U.S. patent application number 14/448745 was filed with the patent office on 2016-02-04 for methods and apparatuses for deuterium recovery.
The applicant listed for this patent is Poongsan Corporation. Invention is credited to Manuel Rivera, Biao Wu.
Application Number | 20160035600 14/448745 |
Document ID | / |
Family ID | 53762349 |
Filed Date | 2016-02-04 |
United States Patent
Application |
20160035600 |
Kind Code |
A1 |
Rivera; Manuel ; et
al. |
February 4, 2016 |
METHODS AND APPARATUSES FOR DEUTERIUM RECOVERY
Abstract
Novel methods, systems, and apparatuses for reclaiming annealing
gases from a high pressure annealing processing system are
disclosed. According to an embodiment, the exhaust gasses from the
high pressure annealing processing system are directed into a gas
reclaiming system only when a precious gas, e.g., deuterium is
used. The annealing gas is the separated from other gasses used in
the high pressure annealing processing system and is then
pressurized, filtered, and purified prior to transferring the gas
to a bulk storage distribution unit. In one embodiment, the
reclaimed gas is then again provided to the high pressure annealing
processing system to anneal the wafers.
Inventors: |
Rivera; Manuel; (San Jose,
CA) ; Wu; Biao; (Cupertino, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Poongsan Corporation |
Seoul |
|
KR |
|
|
Family ID: |
53762349 |
Appl. No.: |
14/448745 |
Filed: |
July 31, 2014 |
Current U.S.
Class: |
95/8 ; 96/111;
96/19; 96/397 |
Current CPC
Class: |
B01D 53/02 20130101;
C01B 4/00 20130101; H05B 1/0202 20130101; H01L 21/67098 20130101;
B01D 46/0036 20130101; B01D 2253/116 20130101; H05B 1/0233
20130101; B01D 53/002 20130101; B01D 53/32 20130101; H01L 21/67103
20130101; C23C 16/4402 20130101; C23C 16/4408 20130101; C23C
16/4412 20130101; B01D 46/0027 20130101; H01L 21/67109 20130101;
H01L 21/67017 20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; C01B 4/00 20060101 C01B004/00; B01D 53/02 20060101
B01D053/02; B03C 3/36 20060101 B03C003/36; B01D 46/00 20060101
B01D046/00; B01D 46/44 20060101 B01D046/44 |
Claims
1. A method of reclaiming at least a first annealing gas from an
exhaust of a high pressure annealing processing system used to
anneal a plurality of substrates in a semiconductor manufacturing
process comprising: receiving a signal about the presence of at
least the first annealing gas in the high pressure annealing
processing system; purging a gas reclaiming system with a second
gas; directing the at least first annealing gas to the gas
reclaiming system, wherein the at least first annealing gas and the
second gas are mixed together to form a mixture of a plurality of
gases in the gas reclaiming system; after the directing, separating
the plurality of gases in a gas separating unit of the gas
reclaiming system, wherein the gas separating unit substantially
separates the at least first annealing gas from the plurality of
gasses to yield a separated annealing gas; conveying the separated
annealing gas to a heat exchange unit of the gas reclaiming system;
testing the separated annealing gas in a gas monitoring system of
the gas reclaiming system to monitor the quality of the separated
annealing gas, wherein if the separated annealing gas has a
concentration of the at least first annealing gas below a
predetermined threshold: conveying the separated annealing gas back
to the gas separating unit to reprocess the separated annealing
gas, and re-testing the quality of the separated annealing gas;
conveying the separated annealing gas to a gas pressurizing unit of
the gas reclaiming system, wherein the separated annealing gas is
pressurized above atmospheric pressure to yield a pressurized first
annealing gas; conveying the first pressurized annealing gas to a
purification system; and storing the purified and pressurized first
annealing gas for at least a period of time before re-using the
pressurized first annealing gas in the high pressure annealing
processing system.
2. The method of claim 1, wherein the quality of the separated
annealing gas is tested or re-tested at least by determining the
concentration of the at least first annealing gas in the separated
annealing gas.
3. The method of claim 1, wherein conveying the separated first
annealing gas back to the gas separating unit comprises passing the
separated first annealing gas through the heat exchange unit
again.
4. The method of claim 1, wherein the first annealing gas is
deuterium and the second gas is an inert gas.
5. The method of claim 1, wherein the gas separation unit heats the
gas to a predetermined temperature in order to extract the first
annealing gas efficiently.
6. The method of claim 1, wherein the signal about the presence of
at least the first annealing gas in the exhaust of the high
pressure annealing processing system is transmitted by an automated
process control device.
7. The method of claim 6, wherein the automated process control
transmits the signal only upon a determining that the concentration
of the first annealing gas is higher than a predetermined
threshold.
8. The method of claim 1, wherein the signal is received from a
first data processing system which controls the high pressure
annealing processing system and the signal is received by a second
data processing system which controls the method of reclaiming the
first annealing gas.
9. The method of claim 8, wherein the signal is derived from a
first recipe stored in the first data processing system, and when a
second recipe used by the first data processing system does not
include a predetermined amount of the first annealing has, the
first data processing system does not provide the signal to the
second data processing system.
10. The method of claim 1, wherein the second gas is the same gas
which is used in the high pressure annealing processing system as
an outer buffer that surrounds the first annealing gas in an
annealing chamber of the high pressure annealing processing
system.
11. The method of claim 1, wherein the purified and pressurized
first annealing gas is stored in a first bank of one or more
vessels while a second bank of one or more vessels is coupled to
the high pressure annealing processing system to provide the first
annealing gas for an annealing process while reclaimed first
annealing gas is stored in the first bank, and wherein the second
bank is switchable with the first bank.
12. A non-transitory computer readable medium comprising
instructions, which when executed by a processing system, including
one or more processors, performs a method of reclaiming at least a
first annealing gas from an exhaust of a high pressure annealing
processing system used to anneal a plurality of substrates in a
semiconductor manufacturing process, the method comprising:
receiving a signal about the presence of at least the first
annealing gas in the high pressure annealing processing system;
purging a gas reclaiming system with a second gas; directing the at
least first annealing gas to the gas reclaiming system, wherein the
at least first annealing gas and the second gas are mixed together
to form a mixture of a plurality of gases in the gas reclaiming
system; after the directing, separating the plurality of gases in a
gas separating unit of the gas reclaiming system, wherein the gas
separating unit substantially separates the at least first
annealing gas from the plurality of gasses to yield a separated
annealing gas; conveying the separated annealing gas to a heat
exchange unit of the gas reclaiming system; testing the separated
annealing gas in a gas monitoring system of the gas reclaiming
system to monitor the quality of the separated annealing gas,
wherein if the separated annealing gas has a concentration of the
at least first annealing gas below a predetermined threshold:
conveying the separated annealing gas back to the gas separating
unit to reprocess the separated annealing gas, and re-testing the
quality of the separated annealing gas; conveying the separated
annealing gas to a gas pressurizing unit of the gas reclaiming
system, wherein the separated annealing gas is pressurized above
atmospheric pressure to yield a pressurized first annealing gas;
conveying the first pressurized annealing gas to a purification
system; and storing the purified and pressurized first annealing
gas for at least a period of time before re-using the pressurized
first annealing gas in the high pressure annealing processing
system.
13. The non-transitory computer readable medium of claim 12,
wherein the quality of the separated annealing gas is tested or
re-tested at least by determining the concentration of the at least
first annealing gas in the separated annealing gas.
14. The non-transitory computer readable medium of claim 12,
wherein conveying the separated first annealing gas back to the gas
separating unit comprises passing the separated first annealing gas
through the heat exchange unit again.
15. The non-transitory computer readable medium of claim 12,
wherein the first annealing gas is deuterium and the second gas is
an inert gas.
16. The non-transitory computer readable medium of claim 12,
wherein the gas separation unit heats the gas to a predetermined
temperature in order to extract the first annealing gas
efficiently.
17. The non-transitory computer readable medium of claim 12,
wherein the signal about the presence of at least the first
annealing gas in the exhaust of the high pressure annealing
processing system is transmitted by an automated process control
device.
18. The non-transitory computer readable medium of claim 17,
wherein the automated process control transmits the signal only
upon a determining that the concentration of the first annealing
gas is higher than a predetermined threshold.
19. The non-transitory computer readable medium of claim 12,
wherein the signal is received from a first data processing system
which controls the high pressure annealing processing system and
the signal is received by a second data processing system which
controls the method of reclaiming the first annealing gas.
20. The non-transitory computer readable medium of claim 12,
wherein the second gas is the same gas which is used in the high
pressure annealing processing system as an outer buffer that
surrounds the first annealing gas in an annealing chamber of the
high pressure annealing processing system.
21. The non-transitory computer readable medium of claim 19,
wherein the signal is derived from a first recipe stored in the
first data processing system, and when a second recipe used by the
first data processing system does not include a predetermined
amount of the first annealing has, the first data processing system
does not provide the signal to the second data processing
system.
22. The non-transitory computer readable medium of claim 12,
wherein the purified and pressurized first annealing gas is stored
in a first bank of one or more vessels while a second bank of one
or more vessels is coupled to the high pressure annealing
processing system to provide the first annealing gas for an
annealing process while reclaimed first annealing gas is stored in
the first bank, and wherein the second bank is switchable with the
first bank.
23.-29. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to semiconductor
manufacturing process. More particularly, the present invention
pertains to methods and apparatuses which use precious gases, like
deuterium, during a high pressure annealing process of
semiconductor manufacturing.
[0003] 2. Description of the Related Art
[0004] During the semiconductor manufacturing process, various
different thermal treatments are performed on a semiconductor
wafer, for example, during or following oxidation, nitridation,
silicidation, ion implantation, and chemical vapor deposition
processes, to create the integrated circuits on the semiconductor
wafer.
[0005] Key determining factors for effective fabrication of
integrated circuits not only include the process temperature, but
also the processing time and the concentration of a particular gas
or a mixture of gases used for a particular application or
treatment. These three factors are generally considered as
independent variables which determine the efficiency of the
processing. For example, by increasing the process temperature
while keeping the gas concentration constant, the process
efficiency will improve. Similarly, by increasing the gas
concentration at the same temperature, the process efficiency can
be improved. It should be noted that exposure of semiconductor
wafers, or more precisely integrated circuits, to excessive heat
generally degrades the quality of the integrated circuits, in an
irreversible and cumulative way. This is, in part, due to the
diffusion of various carriers and ions implanted on the wafer,
whose rate increases, typically superlinearly, with temperature.
Each integrated circuit has an acceptable limit of total thermal
exposure during the whole manufacturing process, which is referred
to as the circuit's thermal budget in the related art.
[0006] As the technology and device structure approaches the
nanometer scale, the limited thermal budget requirement demands
higher concentration of the processing gas. Annealing wafers in a
forming gas containing diatomic hydrogen, typically following
fabrication but before encapsulation or other packaging steps, has
been widely used for repairing various process induced damages
during the semiconductor fabrication process as well as for
sintering process, which is referred to as hydrogen passivation in
the art. The annealing or forming gas generally incorporates
approximately 2% to 10% hydrogen (H.sub.2) with the remainder being
inert gas such as nitrogen (N.sub.2).
[0007] Recently, however, many researchers have reported that pure
(100%) deuterium anneal improves the device characteristics and
performance such as hot carrier reliability, transistor lifetime,
and reduction of dangling bonds and unwanted charge carriers.
Improvement of device lifetime increases the transconductance
(speed performance) of the device. As the device technology and
structure move to the sophistication of the so-called "nanometer
technology", new high pressure application technologies require use
of other gases such as fluorine (F.sub.2), ammonia (NH.sub.3), and
chlorine (Cl.sub.2), which can be highly reactive or toxic. The
forming gas (partial pressure) anneal and/or pure H.sub.2 or
D.sub.2 anneal has been generally done at a temperature range above
450.degree. C., and higher temperature tends to result in better
performance. However, as the device scale reaches 28 nm or below,
the limited thermal budget after first metallization requires
annealing temperatures at or below 400.degree. C., thus potentially
diminishing the hydrogen annealing benefit on semiconductor device
performance.
[0008] As an alternative, hydrogen or deuterium high pressure
annealing can result in excellent performance and improvement.
Particularly, hydrogen and/or deuterium annealing of high-K gate
dielectric device showed significant performance improvement in
charge reduction, dangling bond reduction, and increase of
transconductance. This finding has been disclosed, for example, in
the U.S. Pat. No. 6,913,961 and U.S. Pat. No. 6,833,306. This
improvement is very significant for the manufacturing process of
integrated circuit devices using high-K gate dielectric for the
next several generations of semiconductor device technology.
[0009] High pressure annealing, in particular, in the hydrogen
(H.sub.2) or deuterium (D.sub.2) environment can improve
performance of semiconductor devices. This finding has been
disclosed, for example, in the U.S. Pat. No. 8,481,123. In that
patent, titled: Method For High Pressure Gas Annealing, various
embodiments are disclosed to anneal a silicon substrate wafer in a
high pressure environment. As disclosed in that patent, in a high
pressure annealing process, high pressure hydrogen or deuterium gas
is used in various annealing processes, such as high-K gate
dielectric process anneal, post-metallization sintering anneal, and
forming gas anneal. The use of high pressure gas can significantly
improve the device performance. For example, it could increase the
device's lifetime and its transconductance, and it can decrease the
number of dangling bonds. One of the main advantages of the high
pressure gas annealing is that these improvements in the device
performance can be achieved with a reduced thermal budget cost at a
given temperature and/or a given processing time, which is an
essential requirement for the advanced device technology.
[0010] It is known that one of the main advantages of the high
pressure technology is the increase of the reaction rate by
effectively increasing the gas concentration at high pressure. By
increasing the pressure of the processing gas, the density of the
processing gas will increase. The gas density increases roughly
linearly as the pressure increases. For example, if pure 100%
hydrogen or deuterium is processed in 5 atm high pressure
condition, the actual amount of hydrogen or deuterium gas that
semiconductor silicon is exposed to is 5 times the concentration of
the original (100%) hydrogen or deuterium gas at the atmospheric
pressure. In the case of partial pressure conditions, if the
hydrogen or deuterium concentration is 20% and the silicon wafer is
processed at 5 atm pressure, then the silicon wafer is effectively
exposed to the equivalent of 100% hydrogen or deuterium at
atmospheric pressure. Likewise, processing with 20% hydrogen or
deuterium gas at 20 atm will be roughly equivalent to 4 times of
the processing result with the pure (100%) hydrogen or deuterium
gas at 1 atm.
[0011] By increasing the pressure of the process gas, it is
possible to reduce both the processing temperature and the process
time. As the thermal budget limitation reaches the "extreme limit
level," and as the device technology reaches the 28 nm range, high
pressure processing becomes a viable solution which meets or
exceeds many thermal processing requirements in the semiconductor
fabrication technology. The high pressure processing can provide
the following benefits with respect to the three aforementioned
process parameters; process time reduction, process temperature
reduction, and process gas concentration reduction. (1) By
increasing pressure, the process temperature can be reduced while
maintaining the gas concentration and process time unchanged in
order to obtain equivalent or similar process results. (2) By
increasing pressure, the process time can be reduced significantly
while keeping other parameters of temperature and gas concentration
unchanged in order to obtain equivalent or similar process results.
(3) By increasing pressure, the process gas concentration can be
reduced while maintaining the time and temperature parameters
unchanged in order to obtain equivalent or similar process
results.
[0012] Application of high pressure hydrogen/deuterium process
anneal to high-K gate dielectric process anneal, post-metallization
sintering anneal, and forming gas anneal in the semiconductor
fabrication could achieve a significant improvement in the device
performance, for example in terms of increased device lifetime,
enhanced transconductance, and reduced number of dangling bonds,
and also achieve significant process thermal budget improvement at
a given processing temperature and processing time, which is an
essential requirement for the advanced device technology.
[0013] As described in U.S. Pat. No. 8,481,123, the gas from the
outer chamber is released at the same time and mixed with the
hydrogen/deuterium gas or other toxic or flammable gas from the
inner chamber. Another inert gas such as nitrogen is added during
the venting process thereby further reducing the concentration of
the reactive gas exhausted to the atmosphere from the annealing
vessel. After the process is completed and the gases used for
various purposes are depressurized, any remaining residual gas
trapped in the annealing chamber are safely removed by purging
extra nitrogen flow near, or around, the exhaust valves or pipes of
the annealing vessel before discharging the remaining gases into
the atmosphere. This is done to avoid direct exposure of
concentrated hydrogen or deuterium with the atmosphere, to prevent
a potentially dangerous condition.
[0014] The high pressure annealing processing unit, as described in
U.S. Pat. No. 8,481,123, comprises a vertical high pressure
processing system, as illustrated in FIG. 1. According to that
invention, the annealing vessel has a dual chamber structure,
comprising an inner chamber and an outer chamber, and a reactive
gas, which may be flammable, toxic, or otherwise dangerous, is
confined in the inner chamber. The inner chamber is then protected
by the external pressure exerted by another gas contained in the
outer chamber. This design provides a buffer zone in case where
there is a leakage of the processing gas from the inner processing
chamber, and hence it provides, among other things, two main
benefits: It dilutes the potentially dangerous gas leaked from the
inner chamber, and it prevents the leaked gas from directly
releasing into the air. In certain embodiments, more than one outer
chambers are used to provide multiple layers, or buffer zones, of
protection. The main external vessel, or the outer chamber, shown
in the figure comprises three components, top 37, body 39, and
bottom 38. In some embodiments, these external vessel components
are made of type 316 stainless steel material that has high stress
point to pressure. The vessel top 37 is normally attached to the
main vessel body 39 by screws, and the vessel bottom 38 is attached
to the main vessel 39 using a breech door locking 40, which is also
made of type 316 stainless steel in some embodiments. In this
exemplary design, the vessel bottom is separated from the main
vessel when the vessel door opens for loading and unloading.
[0015] Inside the main vessel, there is a 4-zone main heater 34
that controls each heater zone independently. The heater elements
34 are insulated from the vessel wall by an insulator 33. There is
also a 2-zone plug heater 24 on top of the bottom component of the
vessel 38 in this embodiment, which can heat the wafer holder or
wafer boat 22 from the bottom. The wafer boat holds one or more
semiconductor wafers 23, and in some embodiments, it is made of
quartz. The external main vessel has cooling water lines 31 to
prevent the vessel from overheating by the heater 34 inside the
vessel beyond the safety temperature. Around the plug heater 24,
quartz cap 27 is placed, and it has quartz helix around the plug
heater that will heat the incoming process gas to the process
temperature. The process gas is introduced into the inner
processing chamber, or tube, 21 via a gas injector 26, which
pressurizes the tube. The inner process chamber is made of
non-metallic materials such as quartz and the outer chamber is made
of metals or metallic alloys such as stainless steel.
[0016] In other embodiments, both chambers are made of metallic
materials with high melting points. The inner chamber 21 divides
the space in the vessel into two regions, and the gases in these
two regions can be completely isolated and they can have different
pressures. The gas pressure inside the process chamber, indicated
as 20 in the figure, is called a tube pressure and the pressure
outside the inner chamber, indicated as 30 in the figure, is called
a shell pressure. The outer shell chamber is pressurized by gas
typically different from the processing gas, which may be highly
reactive, flammable, or otherwise dangerous. In some embodiments
inert gas such as nitrogen is used for this purpose. Nitrogen is
introduced into the outer chamber via a shell nitrogen injector 50
in the exemplary embodiment shown in the figure. The figure also
shows two chill plates, top 32 and bottom 28, which are used to
protect components in the temperature protected areas above the top
chill plate 32 and below the bottom chill plate 28 from excessive
heat. The shell pressure area inside the outer chamber and the tube
pressure area inside the processing chamber are separated and
sealed by O-rings 25. O-rings 36 are also used to hold the shell
pressure by preventing the inert shell gas from leaking from the
main vessel to the outside atmosphere.
[0017] Equalizing, or near-equalizing, pressures of the shell
nitrogen 30 and the tube hydrogen 20 will maintain the integrity of
the quartz tube from collapsing, either inward or outward. When the
tube is fully pressurized by hydrogen/deuterium or other processing
gas to the designated pressure level, the shell is also pressurized
by nitrogen or other inert gas to the same or comparable pressure
level.
[0018] When the high pressure processing is completed, the tube
pressure 20 will be released via de-pressurizing exhaust 29, and
the shell pressure 30 will be released via shell pressure exhaust
35, which are controlled by a pressure control valve 41. Both the
shell pressure and the tube pressure is controlled by the same
pressure control valve or a set of valves. When the pressure
control valve 41 releases the pressure, the nitrogen in the shell
and hydrogen or other process gas in the tube are simultaneously
released to the exhaust. The exhaust gases are mixed, and this
effectively dilutes the processing gas such as hydrogen with
nitrogen and also maintains the pressure differential between the
two chambers within a desired range. In the exemplary embodiment
shown in the figure, where the volume of the outer chamber is three
times that of the inner chamber, the concentration of the
processing gas from the inner chamber becomes diluted to the
one-third level of its original concentration. For example, when a
forming gas with 30% hydrogen has been used during the annealing,
the hydrogen concentration in the exhaust will be around 10%. The
pressure of the gases is maintained with the help of a computing
device associated with the high pressure processing unit. Examples
of a computing device can be a programmable logic, control, and
ASIC control, or any computing device that can be integrated and/or
associated with such a system, as known to one of ordinary skill in
the art. Further, it will be appreciated that pressure sensors
within both the inner and outer chambers may be coupled to a
computer which provides the control described herein, and this
control may be implemented through a software program executing on
the computer.
[0019] When the pressure control valve 41 opens, the pressures of
both chambers are simultaneously released while the gases of
nitrogen and hydrogen are still under high pressure. Hydrogen,
though diluted by nitrogen from the shell, should not be exposed to
the atmosphere. Any defects in the exhaust pipe, typically made of
stainless steel, will release hydrogen into the atmosphere. In
order to prevent such unwanted leak from defects in the stainless
steel pipe, the exhaust line stainless steel pipe, 42 in FIG. 1, is
made of double-walled stainless steel in some embodiments of the
present invention. In the double-walled stainless steel
construction, if the first or inner gas pipe experiences a defect
and the gas leaks, the second or external protective pipe will
contain any leaked hydrogen in the pipe. Thus the likelihood of the
gas leak directly into the atmosphere is significantly reduced. The
hydrogen, diluted by the shell nitrogen, flows to the dilution tank
43 via the double-walled exhaust line 42 to be further diluted
prior to moving to the hydrogen/deuterium burning scrubber 45 via
another double-walled stainless steel line 44. After the scrubber
burns the hydrogen and any flammable gas in the exhaust, it will
release the burnt residue into the atmosphere, indicated by the
arrow 53 in the figure. The exhaust vent line will most likely have
water condensation inside the line, particularly if the scrubber is
not used, due to the back streaming air from the atmosphere, which
typically has much lower temperature than the exhaust gas. The
condensation may react with hydrogen since water (H.sub.2O)
contains oxygen. This could be a source of safety problem. In order
to prevent the water condensation and also to increase dilution of
venting hydrogen/deuterium, additional nitrogen is injected in the
exhaust vent line in some embodiments. FIG. 1 shows a nitrogen
injection line 56, which is connected to the exhaust vent line
immediately after the exhaust vent valve, and this injection line
56 serves as a constant source of nitrogen to guarantee a constant
overflow of a gas from the outlet of the scrubber 45. According to
at least one embodiment, low flow of nitrogen is maintained during
the normal operation in order to prevent any condensation in the
vent line and to maintain an always outward flow of nitrogen from
the scrubber 45. During the chamber depressurization, the nitrogen
flow may be increased in order to further dilute the venting
hydrogen/deuterium or any other potentially dangerous processing
gas exhausted from the annealing vessel.
[0020] FIG. 1 shows a source of high pressure hydrogen or deuterium
as the incoming processing gas via canister 49. The incoming
processing gas flows into the gas control panel or cabinet 46
through gas lines 54 and 48, and it is injected into the processing
chamber 21 through gas pipe 51 and through the gas injector 26 (the
gas line between the pipe 51 and the injector 26 is not explicitly
shown in the figure). The incoming hydrogen or deuterium gas may be
100% pure, and the pressure is typically 500 PSI at minimum, and
hence the incoming gas lines, for example, 54, 48, and 51, and
various parts around the gas canister or pump can be one of the
most dangerous areas in the high pressure system. The system also
includes a H.sub.2/D.sub.2 gas panel, where all the gas control
components (not shown in the figure) are installed. An
H.sub.2/D.sub.2 detector sensor is installed inside the control
panel. Thus, the presence of the hydrogen or deuterium sensor
enables the system to distinguish between the gasses used to anneal
the substrate wafer. The high pressure annealing processing system
is not limited to any particular processing gases, and any type of
gas may be used based on application requirements.
[0021] However, when a precious gas (e.g., deuterium) is used as
the annealing gas, the high pressure annealing processing unit
would safely discard the annealing gas from the exhaust. Thus, the
precious gas is discarded and is not reused. No system exists that
could safely extract the used precious annealing gas (e.g.,
deuterium) from the exhaust of the annealing process for reuse.
BRIEF SUMMARY OF THE DESCRIPTION
[0022] Systems, apparatuses, and computer readable medium to
reclaim at least a first annealing gas from an exhaust gas line of
a high pressure annealing process system used to anneal a plurality
of substrates in a semiconductor manufacturing process are
disclosed. In one embodiment, a gas reclaiming system, after
receiving a signal about the presence of at least the first
annealing gas in a high pressure annealing processing (HPAP)
system, purges the gas reclaiming system with a second gas. There
after, the annealing gas mixture can be redirected from the exhaust
system using a siphon system, a vacuum pump system, or other pump
systems, wherein the at least first annealing gas and the second
gas are mixed together to form a mixture of a plurality of gases in
the gas reclaiming system. After the redirecting, the plurality of
gases can be conveyed to a gas separating unit of the gas
reclaiming system, wherein the gas separating unit separates the at
least first annealing gas from the plurality of gasses, and wherein
the gas separating unit can dispose of the reminder of the
plurality of gasses.
[0023] The at least first annealing gas is conveyed to a heat
exchange unit of the gas reclaiming system to cool the at least
first annealing gas after it leaves the gas separating unit, and
then the at least first annealing gas can be directed to a gas
monitoring system to monitor the quality of the at least first
annealing gas. If the concentration of the at least first annealing
gas in the separated gas is not above a predetermined threshold,
then the at least first annealing gas is re-directed to the gas
separating unit to separate the at least first annealing gas from
the plurality of gases. Thereafter, the at least first annealing
gas is conveyed to a gas pressurizing unit of the gas reclaiming
system, wherein the at least first annealing gas is pressurized
above atmospheric pressure to yield a pressurized first annealing
gas. In one embodiment, the gas reclaiming system then diverts the
first pressurized annealing gas to a filter and/or purification
system, reclaiming the purified and pressurized first annealing
gas, after which it is stored for distribution to the high pressure
annealing processing system. In one embodiment, the gas mixture
from the annealing gas is directly received from the high pressure
annealing process apparatus prior to mixing the annealing gas with
non-annealing gasses in the exhaust system of the high pressure
annealing process apparatus.
[0024] In another one embodiment, the quality of the separated
annealing gas is tested at least by determining the concentration
of the at least first annealing gas in the separated annealing gas.
In yet another embodiment, on conveying the separated annealing gas
back to the gas separating unit comprises passing the separated
annealing gas though the heat exchange unit again. In one
embodiment, the at least first annealing gas is deuterium. In
another embodiment, the second gas is an inert gas (e.g.,
nitrogen), which is the same gas used in the outer chamber of the
HPAP system. In yet another embodiment, the gas separation unit
heats the gas to a predetermined temperature in order to extract
the at least first annealing gas efficiently. In one embodiment,
the signal about the presence of at least the at least first
annealing gas in the exhaust of the high pressure annealing
processing unit is transmitted by an automated process control
device. In yet another embodiment, the automated process control
device transmits the signal only upon a determining that the
concentration of the at least first annealing gas is higher than a
predetermined threshold.
[0025] In another embodiment, the signal is transmitted from a data
processing system which controls the HPAP system, and is received
by another data processing system that controls the gas reclaiming
system. In another embodiment, the signal transmitted from the HPAP
is derived from a recipe programmed and/or stored in a data
processing system. In this embodiment, when another recipe is used
by the HPAP system, the data processing system determines that a
predetermined amount of the annealing is not used. In such a case,
the HPAP system would not provide the signal to the gas reclaiming
system to reclaim the gas, and the annealing gas would be safely
discarded.
[0026] In yet another embodiment, the second gas is the same gas
which is used as the outer buffer of an HPAP system, the outer
buffer surrounding the at least first annealing gas in an annealing
chamber of the HPAP system. In another embodiment, the purified and
pressurized first annealing gas is stored in a first bank of one or
more vessels, while a second bank of one or more vessels is coupled
to the HPAP system to provide the at least first annealing gas for
an annealing process while reclaimed first annealing gas is stored
in the first bank. In yet another embodiment, the second bank is
switchable with the first bank.
[0027] In one embodiment, a semiconductor wafer processing system
is disclosed, the system comprising an HPAP system having an inner
chamber configured to hold wafers and either an annealing gas or
another gas in the inner chamber, and having an outer chamber which
surrounds the inner chamber and which is configured to hold an
inert gas while the inner chamber holds either the annealing gas or
the another gas. The system includes a gas reclaiming system and a
valve switchably coupling the inner chamber to either an
atmospheric exhaust or to the gas reclaiming system. The system
also includes a data processing system coupled to the valve to
control the valve to switch the valve between atmospheric
exhausting when the another gas was used in the inner chamber and
has reclaiming when the annealing gas was used in the inner
chamber. In one embodiment the gas reclaiming system also includes,
a low pressure gas capture system to retrieve the annealing gas
from the inner chamber, the low pressure gas capturing system
switchably coupled to the inner chamber though the valve. The gas
reclaiming system can further include a gas separation unit coupled
to the low pressure gas capture system, the gas separation unit
configured to separate the annealing gas from a purge gas, and a
purge gas pump coupled to the gas separation unit and configured to
pump the purge gas into the gas separation unit. The gas reclaiming
system also includes a heat exchanger coupled to the gas separation
unit, the heat exchanger configured to cool the annealing gas that
is output from the gas separation unit, and a gas purifier coupled
to the heat exchanger, the gas purifier including one or more
filters. Further the gas reclaiming system, in one embodiment,
includes a bank of one or more storage vessels coupled to the gas
purifier to store purified annealing gas.
[0028] In another embodiment, a semiconductor wafer processing
system is described. The system comprises, a high pressure
annealing system having an inner chamber configured to hold wafers
and either an annealing gas or another gas in the inner chamber,
and having an outer chamber which surrounds the inner chamber and
which is configured to hold an inert gas while the inner chamber
holds either the annealing gas or the another gas. The system
further comprises a gas reclaiming system, a valve switchably
coupling the inner chamber to either an atmospheric exhaust or to
the gas reclaiming system, and a data processing system coupled to
the valve to control the valve to switch the valve between
atmospheric exhausting when the another gas was used in the inner
chamber and gas reclaiming when the annealing gas was used in the
inner chamber. In one embodiment, the gas reclaiming system can
further comprise a gas capture system to retrieve the annealing gas
from the inner chamber, where the gas capturing system is
switchably coupled to the inner chamber though the valve, a gas
separation unit coupled to the gas capture system, the gas
separation unit configured to separate the annealing gas from a
purge gas, a purge gas source coupled to the gas separation unit
and configured to supply the purge gas into the gas separation
unit, a gas purifier coupled to an optional heat exchanger, the gas
purifier including one or more filters, and a bank of one or more
storage vessels coupled to the gas purifier to store purified
annealing gas. In one embodiment, the gas capture system is a low
pressure gas capture system, while in another embodiment the gas
capture system includes a pump that pumps a flushing gas into the
inner chamber of a HPAP system, to flush the annealing gas out of
the inner chamber and into the gas reclaiming system. In one
embodiment, the purge gas source of the gas reclaiming system
comprises a gas pump. In yet another embodiment, the gas reclaiming
system comprises a heat exchanger coupled to the gas separation
unit, the heat exchanger configured to cool the annealing gas that
is output from the gas separation unit. In one embodiment, the gas
separation unit separates the annealing gas using a molecular sieve
system (e.g. permeable membrane). In another embodiment, the gas
separation unit separates the annealing gas using a cryogenic
process system. In yet another embodiment, the gas separation unit
separates the annealing gas using an electrolysis process
system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The present invention is illustrated by way of example and
not limitation in the figures of the accompanying drawings, in
which like references indicate similar elements and in which:
[0030] FIG. 1 shows an exemplary embodiment of a high pressure
substrate annealing chamber and associated components. It uses a
vertical high pressure gas chamber, and it further comprises an
incoming gas delivery system and a gas exhaust/venting system.
[0031] FIG. 2 shows an illustration of an exemplary gas reclaiming
system in association with one or more high pressure annealing
processing units in an embodiment of the present invention.
[0032] FIG. 3 is a flow chart illustrating an exemplary gas
reclaiming system in association with one or more high pressure
annealing processing units in an embodiment of the present
invention.
[0033] FIG. 4 is a flow diagram illustrating an exemplary process
of an interaction of programmable units between the high pressure
annealing process and a gas reclaiming system, as used in an
embodiment of the present invention.
[0034] FIG. 5 is a flow chart illustrating an exemplary process of
an interaction of programmable units between the high pressure
annealing process and a gas reclaiming system, as used in an
embodiment of the present invention.
[0035] FIG. 6 is a flow chart illustrating an exemplary process
used in an embodiment of the present invention of monitoring the
quality of the separated precious gas.
[0036] FIG. 7 illustrates an exemplary system of a programmable
computing device that can, in one embodiment, automatically control
the gas reclaiming system.
DETAILED DESCRIPTION
[0037] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, in which
various exemplary embodiments of the invention are shown. This
invention may, however, be embodied in many different forms and
should not be construed as limited to the embodiments set forth
herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art. Likewise, for
purposes of explanation, numerous specific details are set forth in
the following description in order to provide a thorough
understanding of the present invention. It will be evident,
however, to one skilled in the art that the present invention may
be practiced without these specific details. Reference in the
specification to "one embodiment" or "an embodiment" or "another
embodiment" means that a particular feature, structure, or
characteristic described in conjunction with the embodiment can be
included in at least one embodiment of the invention. The
appearances of the phrase "in one embodiment" in various places in
the specification do not necessarily all refer to the same
embodiment.
[0038] The annealing system described above safely discards
annealing gases after the annealing process is completed. However,
as described above, some precious annealing gasses (e.g.,
deuterium) when discarded results in an expensive annealing
process. The present invention aims to reclaim precious annealing
gasses by providing methods, apparatuses, and systems to reclaim
such precious gasses using a gas reclaiming system as described
herein.
[0039] Deuterium (D.sub.2) is an isotope of hydrogen, having a
proton and one neutron in the nucleus of the atom. D.sub.2 gas is
one of many gasses that can be used HPAP systems to process
semiconductor device wafers. D.sub.2 gas is typically used in
annealing of semiconductor device wafers to improve performance
characteristics. D.sub.2 gas, especially in a high pressure
annealing environment, is known to further enhance the quality of
the semiconductor wafer during the annealing process.
[0040] However, D.sub.2 gas is highly expensive (with costs
typically 30-40 times or more than hydrogen gas). Furthermore, a
typical annealing process in the HPAP system consumes only a
fractional amount of the high pressure deuterium gas ambient in the
process tool, with the remaining gas safely vented off (discarded)
into the atmosphere.
[0041] To overcome this problem a novel integrated abatement
method, apparatus, and system are described herein that will
reclaim D.sub.2 gas from the discarded gas mixture (comprising
deuterium, trace oxygen, and moisture at parts per million (ppm)
levels) from the HPAP system. The reclaimed D.sub.2 can then be
purified (99.9%) and safely pressurized (at pressures at or higher
than 1500 pounds per square inch gauge (psig)) for reuse in the
semiconductor manufacturing (e.g., HPAP annealing) process.
Recovery and reuse can significantly reduce the cost of the
annealing process. Further, the embodiments of any methods
described herein can also be implemented on a non-transitory
computer readable medium comprising instructions that can be
executed by a processing system.
[0042] It should be noted that while this disclosure, using one or
more embodiments, discusses the invention using deuterium as the
precious annealing gas, a person of ordinary skill in the art would
appreciate that any precious annealing gas (that can be used for in
a annealing process) can be reclaimed (recovered) and re-used in
the HPAP system.
[0043] FIG. 2 describes an embodiment 200 of the Gas Reclaiming
System (GRS) 201 in association with one or more HPAP systems 204.
Each of the HPAP systems can be similar to one or more of the high
pressure annealing systems described in U.S. Pat. No. 8,481,123
which is hereby incorporated herein by reference. As shown in FIG.
2, in one embodiment, the HPAP system 100 can be modified to work
in conjunction with GRS 201, as illustrated by HPAP systems 204.
Specifically, HPAP systems 204 have a modified exhaust in which the
annealing has is not mixed with the inert gas (as shown in FIG. 1).
Instead the annealing gas of the inner chamber, and the inert gas
from the outer chamber are released simultaneously into separate
exhaust gas lines 205 and 207. Specifically, the annealing gas can
be released into exhaust gas line 205 from where it can either
connect with GRS 201 (using flow control valve 206) or it can be
directed to an exhaust system 208 connected with the GRS 201, where
the gasses can be mixed with other non-annealing gasses released
from exhaust gas line 207, for safely discarding the gasses into
the atmosphere. The separate exhaust lines 205 and 207 ensures that
only the annealing gas used in the HPAP system 204 is processed for
reclamation and that the inert gas of the outer chamber does not
enter the GRS 201.
[0044] In an alternative embodiment, HPAP system 100 can be
associated with GRS 201 directly (that is, without modifying the
exhaust system described above). In such an embodiment, the
annealing gas of the inner chamber and the inert gas from the outer
chamber of HPAP system 100 are simultaneously released into a
common exhaust line (instead of releasing the gases into separate
exhaust gas lines 205 and 207). The gas mixture from the common
exhaust line can be controlled by flow control valve 206 to either
direct the gas mixture to GRS 201 or to the exhaust system 208
(from where they can be safely discarded).
[0045] Referring back to FIG. 2, in one embodiment, a HPAP system
204 can be controlled by one or more HPAP controller(s) 202. In the
embodiment illustrated in FIG. 2, a HPAP controller is shown to be
controlling the HPAP system(s) 204. The HPAP controller 202 can be
a programmable logic controller. The HPAP system 204 is connected
to the HPAP exhaust 208 via flow control valves 206. In one
embodiment, the HPAP exhaust 208 is integrated within the Gas
Reclaiming System 201 connected via flow control valves 206. The
flow control valves 206, in one embodiment, are computer
controllable and determine the flow of the annealing gas released
from the HPAP system(s) 204 via exhaust gas lines 205, as shown in
the figure. The flow control valves 206 can either vent off the
HPAP annealing gas mixture to the atmosphere using the HPAP exhaust
208, or can flow the gas mixture to GRS 201. In one embodiment,
HPAP controller 202 is associated with gas reclaim system
controller 203 of the gas reclaiming system 201. In another
embodiment, the gas reclaim system controller 203 is a PLC. In this
embodiment, PLC 203, can control the flow control valves 206 and
can direct the annealing gas mixture from the HPAP system(s) 204 to
the gas reclaiming system 201 instead of the HPAP exhaust system
208. In one embodiment, gas reclaim system controller 203 (after
receiving a signal from HPAP controller 202 about the release of a
precious annealing gas (e.g., deuterium) from the HPAP system(s)
204 directs control valves 206 to flow the gasses towards the gas
reclaiming system 201 instead of the HPAP exhaust system 208.
[0046] In one embodiment, HPAP controller 202 can be coupled to a
precious annealing gas detector (not shown) of the HPAP exhaust
208. In another embodiment, the gas detector can be a part of the
HPAP system(s) 204. In another embodiment, either the HPAP
controller 202 or the gas reclaim system controller 203 can made
aware of the annealing gas by a set of programmable instructions
(based on the recipe of the gasses used to anneal the substrate
wafer) being used. In yet another embodiment, a user or operator
can manually instruct the HPAP controller 202 or gas reclaim system
controller 203 to direct the HPAP system(s) 204 annealing gas
exhaust to the GRS 201. In any case, regardless of the embodiment
used, the system can made aware if a precious annealing gas is
being used by any HPAP system 204. If HPAP controller 202 receives
a signal (either via an instruction by a user, program, or
detector) about the presence of a precious annealing gas from the
gas detectors, HPAP controller 202 can transmit a signal to PLC
203. In yet another embodiment, gas reclaim system controller 203
can be automated or manually controlled to direct flow control
valves 206 to the GRS 201, with or without HPAP controller 202. PLC
203, on receiving the signal indicating to reclaim the gas, can
then control and instruct different aspects of the GRS 201 to
perform accordingly, as described herein.
[0047] As shown in FIG. 2 HPAP system 204A is connected to GRS 201
via control valve 206A, through exhaust gas line 205A. HPAP system
204B is connected to GRS 201 via control valve 206B through exhaust
gas line 205B, and HPAP system 204C is connected to GRS 201 via
control valve 206C through exhaust gas line 205C. HPAP system(s)
204A, 204B, and 204C are also connected to HPAP Exhaust 208 through
exhaust gas lines 207A, 207B, and 207C respectively. In this
embodiment, exhaust gas lines 205A, 205B, and 205C are connected to
the inner chamber of HPAP systems 204 and exhaust gas lines 207A,
207B, and 207C are connected to the outer chamber of the HPAP
systems 204. Furthermore, flow control valves 206A, 206B, and 206C,
are connected to HPAP exhaust 208, but can also direct the used
annealing gas mixture (from exhaust gas lines 205) to GRS 201 to
reclaim the gas. Each of valves 206A, 206B, and 206C can be
three-way valves that allow for three possibilities: (a) closed (no
flow through the valve; (b) open in one direction and (c) open in
another direction.
[0048] Using HPAP system 204A as a non-limiting example the
connection of the HPAP system(s) 204 to GRS 201 is described. In
one embodiment, HPAP system 204A is comprised of an inner (process)
and outer (containment) chamber. The outer chamber is supplied with
a high pressure inert gas (e.g., nitrogen). A high pressure
precious annealing gas (e.g., deuterium up to 370 psig (25 ATM)) is
supplied into the inner HPAP chamber from a high pressure deuterium
bulk storage and distribution unit 228. The precious annealing gas
is exhausted from the inner chamber of HPAP system 204A via exhaust
gas lines 205A, while the outer chamber of HPAP system 204A
exhausting the inert gas simultaneously via gas line 207A.
[0049] In one embodiment, flow control valve 206A is used to convey
the ambient pressure exhausted gases of the inner chamber of HPAP
subsystem 204A from gas line 205A to GRS 201 when a previous
annealing gas is known to be directed towards HPAP exhaust 208 via
exhaust gas line 205A. The HPAP system controller 202 transmits a
signal to gas reclaim system controller 203 about the presence of
the precious annealing gas in exhaust gas line 205A, to begin the
gas reclamation process. If however, HPAP controller 202 does not
transmit the signal, the annealing gas is routed through HPAP
exhaust 208. In one embodiment, HPAP exhaust 208 can be a typical
house scrubber. The outer chamber of HPAP system 204A is allowed to
vent the inert gas used during the annealing process via exhaust
gas line 207A, in a typical manner to house scrubber exhaust
208.
[0050] As discussed above, in one embodiment, each HPAP system 204
can have its own HPAP controller 202, each HPAP controller 202 able
to direct each control valve 206 independently. In one embodiment,
a single HPAP controller 202 can control the flow of flow control
valve 206A, flow control valve 206B, and flow control valve 206C,
independently, depending on the annealing gas used in the annealing
process of each HPAP system. Thus, depending on the presence of a
precious annealing gas in the HPAP system(s) 204 a particular HPAP
system 204 may or may not participate in the gas reclaiming
process. For example, if HPAP system 204A is discarding a precious
annealing gas (e.g., deuterium), and it is further known that HPAP
systems 204B and 204C are discarding a non-precious annealing gas
(e.g., hydrogen), then HPAP controller 202 can transmit a signal to
gas reclaim system controller 203 indicating the presence of a
precious annealing gas only at HPAP system 204A. In turn, gas
reclaim system controller 203 can indicate to flow control valve
206A to direct the annealing gas mixture in exhaust gas line 205A
towards the reclaiming process and can also indicate to flow
control valve 206B and 206C to discard the gas mixture in exhaust
gas lines 205 B and 205C to HPAP exhaust 208. Thus, in one
embodiment, selective control of the flow control valves 206 can be
implemented. Each flow control valve 206 can direct the annealing
gas to be reclaimed (from their respective exhaust gas lines 205)
towards reclaim gas line 209 when a precious annealing gas is to be
reclaimed.
[0051] It should be noted, although FIG. 2 shows three HPAP systems
(HPAP system 204A, HPAP system 204B, and HPAPA system 204C), FIG. 2
represents an exemplary system describing the present invention;
the invention is not limited to any specific numbers of HPAP
systems. As disclosed above, gas reclaim system controller 203 of
the gas reclaiming system 201, on receiving a signal from the HPAP
controller can direct flow control valves 206 to flow the annealing
gas mixture to either begin the reclaiming process or could direct
the gas mixture to the HPAP exhaust 208. In one embodiment, prior
to directing flow control valves 206 towards reclaiming the
annealing gas, gas reclaim system controller 203 instructs another
control valve (not shown) to purge the reclaiming gas system 201
with an inert gas (e.g., nitrogen) as shown at 210. Flow control
valve 210 is connected to a nitrogen purge source and can purge GRS
201 at various points in gas reclaiming system 201 to make it safe
for typical required maintenance activities. The nitrogen purge by
flow control valve 210 flushes the gas reclaiming system 201 of any
residual gas that may have already been in the gas reclaiming
system. Other than safety concerns, this can be done to remove any
traces of oxygen or moisture, or any other gas, that may have
remained in the gas reclaiming system. In one embodiment, the
nitrogen purge 210 can be connected to GRS 201 via reclaim gas line
209. After purging the gas reclaiming system 201 with an inert gas,
gas reclaim system controller 203 can direct the precious annealing
gas mixture (containing impurities, like oxygen and moisture) from
flow control valve 206 to be directed into the GRS 201. In one
embodiment, this can be achieved using a vacuum pump 212. It should
be noted, a person of ordinary skill in the art may substitute a
vacuum pump with any other known mechanism to convey the gas
mixture towards the gas reclaiming system 201 components to reclaim
the precious annealing gas.
[0052] As shown in FIG. 2, Vacuum pump 212 is connected with
another flow control valve 213 which can control the direction of
the annealing gas mixture. In one embodiment vacuum pump 212 is a
dry chemical vacuum pump and is used to pump the ambient pressure
exhausted gas line 207 containing deuterium gas to the appropriate
working pressure for the deuterium gas separation unit 214 of the
gas reclaim system 201. The dry chemical vacuum pump 212 can be
configured for safe handling of deuterium gas as per industry
standards. In another embodiment, a dry chemical siphon pump is
used. In yet another embodiment, the pump 212 can be replaced with
a gas pump that pumps an inert gas into the inner chamber of the
HPAP to flush the inner chamber and thereby exhaust the annealing
as into the gas reclaiming system.
[0053] Initially, gas reclaim system controller 203 directs flow
control valve to direct the annealing gas mixture to the gas
separation unit 214. Gas separation unit 214 can be any unit that
can separate the precious annealing gas from the gas mixture, such
as a molecular sieve system, a cryogenic system, or an electrolysis
system. If D.sub.2 is used as an annealing gas, a D.sub.2 gas
separating unit can be employed. The gas separation unit 214
separates the precious annealing gas from the gas mixture
comprising nitrogen and trace amounts of oxygen and water. For
example, when deuterium is used as the annealing gas, depending on
the method of separating the gas, the gas mixture may be heated if
the gas separation unit separates the gas based on permeability of
the gas. Such temperature control can be performed within the gas
separation unit 214. Gas separation unit 214, in one embodiment,
when configured to separate deuterium gas, comprises a heated
palladium coated membrane. The heated palladium coated membrane
separates the deuterium gas from the nitrogen (purge) gas along
with other low level gases that might be present in exhaust line
205.
[0054] The heated palladium coated membrane is an example of a
molecular sieve system that effectively filters one gas from other
gases; other examples of molecular sieve systems can alternatively
be used. In other embodiments, the gas separation unit can be a
cryogenic system that is designed to cause all gases except the
annealing gas (e.g., deuterium) to transition, in phase, to a
liquid at a temperature range in which the annealing gas remains a
gas. In this cryogenic system, the annealing gas can be vented from
the chamber in which the other gases have been liquefied to thereby
separate the annealing gas from the other gases. In yet another
embodiment, the gas separation unit can be an electrolysis system
that burns the annealing gas. For example, when deuterium is used
as the annealing gas in an electrolysis system, deuterium (D.sub.2)
can be burned, in the presence of oxygen (O.sub.2), to produce
heavy water (D.sub.2O) and then the electrolysis system can use a
conventional electrolysis process to separate D.sub.2 from O.sub.2
and D.sub.2O to produce pure D.sub.2. In some embodiments, a gas
separation unit can include a combination of such systems, such as
a combination of a cryogenic system and a molecular sieve system or
a combination of a molecular sieve system and an electrolysis
system, or a combination of a cryogenic system and an electrolysis
system, etc.
[0055] From there, the deuterium gas is then directed to a heat
exchange unit 216 to cool down the gas. Other gases and impurities
in the annealing has mixture are conveyed to vent by the deuterium
gas separation unit 214. Alternate gas separation/purification
techniques may also be utilized for deuterium gas separation unit
214. In one embodiment, heat exchange unit 216 cools the hot
deuterium gas (with temperatures exceeding 200 degree Centigrade)
that is delivered by the deuterium gas separation unit 214, thereby
preparing the re-claimed deuterium gas for next process steps, as
described herein.
[0056] The gas is then directed towards a gas quality monitor 218
which monitors the purity (percentage of the annealing gas in the
gas mixture) of the gas mixture. In one embodiment, the gas quality
monitor transmits data regarding the purity of the annealing gas to
as reclaim system controller 203. In one embodiment, gas quality
monitor 218 measures and reports the deuterium gas percentage and
oxygen ppm level of the re-claimed deuterium gas to gas reclaim
system controller 203. In one embodiment, an additional dry
chemical booster pump maybe used in re-process loop to achieve
required re-process pressures.
[0057] Gas reclaim system controller 203 can be configured to
reprocess the gas, if the percentage of the annealing gas in the
gas mixture is below a predetermined threshold level (that is, if
other gasses, e.g., nitrogen, trace oxygen, water vapor, etc. are
at a higher concentration than expected). Such reprocessing can
occur by diverting the gas towards the gas separation unit 214 via
flow control valves 220 and 213. In one embodiment, gas reclaim
system controller 203 can be configured to determine the
predetermined threshold level, either manually or programmatically.
If the gas quality is not determined to be at the required level,
the reclaimed gas can be reprocessed through the gas separation
unit 212 via flow control valves 220 and 213 to achieve required
gas quality, as described below. In another embodiment, another
device connected to the gas reclaim system controller 203 can
transmit a signal when the desired predetermined threshold level of
the gas purity has been achieved. In yet another embodiment, the
gas quality monitor 216 transmits a signal to gas reclaim system
controller 203 when the predetermined threshold level of the
annealing gas purity has been achieved.
[0058] In the embodiment shown in FIG. 2, if it is determined that
the annealing gas purity is below a predetermined threshold the gas
mixture is conveyed towards flow control valve 213 via flow control
valve 220. Gas reclaim system controller 203 can control the
directional flow of flow control valves 213 and 220 to re-direct
the gas mixture to the gas separation unit 214 for re-processing.
This process can occur in a loop until the desired gas separation
is achieved. For example, in a high pressure annealing process that
uses 99.9% pure deuterium, the re-processing of the gas can occur
until the gas quality monitor detects a deuterium purity of at
least 99.9%. If during the first processing of the annealing gas at
the gas separation unit 214, a gas purity of 99.9% is not achieved,
the gas is reprocessed by the gas separation unit 214. Each time
the gas is processed by the gas separation unit, its quality is
monitored to ensure the gas has reached the desired purity level by
gas quality monitor 218. This ensures that the non-annealing gasses
like nitrogen, oxygen, and any trace amounts of water are
sufficiently removed from the annealing gas being reclaimed. In
another embodiment, gas separation unit 214 can also connected to a
vent to discard the non-annealing gases like nitrogen, oxygen and
trace amounts of water.
[0059] Once the desired percentage threshold of the annealing gas
mixture is achieved, gas reclaim system controller 203 can direct
flow control valve 220 to convey the gas to booster pump 222 where
the gas is pressurized for reuse. In one embodiment, booster pump
222 pressurizes the gas received from the heat exchange unit 216 to
at least 1500 psig. In one embodiment, booster pump 222 is also
connected to the vent system. The pressurized gas is then conveyed
to filter 224 where any impurities in the gas are removed before
diverting the gas purifier system 226 which purifies the
pressurized gas removing any trace impurities that were not
filtered by filter 224. In one embodiment gas purifier 226 is a ppm
level gas purifier and conditions and cleans the reclaimed
pressurized gas making the precious annealing gas once again usable
for the HPAP system(s) 204. In one embodiment, the gas purifier 226
ensures that the annealing gas is purified to achieve a quality of
99.99% purity.
[0060] The pressurized gas is then conveyed to the bulk storage and
distribution unit 228 from where the reclaimed gas can be
resupplied to HPAP system(s) 204. In one embodiment, the bulk
storage and distribution unit 228 consists of several ASME pressure
vessels for volume storage of the reclaimed pressurized annealing
gas delivered from booster pump 222. In another embodiment, the
bulk storage and distribution unit 228 provides auto switching and
pressure monitoring for simultaneous refilling and redistribution
of the reclaimed pressurized annealing gas to the HPAP system(s)
204. In one embodiment, the reclaimed annealing gas is pressurized
(prior to being conveyed to the bulk storage and distribution unit)
to at least 450 psig for delivery to HPAP systems 204.
[0061] In one embodiment, the bulk storage and distribution unit
228 comprises a plurality of banks, each bank including numerous
one or more vessels to store and/or distribute the reclaimed
annealing gas. In one embodiment, each bank can be used for storage
and/or distribution to the HPAP systems(s) 204. In another
embodiment, each bank can function as a storage bank to store the
reclaimed gas, and can also switch to act as a distribution bank to
deliver the reclaimed gas to the HPAP system(s) 204. Such dual
purpose banks are referred as switchable banks herein. As shown in
FIG. 2, bulk storage and distribution unit 228 comprises two
switchable banks 228A and 228B. Bank 228A stores the purified and
pressurized (reclaimed) annealing gas in one or more vessels, while
bank 228B is coupled to the HPAP system(s) 204 to provide the
annealing gas for an annealing process. Banks 228A and 228B are
switchable, that is, either bank can perform the functionality of
storage or distribution, as described herein.
[0062] In one embodiment, the functionality of switchable banks
228A and 228B is controlled by PLC 203. For example, in one
embodiment, PLC 203 can monitor the quantity of the
available/reclaimed annealing gas at bulk storage and distribution
unit 228. If switchable bank 228B, in one embodiment, is unable to
meet the requirements of HPAP system(s) 204 (due to low quantity of
annealing gas available in switchable bank 228B), then PLC 203 can
instruct switchable bank 228A (assuming switchable bank 228A has
reclaimed gas available, when switchable bank 228B is empty or near
empty), to switch roles with switchable bank 228B. In one
embodiment, HPAP controller 202 can transmit a signal to PLC 203
informing that insufficient amount of annealing gas was provided by
GRS 201. In any case, in such a scenario, switchable bank 228A can
assume the distribution of the reclaimed gas to HPAP system(s) 204,
while switchable bank 228B can assume the functionality of storing
the reclaimed gas received from purifier 226. In another
embodiment, the storage and distribution unit 228 can autonomously
(or semi-autonomously) configure the functionality of each bank,
without receiving any instruction from PLC 203. In one embodiment,
either PLC 203 or the storage and distribution unit 228 controls
the switchable functionality of banks 228A and 228B using flow
control valves (not shown).
[0063] In other embodiments, GRS 201 can reclaim the annealing gas
with varying purity levels. In one embodiment, storage and
distribution unit 228 can accommodate collection of the reclaimed
annealing (e.g., deuterium gas) in gas cylinders that can be
shipped to another party (e.g., gas distribution vendor). In a
situation where it is determined that the reclaimed annealing gas
is unsuitable for use in HPAP system(s) 204 (e.g., the gas is of
inferior purity, the quantity of the reclaimed gas is not enough,
etc.), the reclaimed annealing gas can be collected and shipped off
to the other party (e.g., for further processing). In yet another
embodiment, storage and distribution unit 228 can also accommodate
new cylinders of the annealing gas (e.g., fully processed deuterium
(semi grade gas)) from other parties (e.g., gas distribution
vendors). In one embodiment, the new cylinder(s) received from the
other party are certified cylinders, where the certification
assures that the quality/purity of the annealing gas is suitable
for use by HPAP system(s) 204.
[0064] Apart from the added flexibility of operation of the HPAP
system(s) 204, another, optional, incentive of being able to
replace the reclaimed gas cylinders can be to claim a credit (e.g.,
monetary credit, annealing gas quota credit, etc.) by shipping the
reclaimed deuterium gas (with varying purity levels) to the other
parties. Alternatively, if the purity level of the reclaimed
annealing gas is suitable for use by the HPAP system(s) 204, the
cylinders can also be resold to the other parties (and optionally
certified).
[0065] A person of ordinary skill in the art would appreciate that
any of the above stated components of FIG. 2 can be replaced with
equivalents known in the filed of invention. Further, each
component/unit described above can have its own controller
associated with gas reclaim system controller/PLC 203 to convey the
gas throughout the gas reclaiming system 201.
[0066] FIG. 3 illustrates a flow diagram 300 describing an
embodiment of the gas reclaiming system. At block 301, the gas
reclaiming system receives a signal or indication about the
presence of an annealing gas that has to be reclaimed in the HPAP
gas exhaust line 205. As disclosed above, the HPAP controller 202
can be controlled to transmit a signal to gas reclaim system
controller 203 of the gas reclaiming system 201 only when a
precious annealing gas (e.g., deuterium) was just used in an
annealing process or when the gas (e.g., deuterium) is detected in
the exhaust. For example, if a non-precious gas like hydrogen is
present in HPAP exhaust 208 or was just used in a prior process in
the HPAP, then no signal is transmitted to GRS 201. In another
embodiment, HPAP controller 202 only transmits the signal when the
precious annealing gas is detected to be or is known to be (e.g.,
by values in a recipe) above a certain threshold. For example,
based on the recipe used for annealing the substrate wafers, if
only trace amounts of deuterium are used in the recipe, it may be
not useful to reclaim the gas. In such a situation, HPAP controller
202 can be configured (for example, based on the recipe) to not
transmit a signal to the gas reclaiming system 201, and the
annealing gas mixture in exhaust gas line 205 can be safely purged
(using nitrogen) into the atmosphere via HPAP exhaust 208 (rather
than reclaiming the gas mixture). In such a case, the gasses from
exhaust gas line 207 and exhaust gas line 205 would be released
simultaneously, so that the cases mix in HPAP exhaust 208. In one
embodiment, additional nitrogen from the nitrogen purge valve 210
can be used to ensure the gasses are discarded safely into the
atmosphere.
[0067] In one embodiment, when deuterium is used, HPAP controller
202 transmits a signal to gas reclaim system controller 203
connected to GRS 201 to initiate the gas reclamation process. Upon
receiving the signal, as described at block 303, GRS 201 is purged
with an inert gas (e.g., nitrogen) to remove any gas residues or
impurities from the system. At block 305 GRS 201 directs the
annealing gas mixture (including traces of nitrogen, used during
the nitrogen purge) from the reclaimed gas line 209. In another
embodiment, a gas pump can be used to flush the inner chamber of
the annealing gas to thereby exhaust that gas into the gas
reclaiming system. At block 307, the gas mixture is directed
towards the gas separating unit 214 where the annealing gas is
separated from the gas mixture, and the remaining non-annealing
gases are discarded. The gas separation unit 214 may have to heat
(or cool) the gas, as necessary to optimally separate the annealing
gas from the gas mixture. At block 309 the separated annealing gas
is passed through heat exchange unit 216 where the gas is cooled
down (or heated, depending on the process used to separate the
annealing gas). For example, in one embodiment, a deuterium gas
separating unit 214 using a gas separation process involving
palladium membranes may have to maintain the temperature of the gas
at a specific range required to optimally defuse the deuterium
atoms through the palladium membrane. It should be noted though,
each separation unit or method may have its own requirements, and
thus the specific process may be dependent on the conditions
required to optimally separate the precious annealing gas. As such
the specific functionality or mode of operation of any specific
unit/component described herein are to be considered as
non-limiting examples.
[0068] At block 311, the quality of the extracted gas is monitored,
for example by gas quality monitor 218. At block 313, the purity of
the extracted gas is verified and if it is determined that the
annealing gas is below a predetermined threshold (that is, the gas
is not purified enough to be considered as suitable for an
annealing process in the HPAP(s) systems 204), then the gas is
re-directed to the gas separating unit 214 (block 307) to further
separate the annealing gas from the non-annealing gases (e.g.,
nitrogen, and trace amounts of oxygen, and/or water). This process
continues until the quality/purity of the annealing gas is higher
than a predetermined value.
[0069] Once the desired purity of the annealing gas is achieved,
the annealing gas is pressurized, at block 315. In one embodiment,
the annealing gas is pressurized to at least 1500 psig by booster
pump 222. At block 317, the reclaimed annealing gas is filtered and
further purified (e.g., in one embodiment, by filter 224 and
purifier 226 respectively), before storing it for distribution to a
HPAP system (e.g., bulk storage and distribution unit 228) at block
319. At block 321, the reclaimed annealing gas is supplied to the
HPAP system(s) 204. After the annealing gas is used by the HPAP
system(s) 204 and the annealing process is complete, the gas is
released to HPAP exhaust line 205 (block 323). At block 325, HPAP
controller determines the gasses in the exhaust line 205 are to be
reclaimed, and the process can start over again.
[0070] FIG. 4 describes a flow diagram 400 illustrating an
exemplary process of an interaction of programmable units between
the high pressure annealing process and a gas reclaiming system, as
used in an embodiment of the present invention. Block 401
represents the gas mixture (represented by G) in the exhaust gas
line 205 of a high pressure annealing processing system. The
annealing gas information (represented by x) is received by a
computing device associated with the high pressure annealing
processing system, as represented at block 403. Once the gas
concentration information is received, in one embodiment, the
computing device associated with the high pressure annealing
processing system can make a determination whether a signal should
be transmitted to the gas reclaiming system to start reclaiming
that annealing gas. In one embodiment, such a determination can be
made based on a predetermined threshold. For example, when a
mixture of the annealing gasses comprises only 10% deuterium, in
one embodiment, the high pressure annealing processing system may
be configured to not transmit the signal to the gas reclaiming
system, thus not recovering the deuterium. In another embodiment, a
user is given the ability to configure the system determining when
the signal to initiate the gas reclaiming system should be
transmitted. Once a computing device associated with the gas
reclaiming system, as represented at block 405, receives the
signal, the pumping device of the gas reclaiming system can be
instructed to pump the exhaust gases towards the gas reclaiming
system as represented at block 407.
[0071] FIG. 5 describes a flow chart 500 illustrating an exemplary
process of an interaction of programmable units between the high
pressure annealing process and a gas reclaiming system, as used in
at least one embodiment of the present invention. In one
embodiment, at block 501, the high pressure annealing processing
system computes the concentration of the annealing gas (represented
by x) in the gas mixture (represented by G) from the exhaust gas
line 205. In one embodiment, this can be calculated as:
concentration of annealing gas=x/G
[0072] The concentration of the gasses in the exhaust gas line 205,
in one embodiment, can be determined by using gas sensors. At
decision block 503, HPAP controller 202 can determine if x/G is
more than a predetermined threshold. In one embodiment, this
threshold limit can be programmed by an operator or user of the
system. This threshold can be configured differently depending on
the gas being used and after performing a cost-benefit analysis of
reclaiming the gas, as disclosed herein. For example, if precious
annealing gasses like deuterium are only found in trace amounts in
the exhaust system, it may be determined that it would be more
expensive to reclaim the gas than to discard the annealing gas.
Thus, depending on the threshold limits set, in one embodiment,
HPAP controller 202 can be configured to discard the annealing gas
as shown at block 505. If, however, no precious annealing gas is
determined, then the threshold of the gas concentration (x/G) would
not be met, and the annealing gas can be conveyed to the HPAP
exhaust vent as shown at block 505. However, if the concentration
of x/G is determined to be higher than the predetermined threshold,
then HPAP controller 202 can transmit a signal to gas reclaim
system controller 203 indicating the presence of a precious
annealing gas in the exhaust system, as shown at block 507.
[0073] In yet another embodiment, the concentration of the precious
annealing gas in exhaust gas line 205 is known based on the recipe
used to anneal the substrate wafers and thus, HPAP controller 202
can be configured accordingly.
[0074] FIG. 6 describes a flow chart 600 illustrating an exemplary
process used in an embodiment of the present invention of
monitoring the quality of the separated precious annealing gas. In
one embodiment, gas quality monitor 218 computes data including the
concentration of the annealing gas (represented by x) from the
separated gas mixture (represented by Y). Although concentration Y
is expected to substantially equal to the concentration of x, there
can be factors (e.g., temperature of the gas in the gas separation
unit 214), that may result in an inefficient separation of the
annealing gas from the gas mixture. This information can be
received by gas reclaim controller 203, as shown at block 601. In
one embodiment, gas reclaim system controller 203 can compute the
concentration of x in the gas mixture Y, to determine the quality
or purity of the separated gas. If, as shown at 603, it is
determined that the concentration of x is below a predetermined
threshold, gas mixture Y can be reprocessed through the gas
separation unit as shown at 605. This process can be repeated until
the desired purity/quality of the annealing gas is achieved. One
the desired quality of the annealing gas has been achieved, in one
embodiment, gas reclaim system controller 203 can instruct the
booster pump to pressurize the gas to continue the gas reclaiming
process as described herein.
[0075] FIG. 7 is a block diagram illustrating a data processing
system such as a computing system 700 which may be used with one
embodiment of the invention. For example, system 700 may be
implemented as part of a gas reclaiming system. In one embodiment,
system 700 may represent the control panel of the gas reclaiming
system 201. In another embodiment, system 700 can be a programmable
logic controller such as PLC 203 or PLC 405 or HPAP PLC 202 or 403.
In yet another embodiment, system 700 can represent any computing
device that can, directly or indirectly, interact or control the
gas reclaiming system 201. In one embodiment, system 700 can
interact with a controller of HPAP system(s) 204. System 700 may
have a distributed architecture having dispersed units coupled
through a network, or all of its components may be integrated into
a single unit. Computing system 700 may be implemented as part of a
diverse range of products implemented by Poongsan Corporation of
Korea.
[0076] For example, computing system 700 may represents any of data
processing systems described above performing any of the processes
or methods described above. System 700 can include many different
components. These components can be implemented as integrated
circuits (ICs), portions thereof, discrete electronic devices, or
other modules adapted to a circuit board such as a motherboard or
add-in card of the computer system, or as components otherwise
incorporated within a chassis of the computer system. Note also
that system 700 is intended to show a high level view of many
components of the computer system. However, it is to be understood
that additional or fewer components may be present in certain
implementations and furthermore, different arrangement of the
components shown may occur in other implementations. System 700 may
represent a desktop, a laptop, a tablet, a server, a mobile phone,
a programmable logic controller, a personal digital assistant
(PDA), a personal communicator, a network router or hub, a wireless
access point (AP) or repeater, a set-top box, or a combination
thereof.
[0077] In one embodiment, system 700 includes processor 701, memory
703, and devices 705-708 via a bus or an interconnect 77. Processor
701 may represent a single processor or multiple processors with a
single processor core or multiple processor cores included therein.
Processor 701 may represent one or more general-purpose processors
such as a microprocessor, a central processing unit (CPU), or the
like. More particularly, processor 701 may be a complex instruction
set computing (CISC) microprocessor, reduced instruction set
computing (RISC) microprocessor, very long instruction word (VLIW)
microprocessor, or processor implementing other instruction sets,
or processors implementing a combination of instruction sets.
Processor 701 may also be one or more special-purpose processors
such as an application specific integrated circuit (ASIC), a
cellular or baseband processor, a field programmable gate array
(FPGA), a digital signal processor (DSP), a network processor, a
graphics processor, a network processor, a communications
processor, a cryptographic processor, a co-processor, an embedded
processor, or any other type of logic capable of processing
instructions.
[0078] Processor 701, which may be a low power multi-core processor
socket such as an ultra low voltage processor, may act as a main
processing unit and central hub for communication with the various
components of the system. Such processor can be implemented as a
system on chip (SoC). In one embodiment, processor 701 may be an
Intel.RTM. Architecture Core.TM.-based processor such as an i3, i5,
i7 or another such processor available from Intel Corporation,
Santa Clara, Calif. However, other low power processors such as
available from Advanced Micro Devices, Inc. (AMD) of Sunnyvale,
Calif., an ARM-based design from ARM Holdings, Ltd. or a MIPS-based
design from MIPS Technologies, Inc. of Sunnyvale, Calif., or their
licensees or adopters may instead be present in other
embodiments.
[0079] Processor 701 is configured to execute instructions for
performing the operations and methods discussed herein. System 700
further includes a graphics interface that communicates with
graphics subsystem 704, which may include a display controller
and/or a display device.
[0080] Processor 701 may communicate with memory 703, which in an
embodiment can be implemented via multiple memory devices to
provide for a given amount of system memory. As examples, the
memory can be in accordance with a Joint Electron Devices
Engineering Council (JEDEC) low power double data rate
(LPDDR)-based design such as the current LPDDR2 standard according
to JEDEC JESD 207-2E (published April 207), or a next generation
LPDDR standard to be referred to as LPDDR3 that will offer
extensions to LPDDR2 to increase bandwidth. As examples, 2/4/8
gigabytes (GB) of system memory may be present and can be coupled
to processor 87 via one or more memory interconnects. In various
implementations the individual memory devices can be of different
package types such as single die package (SDP), dual die package
(DDP) or quad die package (QDP). These devices can in some
embodiments be directly soldered onto a motherboard to provide a
lower profile solution, while in other embodiments the devices can
be configured as one or more memory modules that in turn can couple
to the motherboard by a given connector.
[0081] Memory 703 can be a machine readable non-transitory storage
medium such as one or more volatile storage (or memory) devices
such as random access memory (RAM), dynamic RAM (DRAM), synchronous
DRAM (SDRAM), static RAM (SRAM), or other types of storage devices
such as hard drives and flash memory. Memory 703 may store
information including sequences of executable program instructions
that are executed by processor 701, or any other device. For
example, executable code and/or data of a variety of operating
systems, device drivers, firmware (e.g., input output basic system
or BIOS), and/or applications can be loaded in memory 703 and
executed by processor 701. An operating system can be any kind of
operating systems, such as, for example, Windows.RTM. Windows
operating system from Microsoft.RTM., Mac OS.RTM./iOS.RTM. from
Apple, Android.RTM. from Google.RTM., Linux.RTM., Unix.RTM., or
other real-time or embedded operating systems such as VxWorks.
[0082] System 700 may further include IO devices such as devices
705-708, including wireless transceiver(s) 705, input device(s)
706, audio IO device(s) 707, and other IO devices 708. Wireless
transceiver 705 may be a WiFi transceiver, an infrared transceiver,
a Bluetooth transceiver, a WiMax transceiver, a wireless cellular
telephony transceiver, a satellite transceiver (e.g., a global
positioning system (GPS) transceiver), or other radio frequency
(RF) transceivers, network interfaces (e.g., Ethernet interfaces)
or a combination thereof.
[0083] Input device(s) 706 may include a mouse, a touch pad, a
touch sensitive screen (which may be integrated with display device
704), a pointer device such as a stylus, and/or a keyboard (e.g.,
physical keyboard or a virtual keyboard displayed as part of a
touch sensitive screen). For example, input device 706 may include
a touch screen controller coupled to a touch screen. The touch
screen and touch screen controller can, for example, detect contact
and movement or break thereof using any of a plurality of touch
sensitivity technologies, including but not limited to capacitive,
resistive, infrared, and surface acoustic wave technologies, as
well as other proximity sensor arrays or other elements for
determining one or more points of contact with the touch
screen.
[0084] Audio IO device 707 may include a speaker and/or a
microphone to facilitate voice-enabled functions, such as voice
recognition, voice replication, digital recording, and/or telephony
functions. Other optional devices 708 may include a storage device
(e.g., a hard drive, a flash memory device), universal serial bus
(USB) port(s), parallel port(s), serial port(s), a printer, a
network interface, a bus bridge (e.g., a PCI-PCI bridge), sensor(s)
(e.g., a motion sensor such as an accelerometer, gyroscope, a
magnetometer, a light sensor, compass, a proximity sensor, etc.),
or a combination thereof. Optional devices 708 may further include
an imaging processing subsystem (e.g., a camera), which may include
an optical sensor, such as a charged coupled device (CCD) or a
complementary metal-oxide semiconductor (CMOS) optical sensor,
utilized to facilitate camera functions, such as recording
photographs and video clips. Certain sensors may be coupled to
interconnect 707 via a sensor hub (not shown), while other devices
such as a keyboard or thermal sensor may be controlled by an
embedded controller (not shown), dependent upon the specific
configuration or design of system 700.
[0085] To provide for persistent storage of information such as
data, applications, one or more operating systems and so forth, a
mass storage (not shown) may also couple to processor 701. In
various embodiments, to enable a thinner and lighter system design
as well as to improve system responsiveness, this mass storage may
be implemented via a solid state device (SSD). However in other
embodiments, the mass storage may primarily be implemented using a
hard disk drive (HDD) with a smaller amount of SSD storage to act
as a SSD cache to enable non-volatile storage of context state and
other such information during power down events so that a fast
power up can occur on RE-initiation of system activities. Also a
flash device may be coupled to processor 701, e.g., via a serial
peripheral interface (SPI). This flash device may provide for
non-volatile storage of system software, including a basic
input/output software (BIOS) as well as other firmware of the
system.
[0086] Note that while system 700 is illustrated with various
components of a data processing system, it is not intended to
represent any particular architecture or manner of interconnecting
the components; as such details are not germane to embodiments of
the present invention. It will also be appreciated that network
computers, handheld computers, mobile phones, and other data
processing systems which have fewer components or perhaps more
components may also be used with embodiments of the invention.
[0087] Thus, methods, apparatuses, and computer readable medium to
reclaim the gas used in semiconductor devices in a high pressure
gas environment have been provided. Although the present invention
has been described with reference to specific exemplary
embodiments, it will be evident that various modifications and
changes may be made to these embodiments without departing from the
broader spirit and scope of the invention as set forth in the
claims. Accordingly, the specification and drawings are to be
regarded in an illustrative rather than a restrictive sense.
* * * * *