JPH0465148B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reduced pressure vapor phase growth apparatus for forming a metal thin film on a substrate surface under reduced pressure.

(Prior Art) In recent years, with the miniaturization of semiconductor integrated circuits, there has been a strong demand for the formation of metal films.

An example of a conventional reduced pressure vapor phase growth apparatus will be described below with reference to the drawings.

FIG. 2 shows a conventional reduced pressure vapor phase growth apparatus. A reaction chamber 1 is provided with a reaction gas supply port 2 and a gas discharge port 3 for discharging the reaction gas and reaction product gas. Furthermore, a light-transmissive support stand 5 on which a substrate 4 is placed is installed in the reaction chamber 1 .
Further, an infrared lamp 6 for heating the substrate 4 is attached to the outside of the reaction chamber 1.

The operation of selective growth of a tungsten film will be described below as an example of the reduced pressure vapor phase growth apparatus configured as described above.

The substrate 4 placed on the support stand 5 absorbs the irradiation light from the infrared lamp 6 and is heated to 300 to 650°C. Tungsten hexafluoride and hydrogen are supplied as reaction gases from the gas supply port 2 and are discharged from the gas discharge port 3. The gas outlet 3 is directly connected to a vacuum pump (not shown), and the reaction chamber 1 is maintained at a reduced pressure state.

The reaction gas supplied from gas supply port 3 is 300~
A reaction occurs when the tungsten film reaches the surface of the substrate 4 heated to 650°C, and as a result, the tungsten film
Grow your selection on.

(Problem to be Solved by the Invention) However, in the above configuration, although the light absorption rate of the support base 5 is low, the support base 5 is also heated, so silicon is exposed especially on the back surface of the substrate 4. In this case, tungsten may adhere and accumulate on the portion of the support 5 that is in contact with the periphery of the substrate 4. If tungsten is attached even partially,
When it accumulates, light transmission becomes poor in that area.
Therefore, the light absorption rate increases, the temperature of the support base 5 partially rises, and the area where tungsten is attached further expands.

As a result, the selectivity and reproducibility of tungsten film deposition on the substrate 4 deteriorates, resulting in the problem that the support base 5 must be cleaned again every time a film is grown for several cycles.

(Objective of the Invention) The present invention solves this problem and provides a reduced pressure vapor phase growth apparatus that can form a film with good selectivity and reproducibility without causing a metal film to adhere to a light-transmitting support. With the goal.

(Means for Solving the Problems) The present invention provides a light-transmissive support base on which a substrate is placed, a gas supply unit that supplies a reaction gas to the substrate, and In a reduced pressure vapor phase growth apparatus equipped with a heating section equipped with an infrared lamp that radiantly heats the substrate, and an exhaust section, the light-transmitting support base on which the substrate is placed is cooled with an inert gas, air, or water. The above object has been achieved by using a reduced pressure vapor phase growth apparatus that is forcibly cooled with a medium.

(Function) With the above configuration, the present invention forcibly cools the light-transmitting support base on which the substrate is placed. Therefore, although the substrate is directly heated with an infrared lamp and easily reaches the temperature at which the metal film grows, the support table does not reach that temperature. As a result, adhesion and deposition of the metal film is prevented, cleaning work becomes unnecessary, and film formation with good selectivity and reproducibility becomes possible.

(Example) A reduced pressure vapor phase growth apparatus according to an example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a cross-sectional view of an embodiment of the present invention, and FIG.
The same members as those in the figures are given the same reference numerals and explanations will be omitted.

In FIG. 1, a substrate 4 is placed on a light-transmissive support 5. As shown in FIG. In order to prevent the produced film from adhering and depositing on the back surface of the substrate, the light-transmitting support is made wider than the substrate.

The substrate 4 is heated by the irradiation light from the infrared lamp 6 via both the light-transmitting plate 7 and the light-transmitting support 5 and the cooling chamber 8 narrowed therebetween.

The cooling chamber 8 is provided for the purpose of preventing metal film from adhering.
It is provided in contact with the support stand 5. The cooling chamber 8 includes an inert gas supply port 9 and an inert gas discharge port 10.

To explain the operation of the reduced pressure vapor phase growth apparatus with this configuration, the substrate 4 placed on the light-transmitting support 5 is
The irradiation light from the infrared lamp 6 is absorbed through the light-transmitting plate 7, the cooling chamber 8, and the light-transmitting support base 5, and the temperature is heated to 300 to 650°C. As an example, in the case of selective growth of tungsten, tungsten hexafluoride and hydrogen are supplied as reaction gases from the reaction gas supply port, and are discharged from the gas discharge port 3 directly connected to a vacuum pump (not shown). The reaction chamber 1 is maintained at a reduced pressure of 0.1 to 0.5 Torr.

A light-transmitting inert gas is supplied to the cooling chamber 8 from a gas supply port 9 and is discharged from a discharge port 10 . The reaction gas supplied from the reaction gas supply port 3 is 300
When it reaches the substrate 4, which has been heated to ~650°C, a reaction occurs, resulting in the growth of a tungsten film, but since the support base 5 is cooled by the cooling medium in the cooling chamber 8, the temperature does not reach the temperature at which tungsten can grow. It does not rise and tungsten adheres to the support base 5. Deposition is prevented. Therefore, the light-transmitting support base 5
This eliminates the need for frequent cleaning, and enables film formation with good selectivity and reproducibility.

Although the above example shows the selective growth of tungsten, it is clear that the reduced pressure vapor phase growth apparatus with this configuration can also be used to form selectively grown films of materials other than tungsten. it is obvious.

Furthermore, instead of an inert gas, the cooling medium is
As long as the light transmittance is sufficient, it is also possible to introduce and use air or water.

(Effects of the Invention) As described above, by providing a mechanism that forcibly cools the light-transmitting support base on which the substrate is placed, it is possible to prevent the metal film from adhering to the support base, and to clean the support base. can also be omitted, making it possible to provide explanations with good selectivity and reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a reduced pressure vapor phase growth apparatus according to an embodiment of the present invention. FIG. 2 is a similar diagram of the prior art. 1...Reaction chamber, 2...Reaction gas supply port, 3...
Gas discharge port, 4...Substrate, 5...Light-transparent support stand, 6...Infrared lamp, 7...Light-transparent plate, 8...Cooling chamber, 9...Inert gas supply port, 1
0...Inert gas exhaust port.

Claims (1)

[Scope of Claims] 1. A light-transmissive support base on which a substrate is placed, a gas supply unit that supplies a reactive gas to the substrate, and an infrared ray that radiantly heats the substrate via the light-transmissive support base. A reduced pressure vapor phase growth apparatus comprising a heating section equipped with a lamp and an exhaust section, characterized in that the apparatus is equipped with a mechanism for forcibly cooling a light-transmitting support base on which the substrate is placed. Device. 2. The cooling mechanism is a cooling chamber in contact with the light-transmitting support, and the cooling medium introduced into the cooling chamber is
The reduced pressure vapor phase growth apparatus according to claim 1, characterized in that the inert gas, air, or water having optical transparency is used.