U.S. patent application number 13/934251 was filed with the patent office on 2015-01-08 for enhanced selenium supply in copper indium gallium selenide processes.
The applicant listed for this patent is TSMC Solar Ltd.. Invention is credited to Wei-Lun LU, Jyh-Lih WU, Wen-Tsai YEN.
Application Number | 20150011025 13/934251 |
Document ID | / |
Family ID | 52133064 |
Filed Date | 2015-01-08 |
United States Patent
Application |
20150011025 |
Kind Code |
A1 |
LU; Wei-Lun ; et
al. |
January 8, 2015 |
ENHANCED SELENIUM SUPPLY IN COPPER INDIUM GALLIUM SELENIDE
PROCESSES
Abstract
A system for depositing selenium on a substrate comprises
includes a substrate carrier including a body, means for holding
the substrate, and a plurality of selenium vapor outlets formed in
the body to direct a flux of selenium vapor onto the substrate. A
selenium supply container provides selenium vapor to the selenium
vapor outlets. At least one temperature sensor is coupled to the
substrate carrier to sense temperature of the substrate. A heat
source is positioned to heat the substrate. A controller is coupled
to the temperature sensor and the heat source.
Inventors: |
LU; Wei-Lun; (Tainan City,
TW) ; WU; Jyh-Lih; (Tainan City, TW) ; YEN;
Wen-Tsai; (Caotun Township, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TSMC Solar Ltd. |
Taichung City |
|
TW |
|
|
Family ID: |
52133064 |
Appl. No.: |
13/934251 |
Filed: |
July 3, 2013 |
Current U.S.
Class: |
438/14 ; 118/712;
118/728; 269/289R |
Current CPC
Class: |
C23C 14/243 20130101;
H01L 21/67109 20130101; H01L 21/67248 20130101; Y02P 70/521
20151101; Y02E 10/541 20130101; C23C 14/50 20130101; H01L 31/0322
20130101; C23C 14/5866 20130101; Y02P 70/50 20151101 |
Class at
Publication: |
438/14 ; 118/728;
118/712; 269/289.R |
International
Class: |
H01L 21/66 20060101
H01L021/66 |
Claims
1. A substrate carrier, which comprises: a body including a back
plate and a pair of spaced apart, substantially parallel, side
rails on the back plate, each side rail including an inwardly
facing surface extending outwardly of the back plate; and, a
longitudinally extending engagement slot formed in the inwardly
facing surface of each side rail adjacent the back plate to engage
and hold the substrate in proximity to the back plate.
2. The substrate carrier as claimed in claim 1, including: a
longitudinally extending selenium vapor bore formed in each of the
side rails; and, a plurality of inwardly directed selenium vapor
outlets formed in each side rail outwardly of the engagement slot
and in communication with the selenium vapor bore and the inwardly
facing surface.
3. The substrate carrier as claimed in claim 2, wherein the
selenium vapor outlets include a first outlet conduit in
communication with the bore and a second outlet conduit in
communication with the first outlet conduit and the inwardly facing
surface.
4. The substrate carrier as claimed in claim 3, wherein the second
outlet conduit is larger than the first outlet conduit.
5. The substrate carrier as claimed in claim 4, wherein the outlet
conduits each have a circular cross section and are concentric with
each other.
6. The substrate carrier as claimed in claim 2, including: a
longitudinally extending selenium vapor channel formed in the
inwardly facing surface of each side rail outwardly of the
engagement slot; and, a plurality of inwardly directed selenium
vapor outlets formed in each side rail and in communication with
the selenium vapor bore and the selenium vapor channel.
7. The substrate carrier as claimed in claim 2, wherein the
selenium vapor outlets are substantially uniformly spaced apart
along the inwardly facing surface of each side rail.
8. The substrate carrier as claimed in claim 1, including a
temperature sensor holder formed in the back plate.
9. The substrate carrier as claimed in claim 1, including a
plurality of temperature sensor holders formed in the back
plate.
10. The substrate carrier as claimed in claim 1, including: a
selenium supply container formed in an end of the body adjacent the
back plate and the side rails, the selenium supply container
including a shelf portion extending between the side rails
outwardly of the engagement slot, the shelf portion having formed
therein a plurality of selenium vapor ports.
11. The substrate carrier as claimed in claim 1, wherein the body
is substantially rectangular.
12. The substrate carrier as claimed in claim 11, wherein the rails
are positioned on opposite sides of the back plate.
13. The substrate carrier as claimed in claim 1, wherein the body
comprises graphite.
14. A system for depositing selenium on a substrate, which
comprises: a substrate carrier including a body, means for holding
the substrate, and a plurality of selenium vapor outlets formed in
the body to direct a flux of selenium vapor onto the substrate; a
selenium supply container coupled to provide selenium vapor to the
selenium vapor outlets; at least one temperature sensor coupled to
the substrate carrier to sense temperature of the substrate; a heat
source positioned to heat the substrate; and, a controller coupled
to the temperature sensor and the heat source.
15. The system as claimed in claim 14, wherein: the carrier
includes a back plate; the means for holding the substrate includes
a pair of spaced apart, substantially parallel, side rails on the
back plate, each side rail including an inwardly facing surface
extending outwardly of the back plate, a longitudinally extending
engagement slot formed in the inwardly facing surface of each side
rail adjacent the back plate to engage and hold the substrate in
proximity to the back plate; and, the plurality selenium vapor
outlets are formed in each side rail outwardly of the engagement
slot.
16. The system as claimed in claim 15, wherein each selenium vapor
outlet is in communication with a selenium vapor bore formed in the
side rail and the inwardly facing surface of the side rail.
17. The system as claimed in claim 16, wherein each selenium vapor
bore is coupled to the selenium supply container by a tube.
18. The system as claimed in claim 14, wherein the selenium supply
container is integral with the body, and the selenium supply
container includes a shelf positioned above the means for holding
the substrate, and the shelf portion has formed therein the
plurality of selenium vapor outlets.
19. The system as claimed in claim 14, wherein the body comprises
graphite.
20. A process of depositing selenium on a substrate, which
comprises: placing a substrate in a carrier, the carrier carrying
at least one temperature sensor, and the carrier having a plurality
of selenium vapor outlets positioned to direct selenium vapor on to
the substrate; vaporizing solid selenium to form a selenium vapor
flux; coupling the selenium vapor flux to the selenium vapor
outlets; and, monitoring temperature sensed by the at least one
temperature sensor.
Description
BACKGROUND
[0001] This disclosure relates generally to the manufacture of
copper indium gallium selenide (CIGS) photovoltaic cells and/or
panels, and more particularly to methods, devices and systems for
enhancing the selenium supplied in such manufacturing
processes.
[0002] Copper indium gallium selenide (CIGS) is a semiconductor
material useful for the manufacture of solar cells. The CIGS
absorber is deposited on a glass or plastic substrate, along with
electrodes on the front and back to collect current. The material
has a high absorption coefficient and strongly absorbs sunlight.
Accordingly, a thinner CIGS film is required than those of other
semiconductor photovoltaic materials.
[0003] CIGS films are typically made by first depositing copper,
indium and gallium on the substrate and then exposing the precursor
layers to selenium at a high temperature. The selenium supply and
selenization environment are extremely important in determining the
properties and quality of the film produced from precursor layers.
When Se is supplied in the gas phase (for example as H2Se or
elemental Se) at high temperatures the Se will become incorporated
into the film by absorption and subsequent diffusion. During this
step, called chalcogenization, complex interactions occur to form a
chalcogenide. These interactions include formation of Cu--In--Ga
intermetallic alloys, formation of intermediate metal-selenide
binary compounds, and phase separation of various stoichiometric
CIGS compounds.
[0004] A particular problem in selenization is supplying sufficient
selenium to the precursor layers. Current techniques provide small
coverage area of selenium deposition. Also, current techniques have
not provided for in-situ monitor, which leads to uncertainty in
what is actually occurring during processing. Because of the
variety and complexity of the reactions taking place, the
properties of the CIGS film have difficult to control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Aspects of the present disclosure are best understood from
the following detailed description when read with the accompanying
figures. It is emphasized that, in accordance with the standard
practice in the industry, various features are not drawn to scale.
In fact, the dimensions of the various features can be arbitrarily
increased or reduced for clarity of discussion.
[0006] FIG. 1 is a side section view of a selenium supply system in
accordance with various embodiments of the present disclosure.
[0007] FIG. 2 is a side view of a first substrate carrier in
accordance with various embodiments of the present disclosure.
[0008] FIG. 3 is section view taken along line 3-3 of FIG. 2.
[0009] FIG. 4 is a side view of a second substrate carrier in
accordance with various embodiments of the present disclosure.
[0010] FIG. 5 is a section view taken along line 5-5 of FIG. 4.
[0011] FIG. 6 is a section view taken along line 6-6 of FIG. 4.
[0012] FIG. 7 is a side view of a third substrate carrier in
accordance with various embodiments of the present disclosure.
[0013] FIG. 8 is a top view of the third substrate carrier taken
along line 8-8 of FIG. 7.
[0014] FIG. 9 is section view taken along line 9-9 of FIG. 7.
[0015] FIG. 10 is a flow chart if a process in accordance with
various embodiments of the present disclosure.
DETAILED DESCRIPTION
[0016] This description of the exemplary embodiments is intended to
be read in connection with the accompanying drawings, which are to
be considered part of the entire written description. In the
description, relative terms such as "lower," "upper," "horizontal,"
"vertical,", "above," "below," "up," "down," "top" and "bottom" as
well as derivative thereof (e.g., "horizontally," "downwardly,"
"upwardly," etc.) should be construed to refer to the orientation
as then described or as shown in the drawing under discussion.
These relative terms are for convenience of description and do not
require that the apparatus be constructed or operated in a
particular orientation. Terms concerning coupling and the like,
such as "connected" and "interconnected," refer to a relationship
wherein devices or nodes are in direct or indirect electrical
communication, unless expressly described otherwise.
[0017] It is understood that the following disclosure provides many
different embodiments or examples for implementing different
features of various embodiments. Specific examples of components
and arrangements are described below to simplify the present
disclosure. These are, of course, merely examples and are not
intended to be limiting. The present disclosure may repeat
reference numerals and/or letters in the various examples. This
repetition is for the purpose of simplicity and clarity and does
not in itself dictate a relationship between the various
embodiments and/or configurations discussed.
[0018] Referring now to the drawings, and first to FIG. 1, a system
according to an embodiment of the present disclosure is designated
generally by the numeral 100. System 100 includes a substrate
carrier 101 contained in a vacuum chamber 103. As will described in
detail hereinafter, substrate carrier 101 as adapted to carry a
substrate 105 during exposure to selenium vapor will be applied in
accordance with embodiments of the present disclosure. Substrate
105 has copper, indium and/or gallium applied thereto by other
processes prior to the application of selenium according to
embodiments of the present disclosure. Substrate carrier 101 may be
fabricated from graphite, as will be described in detail
hereinafter.
[0019] In some embodiments, the substrate 105 is a photovoltaic
solar cell substrate. Suitable materials for the underlying
substrate include for example without limitation, glass (such as
soda lime glass), ceramic, metals such as thin sheets of stainless
steel and aluminum, or polymers such as polyamides, polyethylene
terephthalates, polyethylene naphthalates, polymeric hydrocarbons,
cellulosic polymers, polycarbonates, polyethers, combinations
thereof, or the like. A back electrode (e.g., Molybdenum) is formed
over the substrate. The absorber film is formed over the back
electrode.
[0020] In some embodiments, the absorber material is copper indium
gallium (di)selenide (CIGS), a I-III-VI2 semiconductor material
composed of copper, indium, gallium, and selenium. CIGS is a solid
solution of copper indium selenide (often abbreviated "CIS") and
copper gallium selenide. CIGS is a tetrahedrally bonded
semiconductor, with the chalcopyrite crystal structure, and a
bandgap varying continuously with x from about 1.0 eV (for copper
indium selenide) to about 1.7 eV (for copper gallium selenide).
[0021] In an embodiment, the photovoltaic may comprise a p-type
material. For example, the absorber layer can be a p-type
chalcogenide material. In a further embodiment, the absorber layer
can be a CIGS Cu(In,Ga)Se2 material. In other embodiments,
chalcogenide materials including, but not limited to, Cu(In,Ga)(Se,
S)2 or "CIGSS," CuInSe2, CuGaSe2, CuInS2, and Cu(In,Ga)S2. can be
used as an absorber layer material. Suitable p-type dopants that
can be used for forming absorber layer include without limitation
boron (B) or other elements of group II or III of the periodic
table. In another embodiment, the absorber layer may comprise an
n-type material including, without limitation, cadmium sulfide
(CdS).
[0022] System 100 includes a selenium supply container 107, which
is adapted to receive and contain solid selenium in the form of
slugs, particles or the like. A heat source 109 is provided in
vacuum chamber 103 to heat substrate carrier 101 and substrate 105
to an appropriate process temperature, in a range about 500.degree.
Celsius to about 550.degree. Celsius, and to vaporize the solid
selenium contained in selenium supply container 107. Selenium
supply container 107 may be coupled by tubes 111a and 111b or the
like to provide a flux of selenium vapor to substrate carrier 101
and then substrate 105 under the influence of gravity. Selenium
supply container 107 and tubes 111a and 111b may be made of
graphite, silicon carbide, molybdenum and/or tantalum, or other
suitable material, capable of withstanding the high process
temperatures.
[0023] As will be described in detail hereinafter, substrate
carrier 101 carries one or more temperature sensors, indicated
generally at 113. Temperature sensors 113 are position in contact
with or in close proximity to substrate 105. Temperature sensors
113 enable in-situ monitoring of the temperature of substrate 105
during processing. Temperature sensors 113 may comprise
thermocouples.
[0024] Temperature sensors 113 and heat source 109 are coupled to a
controller 115, which may include a suitably programed computer
with hardware and software interfaces to communicate with
temperature sensors 113 and heat source 109. Controller 115 is
adapted to maintain substrate 105 at a substantially constant
temperature in the process range and to detect a characteristic
temperature drop during the application of the selenium vapor to
the substrate due to phase changes and reactions occurring during
processing.
[0025] Referring now to FIGS. 2 and 3, a first embodiment of a
substrate carrier is designated generally by the number 200.
Substrate carrier 200 may be fabricated from a single rectangular
block of graphite using conventional milling and boring machines,
such as numerically controlled machines. Substrate carrier 200
includes a rectangular back plate 201 and a pair of spaced apart
side rails 203 extending outwardly from back plate 201. Side rails
203 are substantial mirror images of each other and each includes
an inwardly facing surface 205. Each inwardly facing surface 205 is
machined to include a longitudinally extending engagement slot 207
adjacent back plate 201. Engagement slots 207 engage and hold a
substrate 209 against or in proximity to back plate 201. Although
not shown in the drawings, the outwardly facing side of substrate
209, opposite the side facing back plate 201, has a thin layer of
precursor copper, indium and/or gallium applied thereto prior to
being inserted into substrate carrier 200. Back plate 201 has
formed therein one or more sensor holder bores 211, which are
adapted to receive and position in contact with or in proximity to
substrate 209 one or more temperature sensors, such as
thermocouples (not shown).
[0026] Each side rail 203 has formed therein a longitudinally
extending selenium vapor bore 213. As shown in FIG. 2, each
selenium vapor bore 213 is open at its top end and closed at its
bottom end. The top end of each selenium vapor bore 213 is adapted
to be coupled to tubes 111 and receive selenium vapor from selenium
supply container 107 of FIG. 1. Selenium vapor flows into and fills
selenium vapor bores 213 under the influence of gravity.
[0027] Each side rail 203 also has formed therein a plurality of
longitudinally spaced apart selenium vapor outlets 215. Selenium
vapor outlets 215 are positioned outwardly from engagement slot 207
and allow the flux of selenium vapor to flow from selenium vapor
bores 213 onto substrate 209. In the embodiment of FIGS. 2 and 3,
each selenium vapor outlet 215 includes a relatively small diameter
conduit 217, in communication with selenium vapor bore 213, and a
larger diameter conduit 219, in communication with inwardly facing
surface 205.
[0028] Referring now to FIGS. 4-6, a second embodiment of a
substrate carrier is designated generally by the number 400.
Substrate carrier 400 is similar to substrate carrier 200, of FIGS.
2 and 3, and it too may be fabricated from a single rectangular
block of graphite using conventional milling and boring machines,
such as numerically controlled machines. Substrate carrier 400
includes a rectangular back plate 401 and a pair of spaced apart
side rails 403 extending outwardly from back plate 401. Side rails
403 are substantial mirror images of each other and each includes
an inwardly facing surface 405. Each inwardly facing surface 405 is
machined to include a longitudinally extending engagement slot 407
adjacent back plate 401. Engagement slots 407 engage and hold a
substrate 409 against or in proximity to back plate 401. Back plate
401 has formed therein one or more sensor holder bores 411, which
are adapted to receive and position in contact with or in proximity
to substrate 409 one or more temperature sensors, such as
thermocouples (not shown).
[0029] As in the embodiment of FIGS. 2 and 3, each side rail 403
has formed therein a longitudinally extending selenium vapor bore
413. As shown in FIG. 4, each selenium vapor bore 413 is open at
its top end and closed at its bottom end. The top end of each
selenium vapor bore 413 is adapted to be coupled to tubes 111 and
receive selenium vapor from selenium supply container 107 of FIG.
1. Selenium vapor flows into and fills selenium vapor bores 413
under the influence of gravity.
[0030] Substrate carrier 400 differs from substrate carrier 200 of
FIGS. 2 and 3 in the configuration of its selenium vapor outlets.
More particularly, each side rail 403 has formed therein a
longitudinally extending selenium vapor channel 415 parallel to
engagement slot 407. A plurality of longitudinally spaced apart
selenium vapor outlets 417 connect selenium vapor bore 413 with
selenium vapor channel 415. Selenium vapor outlets 417 allow the
flux of selenium vapor to flow from selenium vapor bores 413 into
selenium vapor channel 415 and then onto substrate 409.
[0031] Referring now to FIGS. 7-9, a third embodiment of a
substrate carrier is designated generally by the number 700.
Substrate carrier 700 is similar to substrate carriers 200 and 400,
and it too may be fabricated from a single rectangular block of
graphite using conventional milling and boring machines. Substrate
carrier 700 includes a rectangular back plate 701 and a pair of
spaced apart side rails 703 extending outwardly from back plate
701. Side rails 703 are substantial mirror images of each other and
each includes an inwardly facing surface 705. Each inwardly facing
surface 705 is machined to include a longitudinally extending
engagement slot 707 adjacent back plate 701. Engagement slots 707
engage and hold a substrate 709 against or in proximity to back
plate 701. Back plate 701 has formed therein one or more sensor
holder bores 711, which are adapted to receive and position in
contact with or in proximity to substrate 709 one or more
temperature sensors, such as thermocouples (not shown).
[0032] Substrate carrier 700 differs from substrate carriers 200
and 400 in that side rails 703 do not include longitudinally
extending bores connectable to a selenium supply container via
tubes. Rather, substrate carrier 700 includes an integral selenium
supply container 713. Selenium supply container is a rectangular,
box-like, structure formed by side walls on top of side rails 703
and back plate 701 into which solid selenium slugs (not shown), or
the like, may be deposited. Selenium supply container 713 includes
a shelf portion 715 that extends between side rails 703. Shelf
portion 715 has formed therein plurality selenium vapor ports 717
outward of engagement slots 707. Selenium vapor ports 717 allow a
flux of selenium vapor formed in selenium supply container 713 to
flow over substrate 709.
[0033] FIG. 10 is a flow chart of an embodiment of a process
according to the present disclosure. The substrate is placed in the
substrate carrier, at block 1001. Then, the substrate carrier is
placed in the process chamber, at block 1003, and a supply of
selenium slugs is placed in the selenium supply chamber, at block
1005. After the substrate carrier is place in the process chamber
and the selenium supply container is supplied with selenium slugs,
the chamber is sealed and evacuated, at block 1007. When the
chamber is evacuated, the heat source is actuated to heat the
chamber to the process temperature, e.g. about 500.degree. C. to
about 550.degree. C., at block 1009. After the chamber reaches the
process temperature, the system monitors the temperature of the
substrate, at block 1011. The system continues to monitor the
temperature of the substrate until it detects the characteristic
temperature drop of about 3.degree. C. or 4.degree. C., at decision
block 1013, whereupon the process is ended.
[0034] In some embodiments, a substrate carrier comprises: a body
including a back plate and a pair of spaced apart, substantially
parallel, side rails on the back plate, each side rail including an
inwardly facing surface extending outwardly of the back plate; and
a longitudinally extending engagement slot formed in the inwardly
facing surface of each side rail adjacent the back plate to engage
and hold the substrate in proximity to the back plate.
[0035] In some embodiments, the substrate carrier includes: a
longitudinally extending selenium vapor bore formed in each of the
side rails; and a plurality of inwardly directed selenium vapor
outlets formed in each side rail outwardly of the engagement slot
and in communication with the selenium vapor bore and the inwardly
facing surface.
[0036] In some embodiments, the selenium vapor outlets include a
first outlet conduit in communication with the bore and a second
outlet conduit in communication with the first outlet conduit and
the inwardly facing surface.
[0037] In some embodiments, the second outlet conduit is larger
than the first outlet conduit.
[0038] In some embodiments, the outlet conduits each have a
circular cross section and are concentric with each other.
[0039] In some embodiments, the substrate carrier includes a
longitudinally extending selenium vapor channel formed in the
inwardly facing surface of each side rail outwardly of the
engagement slot; and a plurality of inwardly directed selenium
vapor outlets formed in each side rail and in communication with
the selenium vapor bore and the selenium vapor channel.
[0040] In some embodiments, the selenium vapor outlets are
substantially uniformly spaced apart along the inwardly facing
surface of each side rail.
[0041] In some embodiments, the substrate carrier includes a
temperature sensor holder formed in the back plate.
[0042] In some embodiments, the substrate carrier includes a
plurality of temperature sensor holders formed in the back
plate.
[0043] In some embodiments, the substrate carrier includes a
selenium supply container formed in an end of the body adjacent the
back plate and the side rails, the selenium supply container
including a shelf portion extending between the side rails
outwardly of the engagement slot, and the shelf portion having
formed therein a plurality of selenium vapor ports outwardly of the
engagement slots.
[0044] In some embodiments, the body is substantially
rectangular.
[0045] In some embodiments, the rails are positioned on opposite
sides of the back plate.
[0046] In some embodiments, the body comprises graphite.
[0047] In some embodiments, a system for depositing selenium on a
substrate comprises: a substrate carrier including a body, means
for holding the substrate, and a plurality of selenium vapor
outlets formed in the body to direct a flux of selenium vapor onto
the substrate; a selenium supply container coupled to provide
selenium vapor to the selenium vapor outlets; at least one
temperature sensor coupled to the substrate carrier to sense
temperature of the substrate; a heat source positioned to heat the
substrate; and, a controller coupled to the temperature sensor and
the heat source.
[0048] In some embodiments, a system for depositing selenium on a
substrate comprises: a substrate carrier including a body, means
for holding the substrate, and a plurality of selenium vapor
outlets formed in the body to direct a flux of selenium vapor onto
the substrate; a selenium supply container coupled to provide
selenium vapor to the selenium vapor outlets; at least one
temperature sensor coupled to the substrate carrier to sense
temperature of the substrate; a heat source positioned to heat the
substrate; and, a controller coupled to the temperature sensor and
the heat source.
[0049] In some embodiments, the carrier includes a back plate; the
means for holding the substrate includes a pair of spaced apart,
substantially parallel, side rails on the back plate, each side
rail including an inwardly facing surface extending outwardly of
the back plate, a longitudinally extending engagement slot formed
in the inwardly facing surface of each side rail adjacent the back
plate to engage and hold the substrate in proximity to the back
plate; and, wherein the plurality selenium vapor outlets are formed
in each side rail outwardly of the engagement slot.
[0050] In some embodiments, each selenium vapor outlet is in
communication with a selenium vapor bore formed in the side rail
and the inwardly facing surface of the side rail. In some
embodiments, each selenium vapor bore is coupled to the selenium
supply container by a tube.
[0051] In some embodiments, the selenium supply container is
integral with the body, and the selenium supply container includes
a shelf positioned above the means for holding the substrate, and
the shelf portion has formed therein the plurality of selenium
vapor outlets.
[0052] In some embodiments, the body comprises graphite.
[0053] In some embodiments, a process of depositing selenium on a
substrate comprises: placing a substrate in a carrier, the carrier
carrying at least one temperature sensor, and the carrier having a
plurality of selenium vapor outlets positioned to direct selenium
vapor on to the substrate; vaporizing solid selenium to form a
selenium vapor flux; coupling the selenium vapor flux to the
selenium vapor outlets; and, monitoring temperature sensed by the
at least one temperature sensor.
[0054] The methods and system described herein may be at least
partially embodied in the form of computer-implemented processes
and apparatus for practicing those processes. The disclosed methods
may also be at least partially embodied in the form of tangible,
non-transient machine readable storage media encoded with computer
program code. The media may include, for example, RAMs, ROMs,
CD-ROMs, DVD-ROMs, BD-ROMs, hard disk drives, flash memories, or
any other non-transient machine-readable storage medium, wherein,
when the computer program code is loaded into and executed by a
computer, the computer becomes an apparatus for practicing the
method. The methods may also be at least partially embodied in the
form of a computer into which computer program code is loaded
and/or executed, such that, the computer becomes a special purpose
computer for practicing the methods. When implemented on a
general-purpose processor, the computer program code segments
configure the processor to create specific logic circuits. The
methods may alternatively be at least partially embodied in a
digital signal processor formed of application specific integrated
circuits for performing the methods.
[0055] The above-described embodiments, are merely possible
examples of implementations, merely set forth for a clear
understanding of the principles of the disclosure. Many variations
and modifications can be made to the above-described embodiments of
the disclosure without departing substantially from the spirit and
principles of the disclosure. All such modifications and variations
are intended to be included herein within the scope of this
disclosure and the present disclosure and protected by the
following claims.
[0056] Further, the foregoing has outlined features of several
embodiments so that those skilled in the art may better understand
the detailed description that follows. Those skilled in the art
should appreciate that they may readily use the present disclosure
as a basis for designing or modifying other processes and
structures for carrying out the same purposes and/or achieving the
same advantages of the embodiments introduced herein. Those skilled
in the art should also realize that such equivalent constructions
do not depart from the spirit and scope of the present disclosure,
and that they may make various changes, substitutions and
alterations herein without departing from the spirit and scope of
the present disclosure.
[0057] While preferred embodiments of the present subject matter
have been described, it is to be understood that the embodiments
described are illustrative only and that the appended claims shall
be accorded a full range of equivalents, many variations and
modifications naturally occurring to those of skill in the art from
a perusal hereof.
* * * * *