JPS61294812A - Gas phase floating epitaxial growth equipment - Google Patents

Abstract

PURPOSE:To make it possible to hole stably the semiconductor wafer set afloat by the jetting reaction gas on the jet flow of the reaction gas, by giving the semiconductor the gas balancing force or the gravitational potential, and by installing in the gas reaction part the means to float and hold the semiconductor wafer at the center of the force. CONSTITUTION:The semiconductor wafer 1 to be treated is mounted on the bend member 4B of the gas reacting part 4 in the reaction vessel 2. When the reaction gas G is supplied in this state from the pre-mixing equipment 6, it jets out upward from the injection hold 4A installed on the bend member 4B, after flowing into the gas vessel 4C of the gas reacting part 4 through the pipe 5. The semi-conductor wafer 1 is set afloat on the bend part 4B by the jet flow of the reaction gas from the injection hole 4A. Thus the semiconductor wafer 1 is held in the state wherein the wafer 1 does not physically contact with other bodies, and the reaction gas G acts on the lower surface of the wafer, where the eptaxial layer is grown and formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for forming an epitaxial layer on the surface of a semiconductor wafer, and particularly relates to an apparatus for forming an epitaxial layer on the surface of a semiconductor wafer by suspending the semiconductor wafer in a reactive gas. The present invention relates to a vapor levitation epitaxial growth apparatus suitable for growth.

[Conventional technology]

As a form of apparatus for growing and forming an epitaxial layer on the surface of a semiconductor wafer, a reaction gas that forms an epitaxial layer on the surface of the semiconductor wafer is spouted upward from a gas reaction section, and this gas jet causes the semiconductor wafer to grow and form an epitaxial layer on the surface of the semiconductor wafer. There is an apparatus called a vapor phase levitation epitaxial growth apparatus which levitates the semiconductor wafer upward and forms an epitaxial layer on the lower surface of the semiconductor wafer in this state. This device was published in the 9th issue of Nikkei Electronics published on April 8, 1985.
1 and 92. This apparatus has the advantage that the reaction can proceed without physical contact of the semiconductor wafer with other objects, thereby preventing dirt and scratches from entering the growing epitaxial layer.

[Problem that the invention seeks to solve]

In the conventional vapor phase levitation epitaxial growth apparatus described above, the semiconductor wafer is held horizontally above the jet of the reactive gas in order to grow and form an epitaxial layer on the lower surface of the semiconductor wafer while the semiconductor wafer is levitated by the jet of reactive gas. Therefore, horizontal holding of the semiconductor wafer has become an important issue to be solved.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vapor phase levitation epitaxial growth apparatus that can stably hold a semiconductor wafer levitated by an ejected reactive gas above a jet of the reactive gas.

[Means for solving problems]

The above-mentioned object is achieved by providing a gas reaction section having a reaction gas injection hole for levitating the semiconductor wafer with means for applying a gas equilibrium force or gravitational potential to the semiconductor and levitating and holding the upper semiconductor wafer above the center thereof. .

[Effect]

If the semiconductor wafer levitated above the gas reaction section by the ejected reaction gas becomes misaligned on the gas reaction section for some reason, the semiconductor wafer floating and holding means provided in the gas reaction section The semiconductor wafer is held suspended horizontally above the gas reaction section by the gas balance force or gravitational potential.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the apparatus of the present invention, in which 1 represents a semiconductor wafer, 2 represents a reaction vessel, and 3 represents a semiconductor wafer.
is a heating device provided around the outer periphery of the reaction vessel 2, and this heating device 3 heats the inside of the reaction vessel 2 to a high temperature atmosphere. Reference numeral 4 denotes a gas reaction section provided in the reaction container 2, and this gas reaction section 4 includes a curved member 4B having a gas ejection hole 4A for ejecting and supplying the reaction gas G to the lower surface of the semiconductor wafer 1, and a curved member 4B provided below the curved member 4B. It is composed of a gas container 4C provided. The aforementioned curved member 4B is curved downward in a concave shape.

A plurality of gas ejection holes 4A provided in this curved member 4B are provided at 83 toward the center of curvature of this curved member 4B, as shown in FIG. The gas container 4C is connected to a premixing device 6 through a pipe 5. This premixing device 6 uniformly mixes the reactant from the reactant feeder 7, the impurity from the impurity feeder 8, and the carrier gas from the carrier gas feeder 9, and controls the components, temperature, and flow rate. Adjust to create reaction gas G. This reaction gas G is supplied to the gas container 4C through the pipe 5. 10 is an exhaust gas hole provided in the reaction vessel 2.

Next, the operation of one embodiment of the above-described apparatus of the present invention will be described.

First, the semiconductor wafer 1 to be processed is placed on the curved member 4B of the gas reaction section 4 in the reaction container 2.

In this state, when the reaction gas G is supplied from the premixing device 6, this reaction gas G flows into the gas container 4C of the gas reaction section 4 through the pipe 5, and then flows upward from the gas jet hole 4A provided in the curved member 4B. gushes out. The jet of reaction gas G from this gas jet hole 4A causes the semiconductor wafer 1 to
floats above the curved member 4B. As a result, the reaction gas G acts on the lower surface of the semiconductor wafer 1 without physically contacting other objects, and an epitaxial layer is grown on the lower surface of the semiconductor wafer.

When an external force acts on the semiconductor wafer 1 due to an external factor such as non-uniformity in the amount of reaction gas ejected from the gas ejection holes 4A during the above-mentioned initial growth process and intermediate growth process of the epitaxial layer.

The semiconductor wafer 1 moves eccentrically along the curvature surface of the curved member 4B, but the semiconductor wafer 1 is affected by the gravitational potential of the semiconductor wafer 1 itself and the gas located at the peripheral edge of the curved member 4B, which are generated due to the eccentric movement. Since the return force of the reactive gas jet from the ejection hole 4A acts, the semiconductor wafer 1 immediately returns to the center on the curved member 4B and is held floating horizontally. As a result, the reaction gas jet flows uniformly on the lower surface of the semiconductor wafer 1, so that a uniform epitaxial layer can be formed on the lower surface of the semiconductor wafer 1.

In the above embodiment, the curved members 4B were formed with the same curvature, but as shown in FIG.
A flat part larger than the semiconductor wafer 1 may be formed in the center thereof, and the peripheral part thereof may be curved so as to be raised. With this configuration, the semiconductor wafer 1 can be floated and held horizontally at the center of the curved member 4B as in the above-described embodiment, and the lower surface of the semiconductor wafer 1 and the curved member opposite thereto can be held horizontally. Since the flying clearance between the wafer 4B and the flat surface is constant everywhere, the epitaxial layer grown on the lower surface of the semiconductor wafer 1 can be formed to have a more uniform thickness.

Further, in the above embodiment, the gas ejection holes 4A were provided in the curved member 4B so as to face the center of curvature of the curved member 4B, but as shown in FIG. It may be provided so as to be perpendicular to the other.

FIG. 5 shows another embodiment of the apparatus of the present invention, in which the same reference numerals as in FIG. 1 are the same parts. In this embodiment, the part of the gas reaction section 4 facing the semiconductor wafer 1 is composed of a flat member 4D, and the flat member 4D is provided with a gas jet hole 4E for supplying a gas jet to levitate the semiconductor wafer 1. , a gas ejection hole 4F is provided for supplying a gas jet inward and diagonally upward toward the periphery of the semiconductor wafer 1.

With this configuration, when the semiconductor wafer 1 moves eccentrically due to an external factor, the gas jet is supplied diagonally inward and upward toward the periphery of the semiconductor wafer 1 from the gas jet holes 4F.

The semiconductor wafer 1 is pushed back to the center of the flat member 4D of the gas reaction section 4, and is held horizontally floating by the gas jet from the gas jet hole 4E. As a result, in order to properly grow and form an epitaxial layer on the lower surface of the semiconductor wafer 1, it is possible to stably hold the semiconductor wafer 1 floating above the gas reaction section 4.

In the above-described embodiment, the gas jet was supplied diagonally inward and upward toward the periphery of the semiconductor wafer 1 through the gas jet holes 4F, but as shown in FIG. Similarly to the embodiments described above, it is also possible to provide a gas jet hole 4G for supplying a gas jet in the orthogonal direction and configure the diameter of the gas jet hole 4G to be larger than the gas jet hole 4E in the center. The wafer 1 can be stably held floating above the gas reaction section 4.

Moreover, in the embodiment described above, the gas ejection holes 4A, 4E
, 4F, 4G so that the gas jets flow in the circumferential direction as shown in FIG.
4F and 4G may be provided obliquely upward in the circumferential direction of the semiconductor wafer 1, as shown in FIG. With this configuration, the semiconductor wafer 1 is rotated in a horizontal plane by a gas jet ejected obliquely upward in the circumferential direction. As a result, the circumferential thickness of the epitaxial layer formed on the lower surface of the semiconductor wafer 1 can be made uniform.

〔Effect of the invention〕

According to the present invention, a semiconductor wafer levitated by the ejected reactive gas can be stably held above the jet of the reactive gas. As a result, stable "processing" in the vapor phase levitation epitaxial growth apparatus can be realized.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing one embodiment of the device of the present invention, Fig.
The figure is a view taken along the line ■-■ in FIG. 1, FIGS. 3 to 6 are longitudinal cross-sectional views showing other examples of the main parts of the device of the present invention, and FIG. 7 is a further view of the device of the present invention. Operation explanatory diagram showing other examples, No. 8
The figure is a longitudinal cross-sectional view showing another example of the gas ejection hole used in the device of the present invention. DESCRIPTION OF SYMBOLS 1... Semiconductor wafer, 2... Reaction container, 3... Heating device, 4... Gas reaction part, 4A, 4E, 4F, 4G
... Gas jet hole, 4B... Curved member, 4C... Gas container, 4D... Planar member, 6... Premixing device. Figure 1, Ward 2, Section 3, Section 4, Figure 7, Entrance 8, Q

Claims (1)

[Claims] 1. The semiconductor wafer is held in a floating state above the gas reaction section by the reaction gas ejected from the gas injection hole of the gas reaction section, and the reaction gas forms an epitaxial layer on the surface of the semiconductor wafer. In phase floating epitaxial growth equipment,
A vapor phase levitation epitaxial growth apparatus characterized in that the gas reaction section is provided with means for floating and holding a semiconductor wafer above the center thereof. 2. In the vapor phase levitation epitaxial growth apparatus as set forth in claim 1, the means for floating and holding the semiconductor wafer includes a gas reaction section formed in a planar member, and located at a position facing the periphery of the semiconductor wafer on the planar member. A vapor phase levitation epitaxial growth apparatus characterized in that the provided gas ejection holes are arranged radially inward of a semiconductor wafer. 3. In the vapor phase levitation epitaxial growth apparatus according to claim 1, the means for floating and holding the semiconductor wafer includes a gas reaction section formed in a planar member, and located at a position facing the periphery of the semiconductor wafer on the planar member. A vapor phase levitation epitaxial growth apparatus characterized in that the gas ejection holes provided are arranged at right angles to the planar member, and the diameter thereof is larger than that of the gas ejection holes in the central part. 4. The vapor phase levitation epitaxial growth apparatus according to claim 2 or 3, wherein the gas ejection holes are provided in a flat member at an angle along the circumferential direction of the semiconductor wafer. Phase floating epitaxial growth device. 5. In the vapor phase levitation epitaxial growth apparatus as set forth in claim 1, the semiconductor wafer floating and holding means has a gas reaction section for floating the semiconductor wafer, and a curved member on the opposite side of the semiconductor wafer. 1. A vapor levitation epitaxial growth apparatus characterized in that the curved member is formed with a gas ejection hole directed toward the center of the semiconductor wafer. 6. In the vapor phase levitation epitaxial growth apparatus according to claim 1, the semiconductor wafer floating and holding means curves the gas reaction section that suspends the semiconductor wafer in a direction opposite to the semiconductor wafer. 1. A vapor phase levitation epitaxial growth apparatus characterized in that a curved member is formed, and a gas ejection hole is provided in the curved member at right angles to the surface of a semiconductor wafer. 7. The vapor phase levitation epitaxial growth apparatus according to claim 5 or 6, wherein the gas ejection holes are provided in a curved member at an angle along the circumferential direction of the semiconductor wafer. Phase floating epitaxial growth equipment.