Substrate dechucking device and substrate dechucking method

Details Substrate dechucking device and substrate dechucking method Substrate dechucking device and substrate dechucking method

1999-11-19

2002-09-10

Mills, Gregory (Department: 1763)

Coating apparatus

Gas or vapor deposition

Work support

C118S7230ER, C156S345420, C438S716000

Reexamination Certificate

active

06447613

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate dechucking device and substrate dechucking method for dechucking from the substrate holder a substrate held in a substrate holder in a plasma processing apparatus, which is used in a thin film formation process, or a patterning process in the manufacture of a semiconductor device, liquid crystal display panel, or photovoltaic cell.
2. Description of the Related Art
Efforts have been vigorously undertaken in recent years to realize plasma processing apparatus that are more precise, faster, capable of handling larger surface areas, produce less damage, and are highly reliable, in order to produce devices with higher functionality, while lowering the processing costs thereof. Uniform, accurate control of the temperature of a substrate on the inner surface of this substrate is required in particular for achieving film uniformity on a substrate in the process of forming a film on a substrate, and for ensuring dimensional accuracy in a dry etching process, which is used in pattern transfer. Consequently, as means for controlling substrate temperature, plasma processing apparatus, which make use of either mechanical suctions, or electrostatic suction electrodes, are coming into use.
A conventional plasma processing apparatus, which utilizes an electrostatic suction electrode, will be described hereinbelow. Examples of conventional plasma processing apparatus are disclosed in Japanese Patent Application Laid-open Nos. 63-72877, 2-7520, 3-102820, 4-100257, and 10-189544.
FIG. 2
is a cross-sectional view of the reaction chamber of a plasma processing apparatus shown in the above-mentioned Japanese Patent Application Laid-open No. 4-100257. This conventional plasma processing apparatus
30
will be explained hereinbelow.
In
FIG. 2
,
31
is a vacuum chamber, this vacuum chamber
31
has a gas inlet
31
a,
which is connected to an etching gas injecting device
32
, and an exhaust opening
31
b
connected to an evacuation device
33
. Inside the vacuum chamber
31
there is provided an electrostatic suction electrode
35
, which has a surface that is an insulating layer, and has a pair of internal electrodes (not shown in the figure) on the inside, and which electrostatically sucks a to-be-processed substrate (hereafter referred to simply as substrate)
34
. To the electrostatic suction electrode
35
are connected a direct current power supply
36
for electrostatically sucking a substrate
34
, and a high frequency power supplying device
37
. Furthermore, the direct current power supply
36
has a switching mechanism
38
for inversion.
Further, in the vacuum chamber
31
, a quartz glass plate
39
is provided opposite the electrostatic suction electrode
35
, and on the outside of the vacuum chamber
31
, an ultraviolet light source
40
, such as a mercury lamp, for example, is provided opposite the quartz glass plate
39
. There is also a lifting mechanism (not shown in the figure), which raises and lowers a substrate
34
for placing and removing a substrate
34
on/from the electrostatic suction electrode
35
. This lifting mechanism utilizes a sliding seal, such as a bellows.
The operation of a conventional plasma processing apparatus
30
constituted in this manner will be explained. First, a substrate
34
placed on top of the electrostatic suction electrode
35
by the lifting mechanism is secured to the surface of the electrostatic suction electrode
35
by applying +voltage and −voltage, respectively, from the direct current supply
36
to a pair of internal electrodes inside the electrostatic suction electrode
35
. And then, in this state, ordinary plasma processing is performed on the substrate
34
.
When plasma processing is complete, a residual electric charge remains in the insulating layer of the surface of the electrostatic suction electrode
35
even after the direct current supply
36
has been shut off, and the substrate
34
is maintained in the state of being sucked to the electrostatic suction electrode
35
. Consequently, if a substrate
34
is lifted by the lifting mechanism in this state as-is, there are cases in which this substrate
34
is damaged.
To prevent this kind of trouble, and to stably lift a substrate
34
from an electrostatic suction electrode
35
without causing damage thereto, the following method for dechucking a substrate
34
from an electrostatic suction electrode
35
is being used.
That is, once plasma processing is complete, after negating the residual electric charge in a substrate
34
by applying a direct current voltage, which inverts polarity, to the internal electrodes of the electrostatic suction electrode.
35
in accordance with the switching mechanism
38
, the lifting mechanism is operated, and the substrate
34
is removed from the electrostatic suction electrode
35
. Further, thereafter, ultraviolet light of the ultraviolet light source
40
is irradiated onto the insulating layer surface of the electrostatic suction electrode
35
via the quartz glass plate
39
in an attempt to extinguish the residual electric charge of the surface of the electrostatic suction electrode
35
.
However, the above-mentioned residual electric charge cannot be completely removed by simply applying a polarity-inversing direct current voltage to the internal electrodes of an electrostatic suction electrode
35
as described above. Further, when the application duration of the above-mentioned direct current voltage is too long, conversely, there are cases in which an electrostatic suction electrode
35
will suck a substrate
34
. As a result thereof, there are cases in which the substrate
34
cannot be safely removed in accordance with the lifting mechanism, giving rise to trouble when the substrate
34
is to be transferred to the next process.
Further, because the above-mentioned lifting mechanism makes use of a sliding seal, such as a bellows, there is a limit to the endurance of a vacuum seal, and due to the deterioration over time of the spring force of the bellows, the balance between the residual suction force and the lifting force can break down. Thus, there is the above-mentioned problem of reliability with a conventional plasma processing apparatus
30
.
Further, as another conventional example, there is a method, which utilizes an electricity-removing plasma, and which reduces residual electric charge by, for example, gradually lowering the power being applied. But the problem is that since the residual suction force is not directly monitored, in view of the temporal risk, there is a tendency to lengthen the plasma discharge duration, thereby lowering throughput.
The present invention is constituted to solve for problems such as these, and has as an object the provision of a substrate dechucking device and a substrate dechucking method, which enable a substrate held in a substrate holder to be safely dechucked from the substrate holder.
SUMMARY OF THE INVENTION
To solve for the above-mentioned problems, the present invention presents a substrate dechucking device which is provided with a substrate holder for holding a substrate in a state where the backside of the substrate makes contact with the holder, and which dechucks from the substrate holder a substrate being held in the substrate holder in a state where the substrate is electrically charged and has a residual suction force, this substrate dechucking device comprising a lifter for lifting a substrate, the lifter being capable of protruding and retracting from the substrate holder, a drive source for generating a driving force to cause the lifter to protrude and retract, and a pair of magnetic coupling portions disposed to face to each other, one of the magnetic coupling portions being mounted to a movable member which is driven to move by the drive source, the other of the magnetic coupling portions being mounted to the lifter side, thereby transmitting the driving force of the drive source to the lifter via the magnetic coupling portions.
According to this consti

Affiliated with

Also associated with

Rating

Substrate dechucking device and substrate dechucking method 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 dechucking device and substrate dechucking method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Substrate dechucking device and substrate dechucking method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2885643