JPH0548307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a vapor phase chemical vapor deposition apparatus used in a thin film forming process in the manufacture of semiconductor devices and the like.

More details: PolySi, Si ₃ N ₄ , SiO ₂ ,
Insulating thin film such as Si ₃ N ₄ , PSG, BPSG, or
Conductive thin film such as Al, Mo, W, or Si,
The present invention relates to a low-pressure vapor phase chemical vapor deposition apparatus that can be used to form thin films of semiconductor materials such as GaAs.

Conventional technology Conventionally, the mainstream of low-pressure vapor phase chemical vapor deposition equipment has been to add a gas inlet and exhaust part to the main body of a vertical or horizontal diffusion furnace, or to add a heater and a gas inlet to the main body of the vacuum evaporation equipment. It's summery.

Problems to be Solved by the Invention However, in conventional equipment, reaction products adhere to the vicinity of the exhaust port, which must be removed frequently, and this maintenance time is a major cause of reduced operating efficiency. I was getting used to it. Furthermore, if this removal of the deposits is not carried out, the deposits may peel off during the formation of the thin film, resulting in contamination of the substrate surface.

For example, a wafer boat 11 as shown in FIG.
In a vertical reduced pressure vapor phase chemical vapor deposition apparatus having a manifold part 16 having a reactor core (furnace tube) 14 surrounded by a gas introduction part 12 and a heater 13, and an exhaust port 15 connected to the reactor core, the manifold is usually The part 16 and the quartz furnace tube 14 are connected by an O-ring or the like, and the manifold part is always cooled to prevent damage to the O-ring due to heating. However, when the entire manifold section is cooled, reaction products 18 generated during thin film deposition adhere to the inner surface of the manifold, as shown in Figure 3, and when the boat is loaded or unloaded, they peel off or re-evaporate, resulting in large particles that contaminate the substrate. It was the cause.

In FIG. 2, 19 is a furnace body, 20 is an elevator, 21 is a furnace tube cover, and 50 is a semiconductor wafer.

Means for Solving the Problems In view of the above-mentioned conventional drawbacks, the present invention provides an internal face plate 1 to prevent the reaction products described above from adhering to the inner surface of the manifold. The feature is that the temperature of the inner face plate is raised to a predetermined temperature or higher.

In other words, in order to prevent thermal deterioration of the O-ring, the temperature of the cooled manifold remains the same, and a high-temperature internal face plate is placed on the inner surface that comes into contact with the reaction gas. By adopting a configuration in which the reaction products that had been in contact and adhered are brought into contact with the surface of the inner face plate (at this time, the temperature of the inner face plate is heated by the heat source radiated from the quartz tube external heater, and the inner face of the manifold is heated. If the structure is such that they do not come into direct contact with each other, the temperature can be sufficiently raised to a temperature at which the reaction products do not adhere.), it is possible to prevent the reaction products from adhering.

Embodiment That is, as shown in FIG. 1, an inner face plate 1 (a cylindrical plate 2 and a disc-shaped plate 3) for preventing reaction products from adhering is installed on the inner surface of a cooled manifold 16. Note that at this time, the cylindrical plate 2 is connected to the furnace core tube 14.
If the structure is such that it contacts the inner surface of the manifold 16 but does not directly contact the inner surface of the manifold 16, and is made of metal such as stainless steel, it is possible to maintain the temperature at a temperature that does not allow reaction products to adhere (for example, SiH ₂ Cl ₂ and NH ₃ When depositing Si ₃ N ₄ using a vacuum cleaner, NH ₄ Cl, etc., adhered to the manifold part, but if the temperature of the cylinder was maintained at 300°C or higher, NH ₄ Cl would not adhere at all. ). Moreover, if the disk-shaped plate 3 was also made of metal without being brought into direct contact with the lid 21, the temperature could be raised to such an extent that reaction products would not adhere to it due to heat radiation from the reactor core.

Effects of the Invention In the vapor phase chemical vapor deposition apparatus equipped with the internal face plate of the present invention, since the cooled surface inside the reactor tube is not exposed, there is no adhesion of reaction products, etc.
There is no need to remove deposits. In addition, it does not peel off or re-evaporate when loading and unloading wafers or during film formation, which has the effect of significantly reducing the cause of contaminating the substrate surface.

In addition, in the embodiment of the present invention, an example was shown in which a high-temperature internal face plate was installed on the inner surface of the manifold, but it is clear that the same effect can be obtained even if the inner surface of the manifold is made high temperature and only the O-ring contact area is cooled. be.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the vicinity of the manifold of a vapor phase chemical vapor deposition apparatus equipped with the internal face plate of the present invention, Fig. 2 is a block diagram of a conventional vertical reduced pressure CVD apparatus, and Fig. 3 is a view of the area where reaction products are deposited. Second to explain the situation
It is a sectional view of the manifold part in a figure. 1... Face plate, 2... Cylindrical plate, 3... Disc-shaped plate, 14... Furnace tube, 16... Manifold part,
50...wafer.

Claims (1)

[Scope of Claims] 1. A reactor core surrounded by a wafer boat, a gas introduction part, and a heater, and a manifold part including an exhaust port connected to the reactor core part, and reaction products adhere to the inside of the manifold. A vapor phase chemical vapor deposition apparatus characterized by having an internal face plate that reaches a high temperature to the extent that it does not. 2. The vapor phase chemical vapor deposition apparatus according to claim 1, wherein the inner face plate is made of metal.