JPS5987813A - Epitaxial growth equipment - Google Patents

Abstract

PURPOSE:To eliminate the time for purge and reduce the contamination during the purge by a method wherein a surface cleaning domain by the vapor phase etching and a vapor phase epitaxial growth domain are provided individually and an entrance, through which a substrate supporting table can be transferred, is provided to a wall separating these domains. CONSTITUTION:Mixed gas of HCl and H2 is introduced into a gas reaction domain 2 of the 1st reaction tube 1 through an inlet 5 and the growth gas, mixture of SiH4, PH3 and H2 is introduced into the gas reaction domain 2' of the 2nd reaction tube 1' through the inlet 5', controlled to a prescribed volume of flow. In the 1st reaction tube 1, the surface of a substrate 3 is etched by 0.1- 1mum in the time tE and then a susceptor 4 is transferred quickly with the substrate 3 into the 2nd reaction tube 1' and N-type Si epitaxial growth whose carrier density is approximately 1X10<16> and thickness is 1-3mum is continued and the flow of the gases SiH4, PH3 and HCl is stopped and the purge is performed by H2 only.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a crystal growth apparatus, and in particular, to a crystal growth apparatus.
), phosphine (PH3), diborane (B2 HI6
), hydrogen (I■2), chloride water 1()icA), etc. for several months, and after corrosive purification of the base surface by the gas phase method and ptcl, P-type or N-type silicon Evita is applied. The present invention relates to a vapor phase epitaxial growth apparatus having a structure suitable for growing a crystalline layer on a St semifluorine substrate.

(Structure of conventional example and its problems) In general, epitaxial growth using the vapor phase growth method, especially the so-called vertical vapor phase crystal growth apparatus shown in FIG.
Since the gas is distributed in the reaction tube 1, it is easy to control the growth, and the gas reaction region 2.1;
It's called a board. ); 3. Since the support bases on which the substrate is placed, that is, the receptors 4, are in the same temperature range within the longitudinal temperature gradient, by using the large receptor 4, the substrate:
It has the advantage that it is easy to obtain a uniform Evita kinial growth layer even if 3 is processed at the same time in a large film. Note that 5 in the figure is the gas supply hole, and 6
1d exhaust hole. However, in order to make this vapor phase growth method industrially viable for large-scale production, the substrate at the start of growth: 3
Unless the surface is clean and homogeneous, this objective cannot be achieved.

Therefore, in general, HCI is added in the reaction tube 1 immediately before the start of growth.
Cleaning is performed by performing so-called gas etching using V or the like.

Therefore, conventionally, in the vapor phase growth process, as shown in FIG. In the meantime, vapor phase growth is performed.

Listing the problems with the conventional vapor phase growth apparatus that performs the above-mentioned time course, the first problem is that an extra time t is required for purging the cutting gas, which reduces the overall time required for growth. Apply pressure for a long time.Secondly, impurities contained in the elementary 4°4 gas during the time tPO for bar 2 are ff
/Cleaned substrate: $, -L Vi-deposition f1, and cleans the substrate 3 again, which becomes a source of crystal defects. No. 1: (Reaction tube) Since the substrate, 3, susceptor 4, etc. are exposed to the substances generated during gas etching, they are not completely discharged from the reaction tube 1 within the purging time t, and are reused again. Substrate: There are many problems such as deposition on the substrate.

(Objective of the Invention) The purpose of the present invention is to eliminate the above-mentioned problems, to shorten the overall growth time by eliminating the purge time during epitaxial growth, and to reduce contamination caused during the purge. That is.

(Structure of the Invention) The present invention is an epitaxial growth device in which a growth reaction tube for etching is connected to an IJ part via a movable partition wall of a substrate support, and in particular, etching and growth are independent of each other. In other words, the reaction tube dedicated to gas etching and the reaction tube dedicated to epitaxial growth are in contact with each other, and part of the wall of each tube at the connecting portion is is drilled and used 11
In this case, the substrate support stand can move freely in one direction.

According to the apparatus of the present invention, each reaction gas is partitioned by a wall, and only the substrate can be moved on the supporting table, so that etching of the substrate and epitaxial growth on the same substrate can be performed quickly.

(Explanation of Embodiment) FIG. 3 is a conceptual configuration diagram of an embodiment of the apparatus of the present invention. 1 and 1' are first and second reaction tubes, 2 and 2' are first and second reaction tubes, 2 is a gas reaction area, 3 is a substrate, 4 is a theceptor, 5 is a gas supply hole, 6 is an exhaust hole, and 7 is a wall.

An example of growing an N-type S1 epitaxial layer using a crystal growth apparatus having such a configuration will be described.

First reaction +? 21 contains a mixed gas of II C1 and 112, and the second reaction tube 1' contains a growth gas of Si H4,
P 113. , H2 is controlled to a predetermined flow needle from the supply holes 5 and 5', respectively, to the gas reaction regions 2 and 2.
' to be introduced. The susceptor 4 on which the substrate 3 is placed is made of gralan-carbon, and the temperature during gas etching and epitaxial growth is approximately 1050°C.

For crystal growth, a high concentration of arsenic (As
) A doped N+ type Si substrate 3 is mounted and placed in a predetermined position as shown in FIG. 3, and after H2 barging, as shown in FIG. The aforementioned gases are introduced into each of the gas reaction regions 2 and 2'.

In the first reaction tube 1, first, the surface of the substrate 3 is etched by 0.1 to 1 μm in a time pattern of tE, and then the susceptor 4 is quickly transferred together with the substrate 3 to the second reaction tube 1'. , and continue with gear rear concentration of about 1 x 1016, 17 x 1
Or; grow 1 notm N-type S1 epitaxial to 5i114. )) II4. n Stop the inflow of Cl gas and purge only with 112.

Using the N-(N) type Si epitaxial wafer obtained in this way, the semiconductor processing such as ) l-rl normal diffusion, ion implantation, and photoetching was performed to create a P-N-(N'') type variable capacitor. When a diode was fabricated E7, although the carrier concentration of the substrate 3 was extremely high, there was little As impurity mixed into the grown N-type layer, and the diode withstand voltage was as high as 35 V at the time of just punching, as designed. Moreover,
An excellent diode with extremely low high-frequency resistance was obtained without a decrease in carrier mobility due to crystal defects or the like.

(Effects of the Invention) As explained above, the present invention has excellent effects in suppressing crystal defects, disordering the impurity distribution between the growth layer and the substrate, and suppressing so-called cross-doping during epitaxial growth. Virtually eliminates the inevitable purging after etching! : It also has the effect of shortening the growth time, and has excellent karmic effects.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the tI' composition of a conventional vertical vapor phase crystal growth chain, Fig. 2 is an explanatory diagram of the relationship between reaction gas introduction and time in the apparatus of Fig. 1, and Fig. 3 is an illustration of the present invention. FIG. 4 is a conceptual diagram of an embodiment of the apparatus, and is a diagram showing the relationship between introduction of a reaction gas and time by the apparatus of the present invention. 1.1'...Reaction tube 1.2.2'...Gas reaction area, :1...Substrate, 4...
...Susceptor, 5 ...... Gas supply hole,
6...Exhaust hole, 7...Wall. Figure 1 Figure 2 □ End P^ Figure 3 Figure 4 □ Opposite h

Claims (1)

[Claims] Surface purification area by vapor phase etching and vapor phase shrimp 7
In addition, a wall separating the inside area and the inside area has a side opening that allows the substrate support to be movable, and the surface purification of the substrate on the support and the vapor phase epitaxy/yaru growth are performed. An epitaxial growth apparatus characterized in that the epitaxial growth apparatus is configured to be able to perform the following steps individually and temporally continuously in the surface purification region and the vapor phase epitaxy/yarn growth region.