U.S. patent application number 10/434376 was filed with the patent office on 2003-10-23 for integrated precursor delivery system.
Invention is credited to Bercaw, Craig Alan, Nguyen, Tue.
Application Number | 20030196603 10/434376 |
Document ID | / |
Family ID | 24387617 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030196603 |
Kind Code |
A1 |
Nguyen, Tue ; et
al. |
October 23, 2003 |
Integrated precursor delivery system
Abstract
An integrated precursor delivery system which integrates a
precursor delivery system with a processing chamber is provided for
improving the precursor delivery lines to the processing chamber,
and for keeping the delivery lines intact during servicing the
processing chamber. The apparatus provides an integrated precursor
delivery system mounted on the processing chamber lid with the
chamber lid being removable for allowing manual access to the
inside of the processing chamber. With the precursor delivery
system is in the close vicinity of the processing chamber, the
delivery lines are shortest possible, minimizing the chance of
precursor contamination. With the delivery system and the chamber
lid in one unit, the removal of the chamber lid will no longer
require breaking the delivery lines, leading to better
contamination control. The present invention is particular suitable
for liquid precursors since liquid is much more difficult to
evacuate than gas. The invention further provides a hybrid system
of integrated precursor delivery system and remote precursor
delivery system. For gaseous precursors, especially non-reactive
precursor such as nitrogen, argon, helium, the cleaning of the
delivery line is very simple. Therefore a hybrid system of
integrated and remote precursor delivery systems offers the best
solution, an integrated precursor delivery system for the
difficult-to-clean precursors, and a remote precursor delivery
system for the easy-to-clean precursors.
Inventors: |
Nguyen, Tue; (Fremont,
CA) ; Bercaw, Craig Alan; (Los Gatos, CA) |
Correspondence
Address: |
Tue Nguyen
496 Olive Ave.
Fremont
CA
94539
US
|
Family ID: |
24387617 |
Appl. No.: |
10/434376 |
Filed: |
May 9, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10434376 |
May 9, 2003 |
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09596517 |
Jun 19, 2000 |
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6572706 |
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Current U.S.
Class: |
118/726 ;
118/715 |
Current CPC
Class: |
C23C 16/4485 20130101;
C23C 16/448 20130101 |
Class at
Publication: |
118/726 ;
118/715 |
International
Class: |
C23C 016/00 |
Claims
What is claimed is:
1. An integrated precursor delivery system apparatus which
integrates a precursor delivery system with a processing chamber,
the apparatus comprising: a hollow processing chamber comprising a
removable chamber lid for allowing manual access to the inside of
the processing chamber; a liquid precursor container mounted on the
chamber lid for storing the precursor in bulk liquid form; a
carrier gas system connected to an inlet of the liquid precursor
container; and a precursor delivery line communicated with the
liquid precursor container and the processing chamber; whereby the
precursor delivery line delivers vaporized precursor and carrier
gas from the liquid precursor container to the processing chamber
with the precursor delivery line remaining intact during the
removal of the chamber lid.
2. An apparatus as in claim 23 further comprising a precursor
heater to heat the precursor container.
3. An apparatus as in claim 23 in which the precursor delivery
system further comprises a delivery line heater to heat the
precursor delivery line.
4. An apparatus as in claim 23 in which the precursor delivery
system further comprises a precursor metering device to control the
flow rate of the vaporized precursor and carrier gas.
5. An apparatus as in claim 26 in which the precursor metering
device is a mass flow controller.
6. An apparatus as in claim 23 further comprising a precursor
refilling system for refilling the liquid precursor container.
7. An apparatus as in claim 28 in which the precursor refilling
system comprising flexible refilling lines to accommodate the
movement of the chamber lid.
8. An apparatus as in claim 23 further comprising a plurality of
integrated precursor delivery systems.
9. An apparatus as in claim 23 further comprising a remote
precursor delivery system.
10. An apparatus as in claim 31 in which the remote precursor
delivery system provides gaseous precursor.
11. An apparatus as in claim 31 in which the remote precursor
delivery system comprises flexible lines to accommodate the
movement of the chamber lid.
12. An apparatus as in claim 31 in which the remote precursor
delivery system comprises an o-ring seal between the chamber lid
and the rest of the hollow processing chamber to accommodate the
movement of the chamber lid.
Description
[0001] This application is a continuation-in-part of application
Ser. No. 09/596,517, filed Jun. 19, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates generally to apparatus for
processing of a semiconductor wafer, and more particularly to a
processing chamber with integrated precursor delivery system.
BACKGROUND OF THE INVENTION
[0003] Conventional chemical vapor deposition (CVD) processes use
precursors for the deposition of thin films on an IC substrate.
Precursors can be classified as reactive precursors and
non-reactive precursors. Reactive precursors are chemical species
to undergo a reaction for the processing of the thin film.
Non-reactive precursors are not reactive, and often used to dilute
the reactive precursor or to carry the reactive precursors to the
processing chamber. Such non-reactive precursor is called a carrier
gas. Traditionally, precursors used in semiconductor processes are
gaseous. To broaden the processes, more and more liquid and solid
precursors have been used, especially in the area of metal-organic
chemical vapor deposition (MOCVD). To perform this task, a liquid
precursor is typically turned to vapor, and the vapor is then
decomposed on the substrate. A solid precursor must often be
dissolved into a solvent to form a liquid precursor. Then, the
liquid precursor needs to be converted into vapor phase before
introduction into the deposition zone.
[0004] The simplest form of liquid precursor delivery system is to
draw the vapor from the liquid precursor. This technique works well
with high volatile liquid with high vapor pressure. The liquid
precursor can also be heat up to further increasing the vapor
pressure. The liquid delivery line then needs to be heating up for
preventing re-condensation. Another technique to increase the
amount of vapor precursor of a liquid precursor is bubbling. A
non-reactive precursor, often called a carrier gas, is bubbled
through the liquid precursor. The carrier gas then carries the
vapor precursor to the processing chamber.
[0005] However, to have high deposition rate with low vapor
pressure precursors, a direct liquid injection system is required.
Basic components of a direct liquid injection system are a liquid
delivery line and a vaporizer. The liquid delivery line carries the
liquid precursor from the liquid container to the vaporizer. The
vaporizer converts the liquid precursor into vapor form before
delivering on the wafer substrate. A carrier gas is normally used
in the vaporizer to carry the precursor vapor to the substrate. In
some applications, a reactive precursor could take place of the
carrier gas, performing the carrying function together with a
chemical reaction.
[0006] FIG. 1 shows a prior art gaseous precursor delivery system.
The precursor 13 is stored in gaseous form in the container 12,
often under high pressure. The delivery line 11 is used to take the
precursor out of the container to the processing chamber. A heater
means 14 is used to heat the container 12 to increase the pressure
of the precursor in the container.
[0007] FIG. 2 shows a prior art liquid precursor delivery system.
The liquid precursor 23 is stored in the container 22 and having a
certain vapor precursor 26 co-existing in the container. The heater
means 24 is used to heat the container 22 to increase the precursor
vapor pressure. The precursor delivery line 21 is used to take the
precursor vapor out of the container to the processing chamber. A
second heater means 25 is used to heat the delivery line to prevent
condensation.
[0008] FIG. 3 shows a prior art solid precursor delivery system.
The solid precursor 33 is stored in the container 32 and having a
certain vapor precursor 36 co-existing in the container. The heater
means 34 is used to heat the container 32 to increase the precursor
vapor pressure. The precursor delivery line 31 is used to take the
precursor vapor out of the container to the processing chamber. A
second heater means 35 is used to heat the delivery line to prevent
condensation.
[0009] FIG. 4 shows another prior art liquid precursor delivery
system. The liquid precursor 43 is stored in the container 42 and
having a certain vapor precursor 46 co-existing in the container.
The heater means 44 is used to heat the container 42 to increase
the precursor vapor pressure. A carrier gas 47 is used to bubble
through the liquid precursor to increase the precursor vapor
through the delivery line 41. The precursor delivery line 41 is
used to take the precursor vapor out of the container to the
processing chamber. A second heater means 45 is used to heat the
delivery line to prevent condensation.
[0010] FIG. 5 shows another prior art liquid precursor delivery
system. This system injects the liquid precursor 53 through the
delivery line 51, and then converts the liquid to vapor form in the
vaporizer 58. The liquid precursor 53 is stored in the container 52
and having a certain vapor precursor 56 co-existing in the
container. A carrier gas 57 is used to push the liquid precursor to
the delivery line 51. The precursor delivery line 51 is used to
take the precursor liquid out of the container to the vaporizer 58.
A heater means 59 is used to heat the vaporizer 58 to convert the
liquid precursor to vapor form.
[0011] In these drawings, all controlled valves have been omitted
for clarity. Such valves are used to control the start, stop and
even the flow rate of the precursor.
[0012] The precursor delivery system delivers the precursor vapor
to a processing chamber, typically to the chamber lid, where the
precursor vapor will react at a wafer surface. The precursor
by-products are then pumped out to the exhaust. The precursor
delivery line often has a showerhead to distribute the precursor
vapor evenly on the wafer surface. The precursor delivery system is
mounted in a remote location from the processing chamber, and
having an enclosure with an exhaust fan to prevent the accidental
leakage of the precursor to the environment. Typical processing
chamber has a removable chamber lid to allow manual access to the
inside of the processing chamber such as repair or servicing the
inside of the processing chamber. Therefore the remote precursor
delivery system will need to have the delivery line broken to
remove the chamber lid.
[0013] FIG. 6 shows a prior art remote precursor delivery system.
The precursor 143 is stored in the precursor container 142, and
will travels through the precursor delivery line 141 to the chamber
lid 110. The chamber lid 110 has an inlet port to the inside of the
processing chamber, in this case a showerhead 120. The chamber lid
110 is removable from the chamber body 112 at the connection 114.
Since the delivery line 141 is solid, to remove the chamber lid 110
means breaking the delivery line at the connection 130. Before
breaking the connection 130, the delivery line needs to be clean to
avoid contaminating the environment. After re-connect the
connection 130, the delivery line needs to be clean again to avoid
contaminating the precursor. These cleaning procedure is time
consuming and difficult, especially for liquid precursor. It is
best to replace the liquid delivery line, or at the very least,
clean in solvent and bake out at high temperature to remove
moisture, every time the connection 130 is broken.
[0014] FIG. 7 shows another prior art remote precursor delivery
system. The chamber lid 110 is removable from the chamber body 112
at the connection 114. Connection 114 also includes a mating o-ring
connection 160 between the chamber lid 110 and the chamber body 112
for the delivery line. This way when the chamber lid is removed,
the delivery line is automatically broken. As with FIG. 6
configuration, this configuration also requires cleaning of the
delivery line before and after breaking the connection 160.
[0015] FIG. 8 shows another prior art remote precursor delivery
system. The delivery line 141 includes a loop section 140 to allow
limited movement of the chamber lid 110 without breaking the
delivery line 141. Similarly, the delivery line 141 of FIG. 9
configuration includes a flexible section 150 to allow limited
movement of the chamber lid 110 without breaking the delivery line
141. The advantage of these two configurations is that the delivery
line 141 remains intact during the removal of the chamber lid 110.
The disadvantages are the extra length of the delivery line and its
long term reliability. In fact, the movable delivery line is not
popular in many equipment vendors.
[0016] It would be advantageous if a precursor delivery line
remains intact during the removal of the chamber lid.
[0017] It would be advantageous if a precursor delivery line does
not move during the removal of the chamber lid.
SUMMARY OF THE INVENTION
[0018] Accordingly, an integrated delivery processing chamber
apparatus is provided to maintaining the delivery line intact
during the removal of the chamber lid. In the present invention,
the precursor delivery system is mounted to the chamber lid,
therefore the delivery line and the chamber lid move together as
one unit. An additional benefit of the present invention is the
short delivery line since the precursor delivery system and the
processing chamber is very close to each other.
[0019] The present invention integrated precursor delivery system
apparatus which integrates a precursor delivery system with a
processing chamber comprises:
[0020] a hollow processing chamber comprising a removable chamber
lid for allowing manual access to the inside of the processing
chamber;
[0021] an integrated precursor delivery system mounted to the
chamber lid and operatively connected to the chamber lid, the
precursor delivery system comprising:
[0022] a precursor container for containing the precursor;
[0023] a precursor delivery line;
[0024] whereby the precursor delivery line delivers the precursor
from the precursor container to the processing chamber with the
precursor delivery line remains intact during the removal of the
chamber lid.
[0025] The output of the precursor delivery system is connected to
the chamber lid to provide the precursor vapor to the processing
chamber. In some aspects of the invention, to improve the
uniformity of the precursor distribution, the chamber lid comprises
a showerhead connected to the output of the precursor delivery
system. The precursor delivery system further comprises various
valves to allow the control of the precursor flow.
[0026] In some aspects of the invention, the apparatus further
comprises a system heater means to heat the precursor delivery
system or to heat the precursor delivery line.
[0027] In some aspects of the invention, the precursor is in solid
form, and the precursor delivery line carries only the precursor
vapor from the precursor container to the processing chamber. In
some aspects of the invention, the precursor is in gaseous form,
and the precursor delivery line carries the gaseous precursor from
the precursor container to the processing chamber. In some aspects
of the invention, the precursor is in liquid form, and the
precursor delivery line carries only the precursor vapor from the
precursor container to the processing chamber. Sometimes the
precursor delivery system further comprises a carrier gas system to
help carrying the precursor vapor from the precursor container to
the processing chamber.
[0028] In some aspects of the invention, the precursor is in liquid
form, and the precursor delivery line carries the precursor liquid
from the precursor container to the processing chamber. The
precursor delivery system further comprises a vaporizer to convert
the liquid precursor to vapor form before reaching to the
processing chamber. The precursor delivery system further comprises
a precursor metering device to control the precursor flow rate from
the precursor container to the processing chamber. The precursor
metering device could be a liquid pump, a liquid flow controller to
measure the liquid flow, or a mass flow controller to measure the
gas flow.
[0029] In some aspects of the invention, the precursor delivery
system further comprises a precursor refilling system for refilling
the precursor container. The precursor refilling system could
comprise flexible refilling lines to accommodate the movement of
the chamber lid. Or the precursor refilling system line will need
to be broken to remove the chamber lid. Since the refilling line
will not be used as much as the delivery line, the cleaning of the
refilling line before and after the breakage will not be
frequent.
[0030] In some aspects of the invention, the apparatus further
comprises a plurality of precursor delivery systems. These multiple
precursor delivery systems could share the same output manifold to
the chamber lid. Various processes require multiple precursors and
multiple separate precursor delivery systems.
[0031] In some aspects of the invention, the apparatus further
comprises a remote precursor delivery system. In some aspects of
the invention, the remote precursor delivery system provides
gaseous precursor. For liquid injection, or bubbling system, a
carrier gas is needed. Since the carrier gas is often inert gas,
this line does not need the extensive cleaning before and after the
line breakage. The remote precursor delivery line could comprise
flexible lines or mating o-ring between the chamber lid and the
chamber body to accommodate the movement of the chamber lid.
[0032] In some aspects of the invention, the precursor delivery
system further comprises an enclosure for capturing potential
precursor leakage. The precursors could be toxic, therefore an
enclosure with an exhaust fan helps in the unlikely scenario of
precursor leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 shows a prior art compressed gaseous precursor
delivery system.
[0034] FIG. 2 shows a prior art liquid precursor delivery system
with vapor delivery line.
[0035] FIG. 3 shows a prior art solid precursor delivery system
with vapor delivery line.
[0036] FIG. 4 shows a prior art liquid precursor delivery system
with vapor delivery line and bubbling system.
[0037] FIG. 5 shows a prior art liquid precursor delivery system
with liquid delivery line and vaporizer.
[0038] FIG. 6 shows a prior art remote precursor delivery system
with breakable precursor delivery line.
[0039] FIG. 7 shows another prior art remote precursor delivery
system with breakable precursor delivery line.
[0040] FIG. 8 shows a prior art remote precursor delivery system
with movable precursor delivery line.
[0041] FIG. 9 shows another prior art remote precursor delivery
system with movable precursor delivery line.
[0042] FIG. 10 shows the present invention integrated precursor
delivery system.
[0043] FIG. 11 shows another aspect of the present invention
integrated precursor delivery system.
[0044] FIG. 12 shows another aspect of the present invention
integrated precursor delivery system using liquid precursor
bubbler.
[0045] FIG. 13 shows another aspect of the present invention
integrated precursor delivery system using liquid precursor vapor
phase draw.
[0046] FIG. 14 shows another aspect of the present invention
integrated precursor delivery system using solid precursor
bubbler.
[0047] FIG. 15 shows another aspect of the present invention
integrated precursor delivery system using solid precursor vapor
phase draw.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT
[0048] FIG. 10 shows the present invention integrated precursor
delivery system. The present invention integrates a precursor
delivery system with a processing chamber for the ease of servicing
the processing chamber. Added benefits are shorter delivery line,
and compact and modular system. The invention provides a precursor
delivery system 141, 142, 143 mounted on a removable chamber lid
110. The precursor delivery system comprises a precursor container
142 to contain the precursor 143, and a precursor delivery line 141
to deliver the precursor 143 from the precursor container 142 to
the processing chamber. The processing chamber comprises a chamber
body 112 and a removable chamber lid 110. The chamber lid 110 can
be removed from the processing chamber at the connection 114 for
servicing the inside of the processing chamber. The precursor
delivery line 141 is operatively connected to the chamber lid 110
to delivering the precursor to the inside of the processing
chamber. An optional showerhead 120 is connected to the precursor
delivery line 141 for better precursor distribution. With the
precursor delivery system mounted to the chamber lid, the removal
of the chamber lid will also move the precursor delivery system,
thus the precursor delivery line remains intact.
[0049] FIG. 11 shows another aspect of the present invention
integrated precursor delivery system. The system is a hybrid of
integrated precursor delivery system and remote precursor delivery
system. The cleaning of liquid delivery line to ensure no
contamination is very difficult and time consuming, thus an
integrated precursor delivery system is well suited for liquid
precursors. The major disadvantage of the integrated precursor
delivery system is that there is not enough room at the chamber lid
to accommodate all the delivery components. However, for gaseous
precursors, especially non-reactive precursor such as nitrogen,
argon, helium, the cleaning of the delivery line is very simple. A
few pump/purge cycles of the delivery line should be adequate.
Therefore a hybrid system of integrated and remote precursor
delivery systems offers the best solution, an integrated precursor
delivery system for the difficult-to-clean precursors, and a remote
precursor delivery system for the easy-to-clean precursors. The
integrated liquid precursor delivery system is mounted to the
chamber lid 310 and the remote gaseous precursor delivery systems
provide gaseous precursor 357 and 375 to the chamber lid 310
through the mated o-ring connections 360 and 361 respectively. The
gaseous precursor 357 is a pushing gas, used to push the liquid
precursor 353 in the liquid precursor container 352. The liquid
precursor travels through the liquid precursor delivery line 351 to
a metering device 370 to control the precursor flow rate. The
liquid precursor is then vaporized in the vaporizer 358. The
vaporizer 358 is heated to a vaporizer temperature by a heater 359.
An optional remote precursor 375 is provides to the output of the
vaporizer 358 and to the processing chamber. The precursor delivery
system is enclosed in an enclosure 380 having an exhaust port 384
to protect the environment from accidental release of
precursors.
[0050] FIG. 12 shows another aspect of the present invention
integrated precursor delivery system using liquid precursor
bubbler. The integrated liquid precursor delivery system is mounted
to the chamber lid and the remote gaseous precursor delivery
systems provide gaseous precursor to the chamber lid through the
mated o-ring connections. The gaseous precursor 457 is a carrier
gas, used to bubbling the liquid precursor 453 in the liquid
precursor container 452. The carrier gas and the liquid precursor
vapor travels through the liquid precursor delivery line 451 to a
metering device 470 to control the precursor vapor flow rate. The
liquid precursor vapor is then entering the showerhead to the
chamber body. The liquid precursor delivery line is heated by a
heater 459A. The liquid precursor container 452 is heated by a
heater 459B to a precursor temperature to increase the vapor
pressure. An optional remote precursor can provide precursor mixing
with the liquid precursor vapor to the processing chamber.
[0051] FIG. 13 shows another aspect of the present invention
integrated precursor delivery system using liquid precursor vapor
phase draw. The integrated liquid precursor delivery system
comprising a liquid precursor container 552 containing liquid
precursor 553 and is mounted to the chamber lid. The liquid
precursor vapor is drawn to the liquid precursor delivery line 551
to a metering device 570 to control the precursor vapor flow rate.
The liquid precursor vapor is then entering the showerhead to the
chamber body. The liquid precursor delivery line is heated by a
heater 559A. The liquid precursor container 552 is heated by a
heater 559B to a precursor temperature to increase the vapor
pressure. An optional remote precursor can provide precursor mixing
with the liquid precursor vapor to the processing chamber.
[0052] FIG. 14 shows another aspect of the present invention
integrated precursor delivery system using solid precursor bubbler.
The integrated precursor delivery system is mounted to the chamber
lid and the remote gaseous precursor delivery systems provide
gaseous precursor to the chamber lid through the mated o-ring
connections. The gaseous precursor 657 is a carrier gas, used to
bubbling the solid precursor 653 in the solid precursor container
652. The carrier gas and the solid precursor vapor travels through
the precursor delivery line 651 to a metering device 670 to control
the precursor vapor flow rate. The solid precursor vapor is then
entering the showerhead to the chamber body. The precursor delivery
line is heated by a heater 659A. The solid precursor container 652
is heated by a heater 659B to a precursor temperature to increase
the vapor pressure. An optional remote precursor can provide
precursor mixing with the solid precursor vapor to the processing
chamber.
[0053] FIG. 15 shows another aspect of the present invention
integrated precursor delivery system using solid vapor phase draw.
The integrated precursor delivery system comprising a solid
precursor container 752 containing solid precursor 753 and is
mounted to the chamber lid. The solid precursor vapor is drawn to
the precursor delivery line 751 to a metering device 770 to control
the precursor vapor flow rate. The solid precursor vapor is then
entering the showerhead to the chamber body. The precursor delivery
line is heated by a heater 759A. The solid precursor container 752
is heated by a heater 759B to a precursor temperature to increase
the vapor pressure. An optional remote precursor can provide
precursor mixing with the liquid precursor vapor to the processing
chamber.
[0054] Although a preferred embodiment of practicing the method of
the invention has been disclosed, it will be appreciated that
further modifications and variations thereto may be made while
keeping within the scope of the invention as defined in the
appended claims.
* * * * *