JPS63112A - Semiconductor manufacture device - Google Patents

Abstract

PURPOSE:To contrive the improvement in yield and to obtain a steep composition change on a boundary between epitaxial layers by providing a sealed container for containing a wafer supporting means rotatably around a rotary shaft and plural reaction chambers. CONSTITUTION:An AsCl3 gas as a reactive gas touches a surface of wafers W, ..., W facing a chamber CH1 and AsCl3 is adsorbed. After a constant time, a susceptor 2 is rotated counterclockwise by 90 deg. to move the wafers W, ..., W to a chamber CH2. At that time, a reactive gas touching the wafers W, ..., W changes from an AsC gas to a GaC gas rapidly and GaC is adsorbed. Furthermore, a reduction reaction of the AsCl3 and GaCl3 adsorbed on the wafer W, ..., W surface is caused by using an H gas, so that an epitaxial layer of GaAs is grown. Thus, the wafers W, ..., W are moved successively and a super-lattice structure composed of a laminar structure of GaAs epitaxial layers is formed on a surface of the wafers W, ..., W.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a semiconductor manufacturing apparatus suitable for epitaxial growth of semiconductors, particularly epitaxial growth for forming a superlattice structure.

(b) Conventional technology A superlattice structure is a structure in which a layered structure consisting of layers of the same or different compositions is formed on the surface of a substrate such as a semiconductor. Conventionally, to form this superlattice structure on the substrate surface,
An epitaxial growth method is applied, and known devices for this purpose include a molecular beam epitaxial (MBE) device and a vapor phase epitaxial (VPE) device.

A molecular beam epitaxial device irradiates a substrate surface with a molecular beam to form an epitaxial layer on the substrate surface. When forming a superlattice structure, a stacked structure of epitaxial layers is formed on the substrate surface by intermittent molecular beams or switching between a plurality of different molecular beams using a shutter or mask, etc.
It has a superlattice structure.

On the other hand, the above-mentioned vapor phase epitaxial apparatus forms an epitaxial layer on the surface of the substrate using a vapor phase chemical reaction in a reactor, and the reactor type can be horizontal, pancake, barrel, etc. There are different types. When forming a superlattice structure using this vapor phase epitaxial apparatus, a laminated structure of epitaxial layers is formed on the substrate surface by switching the reaction gas supplied into the reactor.

The above vapor phase epitaxial equipment is equipped with multiple reactors (called multi-tubes) to increase production efficiency.
Also known is a structure in which epitaxial growth is performed alternately in each reactor.

(c) Problems to be Solved by the Invention When a superlattice structure is formed on a substrate surface using the conventional molecular beam epitaxial apparatus described above, there is a disadvantage that the yield is low.

On the other hand, in the conventional vapor phase epitaxial apparatus described above,
There is a disadvantage that a steep compositional change cannot be obtained at the interface between epitaxial layers. This is because when switching the reaction gas in the reactor, the reaction gas used in the immediately previous reaction remains in the reactor.

The present invention was made in view of the above-mentioned disadvantages, and an object of the present invention is to provide a semiconductor manufacturing apparatus that can improve yield and provide a steep compositional change at the interface between epitaxial layers.

(d) Means for Solving the Problems As a means for solving the above-mentioned disadvantages, the semiconductor manufacturing apparatus of the present invention includes wafer support means for supporting a wafer;
an airtight container that rotatably accommodates the wafer support means around its rotation axis; and an opening provided in the airtight container around the rotation axis of the wafer support means and facing the wafer supported by the wafer support means. and a plurality of reaction chambers into which a reaction gas is supplied.

(E) Function In the semiconductor manufacturing apparatus of the present invention, the wafer supported by the wafer support means is sequentially moved to each reaction chamber by the rotation of the wafer support means. In each reaction chamber, a gas phase chemical reaction is performed using a reaction gas. An epitaxial layer is formed on the wafer surface by a vapor phase chemical reaction in one reaction chamber or by different vapor phase chemical reactions in a plurality of successive reaction chambers. When the wafer is moved to an adjacent reaction chamber, the reactive gas that touches the wafer surface is rapidly switched to another reactive gas, making it possible to form an epitaxial layer having an interface with a steep compositional change.

(F) Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 3 is an external perspective view of the semiconductor manufacturing apparatus 1 according to the embodiment of the invention. Reference numeral 2 denotes a susceptor (wafer supporting means) made of graphite and having a substantially cylindrical shape. The lower end of the shaft 3 is fixed to the upper surface 2a of the susceptor 2 by known means. This shaft 3 moves the susceptor 2 up and down, and also rotates the susceptor 2 around its rotation axis O.

On the side surface of the susceptor 2, a flat wafer mounting part 2b,
..., 2b are provided. The wafers W, . . . , W are mounted on the wafer mounting portions 2b, . . . , 2b by well-known means.

Further, the susceptor 2 has a hollow structure, and an infrared lamp (not shown) is housed inside. The infrared rays from this infrared lamp cause the susceptor 2 and the wafer W,...
..., W is heated.

4 is a closed container. FIG. 1 shows a longitudinal cross-sectional view of this closed container 4. As shown in FIG. The airtight container 4 has four triangular prism-shaped protrusions 4 a s . . . , 4 a. These protrusions 4 a s..., 4a have tip side surface portions 4b,..., 4b centrally located with exhaust pipes 5,...
..., 5 are connected.

On the other hand, on the side surfaces 4C1..., 4C between the protruding parts 4a,..., 4a of the closed container 4, there are gas supply pipes 6,..., 6 for preventing mixing. Connected. Each mixing prevention gas supply pipe 6 has three branch pipes 6as...
6a, and these branch pipes 6a, ..., 6a
are vertically arranged and connected to the side surface 4C.

An opening 4e is formed in the upper surface 4d of the closed container 4 (see FIGS. 2 and 3), and the susceptor 2 is housed in the closed container 4 through this opening 4e.

This opening 4e is covered by a lid 7 through which the shaft 3 is rotatably inserted (see FIG. 2). A gasket (not shown) is provided between the lid 7 and the upper surface 4d of the airtight container 4. The closed container 4 is kept airtight.

The protrusions 4a, .
2, C) (3, CH4 are each provided by partitioning the inside of the protrusion 4a with a partition member 10 having a figure-7 cross section.Chambers CH1, CH2, CH3, CH4
are openings 9 facing the susceptor 2, respectively.
, 9.

The tip of the reaction gas supply pipe 11 to which the reaction gas supply pipe 1 is connected is also branched into three parts, which are connected to the tip 10a in the vertical direction (see Fig. 2). ).

Next, the operation of this embodiment semiconductor manufacturing apparatus 1 will be explained using the following operation example 1 and operation example 2.

Operation Example 1> In this operation example 1, GaAs is deposited on the surface of the GaAs wafer.
(or indium-gallium arsenide (InGaAs))
A superlattice structure is formed by stacking epitaxial layers.

First, the susceptor 2 is taken out from the closed container 4, and the unprocessed wafers W1, . . . , W are mounted on the susceptor 2. The susceptor 2 on which the wafers W, . At this time, susceptor 2
The wafer mounting section 2b is connected to each chamber CH1, CH2, and C.
The susceptor 2 is rotated so as to face the openings 9, . be done.

Next, the susceptor 2 is heated, and the wafer W,...
, W are held at high temperature.

The chambers CHI and CH3 are provided with reaction gas supply pipes 11.
Asclz gas is supplied by 11. Chamber CH2 and chamber CH4 contain GaCl and H2.
Gas is supplied.

- On the other hand, the mixing preventing gas supply pipes 6, . . . , 6 supply a mixing preventing gas such as He to the airtight container 4.
supplied within. This mixing prevention gas flows through the gaps 8, . . . , 8 between the side surface 4C of the closed container 4 and the surface of the susceptor 2.
and a gap 12 between the partition member 10 in the protrusions 4a, 4a adjacent to the side surface 4C and the inner surface of the sealed container 4,..., 1
2 and is exhausted to the outside of the closed container 4 through the exhaust pipe 5 (
(See Figure 1).

The reaction gas in the chambers CHI, CH2, CH3, CH4 flows from the openings 9, . . . , into the gaps 8, .
. . . , 8.12, . The air is exhausted to the outside of the closed container 4. This prevents reaction gas from entering adjacent chambers.

Formation of the superlattice structure on the surface of the wafer W, . . . , W is performed in the following order.

First, attention is paid to the wafers W1, old, . . . , W facing the chamber CHI. On the surface of these wafers W, old..., W, AsCj! is used as a reactive gas. , the gas is in contact with the wafer W,
..., AsC1 is adsorbed on the W surface.

- After a certain period of time has elapsed, the susceptor 2 is rotated 90e counterclockwise, and AsCj! , is adsorbed on the surface of the wafer W1...
..., W moves from chamber CHI to chamber CH2. At this time, the reaction gas that contacts the wafers W, . . . , W rapidly changes from AsCl3 gas to Gac13 gas.

In chamber CH2, first, wafers W1..., W
GaCj? , and then the AsC adsorbed on the surface of the wafer W,..., W is further adsorbed by H2 gas.
l, and GaCj! A GaAs epitaxial layer is grown by the reduction reaction in step 3.

Furthermore, after a certain period of time has elapsed, the susceptor 2 moves 90 degrees counterclockwise.
``The wafer W1 that has been rotated and has an epitaxial layer formed thereon
......, W is closer to chamber CH3 than chamber CH2
Move to. In chamber CH3, rehiwafer W,...
..., AsC on the W surface (surface of epitaxial layer)
/! , gas is adsorbed.

After that, the susceptor 2 rotates, and the wafer W...
, W moves from chamber CH3 to chamber CH4.

In chamber CH4, wafers W, ..., W
GaCl1. on the surface (epitaxial layer surface). is adsorbed, and GaAs epitaxial layers are grown in layers by a reduction reaction using H2 gas.

In this way, the wafers W1..., W are placed in the chamber C.
By sequentially moving H1-CH2-CH3-CH4-CHI, a superlattice structure consisting of a stacked structure of GaAs epitaxial layers is formed on the wafer W, ......, W
formed on the surface.

In addition, if Inch gas is supplied together with QaC1s gas in chambers CH2 and CH4, a superlattice structure consisting of a laminated structure of InGaAs epitaxial layers can be formed on the wafer W,
. . . can be formed on the W surface.

Operation Example 2 In this operation example, a laminated structure of alternately different epitaxial layers is formed on the wafer surface to form a superlattice (Peter type superlattice) structure.

First, a case will be described in which a laminated structure of a GaP epitaxial layer and a GaInP epitaxial layer is formed on the surface of a GaP wafer.

In this case, the following reaction gases are supplied to each chamber.

CH1--Ga C1,, H2, CH37-----GaC1,, Incls, H2, C
H2・CH4...PH,, Hz.

The other points are the same as in operation example 1.

Due to reactions in chamber CHI and subsequent chamber CH2, wafer W1..., W surface (GaInP
A GaP epitaxial layer is grown on the surface of the epitaxial layer. In addition, due to the reaction in chamber CH3 and subsequent chamber CH4, wafers W,..., W
A QalnP epitaxial layer is grown on the surface (the surface of the GaP epitaxial layer).

First, wafer W1 facing chamber CHI...
, a GaP epitaxial layer is formed as a first growth layer (epitaxial layer first grown on the wafer surface). - On the other hand, wafer W1 facing chamber CH3 first.
......, W has i'Ga1n as the first growth layer,
A P epitaxial layer is formed. Therefore, wafers W having two types of superlattice structures with different first growth layers,...
. , W are obtained.

Using the same compound for the first growth layer means that only at the start of epitaxial layer growth,
This is possible by changing the reactant gas supplied to the reactor.

Next, when forming a laminated structure of a GaAs epitaxial layer and an AfGaAa epitaxial layer on the surface of the GaAS wafer, the following reaction gases are supplied to each chamber.

CHI...trimethylgallium (TMG), HtCH
3... trimethylaluminum (TMA), TMG,
Hz.

CH2/CH4...ASH3, H2, chamber CHI
, CH2, wafer W1..., W surface (A
GaAs on the surface of the IGaAs epitaxial layer
Grow the epitaxial layer. Chamber CH3, CH
4, wafer W1..., W surface (G a A
An AlGaAs epitaxial layer is grown on the surface of the S epitaxial layer. As the wafer W1..., W sequentially moves from chamber CHI→CH2→CH3→CH4-CHI, the wafer W,..., W
A laminated structure of an AlGaAs epitaxial layer and a GaAs epitaxial layer is formed on the surface, and GaAs/
A superlattice structure of A I Ga As is obtained.

The semiconductor manufacturing apparatus 1 of this embodiment can form any superlattice structure on the wafer surface by changing the reaction gas, as explained in the operation examples 1 and 2 above.

Note that the semiconductor manufacturing apparatus of the above embodiment has four chambers, which are arranged every 900 around the susceptor rotation axis, but the number and arrangement of the chambers, the shape of the susceptor, etc. are determined by this. The design is not fixed, and the design can be changed as appropriate.

(Effects of the Invention) The semiconductor manufacturing apparatus of the present invention includes a wafer support means for supporting a wafer, a closed container for storing the wafer support means rotatably around its rotation axis, and the wafer support means inside the closed container. The device is arranged around the rotation axis of the device, has an opening facing the wafer supported by the wafer support means, and has a plurality of reaction chambers into which a reaction gas is supplied, so that the yield can be reduced. It has the advantage of being able to improve the chemical properties of the epitaxial layer, and also has the advantage of being able to obtain a steep compositional change at the trench interface between epitaxial layers.

It also has the advantage that any superlattice structure can be formed by changing the reaction gas.

[Brief explanation of drawings]

Each of the drawings shows an embodiment of the present invention, and FIG. 1 is a cross-sectional view of a semiconductor manufacturing apparatus according to this embodiment, and FIG. 2 is a cross-sectional view taken along line nn in FIG. FIG. 3 is an external perspective view of the semiconductor manufacturing apparatus. 2: Susceptor, 4: Sealed container, 9...9: Opening, CHI/CH2/CH3/CH4: Chamber, W...
...W: wafer, 0: rotation axis. Patent applicant ROHM Co., Ltd. agent
Patent Attorney Shigeru Nakamura Figure 2

Claims (1)

[Claims] (1) a wafer support means for supporting a wafer; a sealed container for storing the wafer support means so as to be rotatable about its rotation axis; A semiconductor manufacturing apparatus comprising a plurality of reaction chambers each having an opening facing a wafer supported by a wafer support means and into which a reaction gas is supplied.