Coating apparatus – Gas or vapor deposition – Work support
Reexamination Certificate
1999-07-06
2001-02-20
Lund, Jeffrie R. (Department: 1763)
Coating apparatus
Gas or vapor deposition
Work support
C118S728000, C118S725000, C118S715000, C118S500000
Reexamination Certificate
active
06190460
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for a low pressure chemical vapor deposition, and particularly to an improved apparatus for a low pressure chemical vapor deposition capable of achieving a fabrication of various kinds of thin films having a uniform thickness, preventing breakages of the palts, achieving automation of the system, and combining the use of a low pressure chemical vapor deposition apparatus and a plasma low pressure chemical vapor deposition apparatus.
2. Description of the Conventional Art
As well known to those skilled ill the art, the low pressure chemical vapor deposition (hereinafter called an “LPCVD”) technique has been widely used so as to deposit nitride layers, oxide layers, silicon layers, and the like on a wafer having insulating, dielectric or conductive characteristics.
The deposition apparatus adopted in the LPCVD is directed to depositing a compound-made thin film on a wafer by reacting a chemical source gas in a reactor under a low pressure. This apparatus includes a single wafer input low pressure chemical vapor deposition device for depositing while loading wafer one by one and a vertical type low pressure chemical vapor deposition device for depositing in a state that a plurality of wafers are loaded. In addition, the single wafer input low pressure chemical vapor deposition apparatus has advantages in that it is easy to make the system automated and does not require wide foot point.
Hereinafter, only the single wafer input low pressure chemical vapor deposition apparatus of the conventional low pressure chemical vapor deposition apparatuses will now be explained.
FIG. 1
shows a conventional single wafer input low pressure chemical vapor deposition apparatus, which includes a deposition base
11
having a wafer inlet
11
a
and an outlet
11
b
for discharging reaction substances and opened/closed by an opening/closing plate
11
c
, a reactor
12
disposed above the deposition base
11
for forming a reaction space “S”, a chemical source gas introducer
13
disposed on the upper portion of the reactor
12
, and a substrate
14
which is lifted/lowered within the reaction space “S” by a lifting/lowering ram
15
passing through the opening/closing plate
11
c.
The above-mentioned conventional single wafer input low pressure chemical vapor deposition apparatus is directed to placing a wafer “W” on the susceptor
14
by introducing the wafer “W” through the wafer inlet
11
a
in a state that the susceptor
14
is lowered down to a loading/unloading position lower than the wafer inlet
11
a
, and lifting the susceptor
14
using the lifting/lowering ram
15
, driving a susceptor heating member
16
disposed at the susceptor
14
, and introducing chemical source gas into the reactor
12
through a chemical source gas introducer
13
, whereby the chemical source gas is deposited on the wafer “W” so as to form a compound thin film.
However, the conventional single wafer input low pressure chemical vapor deposition apparatus has disadvantages in that when heat is applied to the susceptor
14
having a wafer “W”, since the heat is not applied to the reactor
12
and its periphery, the thermal effect is deteriorated. Due to the above-mentioned thermal effect, the pin hole is caused at the thin film, and die step coverage is decreased.
In addition, because the conventional single wafer input low pressure chemical vapor deposition apparatus provides the chemical source gas introducer
13
, connected to a lower portion of the introduction tube
13
a
passing through the upper surface of the reactor
12
, and a shower head
13
b
having a plurality of shower apertures so as to simply eject chemical source gas, so that a desired compound mixing cannot be achieved, whereby non-uniform layer can be deposited on the entire wafer surface.
Moreover, in order to overcome the above-mentioned problems, the plasma enhanced low pressure chemical vapor deposition apparatus, which is characterized to reacting the chemical source gas by generating plasma by connecting a plasma generator to the substrate and the electrode of the reactor, was introduced.
As shown in
FIG. 2
, the conventional plasma low pressure chemical vapor deposition apparatus includes a deposition base
21
having an inlet
21
a
formed at one side thereof and an outlet
21
b
formed at the other side thereof, wherein the lower portion thereof is opened/closed by an opening/closing plate
21
c
, a reactor
22
disposed at an upper portion of the deposition base
21
, a chemical source gas introducer
23
disposed at the upper surface of the reactor
22
, a susceptor
24
on which a wafer “W”, which can be lifted/lowered within the reactor
22
by a lifting/lowering ram
25
through the opening/closing plate
21
c
, is mounted, a susceptor heating member
26
disposed at the susceptor
24
, and a plasma generator
27
disposed at the reactor
22
and the susceptor
24
and connected to electrodes
27
a
and
27
b.
The above-mentioned conventional plasma low pressure chemical vapor deposition apparatus is directed to depositing a compound thin film on a wafer “W” by lowering the lifting/lowering ram
25
through the opening/closing plate
21
c
and the susceptor
24
down to a loading/unloading position lower than the inlet
21
a
, by mounting the wafer “W” on the susceptor
24
through the inlet
21
a
, and by generating plasma in the reactor
22
by driving the plasma generator
27
connected to the electrodes
27
a
and
27
b
mounted on an upper portion of the reactor
22
and the susceptor while introducing the chemical source gas into the reactor
22
through the chemical source gas introducer
23
and while heating the susceptor and the wafer “W” by driving the susceptor heating member
26
after lifting the susceptor
24
with the wafer “W” up to the deposition position.
Tile above-mentioned plasma low pressure chemical vapor deposition apparatus has advantages in that it can minimize a characteristic variation of a device due to a deposition temperature by maintaining the process temperature at a low temperature by ionizing the chemical source gas by generating plasma. However, it has disadvantages in that the heat effect is deteriorated because the chemical source gas is introduced into a reaction space “S” in a state that the chemical source gas is not substantially heated since only the susceptor
24
, on which the wafer “W” is mounted, is heated, and its periphery is not substantially heated. In addition, pin hole can occur at the thin film due to the above-mentioned lower heat effect, and the step coverage is deteriorated.
Moreover, because the chemical source gas introducer
23
is simply connected to the introduction tube
23
a
passing through an upper portion of the reactor
22
and a lower portion of the introduction tube
23
a
and includes a shower head
23
b
having a plurality of shower apertures, so that substantial pre-heating and mixing of the introducing chemical source gas are not performed and the wafer “W” which is loaded on the susceptor
24
cannot have substantial flooded by the chemical source gas, the uniformity level of the compound thin film is lowered.
In addition, since the wafer “W” mounted on the susceptor is directly exposed to the lower portion of the shower head, the wafer “W” is not substantially exposed with respect to the chemical source gas, so that the uniformity level of the thin film is lowered.
Moreover, since the waste gas in the chemical reaction is exhausted from the outlet, and the gas in the reactor cannot be exhausted at a desired speed, the remaining gas affects the quality of the thin film.
Referring to
FIGS. 1 and 2
, since the conventional low pressure chemical vapor deposition apparatus and the conventional plasma low pressure chemical vapor deposition apparatus provide the substrates
14
and
24
which are connected to an upper portion of the lifting/lowering rams
15
and
25
lifted/lowered within a range between the loading/unloading position and the deposition positi
Hochberg D. Peter
Holt William H.
Lund Jeffrie R.
Vieyra Katherine R.
LandOfFree
Apparatus for low pressure chemical vapor depostion does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for low pressure chemical vapor depostion, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for low pressure chemical vapor depostion will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608753