JP2802083B2 - Microwave plasma processing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus in a manufacturing process of a semiconductor or a thin film device.

2. Description of the Related Art In a manufacturing process of a semiconductor or a thin film device, an etching apparatus or a resist asher apparatus using a microwave is used.

This will be described below with reference to the drawings. FIG. 5 is a schematic view of a conventional resist asher device. The vacuum chamber 1 has a gas inlet 2 and an exhaust port 3 and a quartz plate 4
Is resting on a vacuum through an O-ring. 5 is a waveguide for transmitting microwaves, and 6 is a chamber for confining microwaves. Reference numeral 7 denotes a sample stage on which the sample 8 is placed.

Oxygen is introduced at 50 SCCM from gas inlet 2 and the pressure is 0.5 Torr
To keep. The resist is etched by generating a plasma by applying a microwave of 400 W. The etching rate of the resist depends on the temperature of the sample stage 7, 3000Å / min at 20 ° C, and 80Å
00Å / min. Uniformity is ± 15% for 6 inch wafers.

Problems to be Solved by the Invention However, there is a problem that it is difficult to etch a large-diameter substrate of 8 inches or more with high uniformity and high speed in the above configuration. This requires the chamber to have a resonant structure to efficiently introduce microwaves,
This is because the structure is limited.

Means for Solving the Problems In order to solve the above problems, the microwave plasma processing apparatus of the present invention mounts a gas inlet, an exhaust port, and a sample in a vacuum vessel partly constituted by a plurality of quartz bell jars. It is composed of a sample stage to be placed, and a helical coil provided as a microwave radiating antenna on each of the plurality of quartz bell jars.

Function In the present invention, the structure of the chamber can be freely designed because the antenna is used as the microwave radiating means, and since a plurality of microwave radiating antennas are provided, even a large-area substrate can be uniformly processed.

Example (Example 1) Hereinafter, a first example of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a microwave plasma processing apparatus according to a first embodiment of the present invention. In FIG. 1, a vacuum chamber 9 has a gas inlet 10 and an exhaust port 11, and is kept in vacuum via a quartz bell jar 12 and an O-ring. Reference numeral 13 denotes a sample stage on which the sample to be etched 14 is placed. 15a and 15b are waveguides for introducing microwaves, 16a and 16b are microwave radiation antennas, and 17 is a shield for preventing microwaves from leaking outside.

FIG. 2 is a perspective view of the microwave radiation antenna 16a. The inner diameter of the antenna is φ60mm, the outer diameter is φ72mm, the length is 170mm,
Slit width 10mm, slit pitch 30mm, total slit length 1040
mm (integer multiple of half wavelength of microwave).

FIG. 3 is a schematic plan view of the microwave plasma processing apparatus. The microwave radiating antenna units 18, 19, 20 are placed in the vacuum chamber 9.
Are arranged as shown in the figure. Each microwave radiating antenna has the same configuration. FIG. 1 is a schematic view of an AA cross section.

The resist was etched using the microwave plasma processing apparatus configured as described above. As the sample, an 8-inch silicon substrate coated with a resist of 1 μm was used. Oxygen flows 50 SCCM from the gas inlet 10 and the pressure is 0.5 Torr
kept at r. Microwaves were applied to each antenna at a rate of 300 W to etch the resist. The resist etching rate was 5000Å / min when the sample stage temperature was 20 ° C and 12000Å / min when the sample stage temperature was 200 ° C. ± 15% uniformity
It is.

As described above, according to this embodiment, a large-area substrate can be etched with high uniformity and at high speed by using three microwave radiation antennas.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a schematic sectional view of a microwave plasma processing apparatus according to the second embodiment. In FIG. 4, a vacuum chamber 21 has a gas inlet 22 and an exhaust port 23, and is kept in vacuum via a quartz bell jar 24 and an O-ring. Reference numeral 25 denotes a sample table on which the sample 26 to be etched is placed. 27a, 27b
Is a coaxial cable for introducing microwaves, 28a and 28b are microwave radiation antennas, and 29 is a shield for preventing microwaves from leaking outside. Microwaves are introduced by coaxial cable from one microwave oscillator through a distributor to each microwave radiating antenna. The configuration is the same as that of the first embodiment, except for the portion where microwaves are introduced by a coaxial cable.

The same microwave radiating antenna as that of the first embodiment was used. Further, three microwave radiation antenna units are provided as in the first embodiment.

Oxygen flows at 50 SCCM from the gas inlet 22 and the pressure is 0.5 Torr
To keep. Microwaves were applied to each radiating antenna by 200 W to etch the resist. The resist etching rate is 3000 ° / min when the sample stage temperature is 20 ° C, and 8000 ° / min when the sample stage temperature is 200 ° C. Uniformity is ± 10%.

As described above, according to this embodiment, a large-area substrate can be uniformly processed at a high speed. The second embodiment has the advantage that the coaxial cable can be used to reduce the size of the device as compared with the first embodiment, but has the disadvantage that the microwave output cannot be increased too much.

Effect of the Invention The first invention is to provide a plurality of microwave radiating antennas and introduce microwaves with a coaxial cable,
A large area substrate can be uniformly and rapidly plasma-processed. Furthermore, there is an advantage that the use of a coaxial cable allows the size to be reduced as compared with a waveguide.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a microwave plasma processing apparatus according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of a microwave radiation antenna, FIG. 3 is a schematic plan view of the microwave plasma processing apparatus, FIG. 4 is a schematic sectional view of a microwave plasma processing apparatus according to a second embodiment of the present invention, and FIG. 5 is a schematic sectional view of a microwave plasma processing apparatus according to a conventional example. 9 vacuum chamber, 10 gas inlet, 11 exhaust port, 12
... Quartz bell jar, 13 ... Sample stand, 14 ... Sample, 15 ...
Waveguide, 16 ... Microwave radiation antenna.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-299338 (JP, A) JP-A-63-274148 (JP, A) JP-A-62-200730 (JP, A)

Claims (3)

(57) [Claims] 1. A vacuum vessel partially constituted by a plurality of quartz bell jars, a gas inlet, an exhaust port, a sample table on which a sample is mounted, and microwaves provided on the outer periphery of each of the plurality of quartz bell jars. A microwave plasma processing apparatus provided with a helical coil as a radiation antenna. 2. The microwave plasma processing apparatus according to claim 1, wherein the microwave is introduced using a waveguide. 3. The microwave plasma processing apparatus according to claim 1, wherein the microwave is introduced using a coaxial cable.