Chuck equipment

Details Chuck equipment Chuck equipment

2001-01-24

2004-08-24

Sircus, Brian (Department: 2836)

Electricity: electrical systems and devices

Electric charge generating or conducting means

Use of forces of electric charge or field

Reexamination Certificate

active

06781812

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to chuck equipments and more particularly to a chuck equipment which can hold insulating substrates.
2. Description of the Related Art
Conventionally, electrostatic chuck equipments have been used to hold substrates in vacuum apparatuses.
A sputtering apparatus, generally denoted at reference numeral
101
in FIG.
9
(
a
), has a vacuum chamber
110
. On the top side ceiling of the vacuum chamber
110
, there is arranged a target
102
. On the bottom wall side, there is arranged a chuck equipment
104
.
The chuck equipment
104
comprises a dielectric layer
121
and a pair of electrodes
122
1
,
122
2
embedded in said dielectric layer
121
. The chuck equipment
104
also has holes, formed in the dielectric layer
121
,and lift pins
106
are inserted into the holes from below.
The electrodes
122
1
,
122
2
are each connected to a chuck equipment power supply
109
which is arranged outside the vacuum chamber
110
.
When a substrate
112
is placed on the chuck equipment
104
, the substrate
112
opposes in parallel to each of the electrodes
122
1
,
122
2
via the dielectric layer
121
, having a thickness of several tens to several hundreds of micrometers disposed between the substrate
112
and the electrodes
122
1
,
122
2
.
The substrate
112
such as a silicon or gallium arsenide wafer is electrical conductive. Therefore, when the substrate
112
is placed on the chuck equipment
104
, and followed by the power supply
109
turned on, there will be formed a capacitor, designated at reference numeral
125
1
in FIG.
9
(
b
), between one of the electrodes
122
1
and the substrate
112
. There will also be formed another capacitor, designated at reference numeral
125
2
in FIG.
9
(
b
), between the other one of the electrodes
122
2
and the substrate
112
.
These two capacitors
125
1
,
125
2
are connected to the power supply
109
in series with each other. Application of a positive voltage to the one electrode
122
1
and a negative voltage to the other electrode
122
2
would allow the capacitors
125
1
,
125
2
to be electrically charged. This will cause an electrostatic pressure to be generated between the substrate
112
and the one electrode
122
1
and between the substrate
112
and the other electrode
122
2
. The electrostatic attraction thus generated clamps the substrate
112
electrostatically on the surface of the chuck equipment
104
.
With the substrate
112
being clamped electrostatically on the chuck equipment
104
, the substrate
112
is in close contact with the chuck equipment
104
. This provides higher heat conductivity between the substrate
112
and the chuck equipment
104
, thereby making it possible to keep the substrate
112
at a desired temperature using a heating or cooling system equipped with the chuck equipment
104
. Therefore, thin film deposition temperatures can be controlled with accuracy upon sputtering the target
102
to form a thin film on the surface of the substrate
112
.
Upon completion of the formation of the thin film, the voltage applied to the electrodes
122
1
,
122
2
is disconnected therefrom and the electrostatic clamping of the substrate
112
is released. The lift pins
106
are raised and the substrate
112
is lifted from the chuck equipment
104
and the substrate
112
transferred out of the vacuum chamber
110
.
As described above, chuck equipment
104
of the prior-art is adapted to employ the substrate
112
as an electrode to form the capacitors
125
1
,
125
2
between the substrate
112
and the electrodes
122
1
,
122
2
embedded in the chuck equipment
104
, thereby generating an electrostatic pressure. Therefore, it is necessary for the substrate
112
to have electrical conductivity so that the substrate can be electrostatically clamped by the chuck equipment
104
.
However, it has been lately wanted to perform vacuum processing on glass substrates which constitute liquid crystal display devices or plasma display devices while the glass substrate is being electrostatically clamped on the chuck equipment.
Semiconductor substrates formed of a single crystal have electrical conductivity even with a high resistance, thus making it possible to generate an electrostatic pressure for clamping the substrate on the chuck equipment. However, glass substrates have too high insulation to form the capacitors shown in FIG.
9
(
b
), thereby allowing the substrate not to be electrostatically clamped on the chuck equipment
104
.
SUMMARY OF THE INVENTION
The present invention was developed to solve the aforementioned prior-art problems and an object thereof is to provide a chuck equipment which can hold insulating substrates.
The present invention is a chuck equipment comprising a plate-shaped base, a first electrode to which a first voltage is applied, and a second electrode to which a second voltage different from said first voltage in magnitude is applied, the first and second electrodes being insulated from each other and arranged on a surface of the base.
The present invention is the chuck equipment, in which surfaces of the first and second electrodes can be exposed.
The chuck equipment of the present invention is constructed in such a manner that a substrate may be placed on the surface of the chuck equipment on which the first and second electrodes are arranged to cause the substrate to be brought into contact with the first and second electrodes.
The chuck equipment of the present invention is characterized in that the surface of the base is even with the surfaces of the first and second electrodes.
According to the chuck equipment of the present invention, an insulating convexity portion can be arranged between the first and second electrodes.
According to the chuck equipment of the present invention, the first and second electrodes can have a protective film arranged on the surfaces thereof.
The chuck equipment of the present invention may be constructed in such a manner that a substrate may be placed on the surface of the chuck equipment on which the first and second electrodes are arranged to cause the substrate to be brought into contact with the protective film formed on the first and second electrodes.
According to the chuck equipment of the present invention, the first electrode can be spaced apart from the second electrode by 2 mm or less.
According to the chuck equipment of the present invention, the first and second electrodes can be made 4 mm or less in width.
The chuck equipment according to the present invention may comprise a plurality of the first and second electrodes arranged thereon, and regions where the first and second electrodes are alternately arranged.
The chuck equipment according to the present invention may have a third electrode to which a third voltage different from first and second voltages is applied.
Furthermore, the present invention also provides a vacuum processing apparatus comprising a vacuum chamber in which the above-described chuck equipment of the present invention is arranged.
The vacuum processing apparatus according to the present invention may comprise a power supply for establishing an electric field of 1.0×10
6
V/m or greater between the first and second electrodes.
According to the vacuum processing apparatus of the present invention, a protective plate may be arranged around the chuck equipment, and a substrate may be placed on the chuck equipment to cause the substrate to be accommodated in the protective plate.


REFERENCES:
patent: 5103367 (1992-04-01), Horwitz et al.
patent: 5229910 (1993-07-01), Kasahara
patent: 5751537 (1998-05-01), Kumar et al.
patent: 5847918 (1998-12-01), Shufflebotham et al.
patent: WO 00/72376 (2000-11-01), None

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