Adhesive bonding and miscellaneous chemical manufacture – Differential fluid etching apparatus – With etchant gas supply or exhaust structure located outside...
Reexamination Certificate
2001-03-19
2003-09-16
McDonald, Rodney G. (Department: 1753)
Adhesive bonding and miscellaneous chemical manufacture
Differential fluid etching apparatus
With etchant gas supply or exhaust structure located outside...
C156S345330, C118S718000, C118S719000, C204S298070, C204S298240, C204S298250, C204S298330, C204S298350
Reexamination Certificate
active
06620288
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate treatment apparatus for forming electronic devices such as a thin film solar battery, particularly to a substrate treatment apparatus characterized in that a gas inlet is provided at a connection tube between a treatment chamber and a buffer chamber.
2. Description of the Related Art
Recently, in view of mass production of thin film solar batteries, a low-cost manufacture process for the thin film solar battery has been expected to be developed. As one means for reducing the manufacture cost, a method of continuously conducting unit operations such as film formation, printing and laser processing in an inline manner while rewinding a rolled-up flexible substrate around another roll is known. Such a method of continuously conveying a flexible substrate from one end to another is referred to as a Roll-to-Roll method. Particularly, the Roll-to-Roll method is generally used as means for continuously forming a semiconductor thin film such as a non-single crystalline silicon film on a flexible substrate (for example, a polymer film, a metal thin film and the like). The non-single crystalline silicon includes amorphous silicon, microcrystalline silicon and thin film polycrytalline silicon.
A Roll-to-Roll film formation apparatus is generally constituted to have a multi-chamber system including a plurality of film formation chambers in addition to a loading chamber and an unloading chamber. It is a long-shaped flexible substrate that is to be dealed in the Roll-to-Roll method film formation apparatus while being continuously conveyed. Accordingly, a gate valve for separating vacuum chambers from each other cannot be used. Therefore, if a film formation process is conducted in a film formation apparatus in which vacuum chambers are provided in a continuous manner, a gas degassed from a flexible substrate and a material gas used in each of the film formation chambers enter an adjacent film formation chamber to cause cross contamination, resulting in degradation of the quality of a semiconductor film.
A conventional method of preventing the cross contamination is disclosed in Japanese Patent Application Laid-Open No. Sho 59-34668. According to this method, a buffer chamber is provided between film formation chambers. An exhaust system, which is independent of each of the film formation chambers, is connected to the buffer chamber so as to obtain a higher degree of vacuum than that in the film formation chambers for controlling the ambience.
FIG. 1
shows a conventional ambience separation method in which a buffer chamber is provided between film formation chambers. A buffer chamber
102
is provided between film formation chambers
101
and
103
. Assuming that ambient pressures in the film formation chambers
101
and
103
are respectively Pc
1
and Pc
2
and an ambient pressure in the buffer chamber
102
is Pb
1
, the relationship: Pc
1
, Pc
2
>Pb
1
is established. It is desirable that a pressure in the buffer chamber
102
is one-tenth or less of that in the film formation chambers
101
and
103
upon film formation. The method described above prevents the cross contamination that a material gas for film formation introduced into each of the film formation chambers enters the adjacent film formation chamber. Although most of the material gas for film formation flowing into the buffer chamber is exhausted from the buffer chamber through an exhaust system of the buffer chamber, a means free path of gas molecules is long due to retention of a high vacuum, resulting in a problem that the ambience control is not sufficient in the buffer chamber by itself. Moreover, since a material gas for film formation flows from the film formation chamber containing a large amount of dust into the buffer chamber, this ambience separation method has such a structure that the dust is likely to be introduced along with the material gas flow. Accordingly, there arises another problem that dust more frequently adheres onto a substrate on which a film is to be formed, such as a flexible substrate.
Another method of preventing the cross contamination is disclosed in Japanese Patent Application Laid-Open No. Hei 9-107116. A connection tube (substantially, a buffer chamber) having an opening of the minimum cross-sectional size that allows a substrate for treatment to pass therethrough is provided between film formation chambers. An inert gas (hydrogen or rare gas) is introduced into the connection tube.
FIG. 2
shows a conventional structure in which an inert gas is introduced through a connection tube that connects film formation chambers with each other for controlling the ambience. An inert gas
208
flows from a connection tube
204
into film formation chambers
201
and
203
. Assuming that ambient pressures in the film formation chambers
201
and
203
are respectively Pc
3
and Pc
4
and an ambient pressure in the connection tube
204
is Ps
1
, the relationship: Ps
1
>Pc
3
, Pc
4
is established. According to this method, ambience control for each of the film formation chambers is effective. Moreover, the adherence of dust onto a substrate on which a film is formed is less. However, the inert gas mixes with a plasma for film formation to alter the quality of a semiconductor film. Although the inert gas is essentially inert, it acts as an impurity in the semiconductor film to alter physical properties such as electrically conductive properties.
SUMMARY OF THE INVENTION
In view of the above problems, the present invention has an object of conducting ambience separation between substrate treatment chambers in a substrate treatment apparatus including a plurality of substrate treatment chambers for continuously treating a substrate so as to prevent cross contamination, thereby preventing the degradation of the quality of a semiconductor film and the substrate treatment capacity due to enter of a gas different from the material gas into the substrate treatment chamber.
The present invention provides a substrate treatment apparatus including at least one treatment chamber and at least one buffer chamber having an exhaust system that is independent of the treatment chamber, wherein a connection tube is provided between the treatment chamber and the buffer chamber; and a gas inlet is provided for the connection tube. The connection tube has an opening of the minimum cross-sectional size that allows a substrate to be treated to pass therethrough.
FIG. 3
shows a structure for separation between substrate treatment chambers in one embodiment of the present invention. A buffer chamber
302
for ambience separation is provided between substrate treatment chambers
301
and
303
. The substrate treatment chambers
301
and
303
and the buffer chamber
302
are connected to each other through connection tubes
304
a
and
304
b
respectively having inlet tubes
307
a
and
307
b
for a substrate treatment gas. The present invention is characterized in that the gas to be introduced through the connection tubes
304
a
and
304
b
is a gas for substrate treatment that is required in an adjacent substrate treatment chamber. For example, an introduced gas
308
is a gas used in the substrate treatment chamber
301
, and an introduced gas
309
is a gas used in the substrate treatment chamber
303
. The present invention makes it possible to treat a highly pure semiconductor film without altering an ambient composition in the substrate treatment chambers. Assuming that ambient pressures in the substrate treatment chambers
301
and
303
are respectively Pc
5
and Pc
6
, ambient pressures in the connection tubes
304
a
and
304
b
are respectively Ps
2
and Ps
3
, and an ambient pressure in the buffer chamber
302
is Pb
2
, the relationship: Ps
2
, Ps
3
>Ps
5
, Ps
6
>Pb
2
is established. Based on this relationship of the pressure, the gas
308
for substrate treatment flows from the connection tube
304
a
into the substrate treatment chamber
301
and the buffer chamber
302
, while the gas
309
for
Kusumoto Naoto
Shinohara Hisato
Yonezawa Masato
Fish & Richardson P.C.
McDonald Rodney G.
Semiconductor Energy Laboratory Co,. Ltd.
LandOfFree
Substrate treatment 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 Substrate treatment apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Substrate treatment apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3082143