Chemistry: electrical and wave energy – Processes and products – Coating – forming or etching by sputtering
Reexamination Certificate
1999-12-23
2001-05-15
McDonald, Rodney G. (Department: 1753)
Chemistry: electrical and wave energy
Processes and products
Coating, forming or etching by sputtering
C204S298090, C204S298150, C204S298280, C118S730000, C156S345420, C427S255500, C427S569000, C216S071000
Reexamination Certificate
active
06231726
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a plasma processing apparatus, such as a sputtering apparatus for forming a thin film of a target material on a substrate in a vacuum chamber.
2. Description of Prior Art
Conventional sputtering apparatuses have, for example, the following configuration: a target and a substrate are arranged in opposition to each other, a gas for generating a plasma between the two is introduced, a plasma is generated by applying a high frequency or a DC voltage in the cathode portion on which the target is arranged, and ions that are accelerated by the magnetic field collide with the target, so that material is knocked out of the target and deposited on the substrate.
FIG. 3
shows the general configuration of such a sputtering apparatus. In
FIG. 3
, numeral
21
denotes a vacuum chamber, and numeral
22
denotes a cathode portion. A power source
23
is connected to the cathode portion
22
. A target
24
of the material to be vapor-deposited is arranged on the cathode portion
22
, and a substrate
25
is arranged in opposition to the target
24
. Numeral
26
denotes a gas inlet portion, and numeral
27
denotes an exhaust port. The substrate
25
is attached to a holder
28
, which can be rotated with a motor
29
. Moreover, cooling water can be introduced to the holder
28
from a cooling water inlet unit
30
and the substrate
25
can be cooled with this cooling water.
With this configuration, a plasma-generating gas, such as argon gas, is introduced from the gas inlet portion
26
into the vacuum chamber
21
, and exhausted from the exhaust port
27
, so as to attain a predetermined sputtering pressure.
Under a predetermined gas pressure in the vacuum chamber
21
, a high frequency or a DC voltage is applied to the cathode portion
22
with the power source
23
, thereby generating a plasma between the substrate
25
and the target
24
. Argon ions in the plasma are accelerated by the magnetic field and collide with the target
24
, so that target material is knocked out and flies off into the vacuum. The target material is thus deposited on the substrate
25
, whereby a thin film forms thereon. The holder
28
, on which the substrate
25
is held, is rotated by the motor
29
and is cooled by introducing cooling water from a cooling water inlet unit
30
.
The substrate
25
needs to be cooled constantly because its temperature rises as the substrate
25
is exposed to the plasma generated between the target
24
and the substrate
25
in proximity to each other during the sputtering. At the same time the substrate
25
needs to be rotated, so as to improve the uniformity of the thin film distribution on the substrate
25
.
However, in such a conventional sputtering apparatus as described above, the holder
28
has to be provided with a motor
29
and a cooling water inlet unit
30
to rotate the substrate while cooling it. Therefore, there is the problem that a plurality of mechanical units and the space for installing the same are necessary, which poses a limit to making the sputtering apparatus smaller and simpler.
SUMMARY OF THE INVENTION
With the foregoing drawbacks of the prior art in view, it is an object of the present invention to provide a plasma processing apparatus that can be made smaller and simpler.
A plasma processing apparatus in accordance with the present invention generates a plasma in a vacuum chamber to perform surface processing of a substrate that is placed inside the vacuum chamber. The plasma processing apparatus is furnished with a rotation mechanism for rotating a rotary holder, on which the substrate is placed, using a fluid as a motive force for the rotation. The substrate can be rotated simply by providing means for supplying a fluid to the rotation mechanism, so that the sputtering apparatus can be made smaller and simpler.
If the apparatus is configured such that the substrate on the rotary holder is cooled by the fluid that is also the motive force for the rotation, the rotation and the cooling of the substrate can be achieved by the same means.
The rotation mechanism may comprise a blade that is provided inside the rotary holder, and means for supplying and draining a fluid so that a rotation force is exerted on the blade. The rotation and cooling of the holder can be performed by the fluid while in direct contact with the holder, so that the rotation and cooling of the substrate can be achieved with a simple configuration.
The plasma processing apparatus can further include a substrate table that extends from a wall of the vacuum chamber toward the inside of the vacuum chamber, the rotary holder being arranged in a concave portion that is provided in the substrate table and being rotatably supported with its outer periphery sealed. A blade is provided inside the rotary holder, and ports for supplying and draining a fluid are formed in the substrate table, such that the fluid exerts a rotation force on the blade, which not only simplifies the internal configuration considerably, but lets the ports for supplying and draining the fluid simply open onto the outer face of the vacuum chamber, thereby allowing the entire apparatus to be made smaller and simpler.
If the apparatus further includes a device for adjusting the pressure and flow volume of the fluid, rotation of the substrate at the desired rotating speed can be achieved with a simple configuration, so that the film thickness distribution and other parameters can be controlled easily.
It is preferable for the fluid to be cooling water or He gas.
Moreover, it is especially advantageous for the above construction to be applied to a sputtering apparatus, in which a sputtering target is placed on a cathode portion in the vacuum chamber and a substrate is arranged in opposition to the sputtering target, due to the marked effect of rotating and cooling the substrate accordingly achieved.
While novel features of the invention are set forth in the preceding, the invention, both as to organization and content, can be further understood and appreciated, along with other objects and features thereof, from the following detailed description and examples when taken in conjunction with the attached drawings.
REFERENCES:
patent: 3803019 (1974-04-01), Robinson et al.
patent: 4860687 (1989-08-01), Frijlink
patent: 241090 (1986-11-01), None
Mori Nobuyuki
Suemitsu Toshiyuki
Yamamoto Masahiro
Yokoyama Masahide
Matsushita Electric - Industrial Co., Ltd.
McDonald Rodney G.
Price and Gess
LandOfFree
Plasma processing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plasma processing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma processing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2465322