JP2701242B2 - Electrode structure for plasma CVD equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure of a plasma CVD apparatus used for forming various thin films on a substrate in a process of manufacturing a semiconductor device or the like. CVD (Chemical Vapo
r Deposition) The present invention relates to an electrode structure for a parallel plate shower type plasma CVD apparatus, which suppresses generation of dust particles due to exfoliation of a product, thereby preventing a film surface defect and extending a continuous operation time of the apparatus.

(Prior art)

In a plasma CVD apparatus, a pair of electrodes to which a high-frequency voltage is applied are installed in a vacuum vessel, and a dilute process gas introduced into the vessel is decomposed and excited by glow discharge between the electrodes to form a plasma state. Gas molecules are selectively fixed and deposited on the surface of a substrate mounted on an electrode to form a thin film. The selectivity of gas molecules and the degree of fixation are governed by the substrate temperature.

As an electrode for a conventional plasma CVD apparatus, for example,
There is a parallel plate type shower system as shown in the figure. A plasma generating electrode comprising a substrate holder 2 and a gas dispersion plate 3 having a large number of pores 7 is provided in a vacuum vessel 1,
It constitutes a pair of parallel plate type electrodes. The substrate 4 on which the thin film is formed is mounted on the substrate holder 2, and the gas dispersion plate 3 is heated by the substrate heater 5 on the gas dispersion plate 3 facing the substrate holder 2, and the substrate 4 is
And is heated to the process condition temperature.

An electrode having a two-pole configuration is formed in which the substrate holder 2 is an anode electrode and the gas dispersion plate 3 having the substrate heater 5 is a cathode electrode.

Reference numeral 6 denotes a gas inlet pipe having a gas inlet 6a, 8 denotes a vacuum seal subjected to high-frequency insulation treatment, 9 denotes an insulator, 10 denotes a high-frequency shield, 11 denotes a heating sheath wire, and 12 denotes a high-frequency power supply.

[Problems to be solved by the invention]

In the conventional example, the substrate heater 5
Is performed, the substrate holder 2 is heated by radiant heat transfer, and the substrate 4 is heated to the process condition temperature by the contact heat transfer. However, since the substrate temperature which affects the process condition is not directly heated, the process condition Not only is it difficult to control the temperature, but also because the substrate 4 serves as a cold wall, a good thin film cannot be formed, and the degree of gas molecules excited by plasma sticking to the lower temperature side of the anode due to the presence of the cold wall. Since the adhered substance is weak, the adhered substance is liable to peel during the CVD operation, and dust particles due to the peeling are the main causes of surface defects in a thin film formed on the substrate 4. Frequent removal of impurities is considered an inevitable condition at present, and this is a factor that greatly hinders the continuous operation of conventional plasma CVD equipment. You have me.

[Means for solving the problem]

In order to solve the above-mentioned problems, the present invention minimizes the temperature difference between the anode side, the cathode side electrode and the substrate by providing a heat radiation member in which ceramics are sprayed on the substrate holder and the gas dispersion plate to increase the radiation heat transfer efficiency. The temperature of the process conditions can be easily controlled by minimizing the temperature, and the adhered substance can be formed firmly on the anode or cathode electrode without a substrate heater, avoiding the detachment of the adhered substance during operation and eliminating dust particles. It is intended to suppress the generation and extend the continuous operation time in the actual apparatus, to form a good thin film and improve the quality.

That is, the electrode structure of the present invention comprises a substrate holder 2 provided in a vacuum vessel 1 and on which a substrate 4 is mounted, and a gas distribution plate 3 disposed opposite to the substrate holder 2. Heat radiation member 14 provided with heater 5 and ceramics sprayed on substrate holder 2 and gas dispersion plate 3 respectively.
Is provided.

(Operation)

Since the electrode structure of the present invention is configured as described above, the substrate heater 5 directly heats the substrate 4 on the substrate holder 2 and the heat radiation member 14 on which the ceramic of the substrate holder has been sprayed, and sprays the ceramic of the substrate holder. The infrared radiation emitted by heating the heat radiation member 14 is absorbed by the heat radiation member 14 sprayed with ceramics of the gas dispersion plate, and the gas dispersion plate 3 is diffused by the heat radiation member 14 sprayed with the ceramic.
Or by heating the gas dispersion plate 3 and the heat radiation member 14 sprayed with the ceramic of the gas dispersion plate by the substrate heater 5, and radiating infrared rays from the heat by the heat radiation member 14 sprayed with the ceramic of the substrate holder. The substrate holder 2 and the substrate 4 are directly heated by infrared rays which absorb heat and radiate therefrom, and the substrate 4 is heated to the process conditions.

Thus, the electrode having the substrate heater 5 (the substrate holder 2)
Alternatively, not only the gas dispersion plate 3) and the substrate 4 are heated, but also the electrode (gas dispersion plate 3 or the substrate holder 2) without the substrate heater 5 and the substrate 4 are also heated, so that the radiation heat transfer efficiency is improved. Can be cathode side electrode, substrate
4. The temperature difference between the anode side electrode is reduced, and a thin film is firmly formed on the substrate 4 by the plasma generation and the reaction gas. The adhered substance (thin film) is firmly adhered to the electrode having no electrode 5, and the generation of dust particles due to peeling is suppressed, and the adhered substance of the anode electrode or the cathode electrode during operation is frequently removed. In addition, a uniform thin film can be formed and the quality can be improved.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing the configuration of a plasma CVD apparatus to which a first embodiment of the electrode structure of the present invention is applied.
Numeral denotes a gas dispersion plate having a substrate holder and a number of fine holes 7 disposed opposite to each other in the vacuum vessel 1. A substrate 4 is mounted on the substrate holder 2, and a substrate heater 5 is mounted on the back of the substrate holder 2.
Are supported through the vacuum vessel 1 and grounded.

A heat radiation member 14 made of non-porous ceramic and a similar heat radiation member 14 having the same hole diameter as the pores 7 of the gas dispersion plate 3 are provided on the substrate holder 2 and the gas dispersion plate 3 by thermal spraying, respectively. The substrate holder 2 having the substrate heater 5 constitutes an anode electrode, and the gas dispersion plate 3 constitutes a cathode electrode.

Reference numeral 6 denotes a gas introduction pipe of the gas dispersion plate 3, which has a gas introduction port 6a. 10 is a high-frequency shield provided on the back of the gas dispersion plate 3 and around the gas introduction pipe 6, 8 is a vacuum seal buried between the high-frequency shield 10 and the gas introduction pipe 6 and subjected to high-frequency insulation treatment, and 9 is a gas dispersion. An insulator 12 provided between the plate 3 and the high-frequency shield 10 is a high-frequency power supply connected between the heater heating sheath wire 11 and the gas introduction pipe 6.

FIG. 2 is a sectional view showing a configuration of a plasma CVD apparatus to which the second embodiment is applied. In the second embodiment, a gas dispersion plate 3 having a substrate heater 5 and a substrate holder 2 are provided with holes and holes, respectively. A heat radiation member 14 sprayed with ceramics is provided, the substrate holder 2 constitutes an anode electrode, and the gas dispersion plate 3 having the substrate heater 5 constitutes a cathode electrode.

The substrate heater 5 directly heats the substrate holder 2 and the substrate 4 on the non-porous, ceramic-sprayed thermal radiation member 14 and also emits infrared radiation radiated by heating the non-porous, ceramic-sprayed thermal radiation member 14. The perforated, ceramic-sprayed heat radiation member 14 absorbs heat, and the perforated, ceramic-sprayed heat radiation member 14 heats the gas dispersion plate 3 or the substrate heater 5 heats the gas dispersion plate 3. And heats the perforated, ceramic-sprayed heat radiation member 14 and absorbs the infrared radiation radiated therefrom by the non-porous, ceramic-sprayed heat radiation member 14, and emits the substrate holder with the infrared radiation radiated from this. 2 and the substrate 4 will be directly heated, and the substrate 4 will be heated to process conditions.

Thus, the electrode having the substrate heater 5 (the substrate holder 2)
Alternatively, not only the gas dispersion plate 3) and the substrate 4 are heated, but also the electrode (gas dispersion plate 3 or the substrate holder 2) without the substrate heater 5 and the substrate 4 are also heated, so that the radiation heat transfer efficiency is improved. Can be cathode side electrode, substrate
4. The temperature difference between the anode side electrode is reduced, and a thin film is firmly formed on the substrate 4 by the plasma generation and the reaction gas. The adhered substance (thin film) is firmly adhered to the electrode having no electrode 5, and the generation of dust particles due to peeling is suppressed, and the adhered substance of the anode electrode or the cathode electrode during operation is frequently removed. In addition, a uniform thin film can be formed and the quality can be improved.

FIG. 3 is a sectional view showing a configuration of a plasma CVD apparatus to which the third embodiment is applied. This third embodiment is different from the first or second embodiment in that a shaft sealing portion 32 is attached to the shaft 2a of the substrate holder 2.
Is slidably mounted, and the shaft sealing portion 32 and the vacuum vessel 1 are connected by a flexible joint 31.

In the third embodiment having such a configuration, since the rotation, horizontal or vertical movement, etc. of the substrate holder 2 can be easily performed, the distance between the cathode side electrode and the anode side electrode can be adjusted,
The substrate 4 can be attached and detached in a short time, and operability can be improved as compared with the conventional electrode structure.

FIG. 4 is a sectional view showing the configuration of a plasma CVD apparatus to which the fourth embodiment is applied. This fourth embodiment is different from the first, second or third embodiment in that the substrate holder A heating plate 41 is provided in a direction perpendicular to the substrate heater 5 and the gas dispersion plate 3, and a shaft 41a of the heating plate 41 and a shaft 2a of the substrate holder 2 are connected to each other.
14 is provided.

When the cathode side electrode and the anode side electrode are arranged upright, there is a low temperature part on the vacuum vessel wall above the electrode, and the fall of dust particles due to the detachment of the adhered substance from the part causes the film surface defect. However, in the fourth embodiment, a heating plate 41 as shown is also provided above the electrodes, and a heat-radiating member 14 sprayed with ceramic is also provided thereon, so that a hot wall is formed on the vacuum vessel wall above the electrodes. Will be
It is possible to prevent dust particles from directly falling from the container wall, and to further enhance the effect of generating a film surface defect.

FIG. 5 is a cross-sectional view showing the configuration of a plasma CVD apparatus to which the fifth embodiment is applied. In the fifth embodiment, two gas dispersion plates 3 each having a substrate heater 5 are installed in a vacuum vessel 1 in opposition. Then, the substrate holder 2 is disposed therebetween, and two sets of gas dispersion plates 3 and 3 and the substrate holder 2 are provided with perforated and non-perforated ceramic radiation-spreading members 14 on both surfaces thereof.

In the fifth embodiment, the substrate holder 2 and the substrate 4
Is heated directly by the infrared rays from the ceramic-sprayed heat-radiating member 14, which is a perforated hole provided in the cathode electrodes on both sides, so that the heating efficiency can be greatly improved compared to the case of single-side heating. Further, since the number of mounted substrates can be doubled, the efficiency of the apparatus can be greatly improved.

FIG. 6 is a sectional view showing a configuration of a plasma CVD apparatus to which the sixth embodiment is applied. In the sixth embodiment, a holder transfer mechanism 61 is provided on the substrate holder 2 in the fifth embodiment.

According to the sixth embodiment, besides having the same operation and effect as the fifth embodiment, the anode-side electrode is a common single-plate type substrate holder (both sides mounted) 2 and the holder transfer mechanism 61 is provided below.
Since a grounding mechanism (including a grounding mechanism) is provided, the substrate holder 2 can be easily fed in and out, and the operation axis for attaching and detaching the substrate can be improved.

By executing the present invention, the effect of suppressing the generation of dust particles due to the peeling of the adhered matter from the peripheral portion of the substrate, the cathode side or the anode side electrode surface during the operation of the plasma CVD apparatus was apparent from the experiment. The continuous operation time of the actual device can be extended, and in the second embodiment shown in FIG. 2, the anode side (ground side) electrode is extremely simplified, so that the operability of the device can be improved. Accordingly, the effect of improving the throughput of the apparatus is extremely large.

〔The invention's effect〕

As is clear from the above description, according to the present invention, not only the electrode (substrate holder 2 or gas dispersion plate 3) having the substrate heater 5 and the substrate 4 are heated by the substrate heater 5, but also the substrate heater 5 is provided. The non-electrodes (gas dispersion plate 3 or substrate holder 2) and the substrate 4 are also heated by the substrate heater 5, and the infrared radiation radiated from the thermal radiation member 14 sprayed with the ceramics on the electrode side having the substrate heater 5 is also applied to the substrate heater. The ceramics on the electrode side having no electrode 5 are thermally absorbed by the thermally radiating member 14 and heated by infrared rays radiated therefrom, so that the radiation heat transfer efficiency can be increased, and the cathode side electrode, anode side electrode, substrate 4 can reduce the temperature difference, and a thin film is firmly formed on the substrate 4 by the plasma generation and the reaction gas, but the excess reaction gas does not have the substrate heater 5 due to hot wall formation. The adhered substance (thin film) can be firmly adhered to the non-conductive electrode, so that the generation of dust particles due to peeling can be suppressed, and it is possible to avoid frequently removing the adhered substance of the anode electrode or the cathode electrode during operation. Uniform film quality can be formed, and quality can be improved. Further, since the substrate 4 can be directly heated by the heat-radiating member 14 sprayed with ceramics provided on both electrodes, the temperature control of the process conditions becomes easy. Not only can be generated, but also the effect that the continuous operation time of the plasma CVD apparatus can be extended can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a plasma CVD apparatus to which the first embodiment of the electrode structure of the present invention is applied, FIG. 2 is a sectional view showing the structure of a plasma CVD apparatus to which the second embodiment is applied, and FIG. Is a sectional view showing a configuration of a plasma CVD apparatus to which the third embodiment is applied, FIG. 4 is a cross-sectional view showing a configuration of a plasma CVD apparatus to which the fourth embodiment is applied, and FIG. 5 is a section to which the fifth embodiment is applied. FIG. 6 is a cross-sectional view illustrating a configuration of a plasma CVD apparatus, FIG. 6 is a cross-sectional view illustrating a configuration of a plasma CVD apparatus to which the sixth embodiment is applied,
FIG. 7 shows a plasma CVD using an example of a conventional electrode structure.
It is sectional drawing which shows the structure of an apparatus. 1 ... vacuum container, 2 ... substrate holder, 2a ... shaft, 3 ...
Gas dispersion plate, 4 ... substrate, 5 ... substrate heater, 14 ... heat radiation member sprayed with ceramic, 31 ... flexible joint, 32 ... shaft sealing part, 41 ... heating plate, 41a ... … Axis, 61…
... holder transfer mechanism.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Daiya Aoki 2-1-1 Shinmeidai, Hamura-cho, Nishitama-gun, Tokyo Inside the Hamura Plant of Kokusai Electric Co., Ltd. (72) Fumio Muramatsu 2- Shinmeidai, Hamura-cho, Nishitama-gun, Tokyo 1-1 Inside the Hamura Plant of Kokusai Electric Inc. (56) References JP-A-62-299014 (JP, A) JP-A-62-218577 (JP, A)

Claims (5)

(57) [Claims] 1. A substrate holder (2) provided in a vacuum vessel (1) and having a substrate (4) mounted thereon, and a gas dispersion plate (3) disposed opposite to the substrate holder (2). Plasma CVD comprising a substrate heater (5) provided on a gas dispersion plate (3), and a thermal radiation member (14) obtained by spraying ceramics on a substrate holder (2) and a gas dispersion plate (3).
Electrode structure for device. 2. A shaft seal (32) is slidably mounted on a shaft (2a) of a substrate holder (2), and a flexible joint is provided between the shaft seal (32) and the vacuum vessel (1). 2. The electrode structure for a plasma CVD apparatus according to claim 1, wherein the electrode structure is connected by (31). 3. A heating plate (41) is provided in a vacuum vessel (1) in a direction perpendicular to the substrate holder (2) and the gas dispersion plate (3).
The shaft (41a) of the heating plate (41) and the shaft (2) of the substrate holder (2)
a) a heat radiation member (14) sprayed with ceramics is provided on the heating plate (41).
3. The electrode structure for a plasma CVD apparatus according to claim 2. 4. A vacuum vessel (1) comprising two gas dispersion plates (3) having substrate heaters (5) opposed to each other, and a substrate holder (2) arranged therebetween, and two sets of gas dispersion plates. Board (3,
3) Plasma that has thermal radiation members (14) with ceramics sprayed on both sides of the substrate holder (2)
Electrode structure for CVD equipment. 5. A holder transfer mechanism (61) for a substrate holder (2).
The electrode structure for a plasma CVD apparatus according to claim 4, further comprising: