JPH06333846A - Thin film forming device - Google Patents

Abstract

PURPOSE:To stabilize a base body temperature and reduce the variation of film quality by controlling power supply to light and a heater so as to permit the quantity of heat which is generated by the heater and transmitted to the base body from a support to be almost equal to the quantity of heat which is generated by the conversion of the partial light in the base body and transmitted to the support from the base body. CONSTITUTION:A base body 2 is arranged on a support 3, the base body 2 is heated from both front and rear coated planes by using a heater 4 and a lighting system 12. At that time, power supply to the heater 4 and the lighting system 12 is permitted to be almost equal to the quantity of heat which is generated by the heater 4 and transmitted to the base body 2, and the quantity of heat which is generated by the conversion of partial light from the lighting system 12 in the base body 2 and transmitted to the support 3 from the base body 2. The base body 2 is also controlled to be at the desired temperature. A reaction chamber 1 is supplied with reaction gas 5 and 6. Then, a thin film is formed on the base body 2. Thus, even when the quantity of transmitting heat is varied, equal quantity of heat is transmitted in the both directions, the base body temperature is stabilized and the variation in film forming speed and film quality is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus used for manufacturing semiconductor elements, electronic circuits and the like, and more particularly to a thin film forming apparatus in which the temperature of a substrate is less likely to change with changes in operating pressure.

[0002]

2. Description of the Related Art A thin film forming apparatus occupies an important position in the manufacturing process of semiconductor elements and electronic circuits, especially VLSI. A low pressure CVD apparatus is used to form a silicide film for a gate electrode or a Si ₃ N ₄ film for a LOCOS mask.
Atmospheric pressure CVD equipment is used for the formation of films and SiO ₂ films for interlayer insulation.
A sputtering apparatus is used to form an Al-Si film for wiring, and a plasma CVD apparatus is used to form an SiO ₂ film for interlayer insulation and a SiN film for protection. Further, an ECR-CVD apparatus or an optical device for lowering temperature and damage is used. Practical use of a CVD apparatus and the like is also expected.

Most of these thin film forming apparatuses form a thin film by keeping the substrate at 200 to 900 ° C. by resistance heating through the substrate support from the back surface opposite to the coated surface of the substrate. Since the surface where the base body and the base body support body are in thermal contact is substantially point-shaped and narrow, heat transfer from the base body support body to the base body is not direct heat conduction but mainly heat radiation and viscous flow in the molecular flow region. In the region, heat conduction is carried out through convection gas between the substrate and the substrate support.

[0004]

However, in the thin film forming apparatus of the above-mentioned conventional example, the heat conduction direction is one direction from the substrate support to the substrate.
When the reaction chamber pressure fluctuates beyond the intermediate flow region of about -100 mTorr, there is a problem that the amount of heat transferred through the convection gas fluctuates, the substrate temperature becomes unstable, and the film formation rate and film quality fluctuate.

The object of the present invention is to solve the problems of the conventional example, and the substrate temperature is stable even when the reaction chamber pressure fluctuates beyond the intermediate flow region during and before film formation, and the film formation rate and film quality are improved. It is to provide a thin film forming apparatus in which the fluctuation of

[0006]

The thin film forming apparatus of the present invention comprises a reaction chamber containing a support for holding a coated substrate, a reaction chamber installed in contact with the support, and the substrate being passed through the support. Apparatus comprising heater for heating, means for supplying gas to the reaction chamber, means for exhausting gas from the reaction chamber, and means for irradiating light including visible infrared light absorbed by the substrate The amount of heat generated by the heater and transmitted from the support to the base is approximately equal to the amount of heat generated by conversion of part of the light in the base and conducted from the base to the support. The electric power supplied to the light and the heater is controlled so that

By the above means, even if the pressure in the reaction chamber exceeds the intermediate flow region and the amount of heat transferred through the convection gas fluctuates during and before film formation, the same amount of heat is bidirectionally transferred, so that the substrate temperature becomes stable. A thin film forming apparatus with less variation in film forming speed and film quality becomes possible.

In order to speed up the formation of a thin film and lower the temperature, an exciting means such as plasma or visible ultraviolet light for exciting a reaction gas or a reaction intermediate attached to a substrate may be used.

[0009]

EXAMPLE 1 An example in which the thin film forming apparatus of the present invention is applied to a low pressure CVD apparatus will be described with reference to FIG. 1 is a film forming chamber, 2 is a coated substrate,
Reference numeral 3 is a support for the base 2, 4 is a heater for heating the base 2 via the support 3, 5 and 6 are reaction gases, 7 is exhaust, 12 is a visible infrared light illumination system, and 13 is a light introduction window. .

First, the substrate 2 is placed on the support 3 and the heater 4 and the illumination system 12 are used to heat the substrate 2 from both the front and back sides of the coating. At this time, the electric power supplied to the heater 4 and the illumination system 12 is generated by converting the amount of heat generated in the heater 4 and conducted from the support 3 to the substrate 2 and a part of the light from the illumination system 12 in the substrate 2. The amount of heat conducted from the base 2 to the support 3 becomes substantially equal, and the base 2 is controlled to a desired temperature. Further, by supplying the reaction gases 5 and 6 to the reaction chamber 1, a thin film is formed on the substrate 2.

A Si substrate is used as the substrate 2, a large number of halogen lamps arranged in an array are used as the illumination system 12, and the reaction gas flow rate is 5 and 6 SiH ₄ 120 sccm / NH ₃ 60
When a film was formed under the conditions of 0 sccm, an operating pressure of 10 Torr, and a substrate temperature of 800 ° C., the substrate temperature hardly changed before and after the introduction of the gas, and the unevenness of the film thickness between the wafers was about ± 2%.

Embodiment 2 An embodiment in which the thin film forming apparatus of the present invention is applied to a plasma CVD apparatus will be described with reference to FIG. 1 is a film forming chamber, 2 is a coated substrate, 3 is a support for the substrate 2, and 4 is a substrate 2 via the support 3.
, 5 is a first reaction gas, 6 is a second reaction gas, 7 is an exhaust gas, 8 is a plasma generation chamber, 9 is a quartz tube,
10 is a 13.56 MHz high frequency electrode, 11 is a quartz tube 9
Is a magnet for generating a magnetic field parallel to the tube wall, 12 is a visible infrared light illumination system, and 13 is a light introduction window.

First, the base 2 is placed on the support 3, and the heater 2 and the illumination system 12 are used to heat the base 2 from both the front and back sides of the coating. At this time, the electric power supplied to the heater 4 and the illumination system 12 is generated by converting the amount of heat generated in the heater 4 and conducted from the support 3 to the substrate 2 and a part of the light from the illumination system 12 in the substrate 2. The amount of heat conducted from the base 2 to the support 3 becomes substantially equal, and the base 2 is controlled to a desired temperature. Further, by supplying the reaction gases 5 and 6 to the reaction chamber 1 and supplying a high frequency to the high frequency electrode 10, a thin film is formed on the substrate 2. A Si substrate is used as the substrate 2, a large number of halogen lamps arranged in an array are used as the illumination system 12, the reaction gas flow rate is N ₂ 800 sccm, the reaction gas flow rate is 6 SiH ₄ 80 sccm, and the operating pressure is 10 mTorr.
When a film was formed under conditions of r, substrate temperature of 300 ° C., and rf power of 500 W, the substrate temperature hardly changed before and after gas introduction, film formation can be started immediately after gas introduction, and the film thickness between wafers and hydrogen content can be increased. Rate unevenness is about ± 3% and about ± 2, respectively
% Was good.

In this embodiment, the plasma generating means 1
High frequency of 3.56MHz was used, but 1-300MHz
Or a microwave of 0.8-5.0 GHz may be used. Although the magnetic field barrel type capacitive coupling is used as the structure of the plasma generating portion, it may be inductive coupling or parallel plate.

Embodiment 3 An embodiment in which the thin film forming apparatus of the present invention is applied to an optical CVD apparatus will be described with reference to FIG. 1 is a film forming chamber, 2 is a coated substrate, 3
Is a support for the substrate 2, 4 is a heater for heating the substrate 2 through the support 3, 5 and 6 are reaction gases, 7 is exhaust gas, 12 is a visible infrared light and ultraviolet light illumination system, and 13 is a light introduction window. Is.

First, the substrate 2 is placed on the support 3 and the heater 4 and the illumination system 12 are used to heat the substrate 2 from both the front and back surfaces of the coating. At this time, the electric power supplied to the heater 4 and the illumination system 12 is generated by converting the amount of heat generated in the heater 4 and conducted from the support 3 to the substrate 2 and a part of the light from the illumination system 12 in the substrate 2. The amount of heat conducted from the base 2 to the support 3 becomes substantially equal, and the base 2 is controlled to a desired temperature. Further, by supplying the reaction gases 5 and 6 to the reaction chamber 1, a thin film is formed on the substrate 2.

A Si substrate is used as the substrate 2, and a large number of low-pressure mercury lamps and halogen lamps alternately arranged in an array are used as the illumination system 12, and a reaction gas flow rate of 5 and 6 is set to Si ₂ H ₆ 9
When a film was formed under the conditions of 0 sccm / N ₂ O 1 slm, operating pressure of 5 Torr, and substrate temperature of 250 ° C., the substrate temperature hardly changed before and after introducing gas, and the unevenness of the film thickness between wafers was about ± 2%. .

In this embodiment, a large number of low-pressure mercury lamps and halogen lamps, which are alternately arranged in an array, are used as the illumination system 12, but the light absorbed by the gas and the light absorbed by the substrate and converted into heat are used. Anything that can be irradiated can be used.

Embodiment 4 An embodiment in which the thin film forming apparatus of the present invention is applied to a photo-assisted plasma CVD apparatus will be described with reference to FIG. 1 is a film forming chamber,
2 is a coated substrate, 3 is a support for the substrate 2, 4 is a heater for heating the substrate 2 via the support 3, 5 is a first reaction gas, 6
Is the second reaction gas, 7 is the exhaust gas, 8 is the plasma generation chamber, and 9 is
Is a quartz tube, 10 is a high frequency electrode, 11 is a magnet that generates a magnetic field parallel to the tube wall of the quartz tube, 12 is a visible infrared light and near-ultraviolet light illumination system, 13 is a light introduction window, and 14 is a film forming chamber 1. And a plasma transparent separation plate for separating the plasma generation chamber 8 from each other.

First, the base 2 is placed on the support 3, and the heater 2 and the illumination system 12 are used to heat the base 2 from both the front and back sides of the coating. At this time, the electric power supplied to the heater 4 and the illumination system 12 is generated by converting the amount of heat generated in the heater 4 and conducted from the support 3 to the substrate 2 and a part of the light from the illumination system 12 in the substrate 2. The amount of heat conducted from the base 2 to the support 3 is equalized, and the base 2 is controlled to a desired temperature. Furthermore, the reaction gases 5 and 6 are supplied to the reaction chamber 1,
By supplying a high frequency to the high frequency electrode 10, a thin film is formed on the substrate 2.

A Si substrate is used as the substrate 2, an Xe lamp is used as the illumination system 12, and the flow rate of the first reaction gas is O _{2 2} sl.
m, the second gas 6 flow rate TEOS 500 sccm, the operating pressure 0.1 Torr, and the substrate temperature 250 ° C. When the film was formed, the substrate temperature hardly changed before and after the introduction of the gas, and the unevenness of the film thickness and hydrogen content between the wafers was observed. Is about ± 3%,
It was good at about ± 2.5%.

[0022]

As described above, the amount of heat generated by the heater and transmitted from the substrate support to the substrate and the amount of heat generated by conversion of a part of light in the substrate and transmitted from the substrate to the substrate support are as follows. By controlling the light and the electric power supplied to the heater so as to be almost equal, bidirectional etc. even if the reaction chamber pressure exceeds the intermediate flow region and the amount of heat transferred through the convection gas fluctuates during and before film formation. Since the amount of conduction is constant, the temperature of the substrate becomes stable, and there is an effect that a thin film forming apparatus in which the film forming speed and the film quality are little changed can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a low pressure CVD apparatus embodying the present invention.

FIG. 2 is a sectional view of a plasma CVD apparatus embodying the present invention.

FIG. 3 is a cross-sectional view of a photo-CVD apparatus embodying the present invention.

FIG. 4 is a sectional view of a photo-assisted plasma CVD apparatus embodying the present invention.

[Explanation of symbols]

1 Film Forming Chamber 2 Coated Substrate 3 Support for Substrate 2 4 Heater for Heating Substrate 2 via Support 3 5 First Reaction Gas (or Reaction Gas) 6 Second Reaction Gas (or Reaction Gas) 7 Exhaust 8 Plasma generation chamber 9 Quartz tube 10 High frequency electrode 11 Magnet that generates a magnetic field parallel to the tube wall of the quartz tube 9 Illumination system 13 Light introduction window 14 Porous transparent separation plate that separates the film formation chamber 1 and the plasma generation chamber 8

Claims (5)

[Claims] 1. A reaction chamber containing a support for holding a coated substrate therein, a heater installed in contact with the support to heat the substrate through the support, and a gas is supplied to the reaction chamber. And a means for evacuating gas from the reaction chamber, and a means for irradiating light including visible infrared light absorbed by the substrate, the thin film forming apparatus comprising: The light and the heater are supplied so that the amount of heat transferred from the support to the base and the amount of heat generated by conversion of part of the light in the base and transferred from the base to the support are approximately equal. A thin film forming apparatus characterized by controlling electric power to be applied. 2. The thin film forming apparatus according to claim 1, wherein the light includes ultraviolet light absorbed by the gas. 3. The thin film forming apparatus according to claim 1, further comprising plasma generating means for supplying high-frequency or microwave power to the reaction chamber. 4. A plasma generating chamber adjacent to the reaction chamber, means for independently supplying gas to the reaction chamber and the plasma generating chamber, and means for supplying high frequency or microwave power to the plasma generating chamber. The thin film forming apparatus according to claim 1, which comprises. 5. The thin film forming apparatus according to claim 4, wherein the light includes visible ultraviolet light that is absorbed by a reaction intermediate attached on the substrate.