JPH02122630A - Apparatus for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To enable a high quality thin film to be formed by providing a portion made of high melting point metal or its compound on a part of a support base. CONSTITUTION:Portions made of a tungsten plate 2 are located at both ends of Si wafers 1 arranged perpendicular to a wafer support base 3. These tungsten plates 2 on both ends may be titanium or molybdenum, or their compound. Atmosphere 9 flowing into a quartz reaction tube 6 easily causes surface reaction with tungsten for example when the Si wafer 1 is mounted and fed into or out of the quartz reaction tube 6. Since the inside of the quartz reaction tube 6 is heated up to 1000 deg.C or higher, the Si wafer 1 can be heated up to approximately 500 deg.C in a very short time. Since the speed at which the Si wafer 1 is oxidized is very low at a temperature around 500 deg.C and most part of the atmosphere 9 having flowed into the quartz reaction tube 6 is spent for reaction with tungsten not for reaction with Si, a naturally oxidized film which is less dense and poorer at characteristics can be prevented from being formed on the Si wafer 1. This enables a good thin oxide film to be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The invention relates to an apparatus for manufacturing semiconductor devices, and in particular to a method for forming an insulator film used in semiconductor elements and semiconductor integrated circuits (process 0). ◎ [Conventional technology] Figure 2 shows the structure of an oxidation furnace used to form a 5i02 thin film 1) on a 131 wafer, which is used for an IC insulating film, by a conventional thermal oxidation method. This is an explanatory diagram. In other words, an 81 wafer (1) is placed in a wafer port in a quartz reaction tube (6) heated to 1000'C or more by an electric furnace (7) from the outside.
) (3) Place K and introduce 02 gas or H20
A thin film 8102 is formed on the surface of the 81 wafer (1) by sending the vapor (5) into the 1fr quartz reaction tube (6). B1 wafers (1) are arranged perpendicularly to the wafer boat (3) on a wafer boat (3) made of quartz or silicon carbide.
The wafer (1) can be subjected to thin film processing.

[Problem to be solved by the invention] Since the conventional 81-wafer thin film processing apparatus fi was INm as described above, as the degree of integration of ICs increases, the gate oxide film thickness of MOa type ICs in particular increases. Thin 5102 films with high dielectric strength are becoming thinner and indispensable, and for this purpose S
Formation of a native oxide film with low density on the B1 wafer must be avoided at all costs.Since the inside of the quartz reaction tube is kept at a high temperature, the B1 wafer should not be oxidized before and after growth. 0, where N2 gas is normally flowed.

81 wafer? When placed on a wafer boat and introduced into a quartz reaction tube, the N2 gas flowing inside the quartz reaction tube is heated, and when placed near the inlet, it becomes an upward airflow and escapes upward. A considerable amount of air flowed into the quartz reaction tube from below.

S1 wafers at high temperatures are easily oxidized,
The same thing happens when an oxide film with the desired characteristics is not formed and the S1 wafer is removed from the quartz reaction tube.
This invention was made to solve the above-mentioned problems, and it is a semiconductor manufacturing bag that can form a high-quality thin film.
[Means for Solving the Problem] The support stand for a horizontal oxidation diffusion furnace according to the present invention is made of a high melting point metal or a compound thereof at least in part as a component. The part of the part, which is a part of the part, is a wafer support stand from the support platform that is a part of the supporter, which is a part of the supporter or a part of the compound that consists of a high fusion metal or compound. When introduced into or taken out from the quartz reaction tube, the air flowing into the quartz reaction tube from below the inlet reacts on the surface of the high-point metal or its compound to form oxides. It is known that this reaction occurs more easily than the incoming atmosphere reacts on the S1 wafer surface, and as a result, the tVi of oxygen reaching the B1 wafer, which is heated to a high temperature, decreases.

As a result, a native oxide film with low density is formed on the S1 wafer.
Non-uniform formation can be avoided.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained.

Figure 1 is a side view showing the configuration of a wafer support for a horizontal oxidation diffusion furnace, which is an embodiment of the invention. The difference between this and a conventional wafer port is that the wafer port is arranged perpendicularly to the wafer support (3). The difference is that there are portions made of tungsten plates (2) at both ends of the S1 wafer (1). The tungsten plates (2) at both ends may be made of titanium, molybdenum, or a compound thereof. If used, 81 wafers (1)
The air (9) that has flowed into the quartz reaction tube (6) when it is introduced into or taken out from the quartz reaction tube (6) easily causes a surface reaction with 1, for example, tungsten. Tungsten begins to oxidize at 300℃ in the atmosphere.
It is known that a rapid reaction occurs at 00'C to form WO3K.The inside of the quartz reaction tube (6) is heated to over 1000°C, so 81 wafer (1) i! At a temperature of about 500°C, which is heated to about 500°C in an extremely short period of time, the rate at which the S1 wafer (1) is oxidized is very slow and most of the air (9) that has flowed into the quartz reaction tube (6) is oxidized. Sl
Since it is used for reaction with tungsten rather than tungsten, it is possible to avoid the formation of a native oxide film with low density and poor characteristics on the Si wafer (1). This prevents the formation of an oxide film with poor uniformity on the S1 wafer (1), making it possible to form a thin oxide film of good quality.

In addition, in the above embodiment, the case where the 5102 film is formed by the thermal oxidation method has been described, but the present invention is also applicable to the impurity diffusion method using a similar wafer support in a horizontal oxidation diffusion furnace type, and the chemical vapor deposition method. It can also be applied to cases such as law.

〔Effect of the invention〕

As described above, according to the present invention, since at least a part of the support for the horizontal oxidation diffusion furnace is provided with a portion made of high melting point gold and its compound, it is possible to uniformly process 81 wafers with good reproducibility. It becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a side view of 81 wafers loaded on a wafer support stand for a horizontal oxidation diffusion furnace equipped with tungsten plates on both sides, which is an embodiment of the present invention. It is an explanatory view showing a state when introducing or leading out a wafer. In the figure, (1) is an S1 wafer, (2) is a tungsten plate, (3) is a wafer support made of quartz or silicon carbide, (
4) is electric furnace, (5) Vin2 gas, (6) is quartz reaction tube, (7) i! A wafer inlet/outlet port, (8) Fi outflowing N2 gas, and (9) inflowing air. In addition, in Figure 1, the same symbols indicate the same or equivalent parts □

Claims (1)

[Claims] 1. An apparatus for manufacturing a semiconductor device, characterized in that a support for a horizontal oxidation diffusion furnace is provided with at least a portion made of a high melting point metal or a compound thereof.