JPH10289881A - Plasma cvd device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge a region where plasma is uniformized in a plasma CVD device. SOLUTION: There is provided a plasma CVD device wherein high frequency power is supplied between upper and lower electrodes 23 and 21 to generate a plasma for treating a substrate. In this device, the upper electrode 23 is divided into a central portion 24 and a peripheral edge portion 25. At least one of the central portion 24 and the peripheral edge portion 25 is arranged vertically movable to control the distance between the upper and lower electrodes at the central portion 24 and the peripheral edge portion 25, thereby enlarging the region where plasma is uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus for generating a plasma by applying high-frequency power between electrodes facing each other, and manufacturing a semiconductor device using the plasma.

[0002]

2. Description of the Related Art Plasma C is one of the semiconductor manufacturing apparatuses.
There is a VD device. The plasma CVD apparatus has electrodes facing each other in a closed space, a substrate to be processed is held on one of the electrodes, a reaction gas is supplied to the closed space, and high-frequency power is applied between the electrodes to generate a plasma. To generate a thin film on the substrate to be processed or to etch the thin film.

Referring to FIG. 4, a conventional plasma CVD apparatus will be described.

[0004] A flat disk-shaped lower electrode 2 is provided at a lower portion of an airtight reaction chamber 1 defined by a vacuum vessel (not shown), and an upper electrode 3 facing the lower electrode 2 is provided above the reaction chamber 1.
Are provided via an insulator 4, and a side wall 5 is provided so as to surround a space below the upper electrode 3. The upper electrode 3 has a high-frequency power source 6 provided outside the reaction chamber 1.
Are connected via a matching unit 7, and the lower electrode 2 and the side wall 5 are grounded.

The reaction chamber 1 is evacuated by a vacuum pump (not shown), a reaction gas is introduced into the reaction chamber 1 in a reduced pressure state and maintained at a predetermined pressure, and a high-frequency power output from the high-frequency power source 6 to the upper electrode 3 Is supplied through the matching device 7 to generate plasma in the reaction chamber 1, and the gas molecules in the reaction gas are decomposed by the plasma, and the decomposed molecules and ions are applied to the surface of the substrate 8 to be processed. Forming a thin film,
Alternatively, etching is performed.

As shown in FIG. 5, the plasma is uniform in the central region 11 of the reaction chamber 1 above the central portion 10 of the lower electrode 2 as in the case where the glass substrate 9 for LCD is formed into a film. In the outer peripheral region 13 of the reaction chamber 1 above the peripheral portion 12 of the lower electrode 2, the plasma becomes non-uniform, and the area of the central portion 10 where the plasma is uniform becomes smaller than the area of the entire lower electrode 2. . As a result, the film forming speed of the peripheral portion 14 of the glass substrate is increased depending on the process conditions such as the type, flow rate, pressure, temperature, and high frequency power of the reaction gas, as shown in FIG. The peripheral portion 14 is faster than the central portion 15 of the glass substrate.
7 becomes thicker than the central portion 15, or conversely, FIG.
As shown in the figure, since the film forming speed of the peripheral portion 14 is lower than that of the central portion 15, the film forming of the peripheral portion 14 may be thinner than that of the central portion 15. In the case of the central portion 15 and the peripheral portion 14, Differences occur in the film formation speed and film quality.

[0007]

In the above-mentioned conventional plasma CVD apparatus, the plasma becomes non-uniform at the peripheral portion of the electrode, and the region where the plasma becomes uniform is the lower electrode 2.
Since the area is smaller than the entire area, the area of the lower electrode 2 cannot be effectively used, and the plasma processing apparatus itself cannot be made compact. In addition, there is a problem that the high frequency power cannot be effectively used.

The present invention has been made in view of the above circumstances, and has an object to expand a region where plasma is uniformly generated, to make a plasma processing apparatus compact, and to make effective use of high-frequency power.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a plasma CVD apparatus for processing a substrate to be processed by supplying high frequency power between upper and lower electrodes to generate a plasma. The present invention relates to a plasma CVD apparatus in which at least one of the central portion and the peripheral edge portion is provided so as to be vertically movable. Also, the peripheral portion is divided into a plurality of portions, and the divided portions are independently movable vertically. According to the plasma CVD apparatus, the distance between the upper and lower electrodes at the central portion and the peripheral portion is adjusted to enlarge a region where plasma is uniformly generated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

A flat plate-like lower electrode 21 is provided below the airtight reaction chamber 20 defined by a vacuum vessel (not shown). The lower electrode 21 has a rectangular substrate 22 to be processed.
Is placed.

An upper electrode 23 is provided above the reaction chamber 20, and the upper electrode 23 is divided into a central portion 24 and a peripheral portion 25, and the central portion 24 and the peripheral portion 25 are electrically integrated. Like, they are electrically connected. Also, the peripheral portion 25
Is a rectangular parallelepiped first peripheral edge 25a, a second peripheral edge 25b, a third peripheral edge 25c, and a fourth peripheral edge 25d provided along four outer peripheral sides of the central portion 24 and the outer peripheral portion 4 of the central portion 24.
Fifth peripheral portion 25e, sixth peripheral portion 25f, seventh peripheral portion 25g, and eighth peripheral portion 25h each having an L-shaped plane provided at the corner.
And the central portion 24 and the peripheral portions 25a, 25b, 25c, 25d, 25e, 25f,
25g and 25h can be independently moved up and down.

A central insulator 26 is fixed to the upper surface of the central portion 24, and the peripheral portions 25a, 25b, 2
On the upper surfaces of 5c, 25d, 25e, 25f, 25g, and 25h, the upper surface insulator 27a for the first peripheral portion, the upper surface insulator for the second peripheral portion (not shown), and the upper surface insulator for the third peripheral portion are separately provided. 27c, fourth insulator upper surface insulator (not shown),
Top insulator for fifth peripheral portion (not shown), top insulator for sixth peripheral portion (not shown), top insulator for seventh peripheral portion (not shown), top insulator for eighth peripheral portion (Not shown), and the peripheral portions 25a, 25b, 25c, 25
d, 25e, 25f, 25g, and 25h are separately provided on the outer peripheral side surfaces of the first peripheral side surface insulator 28a, the second peripheral side surface insulator (not shown), and the third peripheral side surface insulator 28c, respectively. 4th peripheral side insulator (not shown), 5th peripheral side insulator (not shown), 6th peripheral side insulator (not shown), 7th peripheral side insulation A body (not shown) and an eighth peripheral side surface insulator (not shown) are fixed. The insulator 26 for the central portion, the upper surface insulator 27 for each peripheral portion, and the side insulator 28 for each peripheral portion correspond to the central portion 24, the peripheral portions 25a, 25, respectively.
b, 25c, 25d, 25e, 25f, 25g, 25h
It can be moved up and down as one unit.

A side wall 29 is provided so as to surround a space below the upper electrode 23, and the upper electrode 23 and the side wall 29 are insulated by the peripheral side insulator 28,
A high-frequency power supply 30 provided outside the reaction chamber 20 is connected to the upper electrode 23 via a matching unit 31, and the lower electrode 21 and the side wall 29 are grounded.

The operation will be described below.

Before the plasma is generated, the central portion 24 of the upper electrode 23 and the peripheral portions 25a, 25b, 25c according to the process conditions such as the type, flow rate, pressure, temperature, and high frequency power of the reaction gas and the purpose. , 25d, 25e,
25f, 25g, and 25h are moved up and down, and each electrode is set independently.

The reaction chamber 20 is evacuated by a vacuum pump (not shown), a reaction gas is introduced into the reaction chamber 20 in a reduced pressure from a gas introduction pipe (not shown), and the pressure is set by a pressure controller (not shown). The high-frequency power output from the high-frequency power supply 30 is supplied to the upper electrode 23 via the matching unit 31, and the central part 24, the peripheral parts 25a and 25
b, 25c, 25d, 25e, 25f, 25g, 25h
And an electric field having a uniform intensity between the lower electrode 21 and the lower electrode 21 to generate plasma in the reaction chamber 20. The plasma decomposes gas components in the reaction gas to form a thin film on the surface of the substrate 22 to be processed.

The central portion 24 of the lower electrode 21 and the upper electrode 23 which generate an electric field of uniform intensity, and the respective peripheral portions 25a, 25b, 25c, 25d, 25e, 25
The plasma is uniform in the central region 32 sandwiched between f, 25g, and 25h, and non-uniform in the other peripheral region 33. Therefore, as shown in FIG. 3, the area of the central area 32 where the plasma becomes uniform is enlarged, the area of the outer peripheral area 33 where the plasma becomes non-uniform is reduced, and the lower electrode 2 is formed.
The size of the target substrate 22 capable of forming a film can be increased without increasing the area of the substrate 1.

In the above embodiment, the upper electrode is divided into a central portion and a peripheral portion, and the peripheral portion is further divided into eight portions. However, the upper electrode is divided only into the central portion and the peripheral portion. The central part and the peripheral part may be independently movable vertically.
In this case, the intensity of each electric field generated between the central portion and the lower electrode and between the peripheral portion and the lower electrode can be roughly adjusted, and the region where plasma becomes uniform can be enlarged. Further, in the above embodiment, the peripheral portion of the upper electrode is divided into eight, but may be divided into seven or less or nine or more.

[0020]

As described above, according to the present invention, the distance between the upper and lower electrodes at the center and the periphery of the reaction chamber can be adjusted independently, so that the region where the plasma becomes uniform can be expanded. The area where the film can be effectively formed can be expanded, and the size of the substrate to be processed can be increased without increasing the area of the lower electrode. Further, since the region where the plasma becomes non-uniform can be reduced, the plasma processing apparatus itself can be made compact. Furthermore, by expanding the region where the plasma becomes uniform, effective use of high-frequency power can be achieved,
It exhibits various excellent effects such as energy saving.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing a divided state of an upper electrode according to the embodiment.

FIG. 3 is a plan view showing a relationship between a lower electrode and a region where plasma is uniform in the embodiment.

FIG. 4 is a schematic explanatory view showing a conventional example.

FIG. 5 is a plan view showing a relationship between a lower electrode and a region where plasma is uniform in a conventional example.

FIG. 6 is a side view showing a state of film formation on a glass substrate subjected to a conventional film formation process.

FIG. 7 is a side view showing another film formation state of a glass substrate subjected to a conventional film formation process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Lower electrode 23 Upper electrode 24 Central part 25 Peripheral part 29 Side wall 30 High frequency power supply 31 Matching device

Claims (2)

[Claims] 1. A plasma CV for processing a substrate to be processed by supplying high frequency power between upper and lower electrodes to generate plasma.
In the D device, the upper electrode is divided into a central part and a peripheral part,
A plasma CVD apparatus, wherein at least one of the central part and the peripheral part is provided so as to be vertically movable. 2. The plasma C according to claim 1, wherein the peripheral portion is divided into a plurality of portions, and the divided portions can be independently moved up and down.
VD device.