JPH0555154A - Thermal treatment furnace for semiconductor substrate - Google Patents

Abstract

PURPOSE:To provide a thermal treatment furnace with an improved productive yield and electric characteristics, by carrying out an in-plane thermal treatment uniformly for a semiconductor substrate. CONSTITUTION:A thermal treatment furnace for a semiconductor substrate comprises a substrate mounting boat 1, which is inserted into the furnace tube after a plurality of semiconductor substrates W are mounted vertically and in parallel on the mounting boat 1. In the substrate mounting boat 1, a substrate supporting member 2 fixed at each substrate supporting position is made of materials with almost equal thermal capacity to that of the semiconductor substrate W.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate heat treatment furnace (hereinafter referred to as a heat treatment furnace), and more particularly to the structure of a substrate mounting boat in which a semiconductor substrate is mounted and loaded into a furnace core tube.

[0002]

2. Description of the Related Art Conventionally, GaAs (gallium arsenide)
When performing heat treatment such as annealing on a semiconductor substrate such as a substrate, a heat treatment furnace having a schematic structure shown in the partial cross-sectional view of FIG. 3 is used. That is, reference numeral 10 in FIG. 2 is a quartz glass furnace core tube that constitutes a heat treatment furnace, and 11 is a U-shaped plan view in which the semiconductor substrate W to be heat-treated is mounted and then inserted into the furnace core tube 10. The substrate mounting boat is configured such that a large number of semiconductor substrates W are arranged in parallel on the substrate mounting boat 11 in an upright posture with their front and back surfaces facing forward and backward.

The board mounting boat 11 has four
It is used at a high temperature such as 00 to 1200 ° C., and is generally formed of quartz so as not to be contaminated by heavy metal ions or the like implanted as an impurity to the semiconductor substrate W. It has become a target. At this time, each of the semiconductor substrates W is supported by being inserted into each pair of the grooves 12 formed directly at each substrate supporting position of the substrate mounting boat 11 parallel to each other.

[0004]

By the way, since quartz, which is a forming material of the substrate mounting boat 11 having the above-mentioned conventional structure, has a very large heat capacity as compared with the semiconductor substrate W, it is formed on this. A large amount of heat is taken from the semiconductor substrate W that is inserted into and supported by the groove 12 and is in direct contact with the substrate mounting boat 11. As a result, the temperature rise at the insertion portion of the semiconductor substrate W may become insufficient locally, or the temperature rise rate may be delayed as compared with the other portions.
In some cases, the uniform heat treatment in the plane may not be performed, leading to a decrease in product yield. In addition, the sheet resistance becomes non-uniform due to thermal non-uniformity in the surface of the semiconductor substrate W, which causes a problem in that the electrical characteristics of the product may be problematic.

The present invention was devised in view of such inconvenience, and it is possible to perform uniform heat treatment within the surface of the semiconductor substrate, and it is easy to improve the product yield and electrical characteristics. The purpose is to provide a simple heat treatment furnace.

[0006]

In order to achieve such an object, a heat treatment furnace according to the present invention is mounted in a furnace core tube with a large number of semiconductor substrates arranged in parallel in an upright position. And a board supporting member made of a material having a heat capacity similar to that of the semiconductor substrate is attached to each board supporting position of the board mounting boat. ..

[0007]

According to the above construction, since the substrate support made of a material having the same heat capacity as the semiconductor substrate is attached to each substrate support position of the substrate mounting boat, each of the semiconductor substrates is This means that it is indirectly contacted with the board mounting boat having a large heat capacity through the inserted and supported board supporting member. Therefore, a large amount of heat is not taken from each of the semiconductor substrates by the substrate mounting boat, and as a result, the temperature rise and the temperature rise speed at the insertion portion of each semiconductor substrate W become the same as those of the other portions.

[0008]

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

FIG. 1 is a partial sectional view showing a schematic structure of a heat treatment furnace according to this embodiment, and FIG. 2 is an enlarged plan view showing a board mounting boat. Since the structure of this heat treatment furnace is basically the same as that of the conventional example, the same parts as those in FIG. 3 are designated by the same reference numerals in FIG.

The heat treatment furnace according to the present embodiment is used when performing heat treatment such as annealing treatment on a semiconductor substrate W, for example, a semiconductor substrate such as a GaAs substrate, and is used as a heat source in the outer periphery. Quartz glass furnace core tube 10 provided with a halogen lamp (not shown) and the like
And a board mounting boat 1 to be loaded into the furnace core tube 10 after mounting a large number of semiconductor substrates W arranged in parallel in a standing posture. And this board mounting boat 1
Is formed in a U-shape in plan view by using quartz, which is excellent in heat resistance and contamination resistance due to heavy metals and the like, and the open parallel portions of the board mounting boat 1 are integrated by connection. Has been done. Further, for each supporting position of the semiconductor substrate W provided at the position where the parallel portions of the substrate mounting boat 1 face each other, graphite or silicon carbide, which is a material having a heat capacity similar to that of the semiconductor substrate W, is used. The substrate support 2 is attached.

That is, a concave portion (not shown) having a predetermined shape and size is provided at each predetermined position of the parallel portion of the substrate mounting boat 1 which supports the semiconductor substrate W in parallel with each other. Each of them is formed and the substrate support 2 is attached by a technique such as fitting into each of the recesses. Then, for each pair of the substrate supporting members 2 attached so as to face each other, the groove 1 into which a predetermined portion of the semiconductor substrate W is inserted and supported.
2 are formed so that they can face each other in advance. In addition,
Here, the heat capacity of GaAs is 0.34 J · g ⁻¹ ·
K about ^-1, whereas that of quartz is about 1.53J · g ^-1 · K ^-1, heat capacity possessed by the graphite 0.43
J · g ⁻¹ · K ⁻¹ , that of silicon carbide is 0.
It is about 61 J · g ⁻¹ · K ⁻¹ .

By the way, the inventor of the present invention uses the substrate mounting boat 1 having the above-mentioned structure to form a GaAs semiconductor substrate W.
When an annealing treatment test was performed on the substrate, this G
The temperature rise only in the insertion part of the aAs substrate is not locally insufficient, and the temperature rise rate is not delayed compared to the other parts, and uniform heat treatment is performed in the plane of the GaAs substrate. Has been confirmed. In this test, the injection energy is 100
This was performed using a GaAs substrate in which KeV and an implantation amount of 5 × 10 ¹² / cm ² were implanted with Si cations at room temperature, and the annealing temperature during the test was set to 950 ° C.

In this test, the implantation amount of Si cations was changed within the range of 1 × 10 ^{11 to} 5 × 10 ¹⁴ / cm ² , and the implantation energy was 10 to 400K.
Change within the range of eV or change the annealing temperature to 80
Although it was changed within the range of 0 to 1200 ° C., no significant difference was observed with these changes. Also,
The ion species to be implanted in the GaAs substrate are Si, S, Se,
N-type impurities such as Sn, Te or Be, Mg, Zn
I tried changing to p-type impurities such as, but no inconvenience occurred. Furthermore, the type of the semiconductor substrate W to be annealed is an InP substrate or an AlGaAs substrate,
I changed to a compound semiconductor substrate such as an InGaAs substrate, but there is no significant difference due to this, and Si
No inconvenience occurred even if the substrate was changed to a single element semiconductor substrate.

[0014]

As described above, according to the heat treatment furnace of the present invention, the substrate support made of a material having the same heat capacity as the semiconductor substrate to be heat treated is provided at each substrate support position of the substrate mounting boat. Since they are attached, each of the semiconductor substrates is in indirect contact with the board mounting boat having a large heat capacity through the board support member inserted and supported, and the board mounting boat allows a large amount of each semiconductor substrate to be mounted. The heat of will not be taken away.
Therefore, the temperature rise and the temperature rise rate in the insertion portion of each semiconductor substrate are the same as those in the other portions, and uniform heat treatment is performed within the surface, so that the product yield can be improved. Further, as a result of enabling thermal uniformity within the surface of the semiconductor substrate, it is possible to obtain an effect that the sheet resistance can be made uniform and the electrical characteristics of the product can be improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a schematic structure of a heat treatment furnace according to this example.

FIG. 2 is an enlarged plan view showing a board mounting boat.

FIG. 3 is a partial cross-sectional view showing a schematic structure of a heat treatment furnace according to a conventional example.

[Explanation of symbols]

 1 board loading boat 2 board support 10 furnace core tube W semiconductor board

Claims (1)

[Claims] 1. A substrate mounting boat (1) for mounting a large number of semiconductor substrates (W) arranged in parallel in an upright position and loaded into a furnace core tube (10), comprising: A substrate support (2) made of a material having a heat capacity similar to that of the semiconductor substrate (W) at each substrate support position of the mounting boat (1).
A heat treatment furnace for semiconductor substrates, wherein the heat treatment furnace is attached.