U.S. patent application number 11/308830 was filed with the patent office on 2007-01-04 for etching apparatus.
Invention is credited to Ming-Tan Hsu, Wei-Jen Tai, Mei-Kuei Tseng, Chuan-Yi Wu.
Application Number | 20070000609 11/308830 |
Document ID | / |
Family ID | 37588105 |
Filed Date | 2007-01-04 |
United States Patent
Application |
20070000609 |
Kind Code |
A1 |
Tai; Wei-Jen ; et
al. |
January 4, 2007 |
ETCHING APPARATUS
Abstract
An etching apparatus, for etching copper or silver, which
includes a hydrogen peroxide tank, an ammonium hydroxide tank, a
water tank, an etching tank, a piping system and a temperature
control device, is provided. The piping system connects the
hydrogen peroxide tank, the ammonium hydroxide tank, the water tank
to the etching tank, and the temperature control device is disposed
around the hydrogen peroxide tank, the ammonium hydroxide tank and
the etching tank to maintain the temperatures of them below the
room temperature and above 12 degree centigrade. An etching process
is also provided. First, hydrogen peroxide and ammonium hydroxide
having a temperature in a temperature-range below the room
temperature and above 12 degree centigrade, is provided. Then,
water, hydrogen peroxide and ammonium hydroxide are mixed to be an
etchant with a temperature maintained in said temperature
temperature-range. Next, the etchant is utilized for etching copper
or silver.
Inventors: |
Tai; Wei-Jen; (Chiayi
County, TW) ; Wu; Chuan-Yi; (Taipei City, TW)
; Tseng; Mei-Kuei; (Taichung County, TW) ; Hsu;
Ming-Tan; (Miaoli County, TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100
ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Family ID: |
37588105 |
Appl. No.: |
11/308830 |
Filed: |
May 12, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11161309 |
Jul 29, 2005 |
|
|
|
11308830 |
May 12, 2006 |
|
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Current U.S.
Class: |
156/345.18 |
Current CPC
Class: |
C23F 1/34 20130101; C23F
1/08 20130101; C23F 1/40 20130101 |
Class at
Publication: |
156/345.18 |
International
Class: |
C23F 1/00 20060101
C23F001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 30, 2005 |
TW |
94122059 |
Claims
1. An etching apparatus for etching copper or silver, comprising: a
hydrogen peroxide tank; an ammonium hydroxide tank; a water tank;
an etching tank; a piping system, configured to make the hydrogen
peroxide tank, the ammonium hydroxide tank and the water tank to be
connected with the etching tank; and a temperature control device,
disposed around the hydrogen peroxide tank, the ammonium hydroxide
tank and the etching tank to maintain the temperatures of them
below the room temperature and above 12 degree centigrade.
2. The etching apparatus according to claim 1, wherein the
temperatures of the hydrogen peroxide tank, the ammonium hydroxide
tank and the etching tank are maintained among 12 degree centigrade
to 18 degree centigrade.
3. The etching apparatus according to claim 1, wherein the
temperature control device is also disposed around the water tank
to maintain the temperature of the water tank below the room
temperature and above 12 degree centigrade.
4. The etching apparatus according to claim 1, wherein the
temperature control device is also disposed around the piping
system to maintain the temperature of the piping system below the
room temperature and above 12 degree centigrade.
5. The etching apparatus according to claim 1, further comprising a
buffer tank disposed between the hydrogen peroxide tank, the
ammonium hydroxide tank, the water tank and the etching tank, and
the hydrogen peroxide tank, the ammonium hydroxide tank and the
water tank are connected to the buffer tank through the piping
system, and the buffer tank is also connected to the etching tank
through the piping system.
6. The etching apparatus according to claim 5, wherein the
temperature control device is also disposed around the buffer tank
to maintain the temperature of the buffer tank below the room
temperature and above 12 degree centigrade.
7. The etching apparatus according to claim 1, further comprising a
pump connected to the piping system.
8. The etching apparatus according to claim 1, further comprising a
flow meter disposed in the piping system between the hydrogen
peroxide tank, the ammonium hydroxide tank, the water tank and the
etching tank.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application of application Ser. No.
11/161,309, filed on Jul. 29, 2005, which claims the priority
benefit of Taiwan patent application serial no. 94122059, filed
Jun. 30, 2005 and is now pending. The entirety of each of the
above-mentioned patent applications is hereby incorporated by
reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an etching apparatus. More
particularly, the present invention relates to an etching apparatus
and an etching process with stable etching rate.
[0004] 2. Description of Related Art
[0005] In semiconductor processing, an etching process is used to
remove a thin film that is not covered by a photoresist layer or a
mask layer by way of chemical reaction or physical phenomenon to
transfer a pattern from a photomask to the thin film. Meanwhile, a
complete removal of a thin film is often accomplished by an etching
process. The current etching techniques in semiconductor processing
are basically divided into wet etching and dry etching, wherein dry
etching mainly relies on the electron beam to perform the etching
of the thin film, and wet etching mainly relies on chemical
reaction to perform the etching of the thin film.
[0006] Copper (Cu) and silver (Ag) are general used as conductive
material in semiconductor elements. Copper film or silver film can
be used to form a patterned conductive layer with multi-function by
wet etching. When the patterned conductive layer in circuit
structure, it could be the conductive wires, electrodes bonding
pads and others. The etchant mixed with hydrogen peroxide (H2O2)
and ammonium hydroxide (NH4OH) is often used to etch the copper
film of the silver film. That is, a substrate with the copper film
of the silver film formed thereon will be immersed in an etching
tank filled with the etchant mixed with hydrogen peroxide and
ammonium hydroxide during the etching of the copper film or the
silver film. Thereafter, chemical reaction occurs between the
etchant and the copper film or the silver film, and the copper film
or the silver film will be etched. For example, the reaction
between the etchant and the silver film is:
2Ag(s)+H2O2(aq)+2H+2Ag+.fwdarw.2H2O(l) (1)
4NH4OH(aq).fwdarw.4NH3(aq)+4H2O(l) (2)
2Ag++4NH3(aq).fwdarw.2Ag(NH3)2 (3) and the total reaction is
(1)+(2)+(3) as follow:
2Ag(s)+H2O2(aq)+2H++4NH4OH(aq).fwdarw.2Ag(NH3)2+6H2O(l) (4)
[0007] General, the etching apparatus for etching silver or copper
includes a hydrogen peroxide tank, an ammonium hydroxide tank, a
water tank, an etching tank and a piping system, wherein the
etching tank is connected to the hydrogen peroxide tank, the
ammonium hydroxide tank and the water tank by the piping system.
Hydrogen peroxide, ammonium hydroxide and deionized water are
delivered to the etching tank by the piping system to form the
etchant for etching the copper film or the silver film.
[0008] However, hydrogen peroxide, ammonium hydroxide and deionized
water are delivered and mixed in the room temperature in the
etching apparatus, wherein the room temperature is between 22
degree centigrade and 23 degree centigrade. Therefore, part of
hydrogen peroxide and ammonium hydroxide will be influenced by the
room temperature and vaporized during delivering, and the
delivering pipes will be block by the bubbles formed from vaporized
hydrogen peroxide and ammonium hydroxide. The suction of hydrogen
peroxide and ammonium hydroxide is difficult in the blocked
delivering pipes, such that the operation reliability of the
conventional etching apparatus will be decreased. Moreover,
hydrogen peroxide and ammonium hydroxide also influenced by the
room temperature and vaporized during mixing, and the concentration
of the etchant is changed consequently. Therefore, the etching rate
of the etchant for copper film and silver film is unstable. Else,
vaporized ammonium hydroxide produces stimulative smell.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is directed to an etching
apparatus and an etching process for avoiding the block in the
piping system while hydrogen peroxide and ammonium hydroxide are
delivered.
[0010] The present invention is also directed to an etching
apparatus and an etching process for avoiding the decrease of the
concentration of the etchant in the etching tank, such that the
etching rate of the etchant for copper or silver will be more
stable.
[0011] The present invention is further directed to an etching
apparatus and an etching process for avoiding the stimulative smell
produced by vaporized ammonium hydroxide.
[0012] In order to achieve the objects mentioned above, the present
invention provides an etching apparatus. The etching apparatus for
etching copper or silver includes a hydrogen peroxide tank, an
ammonium hydroxide tank, a water tank, an etching tank, a piping
system and a temperature control device. The piping system connects
the hydrogen peroxide tank, the ammonium hydroxide tank and the
water tank to the etching tank. The temperature control device is
disposed around the hydrogen peroxide tank, the ammonium hydroxide
tank and the etching tank to maintain the temperatures of them
below the room temperature and above 12 degree centigrade.
[0013] According to an embodiment of the present invention, the
temperatures of the hydrogen peroxide tank, the ammonium hydroxide
tank and the etching tank can be maintained among 12 degree
centigrade to 18 degree centigrade.
[0014] According to another embodiment of the present invention,
wherein the temperature control device can be also disposed around
the water tank to maintain the temperature of the water tank below
the room temperature and above 12 degree centigrade.
[0015] According to another embodiment of the present invention,
wherein the temperature control device can be also disposed around
the piping system to maintain the temperature of the piping system
below the room temperature and above 12 degree centigrade.
[0016] According to an embodiment of the present invention, the
etching apparatus further includes a buffer tank disposed between
the hydrogen peroxide tank, the ammonium hydroxide tank, the water
tank and the etching tank, and the hydrogen peroxide tank, the
ammonium hydroxide tank and the water tank are connected to the
buffer tank through the piping system, and the buffer tank is also
connected to the etching tank through the piping system.
[0017] According to an embodiment of the present invention, wherein
the temperature control device can be also disposed around the
buffer tank to maintain the temperature of the buffer tank below
the room temperature and above 12 degree centigrade.
[0018] According to an embodiment of the present invention, the
etching apparatus further includes a pump connected to the piping
system.
[0019] According to an embodiment of the present invention, the
etching apparatus further includes a flow meter disposed in the
piping system between the hydrogen peroxide tank, the ammonium
hydroxide tank, the water tank and the etching tank.
[0020] In order to achieve the objects mentioned above, the present
invention further provides an etching process. The first step of
the etching process is providing hydrogen peroxide and ammonium
hydroxide, wherein the temperatures of hydrogen peroxide and
ammonium hydroxide are maintained within a temperature-range below
the room temperature and above 12 degree centigrade. Thereafter,
mixing water, hydrogen peroxide and ammonium hydroxide to form an
etchant, and the temperature of the etchant is maintained within
the temperature-range below the room temperature and above 12
degree centigrade. Afterward, etching copper or silver with the
etchant.
[0021] According to an embodiment of the present invention, wherein
the temperature-range is among 12 degree centigrade to 18 degree
centigrade, for example.
[0022] According to an embodiment of the present invention, wherein
the temperature of water could be within the temperature-range
before mixing water, hydrogen peroxide and ammonium hydroxide.
[0023] According to an embodiment of the present invention, wherein
the weight ratio of (hydrogen peroxide: ammonium hydroxide: water)
of the etchant is (3:8:9), for example.
[0024] With the use of the temperature control device in the
present invention for maintaining the temperatures of hydrogen
peroxide and ammonium hydroxide below the room temperature and
above 12 degree centigrade in the etching process, the block in the
piping system can be avoided. Moreover, the vaporizing rates of
hydrogen peroxide and ammonium hydroxide can be decreased to make
the etching rate of the etchant for copper or silver more stable.
Otherwise, the stimulative smell produced by vaporized ammonium
hydroxide could be decreased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0026] FIG. 1 is a flow chart of an etching process according to
one embodiment of the present invention.
[0027] FIG. 2 is a schematic view of an etching apparatus according
to one embodiment of the present invention.
[0028] FIG. 3 is a schematic view of an etching apparatus according
to another one embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0029] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers are used in the drawings and the description
to refer to the same or like parts.
[0030] Referring to FIG. 1, the first step S1 of etching process
100 is providing hydrogen peroxide and ammonium hydroxide, wherein
the temperatures of hydrogen peroxide and ammonium hydroxide are
below the room temperature and above 12 degree centigrade. The
vaporizing rates of hydrogen peroxide and ammonium hydroxide in
step S1 is slower than the vaporizing rates of hydrogen peroxide
and ammonium hydroxide with the room temperature in the
conventional technology without temperature control. In a preferred
embodiment, the temperatures of hydrogen peroxide and ammonium
hydroxide is among 12 degree centigrade to 18 degree
centigrade.
[0031] Thereafter, hydrogen peroxide, ammonium hydroxide and water
with said temperature are mixed to form an etchant in step 2, and
the temperature of the etchant is maintained below the room
temperature and above 12 degree centigrade. In a preferred
embodiment, water used in the etching process 100 could be
deionized water, wherein the weight ratio of (hydrogen peroxide:
ammonium hydroxide: water) of the etchant is (3:8:9), for
example.
[0032] Comparing to the conventional etching process, the
temperature of the etchant in the etching process 100 is maintained
below the room temperature and above 12 degree, such that
vaporizing rates of hydrogen peroxide and ammonium hydroxide in the
etchant are slow. Therefore, the variation of the concentration of
the etchant caused by the vaporization of the components of the
etchant in the conventional etching process will no occur in the
etchant in the etching process 100, and the etchant in the etching
process 100 according to the present invention has more stable
concentration consequently.
[0033] Afterward, the etchant is used for etching the copper film
or the silver film in step S3. With the etchant having stable
concentration, the etching rates for the copper film or the silver
film in the etching process 100 are more stable than that in the
conventional etching process. The detail etching process and the
corresponding etching apparatus will be described with referring to
the following preferred embodiment.
[0034] FIG. 2 is a schematic view of an etching apparatus according
to one embodiment of the present invention. Referring to FIG. 2, an
etching apparatus 200 includes a hydrogen peroxide tank 210, an
ammonium hydroxide tank 220, a water tank 230, an etching tank 240,
a piping system 250 and a temperature control device 260. In a
preferred embodiment, water inside the water tank 230 can be the
deionized water. The hydrogen peroxide tank 210, the ammonium
hydroxide tank 220 and the water tank 230 are connected to the
etching tank 250 with the piping system 250, wherein a valve 252
can be connected to the piping system 250 optionally as need for
adjusting the flow of hydrogen peroxide, ammonium hydroxide or
water. The temperature control device 260 could be the heat
exchanger such as the refrigerating pipe or similar, and the
temperature control device 260 is disposed around the hydrogen
peroxide tank 210, the ammonium hydroxide tank 220 and the etching
tank 240 for maintaining the temperature below the room temperature
and above 12 degree centigrade. Wherein, if the room temperature is
22 degree centigrade (or 23 degree centigrade), the temperatures of
the tanks 210, 222, 240 are controlled between 12 degree centigrade
to 22 degree centigrade (or 12 degree centigrade to 23 degree
centigrade). In a preferred embodiment, the temperatures controlled
by the temperature control device 260 is prefer to be restricted
within 12 degree centigrade to 18 degree centigrade for the etching
apparatus 200 with the more stable etching rate.
[0035] Hydrogen peroxide, ammonium hydroxide and water are
delivered through the piping system 250 from the hydrogen peroxide
tank 210, the ammonium hydroxide tank 220 and the water tank 230 to
the etching tank 240, respectively. Since the temperatures of
hydrogen peroxide tank 210 and ammonium hydroxide tank 220 are
maintained below the room temperature and above 12 degree
centigrade by the temperature control device 260, the bubbles
formed from the vaporized hydrogen peroxide and ammonium hydroxide
during delivering in the etching apparatus 200 can be decreased
with comparing to the conventional etching apparatus, and the
piping system 250 will not be blocked by the bubbles. Moreover, the
etching apparatus of this embodiment further includes flow meter
270 disposed between the hydrogen peroxide tank 210, the ammonium
hydroxide tank 220, the water tank 230 and the etching tank 240 for
controlling the flow of hydrogen peroxide, ammonium hydroxide and
water in the piping system 250.
[0036] In a preferred embodiment, the piping system 250 can be
optionally connected to the pump 254 as need for providing
sufficient driving force in the etching apparatus 200, such that
hydrogen peroxide, ammonium hydroxide and water can be successfully
delivered to the etching tank 240. It should be noted that the
using of the pump 254 is not necessary in the present invention.
Any other components capable of driving the etching apparatus 200
by gravity or other pressurizing method could be disposed in this
system. Otherwise, in another preferred embodiment, the temperature
control device 260 can be further disposed around the water tank
230 to maintain the temperature of the water tank 230 below the
room temperature and above 12 degree centigrade.
[0037] Hydrogen peroxide, ammonium hydroxide and water are mixed in
the etching tank 240 for forming the etchant, and temperature of
the etching tank 240 is maintained below the room temperature and
above 12 degree centigrade by the temperature control device 260.
Therefore, the vaporizing rates of hydrogen peroxide and ammonium
hydroxide in the etching apparatus 200 are slower than that in the
conventional etching apparatus, such that the concentration of the
etchant would no be changed with the vaporization of hydrogen
peroxide and ammonium hydroxide. Thereafter, the copper film or the
silver film is etched with this etchant. With fewer variation of
the concentration of the etchant in the etching apparatus 200, the
etching rate of the etching apparatus 200 will be more stable than
that of the conventional etching apparatus.
[0038] FIG. 3 is a schematic view of an etching apparatus according
to another one embodiment of the present invention. Referring to
FIG. 3, the etching apparatus 200' is similar to the etching
apparatus 200 shown in FIG. 2, the same elements in the etching
apparatus 200' are designated by the same reference numerals as
those of the etching apparatus 200. The difference between the
etching apparatus 200' shown in FIG. 3 and the etching apparatus
200 shown in FIG. 2 is that a buffer tank 280 is disposed between
the hydrogen peroxide tank 210, the ammonium hydroxide tank 220,
the water tank 230 and the etching tank 240 of the etching
apparatus 200'. Wherein, the hydrogen peroxide tank 210, the
ammonium hydroxide tank 220 and the water tank 230 are connected to
the buffer tank 280 through the piping system 250, and the buffer
tank 280 is also connected to the etching tank 240 through the
piping system 250. Consequently, hydrogen peroxide, ammonium
hydroxide and water will be channelled to the buffer tank 280 and
the etching tank 240 sequentially. In detail, the buffer tank 280
is used to pre-mix hydrogen peroxide, ammonium hydroxide and water
or buffer for the etching tank 240. Moreover, the buffer tank 280
can be used to measure the weights of hydrogen peroxide, ammonium
hydroxide and water, so as to provided hydrogen peroxide, ammonium
hydroxide and water with fixed weight ratio into etching tank
240.
[0039] Referring to FIG. 3, in a preferred embodiment, the
temperature control device 260 may further disposed around the
piping system 250 for maintaining the temperatures of hydrogen
peroxide, ammonium hydroxide and water during delivering, such that
the temperatures of hydrogen peroxide, ammonium hydroxide and water
the will not be affected by the environment during delivering. In
another preferred embodiment, the temperature control device 260
can be further disposed around the water tank 230 for maintaining
the temperatures of the water tank 230 below the room temperature
and above 12 degree centigrade. Hence, the temperatures of hydrogen
peroxide, ammonium hydroxide and water will be changed slowly
during mixing. It should be note that the using of the pump 254,
the flow meter 270 and the buffer tank 280 and the location of the
temperature control device 260 in the described two embodiments are
not restrictions for the present invention. The using of said
device and the location of the temperature control device 260 in
the present invention should be designed to meet the practical
requirements.
[0040] In summary, with the using of the temperature control device
in the etching apparatus of the present invention, the temperatures
of hydrogen peroxide and ammonium hydroxide in the etching process
are maintained below the room temperature and above 12 degree
centigrade. Hence, the piping system will not be blocked by the
bubbles, and the decrease of flow or the block caused by the
bubbles can be eliminated from the piping system. The vaporizing
rates of hydrogen peroxide and ammonium hydroxide in the present
invention are lower than that in the conventional technology, and
the etchant with stable concentration can etch the copper film or
the silver film in steady etching rate. Moreover, the vaporization
of ammonium hydroxide in the present invention can be decreased,
and the stimulative smell produced by vaporized ammonium hydroxide
could be decreased consequently.
[0041] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
present invention cover modifications and variations of this
invention provided they fall within the scope of the following
claims and their equivalents.
* * * * *