JPS62101021A - Semiconductor manufacturing equipment - Google Patents

Abstract

PURPOSE:To heat and control a substrate quickly, and to form a thin-film, which is heated uniformly and has equal film quality, by forming a susceptor, on which the substrate is placed, in a reaction chamber in two layer structure of layer having high thermal conductivity and a layer having high thermal emissivity or three layer structure in which both sides of the layer having high thermal conductivity are held by the layers having high thermal emissivity. CONSTITUTION:A susceptor 8 consists of two layers of a layer 8a having high thermal conductivity and a layer 8b having high thermal emissivity to infrared beams from an infrared-ray lamp 3. The susceptor 8 absorbs infrared beams projected through an infrared-beam entrance window 7 from the infrared-ray lamp 3 by the layer 8b having high thermal emissivity and is heated efficiently, and is composed so that heat is transmitted over a substrate 5 rapidly equally by the layer 8a having high thermal conductivity, thus uniformly heating the substrate 5 efficiency. An air gap 12 is formed between the substrate 5 and the susceptor 8 while the susceptor 8 may be shaped in a so-called three layer structure in which both sides of the layer 8a having high thermal conductivity are held by layers 8b, 8c having thermal emissivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a semiconductor manufacturing method using a photo-excited CVD method, in which light is projected onto a reaction gas to cause a photochemical reaction, and a thin film is formed on a substrate placed in the reaction gas. This relates to manufacturing equipment.

[Conventional technology]

The CVD method (chemical vapor deposition method) is an important technique for forming thin films in integrated circuit devices, and the conventional CVD method mainly heats a reaction gas to cause a chemical reaction. As a result, the reaction temperature becomes high, and the thin film thus formed is easily damaged. Therefore, recently, the photoexcitation CVD method has been attracting attention as a low-temperature CVD technique. This photo-CVD method uses light as an energy source for the CVD method. According to this method, the reaction temperature can be lowered compared to conventional thermally excited CVD methods or plasma CVD methods, and it is possible to reduce the amount of damage to the thin film surface. Damage caused by ions and the like can also be reduced.

Generally, in the photo-excited CVD method, it is known that the intensity of light has a large influence on the thin film formation rate 'Il'. Further, under conditions where the substrate temperature, the composition ratio of the reaction gas, and the pressure are kept constant, the thin film formation rate increases by 1 in proportion to the illuminance of light. Furthermore, under conditions where the composition ratio and pressure of the reaction gas are kept constant, the etching rate of the film slows down as the substrate temperature increases. That is, the characteristics of the thin film change due to changes in substrate temperature.

FIG. 4 is a sectional view showing a semiconductor manufacturing apparatus for forming a thin film by a conventional photo-excited CVD method. In Figure 4, (1) is a reaction chamber, (2) is a light source consisting of a linear lamp, and (3) is a substrate (
(5) is an infrared lamp that heats the reactant gas, (4) is the reactant gas, (6 is
) is a light entrance window made of a light transmitting material, (7) is a light entrance window made of an infrared light transmitting material, and (8) is a light entrance window that completely holds the substrate (5) and absorbs infrared light. The susceptor, which heats (
9) is a holding stand for the susceptor (8) made of a heat insulating material, αO is the supply port for the reaction gas (4), (1υ is the gas after the reaction (4a)
)' is the outlet for discharging the air. Note that the inside of the reaction chamber (1) is generally reduced to a high vacuum state, so the wall of the reaction chamber (1) and the light entrance window (6) made of a light-transmitting material
, (7) naturally has a structure that can withstand this pressure, plate J9VC.
Of course, it is composed of In addition, FIG. 5 shows a configuration in which a gap t13 is provided between the substrate (5) and the susceptor (8) in FIG. 4.

In these conventional devices, the reaction gas (4) is supplied to its supply port 00.
When the reaction gas (4) is introduced into the reaction chamber (1) from
is excited and decomposed by the light beam projected from the light entrance window (6). The resulting reaction product becomes the susceptor (
8), a thin film is formed by depositing on the substrate (5) heated to a relatively low temperature. In addition, the gas (4a) after the reaction
is discharged from the discharge port (lυ).

Furthermore, in the photo-excited CVD method, since the film quality of the thin film is generally affected by changes in the substrate temperature, it is necessary to keep the substrate temperature uniform throughout. For this reason, in the conventional device, the distribution of the infrared rays on the susceptor (8) is made uniform, and the arrangement of the infrared lamps (3) and the density of the filaments of the infrared lamps (3) are all properly controlled.

The entire susceptor (8) had to be heated evenly.

[Problem that the invention seeks to solve]

The conventional semiconductor manufacturing apparatus is configured as described above, and it is desirable that the susceptor (8) efficiently absorbs infrared rays from the infrared lamp (3) and is heated in a short time. In order to arbitrarily control the temperature of the substrate (5), it is desirable to respond quickly to the output of the infrared lamp (3). Therefore, the susceptor (8) placed in the high vacuum reaction chamber (1) needs to have a high heat absorption rate (emissivity) for the infrared rays from the infrared lamp (3). On the other hand, heat from the substrate (5) is removed by convection caused by the flow VC of the reaction gas (4), radiation from the surface of the substrate (5) to the inner wall of the reaction chamber (1), and heat is removed from the surface of the substrate (5) by The heat dissipated above varies depending on the direction of the gas flow of the reaction gas (4), the shape of the reaction chamber (1), etc., and is not necessarily uniformly dissipated.

Therefore, even if the heat resistance distribution from the infrared lamp (3) to the susceptor (8) is uniform, a temperature gradient occurs within the susceptor (8). In order to reduce this temperature gradient, it is desirable to use a material with high thermal conductivity for the susceptor (8).

For the above reasons, Sassehuta (8) is an infrared lamp (3)
It is desirable that the material has a high heat absorption rate (emissivity) with respect to infrared rays from the outside, and also has a high thermal conductivity.

Moreover, it must be made of a material that will not contaminate the substrate (5) when heated.

In conventional semiconductor manufacturing equipment, the material of the susceptor (8) is aluminum, stainless steel, quartz glass, carbon graphite, or the like. However, although aluminum has high thermal conductivity, it has a low absorption rate (emissivity) for infrared light from the infrared lamp (3), and stainless steel has a low absorption rate (emissivity) for infrared light from the infrared lamp (3). It has a high absorption rate (emissivity) for external light, but a relatively low thermal conductivity. In addition, in the case of quartz glass, infrared lamps (3
) and fuel conductivity are both low for infrared light from the infrared lamp (3). Although it also has high thermal conductivity, when heated to high temperatures, the carbon inside may fly out and contaminate the entire substrate (5). For this reason, in conventional equipment, carbon graphite is completely coated with silicon carbide (StC) in an attempt to prevent gold contamination, but this is not always sufficient.

This invention was made to solve the above-mentioned problems, and it quickly responds to the output light of the infrared lamp (3) and controls the heating of the susceptor (8). 5) The purpose is to obtain a semiconductor manufacturing device that can heat the entire area uniformly.

[Means to solve all problems]

In the semiconductor manufacturing apparatus according to the present invention, a susceptor on which a substrate is placed in a reaction chamber has two layers, a layer with high thermal conductivity and a layer with high thermal emissivity, or a layer with high thermal conductivity and a layer with high thermal emissivity. 6N inserted in the high rate layer! It is structured.

[Effect]

In this invention, since the susceptor is provided with a layer having a high thermal emissivity, heating of the substrate can be quickly controlled.

Furthermore, since the layer with high thermal conductivity is provided, the substrate is heated uniformly, thereby making it possible to form a thin film with uniform film quality.

[Embodiments of the invention]

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

In Figure 1, the susceptor (8) is a layer with high thermal conductivity (
It consists of two layers: 8a) and a layer (8b) having a high thermal emissivity with respect to infrared light from the infrared lamp (3). Note that other parts are the same as those of the conventional device shown in FIG. 4, so their explanation will be omitted.

Next, the effects of the above embodiment will be explained.

In this device, the susceptor (8) is an infrared lamp (3)
The infrared light projected from the infrared light through the infrared light incident window (7) is absorbed by the layer (8b) with high thermal emissivity and is efficiently heated.
Moreover, since the structure is such that heat is quickly and uniformly transferred to the substrate (5) by /1t (8a) having high thermal conductivity, the substrate (5) is heated uniformly and efficiently. When the reactant gas (4) is introduced into the reaction chamber (1) from the supply port α4, this reactant gas (4) is excited and decomposed by the light beam projected from the light incidence window (6). The reaction product is deposited on the substrate (5) which is uniformly heated at a relatively low temperature by the susceptor (8), thereby forming a thin film of uniform quality. In addition, the gas (4a) after the reaction is discharged from the exhaust port 0.
It is discharged from υ.

Here, the layer (8b) with a high thermal emissivity needs to be a relatively thin layer as long as it absorbs infrared rays efficiently, and the layer (8a) with a high thermal conductivity is a layer with a relatively thin thickness. It may be plated or coated.

2 and 6 show cross-sectional views of devices according to other embodiments of the invention. That is, in the embodiment shown in FIG. 1, the substrate (5) is brought into close contact with the susceptor (8) to transmit 7f of heat, but in the embodiment shown in FIG.
) and provide a gap Q'2 between the susceptor (8).
This is a so-called three-layer VC structure in which a layer (8a) with high thermal conductivity is sandwiched between layers (8b) and (8c) with high thermal emissivity.

The susceptor (8) is heated by an infrared lamp (3), and as shown in the embodiment of FIG. A two-layer structure including a layer (8d) and a layer (8c) having a high thermal emissivity may be used.

〔Effect of the invention〕

As described above, according to the semiconductor manufacturing apparatus according to the present invention, a thin film of uniform quality can be formed on a uniformly ducked substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a semiconductor manufacturing apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are sectional views of semiconductor manufacturing apparatuses according to other embodiments of the invention, and FIGS. FIG. 3 is a cross-sectional view of each conventional device. In the figure, (1) is a reaction chamber, (2) is a linear lamp light source, (
3) is an infrared lamp, (4) is a reactive gas, (5) is a substrate, (6) is a light entrance window made of a light transmitting material, (7) is an infrared light entrance window made of an infrared light transmitting material, ( 8) is a susceptor, (8
a) is a layer with high thermal conductivity, (8b) is a layer with high thermal emissivity, (8d) is a layer with high thermal conductivity containing a resistance heater, (
9) is a susceptor holding stand made of a heat insulating material, 00 is a reaction gas supply port, αυ is a reaction gas discharge port, and uz is a void. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In a semiconductor manufacturing device 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 susceptor on which the substrate is placed. is a semiconductor manufacturing device characterized by having a two-layer structure including a layer with high thermal conductivity and a layer with high thermal emissivity. (2) A susceptor on which the substrate is placed 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. is a semiconductor manufacturing device characterized by having a three-layer structure in which a layer with high thermal conductivity is sandwiched between a layer with high thermal emissivity. (3) The semiconductor manufacturing apparatus according to claim 1, wherein the susceptor has a two-layer structure including a layer with high thermal conductivity and a layer with high thermal emissivity that includes a built-in resistance heater.