Cleaning and liquid contact with solids – Processes – Including regeneration – purification – recovery or separation...
Reexamination Certificate
1999-07-12
2001-11-13
El-Arini, Zeinab (Department: 1746)
Cleaning and liquid contact with solids
Processes
Including regeneration, purification, recovery or separation...
C134S003000, C134S033000, C134S026000, C134S032000, C134S153000, C134S902000, C216S092000, C216S093000
Reexamination Certificate
active
06315836
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention in related to a fluid processing method of an object to be processed and an apparatus thereof required for the manufacturing process of thin film devices. In particular, the present invention is related to a fluid processing method of an object to be processed and an apparatus thereof suitable for a semiconductor manufacturing process that demands an extremely clean environment.
2. Description of the Related Art
In recent years miniaturization of the structure of thin film devices such as semiconductors, liquid crystal displays and magnetic disks has been progressing and because of the performance of these devices and improved manufacturing yield rates, this is followed by expectations of extremely clean manufacturing processes. Looking at a semiconductor wafer as an example, the size of the foreign matter to be removed for a wafer of 0.2 um or more should be 10 parts or less per wafer, the amount of contaminants of metal ions should be 10
10
atoms/cm
2
or less, and the thickness of the oxide film formed by contact with air should be 1 nm or less.
Furthermore, the mixed production of multiple types of products become unavoidable making necessary equipment that can work with numerous manufacturing processes while putting sheet processing methods which process a plate-shaped object to be processed (hereinafter referred to as simply object to be processed) one wafer at a time.
As a first conventional example,
FIG. 7
shows a substrate process of Japanese Patent Laid-open No. 08-316190. In this conventional example, a plate-shaped object to be processed
53
is fixed to a substrate retention member
54
and also rotates (rotation means not shown in the figure). In order to prevent the front surface of the object to be processed from becoming contaminated due to the turbulent flow produced by the rotation of the plate-shaped object to be processed
53
, the front surface of the plate-shaped object to be processed
53
is covered by a shielding plate
52
(hereinafter referred to front shielding plate) and a fluid process is carried out in which process fluid is injected onto the front surface of the plate-shaped object to be processed
53
only by means of a pure water injection nozzle
51
. In this first conventional example, because a shielding plate (hereinafter referred to rear shielding plate) is not provided on the rear surface of the plate-shaped object to be processed
53
, the following problems occurred.
In addition to the fact that there was no fluid processing of the rear surface, the rear surface of the object to be processed became contaminated due to the turbulent flow generated by the rear surface of the plate-shaped object to be processed
53
. When the rear surface of the object to be processed becomes contaminated, in processes after that the front surfaces of apparatuses such as a transfer arm for the object to be processed that makes contact with the rear surface of the object to be processed and a retention member for the object to be processed (not shown in the figure) undergo transfer contamination and the rear surface of the object to be processed after that becomes even more contaminated reducing the quality of the product. In particular, in processes which are subjected to heat, contaminants developed which were adhering to the rear surface of the object to be processed, reaching the front surface of the object to be processed which in turn caused fatal contamination on the front surface of the object to be processed.
As a second conventional example that can solve this problem,
FIG. 8
shows a processing method of work and apparatus of Japanese Patent Laid-open No.08-78368. In this conventional example, the rear surface of the object to be processed is also covered by a rear shielding plate
62
to prevent the rear surface of the object to be processed from becoming contaminated due to the above-mentioned turbulent flow along with the front and rear surfaces of the object to be processed undergoing fluid processing simultaneously.
However, the object to be processed
64
in this example must be rotated in order to carry out uniform fluid processing on the front surface of the object to be processed. Considering this point, a retention means of the object to be processed
64
is mechanically provided integrally on the rear shielding plate
62
in this second conventional example and the object to be processed
64
and the rear shielding plate
62
are rotated simultaneously with a motor
65
. The fluid is supplied from a supply tank
74
and is then switched by three-way valves
67
,
68
and diverted to front shielding plate
61
and rear shielding plate
62
. Although the connection structure of a supply pipe
76
to the rear shielding plate
62
is not mentioned in the second conventional example, the one rear shielding plate
62
rotates and the other supply pipe
76
is normally fixed. Further, the symbol
70
is a fresh fluid supply portion.
SUMMARY OF THE INVENTION
The following problems were present in the second conventional example however.
At first, because the fluid that processed the rear surface was contaminated, it cannot be re-utilized even it it is collected in a fixed hood
63
. Because of this, fluid that was switched in a three-way valve
69
and collected in the fixed hood
63
had to be discarded. However, if discarded. large quantities of fluid are consumed. Further, looking at the system drawing of
FIG. 8
, although it can be seen that the fluid that processed the rear surface utilizes circulation, because the fluid that processed the rear surface has large contamination, circulation cannot be used even if the fluid is filtered by filters
72
,
75
.
Next, if the fixed supply pipe
76
that supplies fluid is connected to the supply opening provided on the rotating rear shielding plate
62
such that fluid does not leak, the connection portion will rub. Rubbing particles mix with the fluid contaminating the fluid and then pass through the fixed hood
63
, a collection tank
71
, a pump
73
and a supply tank
74
reaching to the front shielding plate
61
and then from the start the rear surface of the object to be processed contaminates the front surface of the object to be processed fatally reducing the quality.
If the fixed supply pipe
76
that supplies fluid and the rotating rear shielding plate
62
are connected such that they do not rub against one another, fluid will leak from the connection portion and in many oases corrosive material contained within the fluid will corrode parts such as the motor
65
.
Thus, a method and an apparatus were not realized which carry out very clean fluid processing on the object to be processed in a sheet process that requires rotation of the object to be processed to allow uniform processing.
The topics of the present invention provide solutions to the above-mentioned problem points of the conventional examples. The first topic provides a fluid processing method of an object to be processed that uses circulation of fluid to allow very clean fluid processing at low-cost. The second topic provides a fluid processing apparatus of an object to be processed that allows very clean fluid processing of the front surface of the object to be processed and the rear surface of the object to be processed. The third topic provides a fluid processing apparatus of an object to be processed that can obtain a very clean object to be processed without generating rubbing particles and without fluid leaks.
The first method of the invention is a fluid processing method of an object to be processed having a front surface and a rear surface that comprises covering said front surface of said object with a front shielding plate and covering said rear surface of said object with a rear shielding plate wherein contamination of said front and rear surface is prevented and wherein, said object is allowed to rotate relative to said front and said rear shielding plates; supplying a fluid between said front surface of said object and said fron
Fujiki Masataka
Morita Fumio
Oka Hitoshi
Yamaoka Akinobu
El-Arini Zeinab
Kokusai Electric Co. Ltd.
Oliff & Berridg,e PLC
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