U.S. patent application number 11/136469 was filed with the patent office on 2005-09-29 for cleaning apparatus of a high density plasma chemical vapor deposition chamber and cleaning thereof.
Invention is credited to Chin, Kyoung Hwan, Hwang, Sung Joon.
Application Number | 20050211279 11/136469 |
Document ID | / |
Family ID | 19711335 |
Filed Date | 2005-09-29 |
United States Patent
Application |
20050211279 |
Kind Code |
A1 |
Chin, Kyoung Hwan ; et
al. |
September 29, 2005 |
Cleaning apparatus of a high density plasma chemical vapor
deposition chamber and cleaning thereof
Abstract
A cleaning apparatus of a high-density plasma chemical vapor
deposition chamber, and a cleaning method thereof, uniformly and
sufficiently supplies a cleaning gas into a chamber to uniformly
clean the chamber. The cleaning apparatus includes a chamber, an
upper electrode provided in an upper portion of the chamber and
applied with radio frequency energy, a lower electrode provided
below the upper electrode and applied with radio frequency energy,
a chuck provided below the upper electrode and formed thereon with
the lower electrode to fix a wafer thereon, and three or more
cleaning gas nozzles provided at regular intervals on the sidewall
of the chamber around the chuck.
Inventors: |
Chin, Kyoung Hwan;
(Kyonggi-do, KR) ; Hwang, Sung Joon; (Seoul,
KR) |
Correspondence
Address: |
VOLENTINE FRANCOS, P.L.L.C.
Suite 150
12200 Sunrise Valley Drive
Reston
VA
20191
US
|
Family ID: |
19711335 |
Appl. No.: |
11/136469 |
Filed: |
May 25, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11136469 |
May 25, 2005 |
|
|
|
09988302 |
Nov 19, 2001 |
|
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Current U.S.
Class: |
134/94.1 ;
134/1.1; 134/22.1 |
Current CPC
Class: |
C23C 16/4405 20130101;
B08B 7/0035 20130101; H01L 21/67069 20130101 |
Class at
Publication: |
134/094.1 ;
134/001.1; 134/022.1 |
International
Class: |
C25F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 26, 2001 |
KR |
2001-0036524 |
Claims
1-5. (canceled)
6. A method of cleaning a high-density plasma chemical vapor
deposition chamber, comprising: supplying a cleaning gas into the
chamber through cleaning gas nozzles provided at a sidewall of the
chamber so that the cleaning gas fills a space between an upper
electrode and a lower electrode in the chamber, increasing a
density of the cleaning gas at a center portion of the chamber and
projecting the cleaning gas to an upper portion of the chamber; and
controlling an amount of the cleaning gas to be supplied in
response to a thickness of polymer deposited on the sidewall of the
chamber.
7. The cleaning method as claimed in claim 6, wherein the cleaning
gas is projected from the sidewall of the chamber with a
predetermined elevation angle toward the center of the chamber and
around the sidewall of the chamber.
8. A method of cleaning a high-density plasma chemical vapor
deposition chamber, comprising: supplying a cleaning gas into the
chamber through at least three cleaning gas nozzles provided along
a sidewall of the chamber so that the cleaning gas fills a space
between an upper electrode and a lower electrode in the chamber;
and projecting the cleaning gas to an upper portion of the
chamber.
9. The method of claim 8, wherein the cleaning gas is projected
from the sidewall of the chamber with a predetermined elevation
angle toward the center of the chamber.
Description
BACKGROUND OF THE INVENTION
[0001] 1) Field of the Invention
[0002] The present invention relates to a cleaning apparatus of a
high-density plasma chemical vapor deposition chamber and a
cleaning method thereof, and more particularly, to a cleaning
apparatus of a high-density plasma chemical vapor deposition
chamber and a cleaning method thereof by which a cleaning gas
supplied from a radio frequency generator that is provided at a
side wall of a chamber is uniformly sprayed into the chamber,
thereby effectively performing a cleaning process.
[0003] 2) Description of the Related Art
[0004] Generally, the high-density plasma (HDP) chemical vapor
deposition (CVD) process is performed to form insulating layers
such as SiO.sub.2 or BiN films between metal layers by a vapor
deposition method in processes for fabricating semiconductor
devices in the range of approximately 0.5 .mu.m and less. The CVD
process is generally performed together with a chemical mechanical
polishing process, thereby forming an oxide film of high
quality.
[0005] While such processes are performed in a HDP CVD chamber,
polymers in a powder state, which are by-products produced during
the course of the processes, are deposited to a predetermined
thickness on the internal surface of a chamber and the deposited
polymers come off from the internal surface and are accumulated on
a wafer, thereby causing defects in the wafer. Accordingly, the
internal surface of chamber requires a periodical cleaning.
[0006] The structure and operation of the HDP CVD chamber will be
explained with reference to the accompanying drawings, FIG. 1 and
FIG. 2.
[0007] The conventional HDP CVD chamber 10 as shown in FIG. 1
comprises an upper electrode 12 formed at its upper portion in a
bell shape and having high radio frequency (RF) energy applied
thereto, and a lower electrode 14 formed on a chuck 16 for fixing a
wafer at the center part of the chamber 10.
[0008] In addition, a plurality of process gas nozzles 18 are
provided at regular intervals on the sidewall of the chamber 10 for
supplying a process gas to be sprayed into the space between the
upper and lower electrodes 12, 14. A cleaning gas nozzle 20 for
spraying the cleaning gas upward is provided at a predetermined
portion of the chamber 10 that is positioned below the process
nozzle 18.
[0009] The operation of the chamber is as follows. When a wafer is
placed into the chamber 10 and fixed to the lower electrode 14 of
the chuck 16, the process gas is ejected into the space between the
upper electrode 12 and the lower electrode 14, i.e., above the
wafer. And, the radio frequency energy is applied to the upper and
lower electrodes 12, 14 so that the process gas is changed into a
plasma state, i.e., excited. The excited process gas serves to
react with a portion of wafer exposed from a photoresist mask
pattern to make an oxide film.
[0010] At this time, byproducts created during such processes,
i.e., various types of polymers, are continuously deposited on the
internal surface of the chamber 10. As a result, the internal
surface of the chamber 10 should be cleaned periodically,
regardless of whether a wafer is positioned on the lower electrode
14.
[0011] The cleaning process for removing polymers deposited on the
internal sidewall of the chamber 10 is as follows. A predetermined
cleaning gas is first supplied into the chamber 10 through the
cleaning gas nozzle 20 in a state where a wafer is not introduced
into the chamber 10. In such a state, when the RF energy is applied
to the upper and lower electrodes 12, 14, the cleaning gas is
excited into a plasma state. As a result, electrons and ions become
different in their speed, and thereby positive ions are gathered at
the internal sidewall of the chamber 10 to form a direct current
voltage there. The cleaning gas having a DC voltage characteristic
reacts with the polymer deposited on the side wall of the chamber
to remove it by the electric power. In this way, the cleaning
process is performed.
[0012] However, in the conventional prior art, there is a problem
that since only one cleaning gas nozzle for supplying a cleaning
gas into the chamber is provided at one side of the chamber, the
cleaning gas being supplied through the nozzle cannot be uniformly
sprayed into the chamber. In other words, since the cleaning gas is
concentrated in one side of the chamber, a portion of the chamber
adjacent to the nozzle is relatively cleaned more than on a portion
remote from the nozzle.
[0013] Such an incomplete cleaning process causes a decrease in
uniformity of the processes after the cleaning process and causes
contamination and defects in a wafer because polymers concentrated
on the one side of the chamber easily fall off the side wall of the
chamber onto the wafer. As a result, the period of time between the
cleaning processes gradually is decreased, thereby decreasing the
rate of operation of the facility and, accordingly,. the
productivity. In addition, there is a problem that the elements of
the chamber should be disjointed and assembled in order to clean
the internal side of the chamber after a predetermined period
lapses, thereby increasing working hours and decreasing operation
efficiency.
[0014] Particularly, the polymer on the internal side of the
chamber is deposited thicker on the center portion of the dome
shaped upper electrode than on the other portions of the chamber.
In addition, the center portion of the upper electrode is remote
from the cleaning nozzle, such that the cleaning gas cannot reach
as much to clean the center portion of the electrode as the other
portions of the chamber. Accordingly, the polymer on the center
portion of the chamber falls off onto a wafer more than that on the
other portions, thereby causing a failure in process and a defect
in a wafer.
SUMMARY OF THE INVENTION
[0015] To solve the problems as described above, it is an object of
the present invention to provide a cleaning apparatus of a
high-density plasma chemical vapor deposition chamber and a
cleaning method thereof by which a cleaning gas is uniformly and
sufficiently supplied into a chamber to uniformly clean the
chamber, thereby increasing uniformity in processes and preventing
contamination and damage of the wafer.
[0016] It is another object of the present invention to provide a
cleaning apparatus of a high-density plasma chemical vapor
deposition chamber and a cleaning method thereof by which a period
between cleanings of the internal side of a chamber can be extended
thereby increasing the productivity, the operation efficiency, the
quality of semiconductor device fabricated and the like, and
reducing working hours.
[0017] Accordingly, a cleaning apparatus of a high-density plasma
chemical vapor deposition chamber comprises: a chamber; an upper
electrode provided in an upper side of the chamber and applied with
a radio frequency; a lower electrode provided below the upper
electrode and applied with a radio frequency; a chuck provided
below the upper electrode and formed thereon with the lower
electrode to fix a wafer thereon; and three or more cleaning gas
nozzles provided at regular intervals on the sidewall of the
chamber around the chuck.
[0018] In addition, it is preferred that the cleaning gas nozzle be
bent toward the upper center of the chamber relative to an upper
surface of the chuck.
[0019] It is desirable that the cleaning gas nozzle be bent in a
spiral form toward the center portion of the chamber and in a
direction of from the lower portion to the upper portion relative
to the upper surface of the chuck.
[0020] It is preferred that the cleaning gas is NF.sub.3.
[0021] In another aspect, a cleaning method of cleaning a
high-density plasma chemical vapor deposition chamber comprises the
steps of: supplying a cleaning gas into the chamber through
cleaning gas nozzles provided at the sidewall of the chamber so
that the gas fills the space between an upper electrode and a lower
electrode; and controlling the amount of the cleaning gas to be
supplied in response to the thickness of polymer deposited on an
internal sidewall of the chamber.
[0022] The cleaning gas may be ejected with a predetermined
elevation angle toward the center of the chamber from the sidewall
of the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The foregoing and other objects, aspects and advantages will
be better understood from the following detailed description of
preferred embodiments of the invention with reference to the
drawings, in which;
[0024] FIG. 1 is a cross sectional view showing the structure of a
chamber in which a high density plasma chemical vapor deposition is
performed according to the conventional prior art;
[0025] FIG. 2 is a cross sectional overview showing the arrangement
of a cleaning gas supply nozzle in the chamber shown in FIG. 1;
[0026] FIG. 3 is a cross sectional view showing the structure of
chamber in which a high density plasma chemical vapor deposition is
performed according to an embodiment of the present invention;
[0027] FIG. 4 is a cross sectional overview showing the arrangement
of a cleaning gas supply nozzle in the chamber shown in FIG. 3;
and
[0028] FIG. 5 is a plane view showing the arrangement of a cleaning
gas supply nozzle in the chamber shown in FIG. 3 according to
another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Herein after, the present invention will be described in
detail with reference to the accompanying drawings. It should be
noted that like reference numerals are used through the
accompanying drawings for designation of like or equivalent parts
or portion for simplicity of illustration and explanation. Also, in
the following description, specifications will be made to provide a
thorough understanding about the present invention. It is apparent
to one skilled in the art that the present invention can be
achieved without the specifications. There will be omission of
detailed description of well-known functions and structures, to
clarify key points of the present invention.
[0030] FIGS. 3 to 5 show a cleaning apparatus of a high-density
plasma chemical vapor deposition chamber 30 a, 30b, having formed
therein a space housed within a dome shaped upper electrode 12. The
upper electrode 12 is provided in an upper side of the chamber and
applied with radio frequency energy. A lower electrode 14 is
provided below the upper electrode 12 and applied with radio
frequency energy. A chuck 16 is provided below the upper electrode
12 and formed thereon with the lower electrode 14 to fix a wafer
thereon. A plurality of process gas nozzles .18 are provided at
regular intervals on the sidewall of the chamber 30a, 30b so that a
process gas is ejected into the space between the upper electrode
12 and lower electrode 14. Three or more cleaning gas nozzles 32a,
32b are provided at regular intervals on the sidewall of the
chamber 30a, 30b below the process gas nozzle 18 so that a cleaning
gas is ejected into the space between the upper electrode 12 and
lower electrode 14.
[0031] In addition, it is preferred that the cleaning gas nozzle
32a, 32b be bent toward the upper center of the chamber 30a, 30b
relative to an upper surface of the chuck 16 and the lower
electrode 14, so that the cleaning gas is ejected into the space
between the electrodes 12, 14 with a predetermined pressure by a
controller (not shown).
[0032] As shown in FIG. 5, the cleaning gas nozzles 32a,32b may be
bent in a spiral form toward the center portion of the chamber 30a,
30b and in a direction from the lower portion to the upper portion
relative to the upper surface of the chuck 16.
[0033] At this time, the cleaning gas used is NF.sub.3.
[0034] The operation of the chamber is as follows. When a wafer is
placed into the chamber 30a, 30b and fixed to the lower electrode
14 of the chuck 16, the process gas is ejected into the space
between the upper electrode 12 and the lower electrode 14, i.e.,
above the wafer through the process gas nozzle 18. And, the radio
frequency energy is applied to the upper and lower electrodes 12,
14 so that the process gas is changed into a plasma state, i.e.,
excited. The excited process gas serves to react with a portion of
the wafer that is exposed from a photoresist mask pattern to make
an oxide film.
[0035] At this time, byproducts created during such processes,
i.e., various types of polymers, are continuously deposited on the
internal surface of the chamber 30a, 30b. As a result, the internal
surface of the chamber 30a, 30b should be cleaned periodically,
regardless of whether a wafer is positioned on the lower electrode
14.
[0036] The cleaning process for removing polymers deposited on the
internal sidewall of the chamber 30a, 30b is as follows. A
predetermined cleaning gas is first supplied into the chamber 30a,
30b through the cleaning gas nozzles 32a, 32b in a state wherein a
wafer is not introduced into the chamber 30a, 30b. At this time,
since the cleaning gas nozzle 32a, 32b are arranged at regular
intervals around the chuck 16, the cleaning gas is uniformly
sprayed into the chamber 30a, 30b with a predetermined ejection
pressure by a controller.
[0037] The cleaning gas is ejected toward the center of the chamber
30a, 30b and may be first concentrated at the center of the chamber
30a, 30b. However, the cleaning gas is uniformly and continuously
diffused toward the sidewall of the chamber, thereby forming a
uniformed distribution of the cleaning gas in the chamber.
[0038] In addition, as shown in FIG. 5, since each of the cleaning
gas nozzles 32b is bent in a spiral shape relative to the center of
the chuck 16, the cleaning gas ejected through the nozzles rotates
along the internal sidewall of the chamber 30b, thereby being
uniformly distributed in all directions in the chamber 30b. At this
time, the density of the cleaning gas is increased at the center
portion of the chamber 30b by the rotation of the cleaning gas. As
a result, the cleaning gas moves toward the upper portion of the
chamber 30b and reaches the upper center port ion of the dome
shaped-upper electrode 12, thereby being distributed in the whole
space of the chamber 30b, resulting from a diffusion phenomenon and
concentrated density at the center portion of the chamber 30b
although the cleaning gas itself is heavy.
[0039] In such a way, when the cleaning gas is uniformly
distributed in the whole space of the chamber, the RF energy is
applied to the upper and lower electrodes 12, 14 and the cleaning
gas is excited into a plasma state. As a result, electrons and ions
become different in their speed, and thereby positive ions are
collected on the internal sidewall of the chamber 30a, 30b to form
a direct current voltage thereon. The cleaning gas having a DC
voltage characteristic reacts with the polymer deposited on the
internal sidewall of the chamber to remove it by the electric
power. In this way, the cleaning process is performed.
[0040] As shown in FIG. 5, since the cleaning gas is rotated and
ejected in a predetermined direction, even the upper center portion
of the upper electrode 12, where more polymer is deposited than in
the other portions of the upper electrode 12, can be entirely
cleaned by the rotating cleaning gas, thereby increasing the
efficiency in the cleaning operation.
[0041] The ejection pressure of the cleaning gas can be controlled
while the cleaning gas is supplied through the cleaning gas nozzle
30b so that the degree of the cleaning efficiency may be
controlled.
[0042] A plurality of cleaning gas nozzles are uniformly arranged
in the chamber, the cleaning gas is supplied so that the cleaning
gas is uniformly distributed in all directions in the chamber, and
therefore the cleaning process is effectively performed, and a
wafer from being damaged, contaminated and made defective by
polymer.
[0043] While the invention has been described in terms of preferred
embodiments, those skilled in the art will recognize that the
invention can be practiced with modifications within the sprit and
scope of the appended claims.
* * * * *