JPH09209155A - Plasma treating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treating device which prevents the leaking in of a high-frequency voltage to a controller side by grounding a panel heater installed on a cathode electrode side and providing this panel heater with a cathode electrode via an insulator. SOLUTION: An electrode body of the cathode electrode 6 of this plasma treating device is formed as a flat planar panel heater 20 and the panel heater 20 is provided with a shower plate 22 via an electrical insulating part 21 in the lower apart thereof. The panel heater 20 on the cathode electrode 6 side and a cap 5 are electrically connected by a wiring 24. This cap 5 is grounded by a grounding line 25. The panel heater 20 is grounded via the grounding line 25 and the cap 5. The shower plate 22 is connected to a high-frequency power source 9 and is impressed with the high-frequency voltage. A vacuum vessel body 1 is grounded as well. As a result, the leaking of the current by the high-frequency component to the controller side does not arise any more when the high-frequency voltage is impressed on the shower plate 22. Then, the need for the conventional filter box is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus which is one of semiconductor manufacturing apparatuses.

[0002]

2. Description of the Related Art A plasma processing apparatus, which is one of manufacturing apparatuses for forming semiconductor elements on a silicon substrate (wafer) or a glass substrate, includes, for example, a plasma formed by a chemical vapor deposition (CVD) method for forming various thin films. There is a CVD device. In the plasma CVD apparatus, the substrate to be processed is loaded into a vacuum chamber, a reaction gas is introduced to generate plasma, and the separated reaction gas is used to generate a thin film on the substrate. .

An outline of the plasma CVD apparatus will be described with reference to FIGS. 4 and 5.

A bottom electrode of the vacuum container body 1 is provided with an anode electrode 3 on the side of a lower electrode in which a heater 2 is embedded. A substrate 4 to be processed can be placed on the anode electrode 3, and a substrate receiving table is provided. Also serves as. A lid 5 that hermetically closes the vacuum container body 1 is fixed to the upper portion of the vacuum container body 1, and a cathode electrode 6 on the upper electrode side facing the anode electrode 3 faces the lid 5 via an insulator 8. It is provided in.

The cathode electrode 6 is connected to a high frequency power source 9, and a high frequency voltage (RF) is applied by the high frequency power source 9. The cathode electrode 6 has an electrode body 7 and a shower plate 10 provided on the lower surface of the electrode body 7. The shower plate 10 has a large number of shower holes 11 for dispersing and introducing the reaction gas into the vacuum container body 1. It is set up. A heater wire 30 (see FIG. 6) is embedded in the electrode body 7, and the electrode body 7 functions as a panel heater to heat the shower plate 10.

A gas reservoir 12 is formed between the cathode electrode 6 and the shower plate 10, and a reaction gas is supplied to the gas reservoir 12 from a reaction gas supply source (not shown) through a reaction gas introducing passage 18. . The reaction gas is dispersed and introduced into the inside of the vacuum container body 1 through the gas reservoir 12 through the shower holes 11 of the shower plate 10.

When a high-frequency voltage is applied between the anode electrode 3 and the cathode electrode 6 by the high-frequency power source 9 with the reaction gas introduced, plasma is generated by the reaction gas. Reaction products generated by plasma are deposited on the surface of the substrate 4. The reaction gas after the reaction is exhausted from the exhaust pipe 13.

The temperature of the substrate 4 during processing is controlled as one of the important requirements for determining the film forming characteristics, and a thermocouple 14 for detecting the temperature of the substrate 4 holds a holder 15 on the lower surface of the vacuum container body 1.
It is installed airtightly through. The detection end of the thermocouple 14 reaches the anode electrode 3, and the temperature of the substrate 4 is detected through the temperature detection of the anode electrode 3.

In the case of such a conventional plasma CVD apparatus,
As described above, the electrode body 7 of the cathode electrode 6 as the upper electrode serves as a panel heater to heat the shower plate 10 and prevent reaction products from adhering to the shower plate 10. The temperature of 10 is the thermocouple 31 provided in the electrode body 7 (see FIG. 6).
Detected by. Therefore, as shown in the circuit diagram of FIG. 6, stray capacitances C ₁ and C ₂ are generated in the electrode body 7 and the thermocouple 31, respectively, and the harmonics of the high frequency voltage V _RF are generated in the electrode body 7 and the thermocouple 31. Wave component leaks. That is, a current equivalent to [C ₁ / (C ₁ + C ₂ )] · V _RF leaks, which is one of the causes for lowering the control accuracy of the controller.

In order to prevent the leakage of current due to the harmonic components, the conventional plasma CVD apparatus allows current in a specific frequency band to pass without interference, but attenuates currents in other frequency bands to prevent passage. Filter box 16 for blocking low-pass filter (low-pass filter: LPF) or the like
Has been installed.

[0011]

However, the filter box 16 occupies a large space in the plasma CVD apparatus, which is one obstacle to multi-stage the vacuum container body 1 and causes a high cost.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to prevent a high frequency high voltage from leaking and to eliminate the need for a filter box in a plasma processing apparatus using a CVD method or the like. .

[0013]

The present invention provides a plasma processing apparatus having a pair of electrodes facing each other and generating a plasma by applying a high frequency voltage between the two electrodes. The panel heater provided in the above is grounded, and the cathode electrode is provided on the panel heater through an insulator to prevent leakage of a current equivalent to a harmonic component due to a high frequency voltage into the controller. That is, the conventional filter box provided to prevent the leak current is not required, and the installation space is reduced accordingly.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. It should be noted that the same or similar components to those of the plasma CVD apparatus shown in FIG.

In FIG. 1, a bottom electrode of a vacuum container body 1 is provided with an anode electrode 3 as a lower electrode in which a heater 2 is embedded, and a substrate 4 to be processed can be placed on the anode electrode 3. . At the top of the vacuum container body 1, the vacuum container body 1
A lid 5 for air-tightly closing is fixed, and a cathode electrode 6 as an upper electrode facing the anode electrode 3 is provided on the lid 5 via an insulating material 19.

The cathode electrode 6 is formed as a flat panel-shaped panel heater 20. The panel heater 20 is provided with a heater wire 30 and a thermocouple 31, and quartz or the like is provided below the panel heater 20. The shower plate 22 is provided via the electrical insulator 21. The shower plate 22 is provided with a large number of shower holes 23 for dispersing and introducing the reaction gas into the vacuum container body 1.

A panel heater 20 on the cathode electrode 6 side
The lid 5 and the lid 5 are electrically connected by a wire 24, and the lid 5 is grounded by a ground wire 25. The panel heater 20
Is grounded through the ground wire 25 and the lid 5.
The shower plate 22 is connected to the high frequency power source 9. The shower plate 22 functions as a cathode electrode, and a high frequency voltage (V _RF ) is applied to the shower plate 22 by a high frequency power source 9 as an RF applying unit.
The insulator 21 is heated by energizing the heater wire 30 of the panel heater 20, and the shower plate 22 is indirectly heated through the heated insulator 21. The vacuum container body 1 is also grounded.

The panel heater 20 on the cathode electrode 6 side
There is a gas reservoir 12 between the shower plate 22 and the shower plate 22, and a reaction gas introducing passage 18 is provided in the gas reservoir 12.
A reaction gas is supplied from a reaction gas supply source (not shown) via the. The reaction gas is dispersed and introduced into the inside of the vacuum container body 1 from the shower holes 23 of the shower plate 22 through the gas reservoir 12. When a high-frequency voltage is applied between the anode electrode 3 and the shower plate 22 by the high-frequency power source 9 with the reaction gas introduced, plasma is generated due to the ionization of the reaction gas. A reaction product is deposited on the surface of the substrate 4 to form a thin film. The reaction gas after the reaction is exhausted from the exhaust pipe 13.

The temperature of the shower plate 22 during processing is detected by the thermocouple 31 through the insulator 21.

With the above structure, in the present embodiment, since the panel heater 20 is grounded by the wiring 24 and the ground wire 25 via the lid 5, the high frequency voltage V is applied to the shower plate 22 which is an RF applying section. _{When RF} is applied,
The heater 30 and the thermocouple 31 have floating capacitances C ₁ and C
Even if ₂ and C ₃ occur, V _H (heater potential) = V _RF
However, since V _RF ≠ 0 and V _H = 0, [C ₁ / (C ₁ + C ₂ )] · V _H = 0, and leakage of current due to harmonic components to the controller side is eliminated.

Therefore, it is not necessary to install the filter box 16 shown in the conventional example of FIG. 6, the cost is greatly reduced, and it is not necessary to secure the installation space in the plasma CVD apparatus. 1 can be realized in multiple stages.

[0022]

As described above, according to the present invention, the panel heater provided on the cathode electrode side is grounded, and the cathode electrode is provided on the panel heater via the insulator, so that the high frequency voltage to the controller side is increased. Can be prevented, and the conventional filter box provided to prevent the leakage current is unnecessary, and the installation space can be reduced by that amount, and the vacuum container body can be multi-staged and the cost can be reduced. It has an excellent effect that it can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a plasma processing apparatus according to the present invention.

FIG. 2 is a sectional view showing a main part of the same embodiment.

FIG. 3 is a circuit diagram of the same embodiment.

FIG. 4 is a block diagram showing a conventional plasma processing apparatus.

FIG. 5 is a configuration diagram showing a part of the prior art example.

FIG. 6 is a circuit diagram of the conventional example.

[Explanation of symbols]

 1 Vacuum Container Main Body 2 Coil Heater 3 Anode Electrode 4 Processed Substrate 5 Lid 6 Cathode Electrode 19 Insulation Material 20 Panel Heater 21 Insulator 22 Shower Plate 24 Wiring 25 Ground Wire 26 Ground Wire of Vacuum Container Main Body

Claims (1)

[Claims] 1. In a plasma processing apparatus having a pair of electrodes facing each other, and applying a high-frequency voltage between the electrodes to generate plasma, a panel heater provided on the cathode electrode side is grounded. A plasma processing apparatus, wherein a cathode electrode is provided on the panel heater via an insulator.