Fluid sprinkling – spraying – and diffusing – Unitary plural outlet means
Reexamination Certificate
2001-03-19
2002-11-05
Evans, Robin O. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Unitary plural outlet means
C239S550000, C239S553300, C239S566000, C239S589000, C239S601000, C239S600000, C239S390000
Reexamination Certificate
active
06474570
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 89128259, filed Dec. 29, 2000.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a gas distribution plate design. More particularly, the present invention relates to a flexible nozzle system for the gas distribution plate of a plasma reaction chamber.
2. Description of Related Art
Plasma is often employed in the fabrication of semiconductor devices and circuits. For example, in thin film deposition, plasma is used for sputtering and plasma-enhanced chemical vapor deposition (PECVD). Plasma is also one of the principle techniques in dry etching operations. In ion implantation, the ion source of an implanting machine is actually plasma produced by conventional plasma production methods. In addition, the ozone used in a tetra-ethyl-ortho-silicate/ozone (TEOS/O
3
) chemical vapor deposition is also produced from oxygen by a plasma method.
Plasma etching is an anisotropic etching process in which particles are accelerated to a high energy level before being bombarded upon a silicon wafer.
FIG. 1
is a schematic cross-sectional view of a conventional plasma reaction chamber. As shown in
FIG. 1
, gases
100
flow into a reaction chamber
106
via nozzle holes
104
on a gas distribution plate
102
near the top of the chamber. By applying a voltage to the low-pressure gases
100
inside the reaction chamber
106
, neutral gaseous molecules are activated and hence forced to dissociate into ions, radicals, molecular fragments and electrons. These particles are accelerated by electric field to high energy before bombarding against a silicon wafer
108
target.
FIG. 2
is a schematic cross-sectional diagram of a portion of the gas distribution plate shown in FIG.
1
. As shown in
FIG. 2
, the gas distribution plate
200
and the nozzle holes
202
in the plate form an integrated unit. The gas distribution plate
200
is made from aluminum, for example and the nozzle holes
202
are formed by drilling. Furthermore, a layer of anodized film
204
(for example, an aluminum oxide Al
2
O
3
) is formed over the plate
200
by cathode plating. In general, complicated steps are required to fabricate a gas distribution plate having an appropriate nozzle profile for producing a fluid field suitable for a particular application. In addition, particles and high molecular weight polymers can easily accumulate around and between nozzle holes
202
. These accumulated particles are difficult to remove in wet cleaning. Furthermore, since the anodized film
206
inside the nozzle holes
202
is frequently bombarded by high-energy plasma during operation, punch-through of the anodized film
206
may occur. As soon as the anodized film
206
is broken somewhere, the gas distribution plate
200
is no longer usable and needs to be replaced. Hence, the gas distribution plate
200
often has a short life expectancy.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide a flexible nozzle system in the gas distribution plate of a plasma reaction chamber. Utilizing plasticity and plasma-resisting properties of engineering plastic, the nozzles are fabricated using engineering plastic and employ a modular, flexible and removable design.
A second object of this invention is to provide a flexible nozzle system for the gas distribution plate of a plasma reaction chamber. Through shaping the internal profile of the removable nozzles, a desired gas flow pattern inside the reaction chamber is obtained.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a flexible nozzle system for the gas distribution plate of a plasma reaction chamber. The flexible nozzle system on the gas distribution plate includes a metal plate having a plurality of nozzle engagement holes formed by drilling such that a plurality of removable nozzle modules can easily be gripped by the engagement holes.
This invention also provides a type of removable nozzle module having a cap section with screw slot thereon for rotation and an engaging section linked to the cap section. Each removable nozzle module has a nozzle hole in the middle linking up the engaging section and the cap section.
In brief, this invention provides a nozzle system made from engineering plastic for the gas distribution plate of a plasma reaction chamber. Since nozzles made from engineering plastic can be easily shaped and are resistant to plasma corrosion, the nozzle can be easily cleaned. Moreover, each plastic nozzle can be mounted or dismounted separately. Hence, operating cost can be reduced. Furthermore, the nozzle hole can be shaped into a variety of different profiles because engineering plastic is a workable material. In addition, different gaseous flow patterns can be produced by inserting different types of nozzle modules on the gas distribution plate. Ultimately, a uniform gaseous flow can be produced inside the plasma reaction chamber and a higher wafer yield can be obtained.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.
REFERENCES:
patent: 103116 (1870-05-01), Yergason
patent: 2204802 (1940-06-01), Gessler
patent: 3771730 (1973-11-01), Nicoloff et al.
patent: 3834629 (1974-09-01), Hellman et al.
patent: 4699047 (1987-10-01), Lee et al.
patent: 4930706 (1990-06-01), Merlin
Evans Robin O.
J.C. Patents
Macronix International Co. Ltd.
LandOfFree
Flexible nozzle system for gas distribution plate of plasma... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flexible nozzle system for gas distribution plate of plasma..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flexible nozzle system for gas distribution plate of plasma... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2951185