JPH10289883A - Method and apparatus for heat treatment of semi-insulative gaas wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for heat treatment of a GaAs wafer wherein the number of wafers subjected to heat treatment can be in creased without inviting defects to an ion-implanted, semi-insulative GaAs wafer. SOLUTION: In performing heat treatment of an ion-implanted, semi-insulative GaAs wafer, half insulative GaAs wafers 2 are perpendicularly arranged on a perpendicular-wafer-arrangement type heat treating tool body 1, and blocks 3 having large thermal capacity are, respectively, arranged between the wafers 2 and at both ends of the heat treating tool body 1, so that the thermal capacity of an entire heat treating tool 4 is increased. Thus, even if the tool 4 is rapidly heated or rapidly cooled, the thermal hysterisis received by the wafers 2 is buffered to suppress generation of slit-shaped defects, thereby permitting the number of wafers for heat treatment to be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semi-insulating GaAs.
The present invention relates to a heat treatment method and a heat treatment apparatus for a wafer.

[0002]

2. Description of the Related Art A high-temperature heat treatment is required to electrically activate ions of a semi-insulating GaAs wafer into which ions have been implanted. Usually, activation of ions implanted into the wafer is performed at a high temperature of 800 ° C. or higher.

[0003]

In recent years, semi-insulating GaAs wafers have attracted attention as wafers for ultra-high-speed integrated circuits. However, a semi-insulating GaAs wafer has a lower critical shear stress than a Si wafer, and is likely to have defects due to thermal stress. For this reason, in a temperature range of 600 ° C. or higher, slow thermal diffusion is likely to occur, and rapid thermal quenching is required to prevent the slow thermal diffusion.

In general, ion-implanted semi-insulating GaAs
The heat treatment jig used for the activation heat treatment of the s wafer is a plate-like member made of a substance having a large heat capacity (mainly SiO ₂ ). Semi-insulating G ion-implanted on the plate-like member
An aAs wafer is placed and activation heat treatment is performed. In this case, since the ion-implanted semi-insulating GaAs wafer is in surface contact with the heat treatment jig and the heat capacity of the heat treatment jig is large, the temperature rise and fall rate in the heat treatment of the ion-implanted semi-insulating GaAs wafer is high. Follows the temperature rise / fall speed of the heat treatment jig. In particular, even if the heat treatment is completed and the wafer is rapidly cooled by opening the heater, the wafer itself is not rapidly cooled and no defect occurs.

However, when the heat treatment jig is dish-shaped, the number of processed wafers cannot be increased due to the limitation of the soaking length of the heater in order to place the wafer horizontally.

On the other hand, when heat-treating a Si wafer, it is general to use a vertical-type wafer heat treatment jig supported at several locations. This wafer vertical type heat treatment jig
An increase in the number of heat-treated wafers per wafer is expected.

However, since this jig has a small heat capacity and is directly affected by the external temperature, when heat-treating a GaAs wafer, rapid heating and quenching causes slit-like defects. Has the disadvantage of doing
It cannot be applied as is.

Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a heat treatment method for a semi-insulating GaAs wafer capable of increasing the number of heat treatments without causing defects in the ion-implanted semi-insulating GaAs wafer. An object of the present invention is to provide a heat treatment apparatus.

[0009]

In order to achieve the above object, a heat treatment method for a semi-insulating GaAs wafer according to the present invention comprises the steps of: The GaAs wafer is heated by sandwiching it between substances having a large heat capacity.

The heat treatment apparatus for a semi-insulating GaAs wafer according to the present invention is a heat treatment apparatus for activating an ion-implanted semi-insulating GaAs wafer.
It has a heat treatment jig for holding and heating the As wafer and a block made of a substance having a large heat capacity and arranged on the heat treatment jig so as to sandwich each semi-insulating GaAs wafer.

According to the present invention, in the heat treatment of an ion-implanted semi-insulating GaAs wafer, the semi-insulating GaAs wafer is lined up in a vertically oriented wafer-type heat treatment jig main body, and the gap between the wafers and the heat treatment jig are determined. By inserting a substance with a large heat capacity at both ends of the main body and increasing the heat capacity of the entire heat treatment jig, the heat history received by the wafer itself is buffered even when rapid heating and rapid cooling is performed, and the occurrence of slit-shaped defects is suppressed. Therefore, the number of heat treatments can be increased.

[0012]

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

FIG. 1 is a sectional view showing a heat treatment jig used in a heat treatment apparatus to which the heat treatment method for a semi-insulating GaAs wafer of the present invention is applied.

Reference numeral 1 denotes a wafer vertical type heat treatment jig main body for holding and heating the semi-insulating GaAs wafer 2. A block (for example, a quartz block) 3 made of a substance having a large heat capacity is arranged on the plate-shaped heat treatment jig main body 1 so as to sandwich each semi-insulating GaAs wafer 2. The heat treatment jig main body 1 and the block 3 constitute a heat treatment jig 4.

The heat treatment jig 4 on which the semi-insulating GaAs wafer 2 is placed is accommodated in a quartz ampoule (not shown) and is subjected to a heat treatment to activate the semi-insulating GaAs wafer 2.

With this configuration, even when rapid thermal quenching is performed, the heat history of the semi-insulating GaAs wafer 2 itself is buffered, and the occurrence of slit-like defects can be suppressed.
The number of heat treatments can be increased.

[0017]

【Example】

(Example) Using Ga 6000 g, As 6600 g, and liquid sealing agent (B ₂ O ₃ ) 1200 g, a weight of 11,000 g, an outer diameter of about 90 mm, and a length of about 320 were obtained by a pulling method.
mm semi-insulating GaAs single crystal was produced. This semi-insulating GaAs single crystal is formed with an outer diameter φ of about 76 mm and a thickness of 670 mm.
The (100) plane wafer was cut out, wrapped, mirror polished and etched to produce a mirror-finished wafer having a thickness of 600 μm. Si was implanted into the wafer by an ion implantation apparatus at an acceleration voltage of 150 KV and a dose of 3 × 10 ¹² cm ⁻² .

In the heat treatment jig shown in FIG. 1, 20 silicon-implanted wafers are arranged at 4.5 mm intervals, and a quartz block having a thickness of 3 mm and an outer diameter of about 76 mm is placed between both ends and the wafer. It was inserted into the furnace. Ar base 1
% And AsH ₃ mixed gas at a flow rate of 3 liters per minute, the temperature was raised to 800 ° C. at 300 ° C./h, held for 30 minutes, and then the heat treatment jig was moved to the non-heated portion.

(Comparative Example) The same heat treatment as in the example was performed with the exception of the quartz block 3 used in the example.

The peripheral portions of the heat-treated wafers of Examples and Comparative Examples were observed with a microscope.

FIG. 2 is a diagram showing a comparative example of a semi-insulating GaAs wafer subjected to a heat treatment.

As shown in FIG. 1, slit-like defects 5 were generated at the four ends of the heat-treated wafer 2a by about 1 cm.

On the other hand, no slits were found in the heat-treated wafers subjected to the heat treatment in the examples.

As described above, according to the present invention, the semi-insulating GaAs wafer is implanted by heating the ion-implanted semi-insulating GaAs wafer by sandwiching it between substances having large heat capacities. Can be increased.

[0025]

In summary, according to the present invention, the following excellent effects are exhibited.

A semi-insulating GaAs wafer capable of increasing the number of heat treatments without causing defects in the semi-insulating GaAs wafer by inserting a substance having a large heat capacity between the ion-implanted semi-insulating GaAs wafers. And a heat treatment apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a heat treatment jig used in a heat treatment apparatus to which a heat treatment method for a semi-insulating GaAs wafer of the present invention is applied.

FIG. 2 is a diagram showing a comparative example of a semi-insulating GaAs wafer subjected to a heat treatment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment jig main body 2 Semi-insulating GaAs wafer 3 Substance (block) with large heat capacity 4 Heat treatment jig

Claims (2)

[Claims] In a heat treatment method for activating an ion-implanted semi-insulating GaAs wafer, each semi-insulating Ga
A heat treatment method for a semi-insulating GaAs wafer, comprising heating an As wafer with a substance having a large heat capacity. 2. A heat treatment apparatus for activating an ion-implanted semi-insulating GaAs wafer, comprising:
A heat treatment jig body for holding and heating the As wafer; and a block made of a substance having a large heat capacity and arranged on the heat treatment jig so as to sandwich each semi-insulating GaAs wafer. Heat treatment apparatus for a semi-insulating GaAs wafer.