Coating apparatus – Gas or vapor deposition – With treating means
Reexamination Certificate
1999-09-07
2002-05-14
Lund, Jeffrie R. (Department: 1763)
Coating apparatus
Gas or vapor deposition
With treating means
C118S728000, C118S500000, C118S503000, C118S504000, C118S505000, C118S7230VE
Reexamination Certificate
active
06386139
ABSTRACT:
FIELD OF THE INTERVENTION
The present invention relates to an apparatus used in the E-Gun evaporating process, and more specifically, to a wafer loading/unloading apparatus for loading/unloading the wafer into/from the clamp ring of the E-gun evaporator.
BACKGROUND OF THE INVENTION
In the semiconductor manufacturing industry, the electron beam evaporation (E-Gun evaporation) technique is widely used and was developed to overcome several known problems in the deposition of the aluminum layer, the nickel layer, the silver layer and other metal materials. This system provides several advantages over known technology. First, the evaporation process has a faster rate to deposit the required metal films. Second, the damage occurring on the wafer surface are not severe after performing the evaporating steps because the collision energy of the metal atoms is lower in the evaporating procedure. In addition, the incorporation of other gases into the deposited films can be prevent effectively because the evaporating procedure is usually done in a vacuum environment. Thus, the purity of the deposited metal films can be promoted considerably. Except for the released thermal energy from the condensation of the deposited films, only the heat radiation from the evaporating source will cause the temperature of the wafer to rise in performing the evaporating procedure. Therefore, the temperature of the wafer can be controlled accurately by using the evaporation process to form the metal films.
Referring to
FIG. 1
, the reactive chamber
10
of the electron-gun evaporator (E-Gun) for depositing metal films on the backside of the wafer is illustrated. Three planetary fixtures
20
with dish shapes are mounted on the chamber
10
for holding the wafers to perform the evaporating procedure. The shafts
28
and the edges of the planetary fixtures
20
are guided and rolled on the first circle rail
24
and the second circle rail
22
respectively. Namely, the planetary fixtures
20
can be rolled along the first circle rail
24
and the second circle rail
22
during the evaporating procedure. Besides, as shown in
FIG. 1
, the wafers can be mounted and fixed on the apertures
26
on the planetary fixtures
20
for depositing metal films onto the backsides of the wafers.
In general, the evaporating source (not shown in
FIG. 1
) is placed in a refractory crucible, and the refractory crucible is located on the bottom of the chamber
10
. Then, the evaporating source is heated by the electron beam until the temperature is raised to the melting point of the evaporating source. The solid source will be evaporated to form the evaporating source atoms, and are deposited on the surface of the wafers above the source to form the metal films. The planetary fixtures
20
will be rotated along the directions of the central vertical axis
15
, and the wafers (not shown in
FIG. 1
) mounted on the planetary fixtures
20
will be rolled along the directions of the shafts
28
of the planetary fixtures
20
. Thus, the films formed on the wafer will have a uniform thickness.
Referring to
FIG. 2
, the method of mounting the wafer
34
onto the planetary fixtures
20
is illustrated. The wafer
34
is put into a clamp ring
30
first, and a top lid
32
is used to cover the wafer
34
and the clamp ring
30
. Then, the clamp ring
30
is mounted into the aperture
26
on the planetary fixture
20
to perform the evaporating procedure. It is noted that the clamp ring
30
has a concave shape, and a hole
36
is formed on the central portion of the clamp ring
30
for exposing the backside of the wafer
34
.
Referring to
FIG. 3
, however, it is not convenient to load the wafer
34
into the concave shaped clamp ring
30
by using a vacuum chucking pen
38
to transit the wafer
34
. As shown in
FIG. 3
, the vacuum chucking pen
38
is tilted firstly at an angle to make the wafer
34
which is held by the vacuum chucking pen
38
in contact with the clamp ring
30
. Then, the operator uses fingers to touch and shift the wafer
34
slightly into the clamp ring
30
, and until then take the vacuum chucking pen
38
out of the clamp ring
30
.
Similarly, after the evaporating procedure is performed, the vacuum chucking pen
38
cannot contact and suck directly the front side (upper surface) of the wafer
34
because there are various devices manufactured on the front side of the wafer
34
. Thus the operator will usually have to touch the backside of the wafer
34
from the hole
36
(as shown in
10
FIG. 2
) of the clamp ring
30
and prop up the wafer
34
to make the edge portion of the wafer
34
out of the clamp ring
30
. Then the vacuum chucking, pen
38
is stretched into the clamp ring
30
for sucking the backside of the wafer
34
. Alternatively, the whole clamp ring
30
can also be overturned to let the wafer
34
pour down for unloading the wafer
34
out of the clamp ring
30
.
However, whether propping up the wafer
34
by fingers to unload the wafer
34
from the clamp ring
30
or turning the clamp ring
30
upside down to pour down the wafer
34
, the wafer
34
usually suffers from the damage such as being cracked or scratched, and this causes a considerable decrease in the yield and performance of the product. So there is still a requirement to have a wafer load/unload apparatus for loading the wafer into the clamp ring or unloading the wafer out of the clamp ring.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a wafer load/unload apparatus for loading the wafer into the clamp ring for performing the evaporating procedure and for unloading the wafer after the evaporating procedure is done.
A wafer load/unload apparatus used to load/unload the wafer into/from the clamp ring for performing the E-Gun evaporation process is disclosed in the present invention. The apparatus comprises a base, a central cylinder and a plurality of peripheral cylinders. The base has an even upper surface, the central cylinder is connected to the upper surface of the base, and the plurality of the peripheral cylinders are connected to the upper surface of the base and are located around the central cylinder. A recessed trench penetrating through sidewalls of the central cylinder is formed on a top surface of the central cylinder. It is noted that the central cylinder can penetrate through a clamp ring, wherein the clamp ring is used to load a wafer for performing the E-Gun evaporating process. The spacing distances between the plurality of peripheral cylinders and the central cylinder are bigger than the width of the clamp ring. The plurality of peripheral cylinders are used to prevent the wafer placed on the top surface of the central cylinder from falling down. It is noted that when loading the wafer into the clamp ring, the clamp ring is first moved downward to hoop the central cylinder and is placed on the upper surface of the base. A vacuum chucking pen attached on a lower surface of the wafer for loading the wafer is then stretched into the recessed trench to transit the wafer onto the top surface of the central cylinder. The clamp ring is next moved upwards to load the wafer which is placed on the top surface of the central cylinder, after the vacuum chucking pen is removed. When unloading the wafer from the clamp ring, the clamp ring containing the wafer is moved downward to hoop the central cylinder and is placed on the upper surface of the base to remain the wafer on the top surface of the central cylinder.
Hung Sheng-Feng
Lee Chun-Chieh
Tseng Hua-Jen
Yang Gwo-Yuh
Lund Jeffrie R.
Mosel Vitelic Inc.
Powell Goldstein Frazer & Murphy
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