JPH07109855B2 - Electrostatic chuck electrostatic charge removal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method for removing electrostatic charges from an electrostatic chuck.

[Conventional technology]

In the conventional technique, for example, as described in Japanese Patent Application Laid-Open No. 60-5539, a circuit for applying a negative voltage to an electrode can be added to forcefully open and detach an object to be processed. .

[Problems to be Solved by the Invention]

Since the above-mentioned conventional technique is provided with an additional circuit capable of applying a negative voltage to the electrode when the object to be processed is detached, no consideration is given to the fact that the apparatus is complicated, and a circuit dedicated to detaching the object to be treated must be provided. There was a problem that it had to be.

An object of the present invention is to facilitate removal of an object to be processed, without providing a circuit for exclusive use of removal.

[Means for Solving the Problems]

The above object is achieved by controlling the output of the DC voltage for electrostatic chucking to stop after the plasma treatment of the sample, discharging only by microwaves, and then stopping the output of microwaves. Is.

[Action]

The electrostatic chuck operates by applying a DC voltage at the same time as applying a microwave output. For example, the DC voltage is stopped after the etching of the object to be processed is completed. After that, the microwave output is stopped. As a result, charges accumulated on the dielectric film attached to the electrodes are removed, so that the object to be processed can be easily separated.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, a quartz discharge tube 2 is provided above the processing chamber 1 to form a vacuum processing chamber. The processing chamber 1 is provided with a gas supply port 3 for supplying an etching gas into the vacuum processing chamber, and the pressure inside the vacuum processing chamber is reduced to a predetermined pressure.
Exhaust port 4 connected to a vacuum exhaust device (not shown) for exhausting
Is provided. An electrode 6 for disposing a wafer 5 as a material to be etched is provided in the processing chamber 1. A high frequency power source 7 and a direct current power source 8 are connected to the electrode 6, and each electrode 6 can be applied. The discharge tube 2 is located outside the discharge tube 2.
A waveguide 9 is provided surrounding the coil, and a coil 10 for generating a magnetic field in the discharge tube 2 is provided outside the waveguide 9. A magnetron 11 that emits microwaves is provided at the end of the waveguide 9.

In such a device, an etching gas is supplied from the gas supply port 3 into the vacuum processing chamber, the vacuum processing chamber is depressurized and exhausted to a predetermined pressure, and the microwave from the magnetron 11 is guided by the waveguide 9 to the discharge tube 2. While being introduced into the inside, a magnetic field is formed by the coil 10, and the etching gas in the discharge tube 2 is turned into plasma by the action of the electric field of the microwave and the magnetic field of the coil 10. Further, a DC voltage is applied to the electrode 6 by the DC power source 8 to attract the wafer 5 to the electrode 6. After the etching is completed, the output of the DC power supply is stopped and the discharge is performed only by the microwaves as shown in FIG. 2, so that the charges accumulated in the dielectric 12 attached to the electrode 6 can be removed. Therefore, the subsequent removal of the object to be processed becomes easy. The control shown in FIG. 2 may be performed manually or automatically.

In this embodiment, the etching apparatus is used as an example,
Any device to which the present invention is applied can be applied.

〔The invention's effect〕

According to the present invention, the electric charge accumulated in the dielectric film attached to the electrode is removed by controlling the stop timing of the DC voltage and the microwave output, and the object to be processed can be easily separated. In addition, there is an effect that it is economical because no new equipment for removing charges is required.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a processing chamber of a dry etching apparatus according to an embodiment of the present invention, and FIG. 2 is an output stop timing chart for discharging electric charges. 1 ... Processing chamber, 2 ... Discharge tube, 3 ... Gas supply port, 4 ...
... Exhaust port, 5 ... Wafer, 6 ... Electrode, 7 ... High frequency power supply, 8 ... DC power supply, 9 ... Waveguide, 10 ... Coil, 11
...... Magnetron, 12 …… Dielectric film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/3065

Claims (1)

[Claims] 1. A high frequency power supply for biasing and a direct current power supply for sample adsorption are respectively connected to electrodes provided in a vacuum container so as to be capable of applying plasma by means of microwaves, and the immediately preceding power supply is used to In a method of controlling a processing apparatus for applying a DC voltage to an electrode to perform plasma processing on a sample, after the plasma processing of the sample is finished, the power output of the DC voltage is stopped and the microwave is discharged only, and then the microwave A method of removing static electricity from an electrostatic chuck, characterized by performing control to stop output.