JPH02111693A - Gas-injection structure in semiconductor epitaxial growth apparatus - Google Patents

Abstract

PURPOSE:To provide the title structure so designed that a stainless gas ring is covered with a quartz cover ring and the opening of the gas ring is covered with a quartz injection cover, thereby eliminating adverse effects on the epitaxial layer due to residual growth gas unreacted. CONSTITUTION:The objective structure equipped with (A) a susceptor 20 to set semiconductor wafers 80 to grow epitaxial layers, (B) a bell jar 10 enclosing said susceptor 20, and (C) a heat source 30 provided around said bell jar 10. This structure is comprised of (1) a gas ring 40 with an opening 41 to set an injection nozzle 60 for feeding a growth gas G into the bell jar 10, (2) a quartz cover ring 50 covering the inside of said gas ring 40, and (3) a quartz injection cover 70 set detachably at the opening 41. Said cover ring 50 is provided with an opening 51 at the position corresponding to the opening 41 on the gas ring 40.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a gas injection structure for a semiconductor epitaxial growth apparatus for growing an epitaxial layer on a semiconductor wafer.

<Prior Art> First, an overview of a conventional semiconductor epitaxial growth apparatus will be explained with reference to FIG. However, the injection structure will be explained with reference to FIG.

Epitaxial growth apparatuses can be broadly classified into horizontal types, vertical types, and cylinder types as shown in FIG.

A horizontal epitaxial growth apparatus consists of a horizontal bell jar and a susceptor set inside the bell jar. A growth gas for growing an epitaxial layer is supplied inside the bell jar, and the susceptor is heated to a temperature at which the growth gas reacts. The epitaxial layer is grown on the semiconductor wafer by heating with a high-frequency coil. In addition, the vertical bitaxial growth device has a vertical bell jar,
The bell jar has a susceptor set inside the bell jar, and is configured to place a semiconductor wafer on the susceptor.

Since these horizontal and vertical epitaxial growth apparatuses have drawbacks such as uniformity within the loft and arrangement of semiconductor wafers, cylinder-type epitaxial growth apparatuses are now the majority.

The current mainstream cylindrical epitaxial growth equipment is a roughly cup-shaped bell jar made of quartz glass.
A susceptor 20 having a substantially trapezoidal cross section is rotatably set inside the bell jar lO, and a susceptor 20, for example, dichlorosilane (SiHz
A growth gas G, which is a silane gas such as Cl2), is supplied. The susceptor 20 is an infrared lamp 30
This activates the growth gas G, and an epitaxial layer grows on the semiconductor wafer 80 set on the susceptor 20.

An injection nozzle 60 for supplying growth gas G into the inside of the bell jar 10 is set in an opening 41 of a gas ring 40 attached to the upper open end of the bell jar 10. This gas ring 40 is made of stainless steel. Then, a cover ring 50 made of quartz is placed in close contact with the inside of the gas ring 40. The reason why the cover ring 50 is made of quartz is that unreacted growth gas G tends to remain in the stainless steel gas ring 40, and when the lid 13 is opened, the remaining growth gas G
This is because the particles react with oxygen in the air and turn into SiO□ powder (hereinafter referred to as particles), and these particles may adversely affect the epitaxial layer.

Although the clear reason why growth gas G does not remain in quartz such as the cover ring 50 and why growth gas G remains in stainless steel such as the gas ring 40 has not been elucidated, the following possibilities are considered. It will be done. That is, since cooling water is circulated inside the gas ring 40 for cooling, the gas ring 40 is always maintained at a temperature at which the growth gas G does not react. On the other hand, since the Belljar IO is heated by the infrared lamp 30, all of the growth gas G reacts and does not remain.

<Problems to be Solved by the Invention> However, the gas injection structure of the conventional semiconductor epitaxial growth apparatus described above has the following problems.

That is, the cover ring 50 is provided with a notch 51 so that the growth gas G is supplied into the bell jar 10. Since this cut 51 is set to be slightly larger than the opening 41, the cover ring 50 does not cover the entire inside of the gas ring 40. Therefore, the growth gas G remains unreacted and the gas ring 4
When lt3 is opened, this unreacted growth gas G becomes particles and adversely affects the growth of the epitaxial layer. Further, since the stainless steel is exposed on the inner surface of the opening 41 of the gas ring 40, this also causes particles to be generated.

The present invention was devised in view of the above circumstances, and provides a gas injection structure for a semiconductor epitaxial growth apparatus that does not generate particles by covering all exposed stainless steel parts that cause particle generation with a member made of quartz. It is intended to.

<Means for Solving the Problems> The gas injection structure of the semiconductor epitaxial growth apparatus according to the present invention includes a susceptor for setting a semiconductor wafer on which an epitaxial layer is to be grown, a bell jar surrounding the susceptor, and a bell jar installed around the bell jar. In the semiconductor epitaxial growth apparatus, the semiconductor epitaxial growth apparatus is equipped with a gas ring having an opening through which an inject nozzle for supplying growth gas to the inside of the bell jar is opened, and a cover ring made of quartz that covers the inside of the gas ring. and an injection cover made of quartz that is detachably set in the opening, and the cover ring has an opening in a cavity corresponding to the opening of the gas ring.

Function> Growth gas is supplied to the inside of the bell jar via the injection nozzle. This growth gas is activated by a susceptor heated by a heat source such as an infrared lamp to grow an epitaxial layer on the semiconductor wafer.

Once the epitaxial layer has grown to a predetermined thickness,
A semiconductor wafer is taken out from a semiconductor epitaxial growth apparatus. At this time, air enters the inside of the bell jar, but since no unreacted growth gas remains, no particles are generated that would adversely affect the epitaxial layer.

<Example> Hereinafter, an example according to the present invention will be described with reference to the drawings. The entire semiconductor epitaxial growth apparatus will be explained with reference to FIG. 4, and the gas injection structure of the semiconductor epitaxial growth apparatus according to the present invention will be explained in FIGS.
This will be explained with reference to the figures.

FIG. 1 is a sectional view schematically showing a gas injection structure of a semiconductor epitaxial growth apparatus according to the present invention, FIG. 2 is a perspective view of a cover ring, FIG. 3 is a perspective view of an inject cover, and FIG. 4 is a semiconductor epitaxial growth device. FIG. 2 is a schematic diagram of the device. In addition, the same reference numerals are given to the conventional parts and the parts between the tracks, etc. in the explanation.

The gas injection structure of the semiconductor epitaxial growth apparatus according to the present invention includes a susceptor 20 for setting a semiconductor wafer 80 on which an epitaxial layer is to be grown, a belljar 10 surrounding the susceptor 20, and a heat source installed around the belljar 10. In a semiconductor epitaxial growth apparatus, an opening 41 for setting an inject nozzle 60 for supplying growth gas G into the inside of the bell jar 10;
The gas ring 40 has a gas ring 40, a cover ring 50 made of quartz that covers the inside of the gas ring 40, and an injection cover 70 made of quartz that is detachably set in the opening 41. An opening 51 is formed in the cover ring 50 at a location corresponding to the opening 41 of the gas ring 40.

An epitaxial growth apparatus is a device that supplies one or more growth gases G containing elements constituting a thin film material to be formed onto a semiconductor wafer 80, and forms a desired thin film (this film) through a vapor phase or a chemical reaction on the surface of the semiconductor wafer 80. C V D (Chemica
A susceptor 20 on which a belljar 10 and a semiconductor wafer 80 on which an epitaxial layer is to be grown is set.
It includes an infrared lamp 30 as a heat source that heats the susceptor 20 to a temperature at which the growth gas G supplied to the inside of the bell jar 10 is activated, and an inject nozzle 60 that supplies the growth gas G to the inside of the bell jar 10. There is.

The bell jar 10 is a tank made of quartz glass, and is formed into a substantially cup-like shape with an open top. This Bellja I
An exhaust port 12 for exhausting the supplied growth gas G is provided at the bottom of the O, and this exhaust port 12 is connected to an exhaust device (not shown). Further, the edge of the upper opening is formed as a flange 11 for mounting a gas ring 40, which will be described later. Note that 13 in the drawings indicates a lid that closes the bell jar 10.

A plurality of infrared lamps 30 are provided around the bell jar 10 as heat sources. This infrared lamp 30 heats the susceptor 20 to approximately 1000 to 1200''C, thereby heating the internal temperature of the bell jar 10 to a temperature at which the growth gas G is activated. is provided with a cooling mechanism 31 that cools the infrared lamp 30 when emitting light.

The gas ring 40 is made of stainless steel, and has a predetermined number (two in the drawing) of openings 41. The injection nozzle 6° is inserted into the opening 41 through the O-ring 6.
Set via 1. Then, the inner surface 41 of the opening 41
1, an inject cover 70 made of quartz is placed on the part of the inject nozzle 6o that is not covered.
is set in a removable manner. That is, the inner surface 411 of the opening 41 is completely covered by the inject cover 70 and the inject nozzle 6o. This injection force bar 70 is provided with at least one hole 71, and the number and shape of this hole 71 depends on the characteristics of the epitaxial layer to be grown, such as the film thickness and resistivity distribution of the epitaxial layer. It shall be changed as appropriate (see Figures 3(a) and 3).

The cover ring 50 is attached to the inside of the gas ring 40 to cover the inside of the gas ring 40, and has openings 51 only at locations corresponding to the openings 41 of the gas ring 40. This covering ring 50 is
It is made of quartz to prevent unreacted growth gas G from remaining. That is, the inside of the gas ring 40 is completely covered by the quartz cover ring 50 in which no unreacted growth gas G remains.

Therefore, the area around the inject nozzle 60 of this semiconductor epitaxial growth apparatus (the inside of the gas ring 40 and the inside surface 411 of the opening 41) is completely covered with quartz, so that unreacted growth that causes particle generation is prevented. No residual gas G is generated.

<Effects of the Invention> The gas injection structure of the semiconductor epitaxial growth apparatus according to the present invention includes a susceptor for setting a semiconductor wafer on which an epitaxial layer is to be grown, a bell jar surrounding the susceptor, and a heat source installed around the bell jar. A semiconductor epitaxial growth apparatus comprising: a gas ring having an opening for setting an inject nozzle for supplying growth gas into the bell jar; a cover ring made of quartz that covers the inside of the gas ring; It is equipped with an inject cover made of quartz that is detachably set, and the cover ring has an opening at a location corresponding to the opening of the gas ring, so that the following effects are achieved.

In other words, the stainless steel gas ring, in which unreacted growth gas remains, is covered with a quartz cover ring, which does not leave unreacted growth gas, and the gas ring opening into which the inject nozzle is set is made of quartz. Since it is covered with an injection cover, particles caused by residual unreacted growth gas are not generated. Therefore, there is no adverse effect on the epitaxial layer due to particles. Furthermore, since particles are not generated, maintenance of the semiconductor epitaxial growth apparatus becomes easy and the operating rate can be improved. Furthermore, since the inject cover can be replaced depending on the characteristics of the epitaxial layer to be grown, epitaxial layers with various characteristics can be grown without replacing the entire injection nozzle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view schematically showing a gas injection structure of a semiconductor epitaxial growth apparatus according to the present invention, FIG. 2 is a perspective view of a cover ring, FIG. 3 is a perspective view of an inject cover, and FIG. 4 is a semiconductor epitaxial growth device. A schematic diagram of the apparatus, FIG. 5 is a perspective view of a conventional gas ring and cover ring. lO... Bellja, 20... Susceptor, 30...
Infrared lamp (heat source), 40... Gas ring, 41.
... Opening (of the gas ring), 411 ... Inner surface (of the opening of the gas ring), 50... Cover ring, 5
1... Opening (of the covering ring), 60... Inject nozzle, 70... Inject cover 80...
・Semiconductor wafer, G...Growth gas.

Claims (1)

[Claims] (1) In a gas injection structure of a semiconductor epitaxial growth apparatus that includes a susceptor for setting a semiconductor wafer on which an epitaxial layer is to be grown, a bell jar surrounding the susceptor, and a heat source installed around the bell jar, the inside of the bell jar a gas ring with an opening for setting an inject nozzle that supplies growth gas to the gas ring, a cover ring made of quartz that covers the inside of this gas ring, and an injector made of quartz that is removably set in the opening. 1. A gas injection structure for a semiconductor epitaxial growth apparatus, comprising: a cover, the cover ring having an opening at a location corresponding to an opening of a gas ring.