JP2625756B2 - Plasma process equipment - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a plasma processing apparatus that utilizes electron cyclotron resonance and is used, for example, for manufacturing highly integrated semiconductor devices.

[Prior Art] FIG. 3 is a schematic vertical sectional view when a plasma processing apparatus is configured as a CVD apparatus.
A sample mounting table 37 holding the wafer 38 is installed so that the wafer 38 is opposed to the opening of the plasma generation chamber 31 which is grounded outside the upper wall of the reaction chamber 32. The plasma generation chamber 31 and the reaction chamber 32 are held in a vacuum state using a vacuum pump or the like in advance. A waveguide 33 is connected to the upper part of the plasma generation chamber 31. The other end of the waveguide 33 is connected to a magnetron (not shown), and the microwave generated by the magnetron is transmitted to the opening of the waveguide 33. Is guided into the plasma generation chamber 31 through the dielectric window 38 provided in the first chamber. Excitation coil arranged so as to surround the plasma generation chamber 31
When a direct current is passed through 35, and a required source gas is supplied into the plasma generation chamber 31 from a gas introduction pipe 32 disposed above the plasma generation chamber 31, plasma is generated in the plasma generation chamber 31, A divergent magnetic field having a low magnetic flux density is formed toward the reaction chamber 32, and the plasma ions and the like are projected. Thus, film formation on the surface of the wafer 38 on the sample mounting table 36 is performed.

FIG. 4 is an enlarged vertical sectional view of the vicinity of the connection between the waveguide 33 and the plasma generation chamber 31. The upper wall of the plasma generation chamber 31 has an opening 31b having a diameter larger than the inner diameter of the waveguide 33. The dielectric window 36 having a diameter slightly larger than the diameter of the opening 31b is concentrically provided on the opening 31b via an O-ring 40 for sealing the vacuum state of the plasma generation chamber 31. . The opening 31
A cooling water passage 41 is provided in a peripheral portion of b, that is, a portion located below the O-ring 40, and when a cooling liquid such as water flows into the cooling water passage 41, the cooling water passage 41 is generated when plasma is generated. The deterioration of the O-ring 40 due to the heat generated is prevented.

The periphery of the dielectric window 36 on the upper wall surface of the plasma generation chamber 31 is separated from the dielectric window 36 by a small gap so as to surround the dielectric window 36.
Is slightly higher than the upper surface of the flange 3 and has a flange 3 having the same outer diameter as the outer diameter of the flange 3 on the protrusion 31a.
3a is attached, and the flange 33a is concentrically connected to the open end of the waveguide 33.

[Problems to be solved by the invention]

By the way, in the plasma processing apparatus configured as described above, the lower portion of the O-ring 40 for mounting the dielectric window 36 and sealing the vacuum state in the plasma generation chamber 31 is cooled by the cooling water passage 41. However, the temperature of the upper portion in contact with the dielectric window 36 rises due to the heat generated by the plasma generated by the dielectric window 36. There is a problem that arises. Further, the deterioration of the O-ring does not progress in a low microwave power region of 1 kw or less, but when the microwave power of several times is applied, it rapidly progresses, and the O-ring becomes unusable in a few minutes.

The present invention has been made in view of such circumstances, and reduces the amount of heat transmitted to the O-ring by cooling the dielectric window, reliably prevents the O-ring from deteriorating, and achieves continuous operation at high microwave power. It is an object of the present invention to provide a plasma processing apparatus capable of operating.

[Means for solving the problem]

The plasma processing apparatus according to the present invention is a plasma processing apparatus having a plasma generation chamber in which one end of a microwave waveguide is arranged to face an outside of an opening sealed by a dielectric window, A cooling liquid passage provided between the microwave waveguide connecting the end portions so as to allow heat transfer and the dielectric window and the end portion, or near the end portion of the microwave waveguide outer peripheral portion; And a flow path.

[Action]

A coolant flow passage is provided between the dielectric window and an end of the microwave waveguide that is heat-transferably coupled to the dielectric window or near the end of the microwave waveguide outer peripheral portion. When the coolant flows through the passage, the dielectric window that is in close contact with the coolant through the microwave waveguide is cooled.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings showing the embodiments. FIG. 1 is a longitudinal sectional view showing the vicinity of a connection portion between a waveguide and a plasma generation chamber of a plasma processing apparatus according to the present invention (hereinafter, referred to as the present apparatus).

An opening 31b having a diameter larger than the inner diameter of the waveguide 33 is provided on the upper wall of the plasma generation chamber 31, and a dielectric window 36 having a diameter slightly larger than the hole diameter is concentrically formed on the opening 31b. Is mounted via an O-ring 40 for sealing the vacuum state of the plasma generation chamber 31. A cooling water passage 41 is provided in a peripheral portion of the opening 31b, that is, a portion located below the O-ring 40.

The periphery of the dielectric window 36 on the upper wall surface of the plasma generation chamber 31 is protruded higher than the upper surface of the dielectric window 36 in a short cylindrical shape with a small gap so as to surround the dielectric 36.
The flange 1 having an outer diameter equal to the outer diameter thereof and having a projection 1a having the same diameter as the inner diameter of the projection 31a at the center of the lower surface has the projection 1a fitted therein. The inner diameter of the flange 1 is the same as the inner diameter of the waveguide 33, and the open end of the waveguide 33 is concentrically connected to the upper surface of the flange 1. The flange 1 has a cooling water passage 1b, which is wider than the cooling water passage 41, provided in a circular shape at a position near the tip end surface of the protruding portion 1a, and has a donut plate shape of the protruding portion 1a. A sheet 3 made of, for example, silicone rubber and having the same shape and the same size as the distal end surface of the protruding portion 1a is sandwiched between the distal end surface and the peripheral portion of the upper surface of the dielectric window 36 in close contact with each other.

When such a sheet 3 is interposed, the degree of contact can be increased without depending on the flatness of the opposing surfaces, the thermal conductivity can be increased, and the dielectric window can be prevented from being damaged.

In the apparatus of the present invention configured as described above, during operation, cooling water is supplied from a tank (not shown) to the cooling water passages 1b and 41, and is passed therethrough, so that the dielectric window 36 located below the cooling water passage 1b is provided. Is cooled via the sheet 3. As a result, the temperature of the upper portion of the O-ring 40 in contact with the dielectric window 36 does not rise, and the lower portion of the O-ring 40 is cooled by the cooling water passage 41, so that the O-ring 40 does not become high temperature and deteriorates. Never do.

FIG. 2 is a vertical sectional view of a main part showing another embodiment of the apparatus of the present invention. A dielectric window 36 is installed on an O-ring 40 in the same manner as that shown in FIG. Similarly, a cooling water passage 41 is provided in a lower portion. The projecting portion 31a projecting in a short cylindrical shape so as to surround the dielectric window 36 has its projecting height set to the same height as the upper surface of the dielectric window 36, and the projecting portion 31a and the dielectric A flange 33a having the same outer diameter as that of the protruding portion 31a is tightly fixed on the window 36, and the flange 33a is formed at the open end of the waveguide 33.

The cooling water pipe 22 as the cooling liquid passage is wound around the outer peripheral surface of the waveguide 33 near the flange 33a.

In the apparatus of the present invention configured as described above, the flange 33a is cooled through the waveguide 33 by flowing water or the like through the cooling water pipe 22, and the peripheral edge of the dielectric window 36 which is in close contact with the flange 33a. The temperature of the upper part of the O-ring 40 in contact with the dielectric window 36 does not rise as the part is cooled. Since the lower portion is cooled by the cooling water passage 41 as in the conventional case, the O-ring 40 does not reach a high temperature and does not deteriorate.

As a result, it has been confirmed that the microwave power has been limited to 1 kw or less in the continuous operation of the plasma processing apparatus due to the deterioration of the O-ring in the related art.

In this embodiment, the sheet is used for the one shown in FIG. 1. However, the flange may be directly adhered to the dielectric window without interposing the sheet.
A configuration in which a sheet is used as shown in the drawing may be employed.

Further, in the above-described embodiment, the configuration in which the present invention is applied to the CVD apparatus is described. However, the present invention is not limited to this, and it goes without saying that the present invention can be applied to, for example, an etching apparatus and a sputtering apparatus.

〔effect〕

As described above, according to the present invention, the antenna is provided between the dielectric window and the end of the microwave waveguide coupled to the dielectric window so as to be able to conduct heat, or near the end of the outer periphery of the microwave waveguide. By cooling the dielectric window by the cooling liquid passage, it is possible to suppress a temperature rise in a portion made of a heat-sensitive material such as an O-ring in contact with the window. The present invention has an excellent effect that the microwave power can be set higher accordingly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an essential part of a plasma processing apparatus according to the present invention, FIG. 2 is a longitudinal sectional view of an essential part showing another embodiment, FIG. 3 is a schematic longitudinal sectional view showing the structure of the plasma processing apparatus, FIG. 4 is a partially enlarged longitudinal sectional view of FIG. 3 showing the structure of the conventional device. 1b Cooling water channel, 3 ... Sheet, 22 ... Cooling water pipe, 31 ...
… Plasma generation chamber, 33… waveguide, 36… dielectric window, 40
...... O-ring

Claims (1)

(57) [Claims] 1. A plasma processing apparatus having a plasma generation chamber in which one end of a microwave waveguide is disposed outside an opening sealed by a dielectric window, wherein the dielectric window and the end are connected to each other. The microwave waveguide coupled so as to allow heat transfer, and a coolant flow passage provided between the dielectric window and the end or near the end of the outer periphery of the microwave waveguide. A plasma processing apparatus, comprising: