JPS62144318A - Thin film manufacturing apparatus - Google Patents

Abstract

PURPOSE:To reduce dispersion in film thickness in the radius direction of a susceptor, by obtaining the distribution of the thickness of a thin film based on heat radiation ratio in two wavelength bands, which are obtained by measuring infrared radiation rays reflected by various points on a substrate by a dichroic radiation thermometer, and based on the displacement of a reflecting mirror, and equalizing the distribution of the thickness of the thin film, which is formed based on the film thickness distribution data. CONSTITUTION:Infrared radiation rays are emitted from a substrate 2 through a quartz window 7. The rays are reflected by a rotary reflecting mirror 8, which is provided over the quartz window 7, and sent to a dichroic radiation thermometer 9. The dichroic radiation thermometer 9 and the rotary reflecting mirror 8 are connected to a computer 10. By the processing in the computer 10, the distribution data of the thickness of a thin film on the substrate in the circumferential direction and the radial direction of a susceptor 1 is obtained. Based on the thickness distribution data of the thin film, a signal is sent to a flow rate regulating valve 11, which is provided in a raw- material-gas feeding line. The flow rate of the raw material gas 6 is regulated, and the thickness distribution of the thin film is adjusted.

Description

[Detailed Description of the Invention] [Required 4] When growing a thin film on a heated substrate on a rotating susceptor, the thickness of the thin film at each part of the substrate is measured with a two-color radiation thermometer by displacing a reflecting mirror, and the thickness of the thin film is measured in the radial direction of the susceptor. By controlling the thin film growth conditions, a thin film with uniform thickness can be obtained.

[Industrial application field]

The present invention relates to a rotating susceptor type thin film manufacturing apparatus for forming a thin film of uniform thickness on a substrate.

One method for monitoring film thickness when forming a thin film on a substrate by CVD or the like is to calculate the film thickness from the interference waveform pattern of infrared radiation from the substrate surface. In this method, in a vertical growth furnace, a thin film is grown by placing the substrate on a rotating heating susceptor inside a Herjar, and a measurement window is provided above the Herjar, and infrared radiation from the substrate passes through this. is received by a fixed monochromatic radiation thermometer,
The film thickness is determined by the interference waveform pattern due to multiple interference occurring between the substrate surface and the growing thin film surface. However, since the radiation thermometer is fixed, the thickness of the thin film can only be measured on a fixed radius of the rotating susceptor, that is, in the direction of rotation of the susceptor, and the thickness distribution of the thin film in the radial direction of the susceptor can only be obtained. That was difficult.

However, since the thickness distribution of the thin film on the substrate is more varied in the radial direction of the susceptor than in the rotational direction of the susceptor, the growth conditions need to be adjusted in the radial direction of the susceptor.

Furthermore, since a monochromatic radiation thermometer measures the absolute value of light intensity in one wavelength band, the film thickness estimation accuracy is not necessarily high due to deviations from the reference value due to the accumulation of reaction products on the measurement window and other disturbances. However, these improvements were desired.

[Conventional technology]

The substrate is placed on a rotating susceptor inside the Herjar, the susceptor is heated from the outside with a coil, and a raw material gas is introduced from above to grow a thin film on the substrate, but the thickness of the thin film can be monitored using conventional methods. Infrared radiation from the substrate surface and thin film surface is measured using a fixed one-color radiation thermometer through a quartz window provided above. Since the susceptor is rotating, the thickness of the thin film on a certain radius of the susceptor can be measured. What a radiation thermometer can directly measure is the intensity of interference light at one specific wavelength, but if you decide on the number of waveform repetitions and the intensity of interference light, you can determine the film thickness from this and automatically stop the reaction. It can be done.

[Problem that the invention seeks to solve]

Thin film production equipment that uses conventional fixed monochromatic radiation thermometers to measure film thickness cannot measure the film thickness distribution in the radial direction of the susceptor, which has large variations in thin film. Therefore, it is necessary to reduce the film thickness variation in this direction. was difficult.

Furthermore, since a monochromatic radiation thermometer is used, it cannot be said that the accuracy of the measured film thickness value is sufficiently high.

[Means for solving problems]

The solution to the above problem is that in a thin film manufacturing device that is placed on a rotating susceptor and forms a thin film on a heated substrate, infrared radiation from each point on the substrate is reflected in a fixed optical path. a movable reflecting mirror that receives reflected infrared radiation, and a two-color radiation thermometer that can measure the thermal radiation ratio of two wavelength bands; This is achieved by the thin film manufacturing apparatus according to the present invention, which is equipped with an automatic control system that determines the film thickness distribution of the thin film from the thermal radiation ratio and the displacement of the reflector, and uses this film thickness distribution data to uniformize the film thickness distribution of the thin film to be formed. be done.

[Effect]

The present invention uses a movable reflecting mirror to measure the heat radiation ratio in two wavelength bands using a two-color radiation thermometer for infrared radiation including multiple interference light extending from the inner circumference to the outer circumference of the susceptor. The accuracy of thickness measurement values can be increased. Furthermore, since the film thickness distribution in the radial direction of the susceptor can also be measured, this can be processed by a computer to automatically control the film thickness growth rate in the radial direction of the susceptor to be uniform.

Embodiment C) FIG. 1 is a diagram of a thin film manufacturing apparatus with a rotating reflecting mirror according to the present invention.

In the figure, reference numeral 1 denotes a rotatable susceptor. A substrate 2 on which a thin film is to be grown is placed on the upper surface of the susceptor 1, and heated by a coil 3 from outside of a Pelger 4, which is a growth furnace. A raw material gas 6 for thin film growth is supplied from a nozzle 5 installed above the Pelger 4, and a thin film (not shown in the figure) is grown and deposited on the upper surface of the heated substrate 2. 7 is a quartz window installed above the Pelger 4 for measuring film thickness.

Infrared radiation emitted by the substrate 2 that comes out through the quartz window 7 is reflected by a rotating reflector 8 installed above the quartz window 7 and sent to a two-color radiation thermometer 9.

The two-color radiation thermometer 9 receives the light as a narrow spot on the substrate 2, and measures the intensity ratio of two specific wavelength bands. Since it is an intensity ratio, deposition of reaction products on the measurement window 7 is canceled because the influence on the two wavelength bands is equal.

The rotating reflecting mirror 8 rotates in the X and Y directions, which are directions in which light from each point on one radius of the susceptor 1 is sent to the two-color radiation thermometer 9.

The relationship between the rotational direction XY of the rotary reflecting mirror 8 and the measurement position on the susceptor 1 is shown in FIG.

FIG. 2 is a view of the susceptor 1 seen from above, and in this figure, the Xa force direction and the Ya force direction on the susceptor 1 are
This corresponds to the X direction and Y direction of the rotating reflecting mirror 8 in the figure, respectively.

Again, in FIG. 1, the two-color radiation thermometer 9 and the rotating reflector 8 are each connected to the computer 10, and the computer 10 processes the thin film on the substrate 2 in the circumferential direction and radial direction of the susceptor 1. The film thickness distribution data can be obtained. Based on the film thickness distribution data of this thin film, the flow f installed in the raw material gas supply line is determined by the computer 10.
A signal is sent to the i adjustment valve 11, and by adjusting the flow rate of the source gas 6, the film thickness distribution of the thin film is adjusted.

In this method, although the angle between the optical path of the infrared radiation to be measured and the substrate 2 is not always constant, the distance between the substrate 2 and the rotating reflection a8 is normally large enough for the diameter of the substrate 2, so
The phase difference correction based on the angular change with respect to the interference light intensity can be omitted.

In the embodiments shown in Figures 1 and 2, a rotating reflector was used as the movable reflector, but by horizontally moving a 45° inclined reflector, the reflected light can be fixed at a two-color radiation temperature. It can be easily sent to the computer. According to this method, the radiation light is always measured in a direction at a constant angle with respect to the substrate surface, so there is no error due to angle changes.

The following configurations of the substrate and thin film can be applied.

Si on 5apphire,,Poly Si
on Sin,, 5iOz on Si, 5iO
z on Al [Effects of the Invention] As described in detail above, according to the thin film manufacturing apparatus according to the present invention, a thin film with a uniform thickness can be grown.

[Brief explanation of drawings]

FIG. 1 is a diagram of a thin film manufacturing apparatus with a rotary reflector according to the present invention, and FIG. 2 is a diagram showing the relationship between the rotation direction of the rotary reflector and the measurement position on a susceptor according to the present invention. In the figure, 1 is a susceptor, 2 is a substrate, 3 is a coil, 4 is a herger, 5 is a nozzle, 6 is a source gas, 7 is a quartz window, 8 is a rotating reflector, 9 is a two-color radiation thermometer, 10 is a Computer, 11 is the flow rate regulating valve 10. Application No. 286211 2, Name of invention Thin film manufacturing device 3, Person who performs M correction Relationship with Hanyu Patent applicant address 1015 Kamiodanaka, Nakahara-ku, Yozaki-shi, Kanagawa (5)
22) Name: Fujitsu Co., Ltd. Company 4, Agent address: 1015 Kamiodanaka, Nakahara-ku, Yozaki-shi, Kanagawa Prefecture February 25, 1986 (Delivery date) 6. Drawing subject to amendment ω4 round A1 (mi.

Claims (1)

[Claims] A thin film manufacturing apparatus that is placed on a rotating susceptor and forms a thin film on a heated substrate includes a movable reflecting mirror that reflects infrared radiation from each point on the substrate into a fixed optical path; A two-color radiation thermometer that can measure the thermal radiation ratio in two wavelength bands by receiving infrared radiation, and the thermal radiation ratio in the two wavelength bands measured by this two-color radiation thermometer and the displacement of the reflector 1. A thin film manufacturing apparatus comprising: an automatic control system that determines the film thickness distribution of the thin film and uses the film thickness distribution data to uniformize the film thickness distribution of the thin film to be formed.