JPH0536641A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To make plasma density in a plasma reaction chamber uniform, in order to improve the uniformity of etch rate and film formation in a wafer surface, in a dry etching equipment, a plasma CVD equipment, etc. CONSTITUTION:After microwave is introduced into a microwave stirring chamber 108 and stirred, said microwave is introduced into a plasma reaction chamber 101 from a microwave introducing window 107, and a wafer substrate 2 is subjected to etching process or film forming process. Since the microwave is introduced into the plasma reaction chamber after stirring, plasma of uniform density distribution can be formed in the the plasma reaction chamber, and etching and film formation excellent in uniformity are realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a dry etching apparatus for etching using plasma in a semiconductor manufacturing process or a plasma CVD apparatus for forming a film by using plasma. Is.

[0002]

2. Description of the Related Art FIG. 3 is a schematic configuration diagram showing a conventional dry etching apparatus disclosed in, for example, Japanese Patent Laid-Open No. 61-75527. In the figure, 1 is a plasma generating chamber for generating plasma, 5 (5A to 5C) is an ion extracting electrode plate for extracting ions from the plasma in the plasma generating chamber 1 to form a shower-like ion beam, and 6 is the shower-like ions. A sample chamber for irradiating the surface of the sample (wafer substrate) 8 with a beam, 7 a sample table on which the sample (wafer substrate) 8 is mounted, 11 a gas inlet, 12 an exhaust system for evacuating the sample chamber 6, 13 Is a microwave introduction window provided in the plasma generation chamber 1, and 14 is a rectangular waveguide for introducing microwaves, which is connected to a microwave source (not shown). Reference numeral 15 is a magnetic coil provided on the outer periphery of the plasma generation chamber 1 for generating a magnetic field necessary for causing electron cyclotron resonance.

Next, the operation of the dry etching apparatus will be described. First, after the plasma generation chamber 1 and the sample chamber 6 are evacuated to vacuum, a Freon-based or chlorine-based reactive gas is introduced from the gas introduction port 11 and set to a predetermined pressure, and the microwave is introduced into the microwave introduction window 13 Introduced from. When the microwave frequency is 2.45 GHz, the magnetic coil 15 forms a magnetic field of 875 Gauss that causes electron cyclotron resonance in the plasma generation chamber 1 to generate plasma in the plasma generation chamber 1. After controlling the reactive species by the ion extraction electrode plate 5, the generated plasma is transported to the sample chamber 6 as a shower-like ion beam, and the sample (wafer substrate) 8 is etched.

[0004]

The conventional dry etching apparatus is configured as described above, and some of the plasma generated in the plasma generation chamber 1 is diffused to the side wall surface of the plasma generation chamber 1. Disappears. Therefore, the plasma density in the peripheral portion is lower than that in the central portion of the plasma generating chamber 1. Further, the energy distribution of the microwaves injected into the plasma reaction chamber 1 becomes strong near the microwave introduction window, that is, in the central portion because the microwave introduction window 13 is smaller than the inner diameter of the plasma generation chamber 1, and thus the plasma density is increased. It is a factor that makes the distribution uneven. as a result,
The plasma density in the radial direction of the plasma generation chamber 1 is high in the central part and low in the peripheral part, resulting in an uneven distribution. The nonuniformity of the plasma density in the inner diameter direction of the plasma generation chamber 1 is
Since it is reflected in the density distribution of the reactive species transported on the surface,
There arises a problem that the etching rate on the surface of the sample 8 becomes non-uniform.

The present invention has been made in order to solve the above problems, and provides a semiconductor manufacturing apparatus for generating a plasma having a uniform distribution density and performing an etching process with good uniformity. With the goal.

[0006]

A semiconductor manufacturing apparatus according to the present invention includes a plasma reaction chamber for introducing a reactive gas or the like to generate plasma by a magnetic field generating means, and a microwave generating apparatus through a waveguide. A microwave stirring means for stirring the introduced microwave is provided, and the stirred microwave is introduced into the plasma reaction chamber through the microwave introduction window.

[0007]

In the present invention, since the microwave is stirred and introduced into the plasma reaction chamber, plasma having a uniform density distribution of the reactive gas can be generated in the plasma reaction chamber, and the sample can be uniformly etched or uniformly deposited. I made it possible.

[0008]

EXAMPLES Example 1. A semiconductor manufacturing apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of a dry etching apparatus to which this embodiment is applied.
In the figure, 101 is a plasma reaction chamber, 102 is a sample (wafer substrate) placed on a sample table 103, and 104 is a plasma reaction chamber 101.
An evacuation device for evacuating the air, 106 is a coil for generating a magnetic field, 1
05 is a gas inlet. Reference numeral 107 denotes a microwave introduction window, which is vacuum-sealed in the plasma reaction chamber 101 by an O-ring or the like (not shown) (made of a microwave transmitting material such as quartz or alumina). Reference numeral 108 is a microwave stirring chamber, 109 is a waveguide for guiding microwaves from a microwave generator (not shown), 110 is a microwave stirring blade provided in the microwave stirring chamber 108, metal, etc. Made of microwave reflective material. 111 is a rotary rod inlet,
For example, a cut-off structure is provided so that microwaves do not leak to the outside of the microwave stirring chamber 108 when the dielectric rotary rod 112 is inserted. 113 is a microwave stirring blade 110
Is a drive device that rotates the.

In the dry etching apparatus configured as described above, the inside of the plasma reaction chamber 101 is evacuated to a predetermined vacuum pressure by the exhaust device 104, and then the etching gas is introduced from the gas inlet 105. Next, microwaves are introduced into the microwave stirring chamber 108 from the waveguide 109. Here, when the driving device 113 is operated to rotate the rotary rod 112, the microwave introduced from the waveguide 109 is stirred by the microwave stirring blade 110 and spreads in all directions in the microwave stirring chamber 108. The microwaves spread in all directions in the microwave stirring chamber 108 form a uniform plasma in the plasma reaction chamber 101 through the microwave introduction window 107. On the other hand, the plasma reaction chamber 10
When a magnetic field of 875 Gauss is generated in 1, plasma can be formed by electron cyclotron resonance.

As a concrete example, the inner diameter of the plasma reaction chamber is 300 m.
When the magnetic flux density in the plasma reaction chamber is 875 gauss and the rotation speed of the microwave stirring blade is one revolution per second under a microwave of m, etching gas pressure of 0.5 Torr, and frequency of 2.45 GHz, plasma reaction occurs by probe measurement. As a result of measuring the plasma density in the inner diameter direction of the chamber 101, the microwave stirring blade 110 was used for a short time of 1 second or less at each measurement position.
The plasma density fluctuates according to the rotation position of
The plasma density averaged over several seconds or more was almost the same at any position, and a plasma with very good uniformity could be formed. As a result, it is possible to perform highly uniform etching processing on the surface of the wafer substrate 104.

Embodiment 2. Further, in the above-described embodiment, the structure in which the positions of the waveguide and the microwave stirring blade are shifted has been described, but as shown in FIG. 2, the rotating rod 202 for the microwave stirring blade is provided on the center line of the waveguide. May be located. In this case, the rotating rod inlet 202 is provided in the corner waveguide 201 to rotate the microwave stirring blade 110.

The microwave stirring blade shown in the above embodiment can be composed of one to a plurality of blades. Further, in the above embodiment, the rotation speed of the microwave stirring blade was set to one rotation per second, but it can be freely changed in consideration of the etching speed. Further, although the dry etching apparatus has been described in the above embodiment, the same effect can be obtained even when applied to the plasma CVD apparatus. For example, when silane-based SiH ₄ is introduced as the CVD gas, the gas is decomposed by discharge and a silicon deposition film can be formed on the sample (wafer substrate).

Embodiment 3. In the above-described embodiment, as shown in FIG. 1, the plasma reaction chamber and the sample chamber are integrally formed. However, an ion extraction electrode is installed between the plasma reaction chamber and the sample chamber as in the conventional case, and the plasma is Ions may be extracted from the plasma generated in the reaction chamber to irradiate the sample in the sample chamber as a shower-like ion beam. For example, three electrode plates are provided as ion extraction electrodes, and the uppermost electrode plate has the same potential as the plasma reaction chamber,
A positive potential of 0 to 2 kV is applied to the ground potential. The lowermost electrode plate has the ground potential and the same potential as the sample chamber. Intermediate electrode plate is 0 to -300 with respect to ground potential
By applying a negative potential of V, the parallelism of the shower-like ion beam is improved and the invasion of electrons from the sample chamber side is prevented. Here, the ions are extracted from the plasma reaction chamber and accelerated by a voltage of 0 to 2 kV applied between the uppermost electrode plate and the lowermost electrode plate,
The sample becomes a shower-like ion beam and is irradiated onto the sample.

[0014]

As described above, according to the present invention, the microwave is agitated and homogenized, and then introduced into the plasma reaction chamber, so that uniform plasma can be formed in the entire plasma reaction chamber. There is an effect that an etching process or a film forming process with good uniformity can be performed.

[Brief description of drawings]

FIG. 1 is a sectional side view showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional side view showing a semiconductor manufacturing apparatus according to another embodiment of the present invention.

FIG. 3 is a cross-sectional side view showing a conventional semiconductor manufacturing apparatus.

[Explanation of symbols]

 101 Plasma reaction chamber 102 Sample 103 Sample stage 104 Exhaust device 105 Gas inlet 106 Coil 107 Microwave inlet window 108 Microwave stirring chamber 109,201 Waveguide 110 Microwave stirring blade 111 Rotating rod inlet 112,202 Rotating rod 113 Driving device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Washiya 4-1-1 Mizuhara, Itami-shi Kita-Itami Works, Mitsubishi Electric Corporation

Claims (1)

Claim: What is claimed is: 1. A plasma reaction chamber having a gas introduction port for introducing a reactive gas or the like, in which plasma is generated in the chamber, and an electron cyclotron resonance is caused in the plasma reaction chamber. Magnetic field generating means for generating a necessary magnetic field, microwave stirring means for stirring the microwave introduced from the microwave generator through the waveguide, and microwave introducing the stirred microwave into the plasma reaction chamber. Semiconductor manufacturing equipment with wave introduction window.