JPS61128517A - Production unit for semiconductor - Google Patents

Abstract

PURPOSE:To improve the uniformity of film thickness, and to prevent the deterioration in film quality by dust by mounting a table moving mechanism moving a substrate and an air outlet for discharging a reaction product, etc. CONSTITUTION:A moving table 19 is rocked and shifted in the direction that reaction gases flow, and all of each section of the surface of a substrate 5 are exposed to the reaction gases having several concentration at reapective position in said direction at every same time in said direction, thus equalizing the whole quantities of the reaction gases, to which each section of the surface is exposed, as the result of integration. Consequently, even when concentration distribution along the direction of the flow of the reaction gases is made unequal by the change of the concentration of the reaction gases due to the diffusion and the distubance of flow of the reaction gases, a thin-film having uniform film thickness is formed. A reaction product is discharged outside a device through exhaust paths 25, 26, and does not collect on the table 19.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a method of projecting light onto a reaction gas to cause a photochemical reaction and forming a thin film on a substrate placed in the reaction gas.
The present invention relates to a semiconductor manufacturing apparatus that forms a thin film using a photo-excited CVD method (hereinafter referred to as photo-excited CVD method).

[Conventional technology]

The CVD method is an important technology for forming thin films in integrated circuit devices, but the conventional CVD method mainly heats the reaction gas to cause a chemical reaction, which results in a high reaction temperature. The thin film formed is less susceptible to damage.

Therefore, recently, a photo-excited CVD method has been attracting attention as a low-temperature CVD technique. This photo-excited CVD method uses light as an energy source for CVD. According to this method, the reaction temperature can be lowered compared to conventional thermally-excited CVD methods, plasma CVD methods, etc., and damage to thin films can be reduced. It can be reduced.

Further, it is generally known that in the photo-excited CVD method, the concentration of the reactant gas and the illuminance of the light have a large influence on the thin film formation rate.

Figure 2 shows the basic configuration of a thin film forming apparatus using such a conventional photo-excited CVD method, and Figure 2 shows the m-m of Figure 2.
A line cross-sectional view is shown.

In both figures, 1 is a reaction chamber in which the pressure is reduced to a high vacuum during film formation, 2 is a light source consisting of a linear lamp, 3 is a heater for heating the substrate, 4 is a reaction gas, 5 is a substrate, and 6 is a light source. A light entrance window made of a transparent material, 7 a reaction gas supply port, 8 a gas discharge port for discharging the gas 4a after the reaction, and 9 a table on which the substrate 5 is placed.

In this conventional device, the reaction gas 4 is supplied from the supply lower to the reaction chamber 1.
When introduced into the reactor gas 4, the reaction gas 4 is excited and decomposed by the light beam projected from the entrance window 6. The resulting reaction product is deposited on the substrate 5 heated at a low temperature by the heater 3, and a thin film is formed on the substrate 5. The gas 4a after the reaction is discharged from the discharge port 8.

[Problem that the invention seeks to solve]

In such a conventional thin film forming apparatus, a reaction gas supply lower is provided at one end of the reaction chamber 1, a gas exhaust port 8 is provided at the other end,
Although the reaction gas 4 is made to flow into the reaction chamber 1, it is very difficult to keep the reaction gas 4 flowing from the supply lower to the discharge port 8 at a uniform concentration. That is, reaction gas 4
The reaction gas concentration on the substrate 5 along the flow of the reaction gas 4 is not constant because the reaction gas 4 is diffused in the reaction chamber 1 and the flow of the reaction gas 4 is disturbed near the reaction chamber wall. The reactant gas concentration is high near the gas supply lower, and becomes lower as it approaches the reactant gas outlet 8. For this reason, in the conventional device described above, even if the intensity of the light beam that causes the photochemical reaction, the substrate temperature, etc. are kept constant, the concentration of the reaction gas 4 differs on the substrate 5, so that a high-performance semiconductor with a uniform film thickness can be produced. was difficult to produce efficiently.

In addition, since the above conventional device uses a linear lamp as the light source 2, the illuminance distribution on the substrate 5 due to the linear lamp 2 is not uniform both in the axial direction of the lamp and in the direction perpendicular to the axis. It was difficult to form a thin film with uniform thickness.

Furthermore, in the conventional apparatus described above, there is a problem in that reaction products and the like tend to accumulate around the reaction chamber 1 (this becomes dust and adheres to the substrate 5, degrading the quality of the thin film).

This invention was made to solve these conventional problems, and it is possible to form a thin film with a uniform thickness on a substrate even if the concentration or illuminance of the reactant gas on the substrate becomes non-uniform. It is an object of the present invention to provide a semiconductor manufacturing apparatus that can prevent deterioration of film quality due to dust.

[Means for solving problems]

A semiconductor manufacturing apparatus according to the present invention is provided with a table moving mechanism for moving a substrate and an exhaust port for exhausting reaction products and the like.

[Effect]

In this invention, since the substrate is oscillated in the reaction chamber by a table moving mechanism, the amount of reactive gas and the amount of light energy that contribute to film formation on each part of the substrate are determined by the concentration distribution of the reactive gas over the movement range of the substrate.

The amount corresponds to the integral value of the illuminance distribution, so even if the respective distributions are uneven, the thickness of the thin film formed on the substrate will be uniform in the above-mentioned swing direction, and reaction products etc. will be directed outward. Since the gas is discharged, no dust will accumulate in the reaction chamber, and therefore no dust will adhere to the substrate.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a semiconductor manufacturing apparatus according to an embodiment of the present invention, in which 1 is a reaction chamber, 4 is a reaction gas, and 12 is a plurality of linear lamps arranged at appropriate intervals in the flow direction of the reaction gas. 3 is a heater for heating the substrate, 5 is a substrate, and 6 is a light entrance window made of a light transmitting material.

Further, 7 is a reaction gas supply nozzle, and '8 is a gas 4a after reaction.
The ends of both nozzles 7°8 on the reaction chamber side are connected to a moving table 19 for loading substrates.
extends upward.

Reference numeral 20 denotes a table moving mechanism that swings the moving table 19 along the flow direction of the reaction gas, and this mechanism includes a ball screw 23 screwed into a connector 19a fixed to the table 19, and a ball screw 23 that rotates the moving table 19. It is composed of a motor 24.

Reference numerals 25 and 26 denote exhaust passages, each passage 25 and 26 is disposed between each of the supply nozzle 7 and the discharge nozzle 8 and the moving table 19, and the end thereof on the reaction chamber side is connected to the end of the table 19. It opens at the top, and its rear end is connected to an exhaust device (not shown).

Next, the operation will be explained.

In the apparatus of this embodiment, similarly to the conventional apparatus, the reaction gas 4 introduced into the reaction chamber 1 causes a photochemical reaction by the light beam projected from the entrance window 6, and the substrate 5 is heated at a low temperature by the heater 3. Form a thin film on the surface.

At this time, the moving table 19 is oscillated along the flow direction of the reaction gas, and all parts of the surface of the substrate 5 along the direction are exposed to the reaction gas at each concentration at each position along the direction for the same amount of time. Therefore, the amount of reaction gas to which each part of the surface is exposed is the same as a result of integration. Therefore, even if the concentration distribution along the flow direction of the reactant gas is uneven due to changes in the concentration of the reactant gas due to diffusion of the reactant gas or disturbances in the flow, a thin film with a uniform thickness can be formed. Become.

Furthermore, in this embodiment, a plurality of linear lamps arranged in parallel in a direction perpendicular to the flow direction of the gas is used as the light source 12. Although the illuminance distribution on the substrate 5 along the direction becomes uniform, the illuminance distribution becomes uneven on the substrate 5 along the axial direction of the lamp, which is the flow direction of the gas, as described above. By swinging the substrate 5 in the axial direction, each part of the substrate surface in that direction is exposed to the same intensity of light for the same amount of time, and the film thickness distribution becomes uniform.

In addition, in conventional equipment, the periphery of the substrate loading table has
Although there was a problem that reaction products tend to accumulate, in this embodiment, the reaction products are discharged to the outside of the apparatus through the exhaust passages 25 and 26, and do not accumulate on the table 19. Furthermore, when the reaction gas 4 tries to enter the lower part of the table 19 in the reaction chamber 1, the exhaust passage 25.
26 and the amount of gas entering below the table 19 is reduced.

In this way, in this apparatus, the speed of forming a thin film on the substrate 5 is not affected by changes in the intensity of the light beam or uneven concentration of the reactant gas, and a thin film with a uniform thickness can be efficiently formed over the entire surface of the substrate 5. In addition, since the reaction products generated near the peripheral edge of the table 19 are discharged, this can be prevented from becoming dust and deteriorating the film quality of the substrate 5, and high-performance semiconductors can be manufactured efficiently and at low cost. Furthermore, the amount of reaction gas 4 entering below the table 19 is reduced, and therefore the corrosion resistance of the table moving mechanism 20 can be improved.

In the above embodiment, the substrate is moved in the axial direction of the linear lamp, but the substrate may also be moved in a direction perpendicular to the lamp axis.

〔Effect of the invention〕

As described above, according to the semiconductor manufacturing apparatus according to the present invention, since the table moving mechanism for moving the substrate is provided, the uniformity of the film thickness can be improved, and the exhaust port for exhausting reaction products etc. is provided. The provision of such a film prevents deterioration of film quality due to dust, and has the effect of making it possible to manufacture high-performance semiconductors efficiently and at low cost.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of a semiconductor manufacturing apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional side view of a conventional semiconductor manufacturing apparatus,
FIG. 3 is a sectional view taken along line mm in FIG. 2. 1... Reaction chamber, 12... Light source, 4... Reaction gas,
5... Board, 19... Table, 20... Table moving mechanism, 25.26... Exhaust passage. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) In a semiconductor manufacturing apparatus that projects light from a light source onto a reaction gas in a reaction chamber to cause a photochemical reaction and form a thin film on a substrate placed in the reaction gas, a table on which the substrate is placed is used. 1. A semiconductor manufacturing apparatus comprising: a table moving mechanism for moving the table; and an exhaust passage that opens at the peripheral edge of the table and exhausts reaction products and the like near the peripheral edge.