JPH05144406A - Processing device - Google Patents

Abstract

PURPOSE:To provide a semiconductor heating device which uses a lamp heating technique, and which enables maintenance of uniform temperature over a wafer as a whole with no use of any susceptor. CONSTITUTION:A wafer 1 is disposed within a vacuum vessel 2 having a qualtz window on the underside thereof, and a plurality of lamps 8 are disposed on a turn table 7 under the qualtz window 5 in a manner that they are arranged thereon. The lamps 8 are arranged so that an optical axis 18 of each lamp 8 is situated on the peripheral edge portion of the wafer 1. A rotating axis 10 of the turn table 7 is disposed eccentrically from a center 9 of the arrangement of the lamps 8. A lamp tilting mechanism is provided to each lamp 8 disposed on the turn table 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single wafer processing apparatus for processing wafers one by one, and more particularly to a wafer heating apparatus using lamp heating.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as IC and LSI, a semiconductor substrate such as silicon is repeatedly processed to form a desired semiconductor on a wafer. Processing of such a semiconductor wafer includes processing of forming a thin film on the wafer by sputtering, CVD or the like. In such processing, it is necessary to uniformly and uniformly heat the entire surface of the wafer to grow a thin film on the wafer.
Such wafer heating methods are roughly divided into heating by a heater and heating by a lamp. In the lamp heating, since heat energy is supplied in the vacuum as radiation, the rate of temperature rise depends on the density of the heat transfer medium. Since it does not change, it is being used more often.

FIG. 5 shows an example of heating by a conventional lamp. A wafer 1 made of silicon or the like is placed in a vacuum container 2, and a reaction gas such as silane is supplied onto the wafer. A parallel light beam from a lamp reflector module 8 fixed to the outside of the vacuum container passes through a quartz window 5 and is irradiated, so that the wafer is heated from the lower surface. In the heating by the light beam from such a lamp, the temperature of the portion where the irradiation amount of the light beam is high becomes higher than the temperature of the other portion, so that it is difficult to uniformly heat the entire wafer.

In order to solve this problem, it has been proposed to dispose a susceptor 20 made of quartz, silicon carbide, carbon or the like between the wafer and the lamp. That is, a lamp using a susceptor, which irradiates and heats the susceptor with light, converts the given energy into uniform heat energy, and radiates this heat to the wafer to heat the entire surface of the wafer to a uniform temperature. A heating method has been proposed.

According to such a heating method using radiant heat from the susceptor, the entire surface of the wafer can be heated to a uniform temperature, but a lamp with a large output and a large capacity is required to heat the susceptor, and energy efficiency is improved. Not only does the temperature decrease, but the thermal conductivity of radiant heat varies depending on the pressure of the reaction gas in the vacuum container, so that the heating rate of the wafer varies depending on the pressure of the reaction gas, which complicates temperature control. In addition, since the susceptor contains a trace amount of impurities such as alkali metal, when it is irradiated and heated by a light beam from a lamp, the impurities in the susceptor are released and float in a vacuum container to contaminate a wafer to be processed. There is a risk. Further, in a process such as CVD, when the process or the like changes significantly, the heat radiation from the wafer may differ depending on the process, so the light irradiation pattern may need to be changed. Cannot respond to such changes in the situation. In addition, in order to hold the wafer in the vacuum container, the periphery of the wafer is supported by pusher pins, and the clamp ring is fixed from above the periphery of the wafer, but the heat supplied from below is clamped. Although it escapes through the ring and heat is uniformly supplied to the entire surface of the wafer, the temperature at the peripheral portion of the wafer is lowered.

[0006]

In view of the above problems of the lamp heating type semiconductor wafer processing apparatus, the present invention can uniformly heat the entire surface of a semiconductor wafer by a lamp without using a susceptor, and can also improve the temperature of the clamp ring. (EN) Provided is a processing apparatus having a heating means capable of compensating for heat dissipation and obtaining a uniform temperature over the entire surface of a wafer even if there is heat dissipation. Further, in such a processing apparatus, even if the size of the wafer to be processed changes,
Provided is a processing device capable of easily obtaining an optimum heating pattern.

[0007]

An apparatus for treating an object to be heated placed on a placing means provided in a vacuum container, the apparatus comprising:
A processing apparatus is composed of a plurality of lamps provided so as to face the object to be heated, a rotating body on which the plurality of lamps are circumferentially arranged and mounted, and a drive source for driving the rotating body.

In one embodiment, the plurality of lamps are arranged in substantially the same shape as the outer peripheral edge of the object to be heated.

In another embodiment, the rotary shaft of the rotary body and the center of the lamp array arranged on the rotary body are eccentric.

In still another embodiment, a ramp tilt mechanism for tilting the lamps arranged on the rotating body is provided.

[0011]

[Embodiment 1] FIG. 1 shows a configuration in which the present invention is applied to a sputtering process or a CVD process of a semiconductor wafer.
Will be explained. The semiconductor wafer 1, which is the object to be heated, which is heated to the optimum temperature for performing the above process,
It is mounted on a pusher pin 3 which is a mounting means provided in the vacuum container 2 and is fixed by a clamp ring (not shown). An optical duct 4 whose inner surface is a reflecting surface is provided in the central portion of the vacuum container 2 so that the irradiation light is concentrated and applied to the wafer. At the lower opening of the vacuum container 2, a window 5 made of quartz glass for introducing light from a light source provided outside the container into the vacuum container is airtightly provided, and the vacuum in the container is set to a vacuum degree suitable for wafer processing. (For example, in CVD, a vacuum of about 50 Torr to 10 mTorr) is maintained.

A light source chamber 17 composed of a frame 6 and a housing 15 is provided below the vacuum container 2 and a turntable 7 on which a plurality of lamps 8 are mounted is disposed in the light source chamber 17. The turntable 7 is a shaft 1 driven via a pulley 13 by an induction motor 12 attached to the outside.
It is attached to 1. The rotation center line 10 of the rotation shaft 11 is provided so as to coincide with the center line of the wafer 1, and the turntable 7 is configured to rotate 30 to 60 minutes per minute in the light source chamber. For example, six lamps 8 arranged on the turntable are the rotation center shafts 10 of the turntable 7.
Are arranged at equal intervals along a circumference having a central axis 9 eccentrically provided. Therefore, the rotation locus of the lamp 8 does not become one line, and the rotation center axis 1 of the turntable 7
A plurality of circles having a constant width are formed in the vicinity of the periphery of the wafer with 0 as the center. The plurality of rotating lamps 8 has a slip ring 1 provided below a rotating shaft 11.
4 is provided with power, and around each lamp 8 is provided a reflecting mirror 16 having a parabolic or spheroidal surface in which the filament of the lamp 8 is located at the focal point.

The positional relationship between the center of the array of the wafer 1 and the lamp 8 will be described with reference to FIG. The wafer 1 mounted on the pusher pins 3 is shown in broken lines. The center 9 of the turntable 7 attached to the upper end of the rotary shaft 11 is provided eccentrically from the center 10 of the rotary shaft 11, that is, the center of the wafer, as shown in the figure. Therefore, when the shaft 11 rotates, among the lamps 8 provided on the turntable 7,
The lamp at the 3 o'clock position in the drawing rotates concentrically with the wafer 1 and draws a circle of the smallest diameter. Further, the lamp at the 9 o'clock position in the drawing rotates concentrically with the wafer 1 and draws a circle having the maximum diameter. Similarly, the lamps at the 1 o'clock and 7 o'clock positions and the lamps at the 5 o'clock and 11 o'clock positions in the drawing rotate in circles each having a diameter between the concentric circles. .. As described above, since the plurality of circles drawn by the rotation of the lamp are all located in the peripheral portion of the wafer 1, the amount of light supplied to the wafer is large in the peripheral portion of the wafer. .. Therefore, the amount of heat commensurate with the heat dissipation from the clamp ring in contact with the periphery is supplied to the periphery of the wafer in excess compared to the center, so that the temperature of the periphery and the center of the wafer are uniform. It is maintained, and a uniform reaction proceeds over the entire surface of the wafer, and a wafer having excellent characteristics and uniform characteristics can be obtained.

The relationship between the irradiation intensity of the lamp and the temperature of the wafer is shown in FIG. 4 for the present invention and the prior art. In the case of the technique of uniformly heating the wafer using the conventional susceptor, the distribution of heat applied to the wafer is uniform as indicated by the thick broken line, but since the heat escapes from the clamp ring in contact with the wafer, The temperature of the wafer decreases at the peripheral portion of the wafer as indicated by the thin broken line, and it is not possible to obtain a uniform temperature over the entire surface of the wafer. In the present invention, since the center of the irradiation axis of the heating lamp can be located on the outer peripheral edge of the wafer to be heated, the light irradiation intensity is on the outer peripheral edge of the wafer as indicated by the thick solid line. Is the maximum. Therefore, the heat dissipation from the clamp ring in contact with the wafer can be compensated, and the temperature of the wafer is maintained at a uniform temperature over the entire surface without a difference in temperature between the central portion and the peripheral portion of the wafer as shown by the thin solid line. ..

[Second Embodiment] A second embodiment will be described with reference to FIG. In the second embodiment, the turntable 7
The center of the array of the lamps 8 arranged above is provided coaxially with the rotation center axis 10 of the rotating shaft 11, and the lamps 8 arranged on the turntable 7 are inclined in the radial direction of the array. This embodiment is different from the embodiment shown in FIG. 1 in that the ramp tilting mechanism is provided, and is otherwise the same as the embodiment in FIG. The same reference numerals as in FIG. 1 represent the same elements.

That is, in this embodiment, when the turntable 7 having the lamp array arranged coaxially with the central axis of the wafer 1 is rotated, the lamp 8 provided on the turntable is concentric with the wafer 1. Is rotated. Here, each lamp 8 is configured so as to be able to be rocked and tilted in the radial direction of the lamp arrangement by a lamp tilting mechanism 19 provided in each lamp, and the optical axis 18 can be freely tilted. There is. Therefore, when the inclination angles of the lamps are made different, a plurality of rotation loci of the lamps can be obtained as in the embodiment shown in FIG. 1, and the irradiation amount of light is increased in a wide width as in FIG. be able to. Further, when the inclination angle of each lamp is changed equally, it is possible to easily obtain a light irradiation circle of a desired size corresponding to the size of the wafer, and even if the process changes and the heat radiation pattern changes, A heating pattern corresponding to the change can be obtained quickly and easily.

[0017]

As described above, according to the present invention, since (1) the direct heating system using the lamp is adopted, the wafer can be heated quickly regardless of the pressure of the reaction gas. At the same time, since the lamp is rotated, the irradiation amount of light on the wafer can be made constant in the circumferential direction, and the susceptor required for lamp heating can be dispensed with, and the wafer is contaminated by impurities contained in the susceptor. (2) Since the wafer can be heated so as to compensate for the heat dissipation from the clamp ring by increasing the light irradiation amount at the peripheral portion of the wafer, the temperature of the peripheral portion of the wafer is It is possible to prevent the temperature from becoming lower than that of the above, and it is possible to easily obtain a uniform temperature over the entire surface of the wafer and perform good wafer processing. By eccentric from the center of the rotation axis, it is possible to widen the large range of light irradiation amount. (4) Since the lamp tilt mechanism is provided, the heating region can be freely changed by a simple mechanism. Even if there is a process change such as a change in pressure or gas type, it is possible to obtain an excellent effect that the heating pattern can be promptly dealt with.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement relationship between a wafer and a lamp of the present invention.

FIG. 3 is a diagram showing the configuration of another embodiment of the present invention.

FIG. 4 is a diagram showing heating characteristics of the present invention and a conventional example.

FIG. 5 is a diagram showing an example of conventional lamp heating.

[Explanation of symbols]

1 wafer, 2 vacuum vessels, 3 pusher pins,
4 light ducts, 5 quartz glass windows, 6 frames, 7
Turntable, 8 lamps, 9 lamp array center, 10 rotating shaft center, 11 rotating shaft, 12 induction motor, 13 pulley, 14 slip ring,
15 housing, 16 reflecting mirror, 17 light source room,
18 optical axis, 19 ramp tilt mechanism, 20 susceptor.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hirohiro Kumagai 2-3-1 Nishishinjuku, Shinjuku-ku, Tokyo Tokyo Electron Limited

Claims (4)

[Claims] 1. An apparatus for treating a heated object placed on a placing means provided in a vacuum container, comprising: a plurality of lamps provided facing the heated object; 2. A processing apparatus comprising: a rotating body in which the lamps of FIG. 1 are circumferentially arranged and mounted; and a drive source for driving the rotating body. 2. The processing apparatus according to claim 1, wherein the plurality of lamps are arranged in substantially the same shape as the outer peripheral edge of the object to be heated. 3. The processing apparatus according to claim 1, wherein a rotating shaft of the rotating body and a center of a lamp array arranged on the rotating body are eccentric. 4. The processing apparatus according to claim 1, further comprising a ramp tilting mechanism that tilts the lamps arranged on the rotating body.