U.S. patent application number 12/932249 was filed with the patent office on 2011-06-23 for apparatus and method for transformation of substrate.
Invention is credited to Nathaniel R. Quick.
Application Number | 20110151648 12/932249 |
Document ID | / |
Family ID | 41279620 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110151648 |
Kind Code |
A1 |
Quick; Nathaniel R. |
June 23, 2011 |
Apparatus and method for transformation of substrate
Abstract
A method is disclosed for forming a layer of a wide bandgap
material in a non-wide bandgap material. The method comprises
providing a substrate of a non-wide bandgap material and converting
a layer of the non-wide bandgap material into a layer of a wide
bandgap material. An improved component such as wide bandgap
semiconductor device may be formed within the wide bandgap material
through a further conversion process.
Inventors: |
Quick; Nathaniel R.; (Lake
Mary, FL) |
Family ID: |
41279620 |
Appl. No.: |
12/932249 |
Filed: |
February 22, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12587399 |
Oct 6, 2009 |
7897492 |
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12932249 |
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11062011 |
Feb 18, 2005 |
7618880 |
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12587399 |
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60546564 |
Feb 19, 2004 |
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Current U.S.
Class: |
438/478 ;
257/E21.09 |
Current CPC
Class: |
H01L 21/02381 20130101;
H01L 21/02521 20130101; H01L 21/0242 20130101; H01L 21/02529
20130101; H01L 21/02689 20130101; H01L 21/0254 20130101; H01L
21/02667 20130101 |
Class at
Publication: |
438/478 ;
257/E21.09 |
International
Class: |
H01L 21/20 20060101
H01L021/20 |
Claims
1. (canceled)
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. (canceled)
19. (canceled)
20. A method of forming a wide bandgap material within a non-wide
bandgap material, comprising the steps of: providing a substrate of
a non-wide bandgap material having a first and a second substrate
surface; applying a doping gas to the first surface of the
substrate; and directing a thermal energy beam onto the first
surface of the substrate for heating the non-wide bandgap material
of the substrate in the presence of the doping gas for converting a
layer inside of the non-wide bandgap material of the substrate into
the wide bandgap material defined between a first and a second wide
bandgap surface with the first wide bandgap surface of the wide
bandgap material being coincident with the first surface of the
substrate and with the second wide bandgap surface of the wideband
gap material being embedded between first and second surfaces of
the substrate.
21. A method of forming a wide bandgap material as set forth in
claim 20, wherein the non-wide bandgap material has a bandgap equal
to or less than two electron volts (2 eV) and wherein the wide
bandgap material has a bandgap greater than two electron volts (2
eV).
22. A method of forming a wide bandgap material as set forth in
claim 20, wherein the step of providing the substrate of the
non-wide bandgap material includes selecting a substrate from the
group consisting of silicon (Si) and gallium arsenide (GaAs).
23. A method of forming a wide bandgap material as set forth in
claim 20, wherein the wide bandgap material is selected from the
group consisting of silicon carbide (SiC) and gallium nitride
(GaN).
24. A method of forming a wide bandgap material as set forth in
claim 20, wherein the step of converting the layer of the non-wide
bandgap material includes directing a thermal energy beam selected
from the group consisting of a beam of charged particles, a beam of
electrons, a beam of ions, a beam of electromagnetic radiation onto
the layer for converting the layer into a wide bandgap
material.
25. A method of forming a wide bandgap material as set forth in
claim 20, wherein the step of converting the layer of the non-wide
bandgap material includes directing a laser beam onto the layer for
converting the layer into a wide bandgap material by laser
synthesis.
26. A method of forming a wide bandgap material as set forth in
claim 20, wherein the step of directing a thermal energy beam onto
the non-wide bandgap substrate includes directing a laser beam
selected from the group consisting of a Nd;YAG laser, a frequency
doubled Nd:YAG laser and a excimer laser.
27. A method of forming a wide bandgap material as set forth in
claim 20, wherein the step of applying a doping gas to the non-wide
bandgap material comprises applying a doping gas selected from the
group consisting of methane, acetylene, nitrogen and ammonia.
28. A method of forming silicon carbide in a silicon material,
comprising the steps of: providing a substrate of a silicon
material having a first and a second substrate surface; providing a
doping gas having carbon atoms; applying a doping gas to the first
surface of the substrate; and directing a laser beam onto the first
surface of the substrate for heating the silicon material of the
substrate in the presence of the doping gas for converting a layer
inside of the silicon material substrate into a wide bandgap
material defined between a first and a second wide bandgap surface
with the first wide bandgap surface of the wideband gap material
being coincident with the first surface of the substrate and with
the second wide bandgap surface of the wideband gap material being
embedded between first and second surfaces of the substrate.
29. A method of forming silicon carbide in a silicon material as
set forth in claim 28, wherein the step of providing a doping gas
having carbon atoms comprises providing a doping gas selected from
the group consisting of methane and acetylene.
30. A method of forming silicon carbide wide bandgap semiconductor
in a silicon semiconductor, comprising the steps of: providing a
substrate of a silicon semiconductor having a first and a second
substrate surface; applying methane gas to the first surface of the
silicon semiconductor substrate; and directing a laser beam onto
the first surface of the silicon semiconductor substrate for
heating the silicon semiconductor surface in the presence of
methane for providing carbon atoms to react with the silicon for
converting a layer inside of the silicon semiconductor substrate
into silicon carbide defined between a first and a second surface
with the first silicon carbide surface being coincident with the
first silicon semiconductor surface and with the second silicon
carbide surface being embedded between the first and second
surfaces of the silicon semiconductor substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Patent Provisional
application Ser. No. 60/546,564 filed Feb. 19, 2004. All subject
matter set forth in provisional application Ser. No. 60/546,564 is
hereby incorporated by reference into the present application as if
fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to wide bandgap materials and more
particularly to a method for forming a layer of a wide bandgap
material in a non-wide bandgap material. The invention relates
further to an improved component such as wide bandgap semiconductor
device formed within the wide bandgap material.
[0004] 2. Background of the Invention
[0005] Presently, silicon and gallium arsenide are the dominant
conventional semiconductor materials used in the manufacture of
semiconductor device. Silicon and gallium arsenide are considered
non-wide bandgap semiconductors. In contrast, wide bandgap
semiconductors have superior properties including breakdown field,
dielectric constant, thermal conductivity and saturated electron
drift velocity. Unfortunately, wide bandgap semiconductors are
expensive due to high processing costs and poor yields emanating
from wafer growth through device packaging.
[0006] Ceramic substrates having wide bandgap semiconductor
compositions, such as silicon carbide (SiC) and aluminum nitride
(AlN), are known to exhibit electrical properties ranging from
insulating electrical properties, semiconducting electrical
properties and conducting electrical properties.
[0007] The wide-bandgap semiconductor phases of ceramics and other
wide-bandgap semiconductors including diamond are used to create
devices such as conductive tabs, interconnects, vias, wiring
patterns, resistors, capacitors, semiconductor devices and the like
electronic components by laser synthesis on the surfaces and within
the body of such wide-bandgap semiconductor to thereby eliminate
photolithography processes which require numerous steps and
generate undesirable chemical pollutants when processing such
traditional electronic devices, components and circuitry.
[0008] It is well known that alumina (Al.sub.2O.sub.3) dominates
the dielectric market as an integrating substrate or device carrier
in electronics packaging. Boron nitride (BN), aluminum nitride
(AlN), silicon carbide (SiC) and diamond are also of interest due
to the thermal coefficient of expansion (TCE) and for the
dielectric constant and higher thermal conductivity than that of
aluminum oxide (Al.sub.2O.sub.3). Silicon carbide (SiC), aluminum
nitride (MN), boron nitride (BN), gallium nitride (GaN) and diamond
also exhibit a wide-band gap and chemical resistance as well as
exhibiting properties from a semiconductor to an insulator. These
properties are of substantial interest for high temperature
applications approaching 1000.degree. C. and for aggressive
environment applications. In addition, these properties are
desirable for high density integrated circuit packing.
[0009] In the prior art, metallization methods, including dry-film
imaging and screen printing have been used for the production of
conductive patterns on alumina. However, metal compatibility
difficulties with high thermal conductivity ceramic materials such
as aluminum nitride (AlN) and silicon carbide (SiC), have not been
completely solved. Copper and silver paste exhibits a thermal
coefficient of expansion (TCE) mismatch aggravated by high
temperatures as well as being subject to oxidation that increases
the resistivity. In particular, bonding of copper to aluminum
nitride (AlN) has proved to be nontrivial. Alumina or
stoichiometric aluminum oxynitride (AlON) coatings must be
developed on the aluminum nitride (AlN) surface through passivation
processes. These passivation processes have poor reproducibility.
Thus, the direct laser synthesis of conductors in aluminum nitride
(AlN), silicon carbide (SiC) and diamond substrates appears to
provide solutions to this long standing prior art problem with
regard to metallization and for more simple processing techniques
for creating devices and circuitry that are compatible with
selected ceramic substrates, while satisfying the need for higher
temperature, aggressive environment, and higher density integrated
circuit packaging applications.
[0010] Discussion of wide bandgap materials and the processing
thereof are discussed in my U.S. Pat. No. 5,145,741; U.S. Pat. No.
5,391,841; U.S. Pat. No. 5,793,042; U.S. Pat. No. 5,837,607; U.S.
Pat. No. 6,025,609; U.S. Pat. No. 6,054,375; U.S. Pat. No.
6,271,576 and U.S. Pat. No. 6,670,693 are hereby incorporated by
reference into the present application.
[0011] Therefore, it is an object of the present invention is to
advance the art by providing a method for forming a layer of a wide
bandgap material in a non-wide bandgap material.
[0012] Another object of this invention is to provide a method for
forming a wide bandgap semiconductor device within the wide bandgap
material.
[0013] Another object of this invention is to provide a wide
bandgap semiconductor device within the wide bandgap material layer
of the non-wide bandgap material.
[0014] The foregoing has outlined some of the more pertinent
objects of the present invention. These objects should be construed
as being merely illustrative of some of the more prominent features
and applications of the invention. Many other beneficial results
can be obtained by modifying the invention within the scope of the
invention. Accordingly other objects in a full understanding of the
invention may be had by referring to the summary of the invention,
the detailed description describing the preferred embodiment in
addition to the scope of the invention defined by the claims taken
in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
[0015] The present invention is defined by the appended claims with
specific embodiments being shown in the attached drawings. For the
purpose of summarizing the invention, the invention relates to a
method of forming a wide bandgap layer in a non-wide bandgap
material, comprising the steps of providing a substrate of a
non-wide bandgap material and converting a layer of the non-wide
bandgap material into a layer of a wide bandgap material.
[0016] It is understood that the conversion can be initiated at any
point on the surface of the non-wide bandgap material surface and
terminated at any point in the non-wide bandgap materials surface
resulting in wide bandgap layers, layer portions, patterns and
combinations thereof.
[0017] In a more specific example of the invention, the non-wide
bandgap material has a bandgap equal to or less than two electron
volts (2 eV) and the wide bandgap material has a bandgap greater
than two electron volts (2 eV). The non-wide bandgap material is
selected to be sensitive to the thermal conversion process of
converting the layer into a wide bandgap material. In one specific
example, the non-wide bandgap material is selected from the group
consisting of a silicon material (Si), an alumina material
(Al.sub.2O.sub.3) and a silica material (SiO.sub.2). In another
specific example, the layer is converted into a wide bandgap
semiconductor material capable of being converted into an
electrical component upon further irradiation by an energy
beam.
[0018] In another embodiment of the invention, the step of
converting a layer of the non-wide bandgap material into a wide
bandgap material includes directing a thermal energy beam onto the
surface to be converted. The thermal energy beam may be selected
from the group consisting of a beam of charged particles, a beam of
electrons, a beam of ions, a beam of electromagnetic radiation onto
the surface for converting the surface into a wide bandgap layer.
Preferably, a laser beam is directed onto the layer for converting
the layer into a wide bandgap material by laser synthesis.
[0019] The invention is also incorporated into an improved
component comprising a substrate of a non-wide bandgap material
having a bandgap equal to or less than two electron volts (2 eV)
and a layer of a wide bandgap material having a bandgap greater
than two electron volts (2 eV) formed within the substrate. The
component may comprise the layer of the wide bandgap material
interconnecting a first and a second component.
[0020] In another example, the invention is incorporated into an
improved semiconductor device comprising a substrate formed from a
non-wide bandgap material and a wide bandgap semiconductor device
formed in the layer of the wide bandgap semiconductor material. The
wide bandgap semiconductor device may be an electrical device, a
photonic device, an optical device and a spintronic device.
[0021] In a further example, the invention is incorporated into an
improved semiconductor device comprising a substrate formed from a
non-wide bandgap material and a layer of a wide bandgap
semiconductor material formed in a portion of the substrate. A wide
bandgap semiconductor device is formed in the layer of the wide
bandgap semiconductor material. A non-wide bandgap device is formed
in the non-wide bandgap material. An electrical connector
interconnects the wide bandgap semiconductor device and the
non-wide bandgap semiconductor devices.
[0022] The foregoing has outlined rather broadly the more pertinent
and important features of the present invention in order that the
detailed description that follows may be better understood so that
the present contribution to the art can be more fully appreciated.
Additional features of the invention will be described hereinafter
which form the subject of the claims of the invention. It should be
appreciated by those skilled in the art that the conception and the
specific embodiments disclosed may be readily utilized as a basis
for modifying or designing other structures for carrying out the
same purposes of the present invention. It should also be realized
by those skilled in the art that such equivalent constructions do
not depart from the spirit and scope of the invention as set forth
in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] For a fuller understanding of the nature and objects of the
invention, reference should be made to the following detailed
description taken in connection with the accompanying drawings in
which:
[0024] FIG. 1 is a side view of an air-tight chamber with a thermal
energy beam impinging on a non-wide bandgap material for forming a
layer of a wide bandgap material in the non-wide bandgap
material;
[0025] FIG. 2 is an enlarged isometric view of the layer of the
wide bandgap material formed in the non-wide bandgap material;
[0026] FIG. 3 is an enlarged partial sectional view of a first
embodiment of an aluminum nitride (AlN) wide bandgap material
formed in an alumina (Al.sub.2O.sub.3) non-wide bandgap
material;
[0027] FIG. 4 is an enlarged partial sectional view of a second
embodiment of a silicon carbide (SiC) wide bandgap material formed
in a silica (SiO.sub.2) non-wide bandgap material;
[0028] FIG. 5 is an enlarged partial sectional view of a third
embodiment of silicon carbide (SiC) wide bandgap material formed in
a silicon (Si) non-wide bandgap material;
[0029] FIG. 6 is an enlarged partial sectional view of a fourth
embodiment of a diamond like carbon material formed in the silicon
carbide (SiC) wide bandgap material defined in a silicon (Si)
non-wide bandgap material;
[0030] FIG. 7 is an enlarged isometric view of a fifth embodiment
of an improved component formed in the wide bandgap material;
[0031] FIG. 8 is a sectional view along line 8-8 in FIG. 7;
[0032] FIG. 9 is a sectional view along line 9-9 in FIG. 7;
[0033] FIG. 10 is an enlarged isometric view of a sixth embodiment
of an improved semiconductor device formed in the wide bandgap
material;
[0034] FIG. 11 is a sectional view along line 11-11 in FIG. 10;
and
[0035] FIG. 12 is a sectional view along line 12-12 in FIG. 10.
[0036] Similar reference characters refer to similar parts
throughout the several Figures of the drawings.
DETAILED DISCUSSION
[0037] FIG. 1 is a side view of an apparatus 5 for forming a layer
of a wide bandgap material 10 in a non-wide bandgap material 15.
The non-wide-bandgap material 15 is shown as a substrate 20 located
in an air-tight chamber 30. The chamber 30 has an inlet and valve
combination 31 and outlet and valve combination 32 connected to the
side wall of the chamber 30 for injecting and removing gases into
and therefrom, respectively. The chamber 30 includes an airtight
transmission window 34. The chamber 30 is disposed on a support
member 36 forming an airtight seal therewith.
[0038] FIG. 2 is an enlarged isometric view of the wide bandgap
material 10 formed in the substrate 20 shown in FIG. 1. The wide
bandgap material 10 defines a first and a second surface 11 and 12
and a peripheral edge 13. The substrate 20 defines a first and a
second surface 21 and 22 and a peripheral edge 23. Although the
substrate 20 is shown as a square, the present invention is not
limited by the physical configuration of the substrate 20 as shown
herein.
[0039] A thermal energy beam 40 is shown emanating from a source 42
and passing through the airtight transmission window 34 to impinge
on the first surface 21 of the substrate 20. In one example, the
thermal energy beam 40 is a beam of charged particles such as a
beam of electrons or a beam of ions. In another example, the
thermal energy beam 40 is a beam of electromagnetic radiation such
as a laser beam. Examples of a suitable source of the laser beam
include a Nd:YAG laser, a frequency double 2.omega. Nd:YAG laser or
an Excimer laser.
[0040] The thermal energy beam 40 is scanned in two dimensions
across the first surface 21 of the substrate 20 to form the wide
bandgap material 10. In this example, the wide bandgap material 10
is shown partially formed within the first surface 21 of the
substrate 20 after a partial scan of the thermal energy beam 40
across the first surface 21 of the substrate 20.
[0041] The first surface 11 of the wide bandgap material 10 is
coincident with the first surface 21 of the wideband gap
semiconductor substrate 20 with the remainder of the wide bandgap
material 10 including the second surface 12 and the peripheral
surface 13 being embedded between first and second surfaces 21 and
22 of the substrate 20.
[0042] The substrate 20 may be formed as a monolith or a thin film
substrate having suitable properties for forming the wide bandgap
material 10. The non-wide bandgap material 15 has a bandgap equal
to or less than two electron volts (2 eV). The wide bandgap
material 10 has a bandgap greater than two electron volts (2
eV).
[0043] Preferably, the non-wide bandgap material 15 is sensitive to
a thermal conversion process for transforming a layer of the
non-wide bandgap material 15 into the wide bandgap material 10. In
one example, the non-wide bandgap material 15 is selected from the
group consisting of a silicon material (Si), an alumina material
(Al.sub.2O.sub.3), a silica material (SiO.sub.2). Preferably, the
non-wide bandgap material 15 is capable of being transformed from a
non-wide bandgap material 15 into the wide bandgap material 10 and
is capable of being subsequently transformed into an electrical
component or device upon further irradiating by the thermal energy
beam 40.
[0044] Table 1 contrast various properties of two popular non-wide
bandgap semiconductor materials namely silicon (Si) and gallium
arsenide (GaAs) with a wide bandgap semiconductor namely silicon
carbide (SiC) and diamond.
TABLE-US-00001 TABLE 1 Semiconductor Properties Gallium 6H Silicon
Property Silicon Arsenide Carbide Diamond Band Gap 1.12 eV 1.424 eV
3 eV 5.45 eV Breakdown field 0.3 MV/cm 0.4 MV/cm 3 MV/cm 10 MV/cm
Dielectric 11.7 12.9 10 5.5 constant Thermal 1.3 W/K-cm 0.55 W/K-cm
5 W/K-cm 22 W/K-cm Conductivity Saturated electron 1 .times.
10.sup.7 cm/sec 1 .times. 10.sup.7 cm/sec 2 .times. 10.sup.7 cm/sec
2.7 .times. 10.sup.7 cm/sec drift velocity
[0045] The advantages of the properties of the wide bandgap
material 10 is evident from a review of Table 1. Unfortunately,
wide bandgap material 10 are currently expensive due to high
processing costs and poor yields emanating from wafer growth
through device packaging. The present invention transforms a layer
of the non-wide bandgap material 15 into a wide bandgap material 10
to provide the advantages of the properties of the wide bandgap
material 10 with the cost advantages of the non-wide bandgap
material 15.
[0046] The present invention may utilize a conventional
semiconductor material such as silicon (Si) as the non-wide bandgap
material 15. In the alternative, the present invention may utilize
a low cost ceramic material such as alumina (Al.sub.2O.sub.3) or a
low cost glass material such as silica (SiO.sub.2).
[0047] FIG. 3 is an enlarged sectional view of a first embodiment
of the invention illustrating a wide bandgap material 10A formed in
the substrate 20A. In this example, the non-wide bandgap material
15A of the substrate 20A is a silicon (Si) material whereas the
wide bandgap material 10A is silicon carbide (SiC).
[0048] The silicon (Si) non-wide bandgap material 15A is converted
into the silicon carbide (SiC) wide bandgap material 10A as the
thermal energy beam 40 scans across the first surface 21A of the
substrate 20A. The thermal energy beam 40 scans across the first
surface 21A of the substrate 20A in an atmosphere of methane gas or
acetylene gas. The thermal energy beam 40 heats the silicon atoms
of the non-wide bandgap material 15A. The heated silicon atoms of
the non-wide bandgap material 15A react with the carbon atoms of
the methane gas or acetylene gas atmosphere to create the silicon
carbide (SiC) wide bandgap material 10A.
[0049] FIG. 4 is an enlarged sectional view of a second embodiment
of the invention illustrating a wide bandgap material 10B formed in
the substrate 20B. In this example, the non-wide bandgap material
15B of the substrate 20B is aluminum oxide (Al.sub.2O.sub.3)
material whereas the wide bandgap material 10B is aluminum nitride
(AlN).
[0050] The aluminum oxide (Al.sub.2O.sub.3) non-wide bandgap
material 15B is converted into the aluminum nitride (AlN) wide
bandgap material 10B as the thermal energy beam 40 scans across the
first surface 21B of the substrate 20B. The thermal energy beam 40
scans across the first surface 21B of the substrate 20B in an
atmosphere of nitrogen to create the aluminum nitride (AlN).
[0051] Typically, the formation of aluminum nitride (AlN) is not
chemical and thermodynamically feasible because of the preferred
affinity of aluminum for oxygen. A reacting getter such as source
of heated carbon is used to remove the oxygen from reacting with
the aluminum since oxygen has preferred reactions with carbon. The
carbon can be a solid source or a gaseous source such as methane or
acetylene. With the gaseous carbon sources the thermal energy beam
40 would be conducted under a mixed atmosphere of methane and
nitrogen in simultaneous or subsequent steps.
[0052] The carbothermal process described above or a similar
process is used only when the chemistry of the existing substrate
is more stable than that of the desired or new substrate surface
composition. Once the oxygen is removed, the surface 21B of the
substrate 20B can be scanned with the thermal energy beam 40 in the
presence of a doping nitrogen gas to create aluminum nitride (MN).
Subsequently, the aluminum nitride (AlN) wide bandgap material 10B
may be converted to semiconductors and conductors, or other device
in accordance with the teaching of my previously mentioned U.S.
patents.
[0053] FIG. 5 is an enlarged sectional view of a third embodiment
of the invention illustrating a wide bandgap material 10C formed in
the substrate 20C. In this example, the non-wide bandgap material
15C of the substrate 20C is a silica (SiO.sub.2) material whereas
the wide bandgap material 10C is silicon carbide (SiC).
[0054] The silica (SiO.sub.2) non-wide bandgap material 15C is
converted into the silicon carbide (SiC) wide bandgap material 10C
as the thermal energy beam 40 scans across the first surface 21C of
the substrate 20C. The thermal energy beam 40 scans across the
first surface 21C of the substrate 20C in an atmosphere of methane
gas or acetylene gas. The thermal energy beam 40 heats the silicon
atoms of the non-wide bandgap material 15C. The heated silicon
atoms of the non-wide bandgap material 15C react with the carbon
atoms of the methane gas or acetylene gas atmosphere to create the
silicon carbide (SiC) wide bandgap material 10C.
[0055] FIG. 6 is an enlarged sectional view of a fourth embodiment
of the invention illustrating a component 50D defined in a wide
bandgap material 10D formed in the substrate 20D. In this example,
the component 50D is a diamond like carbon material (DLC) formed in
the silicon carbide (SiC) wide bandgap material 10D defined in a
silicon (Si) non-wide bandgap material 15D. The silicon (Si)
non-wide bandgap material 15D is converted into the silicon carbide
(SiC) wide bandgap material 10D as the thermal energy beam 40 scans
a cross the first surface 21D of the substrate 20D as set forth
with reference to FIG. 3.
[0056] After the silicon (Si) non-wide bandgap material 15D is
converted into the silicon carbide (SiC) wide bandgap material 10D,
the silicon carbide (SiC) is converted into the diamond like carbon
material (DLC) by selectively removing silicon atoms to create
vacancies. The vacancies are then filled with carbon creating the
diamond like carbon material (DLC). The thermal energy beam 40
irradiation of the SiC region in a CO/CO.sub.2 containing
atmosphere diffuses silicon to the surface where the silicon reacts
with CO.sub.2 to form SiO gas. An increased number of vacancies are
left behind in the lattice.
[0057] An excimer laser (50 mJ/pulse, 10 Hz pulse repetition rate,
60 pulses, 193 nm wavelength, 20 ns pulse time, CO(partial
pressure)/CO.sub.2(partial pressure)=5.times.10.sup.4) creates the
temperature range 2000-2300.degree. C. necessary to energize
silicon (Si) self diffusion in silicon carbide (SiC). Carbon is
then diffused into the substrate to fill the vacancies by laser
irradiation, for example by (Nd:YAG, excimer etc.) in a methane or
acetylene atmosphere to dissociate the hydrocarbon and drive
(diffuse) atomic carbon into the silicon carbide (SiC) and if
necessary orient or recrystallize the crystal structure.
[0058] FIG. 7 is an enlarged isometric view of a fifth embodiment
of the invention illustrating a semiconductor device 50E defined in
the wide bandgap material 10E formed in the substrate 20E. The
semiconductor device 50E may be one or more of a variety of devices
such as an active or passive electrical device, a photonic device,
an optical device, a sensor device, a spintronic device o or any
other suitable semiconductor device. In this example, the
semiconductor device 50E is shown as a first semiconductor device
51E and a second semiconductor device 52E.
[0059] FIG. 8 is a sectional view illustrating the first
semiconductor device 51E of FIG. 7. The first semiconductor device
51E is defined in the wide bandgap material 10E. The first
semiconductor device 51E is connected by an electrode 61E to a
first conductor 71E. An electrode 62E connects the first
semiconductor device 51E to a connector 73E.
[0060] FIG. 9 is a sectional view illustrating the second
semiconductor device 52E of FIG. 7. The second semiconductor device
52E is defined in the wide bandgap material 10E. The second
semiconductor device 52E is connected by an electrode 63E to a
second conductor 72E. An electrode ME connects the second
semiconductor device 52E to the connector 73E.
[0061] Preferably, the first and/or second semiconductor device 51E
and 52E are formed in the wide bandgap material 10E by scanning the
thermal energy beam 40 across selected portions of the wide bandgap
material 10E in the presence of a doping atmosphere to form the
first and/or second semiconductor device 51E and 52E. In the
alternative, the first and/or second semiconductor device 51E and
52E may be formed in a conventions manner as should be well known
in the art.
[0062] FIG. 10 is an enlarged isometric view of a sixth embodiment
of the invention illustrating a first semiconductor device 51F
defined in the wide bandgap material 10F and a second semiconductor
device 52F defined in the non-wide bandgap material 15F.
[0063] FIG. 11 is a sectional view illustrating the first
semiconductor device 51F of FIG. 10. The first semiconductor device
51F is defined in the wide bandgap material 10F. The first
semiconductor device 51F is connected by an electrode 61F to a
first conductor 71F. An electrode 62F connects the first
semiconductor device 51F to a connector 73F. The first
semiconductor device 51F may be one or more of a variety of devices
such as an active or passive electrical device, a photonic device,
an optical device, a sensor device, a spintronic device or any
other suitable semiconductor device.
[0064] Preferably, the first semiconductor device 51F is formed in
the wide bandgap material 10F by scanning the thermal energy beam
40 across selected portions of the wide bandgap material 10F in the
presence of a doping atmosphere to form the first semiconductor
device 51F. In the alternative, the first semiconductor device 51F
may be formed in a conventions manner as should be well known in
the art.
[0065] FIG. 12 is a sectional view illustrating the second
semiconductor device 52F of FIG. 10. The second semiconductor
device 52F is defined in the non-wide bandgap material 15F. The
second semiconductor device 52F is connected by an electrode 63F to
a second conductor 72F. An electrode 64F connects the second
semiconductor device 52F to the connector 73F.
[0066] Preferably, the second semiconductor device 52F is formed in
the non-wide bandgap material 10F a conventions manner as should be
well known in the art. In the alternative, the second semiconductor
device 52E may be formed by scanning the thermal energy beam 40
across selected portions of the non-wide bandgap material 10F in
the presence of a doping atmosphere to form the second
semiconductor device 52F.
[0067] The thermal energy beam 40 conversion and doping technology
can be applied to the fabrication of conductors, different
semiconductor and insulator phases in silicon carbide (SiC).
Conductors can be fabricated by doping titanium into silicon
carbide (SiC) by laser scanning in a titanium tetra chloride, or
other titanium metallo-organic gas atmosphere. Different
semiconductor phases can be created by scanning a material with the
thermal energy beam 40 in an atmosphere of nitrogen (n-type),
phosphine (n-type) or di-borane (p-type), trimethylaluminum
(p-type) etc. Insulators can be created by scanning a material with
the thermal energy beam 40 in an atmosphere of oxygen.
[0068] The present disclosure includes that contained in the
appended claims as well as that of the foregoing description.
Although this invention has been described in its preferred form
with a certain degree of particularity, it is understood that the
present disclosure of the preferred form has been made only by way
of example and that numerous changes in the details of construction
and the combination and arrangement of parts may be resorted to
without departing from the spirit and scope of the invention.
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