JPS63114117A - Apparatus for manufacturing semiconductor - Google Patents

Abstract

PURPOSE:To raise only the temperature of source gas without abnormally raising the temperature of a semiconductor wafer by forming a susceptor in a frame having a hollow part made of carbon, disposing the wafer in the hollow part, and feeding the source gas. CONSTITUTION:A susceptor 11 made of carbon is formed in a frame shape, and a semiconductor wafer 12 is disposed in a hollow part 11A. When the susceptor 11 is attached to a reaction tube 13, source gas is fed in the part 11A in which the wafer 12 is disposed. Since the susceptor 11 is entirely heated with high frequency energy from a high frequency coil 14, source gas fed in the part 11A is heated from its periphery. Thus, even if the temperature of the susceptor 11 is not abnormally raised, the temperature of the gas is sufficiently raised to accelerate a decomposition.

Description

[Detailed Description of the Invention] [Summary] The present invention provides a semiconductor manufacturing apparatus that performs organometallic chemical vapor deposition, etc., in which a susceptor is formed in the shape of a frame body made of carbon and has a hollow portion, and the hollow By arranging the semiconductor wafer within the section and allowing the source gas to flow, the source gas is heated from all around, so that thermal decomposition occurs with high efficiency.

[Industrial application field]

The present invention is directed to metalorganic chemical vapor deposition (metalorganic chemical vapor deposition).
nics chemical vap.

The present invention relates to a semiconductor manufacturing apparatus suitable for carrying out a microelectronic chemical vapor deposition (MOCVD) method and the like.

[Conventional technology]

FIG. 5 shows a perspective view of essential parts of a susceptor used in a conventional MOCVD apparatus.

In the figure, 1 indicates a carbon susceptor, and 2 indicates a semiconductor wafer placed on the susceptor.

FIG. 6 shows a cutaway side view of essential parts for explaining a conventional MOCVD apparatus, and the same symbols as those used in FIG. 5 represent the same parts or have the same meanings.

In the figure, 3 represents a reaction tube, 3A represents an air supply pipe, 3B represents an exhaust pipe, and 4 represents a high frequency coil.

In this MOCVD apparatus, a susceptor 1 is heated by a high-frequency coil 4, the wafer 2 and the source gas are heated by the heat, and the source gas is thermally decomposed on the surface of the wafer 2 to deposit the required substance. The film is formed accordingly.

[Problem that the invention seeks to solve]

Currently, regarding MOCVD technology, selectively doped heterojunction structure wafers, i.e., high electron mobility transistors (hig
h electron mobility tr
Much research and development has been carried out at the expense of mass producing wafers suitable for use in HEMT.

However, it is extremely difficult to reproducibly grow a semiconductor layer having a good heterojunction interface using a conventional MOCVD apparatus such as that described with reference to FIGS. 5 and 6.

One of the reasons for this is the relationship between decomposition of the source gas and heat.

That is, in the conventional MOCVD apparatus, as is clear from FIG. 5 and FIG. Once mounted, source gas flows over the surfaces of the semiconductor wafer 2 and the susceptor 1.

In this case, the flowing source gas is only supplied with heat from the high-frequency heated susceptor 1.
Although the temperature of the semiconductor wafer 2 increases, the temperature of the source gas does not increase.

As described above, when the temperature of the source gas is low, good thermal decomposition is not promoted, so that the growth of the semiconductor layer does not proceed.

To solve this problem, it is sufficient to raise the temperature of the source gas sufficiently, but this requires raising the temperature of the susceptor 1. However, if this is done, the temperature of the semiconductor wafer 2 will naturally rise further, and the surface will be damaged due to, for example, As being dissipated. In particular, such abnormalities often occur at interfaces where different types of semiconductors are grown by switching the source gas, and this is exactly the case when manufacturing wafers with selectively doped heterojunction structures.

The present invention aims to provide a semiconductor manufacturing apparatus that can sufficiently raise the temperature of a source gas without abnormally raising the temperature of a semiconductor wafer.

[Means for solving problems]

FIG. 1 shows a perspective view of essential parts of a susceptor used in the present invention.

In the figure, 11 is a frame-like susceptor made of carbon;
IIA indicates a hollow portion, and 12 indicates a semiconductor wafer.

FIG. 2 shows a cutaway side view of the essential parts of the MOCVD apparatus to which the susceptor 11 is attached, and the same symbols as those used in FIG. 1 indicate the same parts or have the same meanings.

In the figure, 13 is a reaction tube, 13A is an air supply pipe, 13B is an exhaust pipe, and 14 is a high frequency coil.

As is clear from FIGS. 1 and 2, the susceptor 11 in the present invention has a frame shape, and the hollow portion 11
When the semiconductor wafer 12 is placed inside A and the susceptor 11 is attached to the reaction tube 13, the source gas flows through the hollow portion 11A where the semiconductor wafer 12 is placed.

Of course, since the entire susceptor 11 is heated by the high-frequency energy from the high-frequency coil 14, the source gas flowing inside the hollow portion 11A is heated from all sides, and the temperature of the susceptor 11 cannot be changed as in the conventional case. The temperature of the source gas can be raised sufficiently to promote decomposition without raising it abnormally.

Therefore, in the semiconductor manufacturing apparatus according to the present invention, a frame body is made of carbon and has a hollow part (for example, hollow part 11A) in which a semiconductor wafer (for example, semiconductor wafer 12) is placed and through which source gas flows. It has a structure comprising a shaped susceptor (for example, frame shaped susceptor 11) and a reaction tube (for example, reaction tube 13) that accommodates the frame shaped susceptor and is installed in a high frequency coil (for example, high frequency coil 14). ing.

[Effect]

By adopting the above method, only the temperature of the source gas can be increased without abnormally increasing the temperature of the wafer, and there is no risk of As being detached during growth. It is possible to obtain a semiconductor layer having a surface, and is particularly effective in preventing the occurrence of abnormalities at the interface of different semiconductor layers, and is suitable for forming a selectively doped heterojunction structure.

〔Example〕

FIG. 3 shows an explanatory view of essential parts of an embodiment of the present invention, and the same symbols as those used in FIGS. 1 and 2 indicate the same parts or have the same meanings.

In the figure, 15 is trimethyl gallium (TMG:
(CH3) 3 G a ) cylinder, 16 is arsine (A s H3) cylinder, 17 is A, S H3
18 is a TMG cylinder, 19 is a trimethylaluminum (TMA: (CH3) 3Aj cylinder), and 20 is a monosilane (SiH4) cylinder.

Using this MOCVD equipment, Aj7GaAs/GaA
When growing an s-selectively doped heterojunction structure, first open the cylinders 15 and 16 to grow undoped GaAsJi on the semi-insulating GaAs substrate, then open the cylinders 17 to 20 to grow the n-type A# Grow a GaAs layer.

Figure 4 shows an undoped G as explained in Figure 3.
aAs layer and n-type Aj! FIG. 3 is a diagram showing carrier concentration distribution at a heterojunction interface when a GaAs layer is grown.

In the figure, the horizontal axis represents the distance from the wafer surface, and the vertical axis represents the carrier concentration N. The solid line C1 is the characteristic line obtained when the present invention is implemented, and the broken line C2 is the characteristic line obtained when the conventional technology is implemented. The characteristic lines obtained in each case are shown.

Note that the growth temperature of both the undoped GaAsN and n-type AI Ga As layers at which this data was obtained was 700°C.
c).

As can be seen from the figure, when the conventional technique is used, a large drop in the carrier concentration NO is observed near the Peter junction interface, and this is due to the large detachment of As due to heat. On the other hand, in the case of the present invention, there is almost no drop in the carrier concentration N.

Generally, the optimal temperature for growing high-purity GaAs and doped AfGaAs is often different, so when changing the temperature to deal with this, ASH3 is continued to flow or the growth is interrupted. In such a case, if the temperature of the semiconductor wafer 12 is high, the detachment of As will be particularly significant, and the drop as shown in FIG. be.

〔Effect of the invention〕

In the semiconductor manufacturing apparatus according to the present invention, the susceptor is made of carbon and formed into a frame shape having a hollow part, and the semiconductor wafer is placed in the hollow part, and the source and
It has a structure that allows gas to flow.

By adopting the above configuration, only the temperature of the source gas can be increased without abnormally increasing the temperature of the wafer, and there is no risk of detachment of AS during growth, resulting in a good condition with no damage. It is possible to obtain a semiconductor layer having a surface, and is particularly effective in preventing the occurrence of abnormalities at the interface of different semiconductor layers, and is suitable for forming a selectively doped heterojunction structure.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a main part illustrating the susceptor used in the present invention, and Fig. 2 is an MOC equipped with the susceptor shown in Fig. 1.
FIG. 3 is a cross-sectional side view of the main part of the VD device, FIG. 3 is an explanatory diagram of the main part of an embodiment of the present invention, and FIG. Type AlGaA
A diagram showing the carrier concentration distribution at the heterojunction interface of the s-layer, Figure 5 is a perspective view of the main part of a susceptor used in a conventional MOCVD device, and Figure 6 is a cutaway of the main part to explain the conventional MOCVD device. Each represents a side view. In the figure, 11 is a frame-like susceptor made of carbon;
11A is a hollow part, 12 is a semiconductor wafer, 13 is a reaction tube, 13A is an air supply pipe, 13B is an exhaust pipe, 14 is a high frequency coil, 15 is a TMG cylinder, 16 is an AsH3 cylinder,
17 is As H3 cylinder, 18 is TMG cylinder, 1
9 indicates a TMA cylinder, and 20 indicates a SiH4 cylinder. Patent Applicant: Fujitsu Ltd. Representative Patent Attorney: Akira Aitani Representative Patent Attorney: Hiroshi Watanabe Figure 1: Slope view of essential parts of one embodiment ooooooo. Figure 2 Cutaway side view of main parts of Example Distance from surface (μm) Diagram showing carrier concentration distribution Figure 4

Claims (1)

[Claims] A frame-like susceptor made of carbon and having a hollow part in which a semiconductor wafer is placed and through which a source gas flows; 1. A semiconductor manufacturing device comprising a reaction tube.