gaseous
starting substances, for example trimethylgallium, trimethylindium,
trimethylaluminum, phosphine or arsine, in a process chamber of a
reactor.
[0003] The deposition of III nitride semiconductors on substrates
of a different type, such as for example sapphire, silicon carbite
or silicon, is a cost-saving process, since this substrate material
is less expensive than III-V substrate material. However, one
problem of this process is the lattice mismatch of the layer on the
substrate. Suitable selection of the substrate material for the
layer material allows matching to be effected, for example gallium
nitride grows at a position rotated through 30.degree. with respect
to the sapphire, and thereby eliminates part of the lattice
mismatch. However, on account of this rotated growth there is no
common fracture or cleavage direction for the layer and the
substrate. The fracture line generally runs along the fracture line
or cleavage line of the substrate, since the latter is considerably
thicker than the layer deposited thereon. In the case described
above, this leads to a rough laser facet which has to be reworked.
Also, with laser mirrors produced in this manner, undesirable
losses are produced in the event of, for example, a wet-chemical
after treatment. The roughness of the laser mirrors or facets which
are not precisely oriented lead to losses and thereby cause a high
threshold current, which is associated with an increased thermal
load in the subsequent component.
[0004] The invention is based on the object of providing an
inexpensive method for producing high-quality lasers.
[0005] The object is achieved by the invention defined in the
claims, in which it is substantially provided that first of all an
aluminum-containing buffer layer is deposited on an Si substrate,
in particular an Si(111) substrate. This is carried out by means of
MOCVD. This buffer layer may consist of aluminum nitride and may be
20 to 100 nm thick. Then, in the same reactor and preferably
without any further intermediate steps, the active III-V layer,
preferably a III nitride layer, and particularly preferably a
gallium nitride layer, or a sequence of such layers for component
layers, is deposited on this buffer layer, in such a manner that
the lattice plane of the layer runs parallel to the cleavage
direction of the substrate. When the substrate is fractured, the
fracture then takes place along a crystalographically suitable
surface. The fracture takes place substantially along one plane.
The fracture or cleavage lines of the Si(111) substrate can then be
selected in such a way that plane-parallel layer fracture surfaces
are formed. These layer fracture surfaces then form the laser
facets. The laser facets are therefore formed simply by breaking or
cleaving. This is possible on account of the fact that the
crystalographic fracture direction of the silicon substrate and of
the structure based on gallium nitride coincide.
[0006] A pertinent factor in this context is the
aluminum-containing seed layer. A seed layer of this type even
allows gallium nitride which is matched in terms of fraction
direction to be deposited on Si(001). The only problem in this case
is the absence of common crystal symmetry.
[0007] If necessary, further, in particular electrically active,
layers can be deposited on the layer sequence described above. The
pertinent factor, however, is that the hexagonal crystal of gallium
nitride is deposited on the cubic crystal lattice of the silicon
with a corresponding crystal orientation, in such a manner that the
natural fracture directions of the two crystals coincide in the
plane in such a manner that plane-parallel laser facets are formed
by simply fracturing the substrate along the natural fracture
lines.
[0008] All features disclosed are (inherently) pertinent to the
invention. The disclosure content of the associated/appended
priority documents (copy of the prior application) is hereby
incorporated in its entirety in the disclosure of the application,
partly with a view to incorporating features of these documents in
claims of the present application.
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