Coating apparatus – Gas or vapor deposition – With treating means
Reexamination Certificate
2000-06-19
2003-06-03
Bueker, Richard (Department: 1763)
Coating apparatus
Gas or vapor deposition
With treating means
C118S715000, C118S726000
Reexamination Certificate
active
06572706
ABSTRACT:
FIELD OF THE INVENTION
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
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.
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.
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 is 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.
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.
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.
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.
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.
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.
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.
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 are 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.
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 a 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.
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
.
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
Bercaw Craig Alan
Nguyen Tue
Bueker Richard
Nguyen Tue
Simplus Systems Corporation
LandOfFree
Integrated precursor delivery system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Integrated precursor delivery system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated precursor delivery system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3102719