JPH05335252A - Semiconductor thin film manufacturing device - Google Patents

Abstract

PURPOSE:To reduce the cost of manufacturing a semiconductor thin film and to improve uniformity of the thin film by using raw material effectively by enabling promotion of decomposition of group V raw material alone in an area near a wafer and by providing a structure which prevents group III raw material from being exhausted in a down stream regarding a structure of a raw gas introduction port. CONSTITUTION:This device is provided with a reaction chamber 5, a group V raw gas introduction tube introduced into the reaction chamber 5, a group III raw gas introducing tube provided to a periphery of the group V raw gas introduction tube and introduced into the reaction chamber 5 separately from the group V raw gas, an umbrella-like heat screening board 3 provided to a periphery of an end of the group V raw gas introduction tube inside the reaction chamber 5 and a heater 4 provided in opposition to the screening board 3. A first space is provided between the heat screening board 3 and an inner wall of the reaction chamber 5, and group III raw gas is introduced onto a wafer 7 through the first space. A second space is provided between the heat screening board 3 and the heater 4 and group V raw gas is introduced onto the wafer 7 through the second space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barrel type semiconductor thin film manufacturing apparatus, and more particularly to the structure of a raw material gas inlet.

The vacuum barrel type vapor phase growth (CVD) furnace is excellent in mass productivity, but has a problem of low raw material use efficiency. In particular, the use efficiency of the group V raw material is remarkably low at 1% or less. In addition, hydrides such as arsine and foshin are usually used as the group V raw material, but recently, organic materials such as tVA (tertiary butyl arsine) tend to be used to improve safety. In this case, since the use efficiency of the group V raw material greatly affects the wafer price, it is necessary to use the group V raw material efficiently.

[0003]

2. Description of the Related Art FIG. 3 is an explanatory view of a conventional barrel type film forming apparatus. In the figure, 31 is a reaction chamber, a bell jar, 32 is a source gas introduction port, 33 is an exhaust port, 34 is a susceptor for holding a wafer, and 35 is a wafer.

Conventionally, both group III and group V raw materials are introduced into the bell jar 31 through one inlet 32 and follow the same route,
It has reached the surface of the wafer 35. If the upstream temperature is increased in an attempt to accelerate the decomposition of the group V raw material, the decomposition of the group III raw material is also promoted, and the amount of deposits on the upstream increases and the raw material reaching the wafer decreases. And at the same time, large variations occur in the film thickness and composition on the upstream and downstream sides. This will decrease to some extent if the temperature near the upstream of the wafer is lowered, but this will adversely affect the film quality.

[0005]

In order to eliminate the drawbacks of the conventional example, the present invention suppresses the decomposition of the group III raw material so that it will not be exhausted downstream,
A structure that promotes decomposition is desired in order to increase the use efficiency of only Group V raw materials. In addition, in order to switch the source gas quickly, the gas path on the reaction chamber side of the source gas switching section should have as little dead space as possible to prevent decomposed raw materials from accumulating in extra places. It is desired to be performed near the wafer.

The present invention makes it possible to promote the decomposition of only the group V raw material in the vicinity of the wafer so that the raw material can be used efficiently, and also provides a structure for preventing the group III raw material from being exhausted downstream, The purpose is to reduce the manufacturing cost of the thin film and improve the uniformity of the thin film.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, 1) a reaction chamber 5, a group V source gas introducing pipe to be introduced into the reaction chamber, and a group V source gas introducing pipe are provided around the reaction chamber 5. Separated from the group V source gas and introduced into the reaction chamber III
A group source gas introducing pipe, an umbrella-shaped heat shield plate 3 provided around the end of the group V source gas introducing pipe in the reaction chamber, and a heater 4 provided opposite to the shield plate. A first space is provided between the heat shield plate and the inner wall of the reaction chamber, and III
A group source gas is introduced onto the wafer 7 through the first space, a second space is provided between the heat shield plate and the heater, and a group V source gas is used in the second space. Or a semiconductor thin film manufacturing apparatus which is guided onto a wafer through
The inner tube of the radial type gas switching valve 1 is used for the group source gas introduction pipe, and the inner tube of the radial type gas switching valve 2 having a large inner tube diameter is used for the group III source gas introduction tube for both radial type gas The semiconductor thin film manufacturing apparatus according to 1) above, in which the switching valve is directly connected to the upper and lower sides, or 3) The semiconductor thin film manufacturing according to 1) or 2), in which a quartz plate having a refractory metal deposited on the heat shield plate 3 Achieved by the device.

[0008]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 1 is a group V source gas switching valve, 2 is a group III source gas switching valve, 3 is a heat shield plate, 4 is a heater, 5 is a bell jar, 6 is a liner tube containing a heating lamp, 7 is a wafer, 8 Is a susceptor for holding a wafer. Here, the heater 4 is heated and the bell jar 5 is cooled.

The group V source gas collides with the heater 4, which is switched by the valve 1 and heated, and promotes decomposition. On the other hand, II
The group I raw material is switched by the valve 2 and passes between the heat shield plate 3 and the bell jar 5, but the heat of the heater 4 is shielded by the heat shield plate 3 and the bell jar 5 is cooled, so it is decomposed here. Not done.

At this point, the group V raw material and the group III raw material merge, and are appropriately decomposed by the heated susceptor 8 and reach the wafer 7. Further, the raw material gas switching valves 1 and 2 can be made extremely small in dead space in the reaction chamber by using radial type gas switching valves in two stages. The radial type gas switching valve has a compact structure in which multiple gas introduction valves are provided on the outer circumference to switch the gas and the desired gas can be introduced into the reaction chamber from the inner tube.

Further, since the upstream of the route of the group III raw material is cooled, the group III raw material is not decomposed in the upstream and is not exhausted in the downstream.

[0012]

2 is a sectional view of an embodiment of the present invention. In the figure, the shield plate 3 is made of quartz having a low thermal conductivity, and the heat of the heater 4 is shielded by depositing a refractory metal, for example, tungsten on the side facing the heater 4.

The heater 4 and the susceptor 8 are made of carbon, and 9 is an infrared lamp for heating the heater 4, which are arranged concentrically. Reference numeral 10 is an infrared lamp for heating the susceptor 8.

The gas switching valves 1 and 2 differ in the diameter of the central tube, and are directly connected to be coaxial. Both
In order to prevent the raw material gas from staying, hydrogen is flown from upstream as a carrier gas.

A heat shield plate 3 is fixed to an end of the gas switching valve 1 of the group V raw material via an O-ring 11. In this example, the bell jar 5 has a double wall structure and is cooled by flowing a refrigerant in the middle part of the wall, and the bell jar 5 is divided into 5a and 5b, and the heat shield plate 3 can be attached and detached. Therefore, the quartz rectifying plate 12 is provided so that the gas flow is not disturbed at the joint between the bell jars 5a and 5b.

[0016]

EFFECTS OF THE INVENTION According to the present invention, it is possible to accelerate the decomposition of only the group V raw material in the vicinity of the wafer to improve the efficiency of the raw material, and the group III raw material is decomposed upstream and exhausted downstream. It was possible to contribute to the reduction of the manufacturing cost of the semiconductor thin film and the improvement of the uniformity of the thin film.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is a sectional view of an embodiment of the present invention.

FIG. 3 is an explanatory view of a conventional barrel type film forming apparatus.

[Explanation of symbols]

 1 Group V source gas switching valve 2 Group III source gas switching valve 3 Heat shield plate 4 Heater 5, 5a, 5b Belja 6 Liner tube with built-in heating lamp 7 Wafer 8 Susceptor 9 Infrared lamp for heating heater 4 10 Infrared lamp for heating susceptor 11 O-ring 12 Quartz plate

Claims (3)

[Claims] 1. A reaction chamber (5), a V-group source gas introduction pipe introduced into the reaction chamber, and a V-group source gas introduction pipe provided around the separation chamber and separated from the V-group source gas. A group III source gas introduction pipe introduced into the reaction chamber, an umbrella-shaped heat shield plate (3) provided around the end of the group V source gas introduction pipe in the reaction chamber, and the shield. Heater provided facing the plate
(4) and the heat shield plate has a first space between the heat shield plate and the inner wall of the reaction chamber.
Space is provided, the group III source gas is introduced onto the wafer (7) through the first space, and the heat shield plate is provided with a second space between the heater and the heater. An apparatus for manufacturing a semiconductor thin film, wherein a group source gas is introduced onto a wafer through the second space. 2. A radial type gas switching valve using a radial type gas switching valve (1) as the group V source gas introducing pipe, wherein the group III source gas introducing pipe has a large inner diameter.
2. The semiconductor thin film manufacturing apparatus according to claim 1, wherein both radial type gas switching valves are directly connected to each other by using the inner pipe of (2). 3. The quartz plate having a high melting point metal adhered to said heat shield plate (3) is used.
The semiconductor thin film manufacturing apparatus described.