JPH07122569A - Radiation heat treatment system for semiconductor wafer - Google Patents

Abstract

PURPOSE:To provide a radiation heat treatment system for semiconductor wafer in which the semiconductor wafer can be heat treated without causing any slippage. CONSTITUTION:The radiation heat treatment system 2 comprises Q vessel 3, a supporting member 3a for semiconductor wafer 1, and a heat source 4 disposed on the outside of the vessel 3 and heating the wafer 1 through radiation, wherein a part of the supporting member 3a touching the semiconductor wafer 1 is made of a material which absorbs radiation heat to cause temperature rise at same rate as the semiconductor wafer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus for semiconductor wafers by radiant heat, and more particularly to a support member for supporting semiconductor wafers.

[0002]

2. Description of the Related Art Conventionally, the heat treatment of silicon wafers has been
A large number of wafers are placed on a carrier called a boat, inserted into a heat treatment furnace, the gas in the heat treatment furnace is heated, and the heat transfer action between this gas and each wafer heats each silicon wafer. I was doing. However, this method
Since the heat transfer efficiency is low, a heat treatment at a high temperature for a long time is required, which may cause problems such as wafer contamination and slip. Therefore, the present inventor repeatedly studied direct heating by radiant heat. Although no conventional literature relating to this method is found, the present inventor has found that a quartz supporting leg is also provided upright to support a silicon wafer in a quartz container, and a halogen lamp is arranged outside the container. The silicon wafer was heated by the radiant heat emitted from the lamp to perform heat treatment on the wafer.

[0003]

However, when the above heat treatment was carried out, slips 5 were produced on the silicon wafer 1 in the portion in contact with the supporting legs as shown in FIG. Therefore, an object of the present invention is to provide a heat treatment apparatus for semiconductor wafers by radiant heat, which can heat treat semiconductor wafers without causing slippage.

[0004]

The present invention has been made to achieve the above-mentioned object, that is, a support member for supporting a semiconductor wafer is provided in a container, a heat source is arranged outside the container, and In a heat treatment apparatus for semiconductor wafers by radiant heat that heats semiconductor wafers by radiant heat that is radiated, the portion of the support member that contacts the semiconductor wafer absorbs the radiant heat and rises in temperature at the same rate as the semiconductor wafer. It is a heat treatment apparatus for semiconductor wafers by radiant heat, characterized by being formed of a material.
In that case, when the semiconductor wafer is a silicon wafer, the portion of the supporting member that comes into contact with the silicon wafer can be formed of silicon or silicon carbide, and can be coated by chemical vapor deposition of silicon or silicon carbide. You can also

[0005]

The conventional support leg material, quartz, has a lower absorption rate of radiant heat than silicon (see FIGS. 3 and 4) and a large specific heat (quartz glass is 1.12 kJ / 800 ° C.).
kg ・ K, 0.885kJ / kg for silicon at 800 ℃
-K), the rate of increasing the temperature by absorbing radiant heat is low. Therefore, the conventional support leg does not heat up as quickly as the silicon wafer, and as a result, a temperature gradient is generated in the contact portion between the support leg and the silicon wafer, and thermal stress is applied to the silicon wafer in the portion contacting the support leg. Caused a slip. However, in the present invention, the portion of the support member that contacts the semiconductor wafer is formed of a material having a rate of absorbing radiant heat and increasing the temperature, which is equivalent to that of the semiconductor wafer. There is no temperature gradient in the area and therefore no slippage of the semiconductor wafer.

[0006]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a single-wafer lamp heater 2 according to a first embodiment of the present invention.
The lamp heater 2 comprises a quartz container 3 and a halogen lamp 4, and three or more supporting legs 3a are erected in a non-linear manner in the container 3, and silicon wafers are mounted on the supporting legs 3a. 1 is mounted. The support leg 3a is formed by coating a body made of silicon carbide with silicon carbide by chemical vapor deposition. On the other hand, the halogen lamp 4 uses a plurality of rod-shaped lamps in parallel and is arranged so as to irradiate the upper and lower surfaces of the silicon wafer 1 from the upper side and the lower side of the container. In the present embodiment, the plurality of lower halogen lamps 4 are arranged so as to be orthogonal to the plurality of upper lamps in a grid pattern, but the plurality of upper and lower lamps may be arranged in parallel. It is possible to arrange it so that, for example, only the upper surface of the silicon wafer 1 is irradiated from above. A point light source may be used, or a heat source other than a halogen lamp may be used.

The intensity of the light emitted from the halogen lamp 4 has a spectrum as shown in FIG.
Since quartz, which is the material of, has a transmittance as shown in FIG. 3, the light emitted from the halogen lamp 4 is hardly absorbed by the quartz container 3 and passes through it to reach the silicon wafer 1. To do. FIG. 4 shows the absorptance of silicon. Since the silicon fully absorbs the intensity spectrum of the halogen lamp shown in FIG. 2, the silicon wafer 1 can be directly heated from outside the container 3.

Since the supporting legs 3a of this embodiment are made of silicon carbide, and the physical properties of silicon carbide are similar to those of silicon, the rate of temperature rise upon receiving radiant heat is the same as that of the silicon wafer 1. There is no difference from the support leg 3a. Therefore, a temperature gradient is not generated in the contact portion between the two, and no slip occurs in the portion of the silicon wafer 1 that contacts the support leg 3a.

Since the amount of heat generated by radiant heat is generally given as the amount of heat per unit volume and unit time (J / m ³ · s), multiplying this by the density (kg / m ³ ) gives the unit mass and unit. It becomes the heat quantity per unit time (J / kg · s), and by dividing this by the specific heat (J / kg · K),
The temperature rise rate (K / s) is obtained. Therefore, even if the calorific value is the same as that of the silicon wafer 1, the temperature rise rate does not necessarily become the same as that of the silicon wafer 1.
On the other hand, even if each physical property value is different from that of the silicon wafer 1, there may be a material whose final temperature rise rate is almost the same as that of the silicon wafer 1. Therefore, the supporting leg 3a may be formed of such a material. it can. However, as shown in FIG. 4, since the amount of heat generated by the silicon wafer 1 itself changes depending on the temperature, the support leg 3a is formed of silicon, or the support leg 3a is formed of a material having the same physical properties as silicon, for example, silicon carbide. Is the simplest.

The portion of the support leg 3a that comes into contact with the silicon wafer is preferably formed of a high-purity material, and therefore the portion that comes into contact with the silicon wafer is preferably coated by chemical vapor deposition of silicon or silicon carbide. In this case, as the material of the support leg body to be coated, silicon or silicon carbide can be used, and other materials can be used as long as there is almost no temperature gradient at the contact portion between the silicon wafer 1 and the support leg 3a. It can also be used. If it is a much thinner member, that member can be used for the contact portion of the support leg 3a that contacts the silicon wafer, and for example, silicon or silicon carbide can be used for the portion following the member. In this case, since the member used for the contact portion of the support leg 3a is thin, a temperature gradient is hardly generated at the contact portion between the silicon wafer 1 and the support leg 3a due to heat conduction. In addition, at least the portion of the support leg that contacts the silicon wafer,
It is preferable to form it by a material whose rate of absorbing radiant heat and raising the temperature is the same as that of the silicon wafer, but as long as there is almost no temperature gradient at the contact portion between the silicon wafer and the supporting leg, it is separated from the contact portion. The support legs of the part can also be made of another material. That is, it is not always necessary to form all of the supporting legs by using a material having a rate of absorbing the radiant heat and increasing the temperature, which is equivalent to that of the silicon wafer.

Next, FIG. 6 shows a second embodiment. In this embodiment, a carrier (not shown) is formed so that the carrier 6 can be inserted into and removed from the container without standing legs. Then, this carrier 6
Support legs are erected on. That is, the carrier 6 has a grip 6a and a ring portion 6b, and three support legs 6c are provided at intervals of approximately 120 ° in the circumferential direction on the upper surface of the ring portion 6b.
Is formed upright, and a silicon wafer (not shown) is placed on the support legs 6c. The grip 6a and the ring portion 6b are made of quartz so that almost all of the radiant heat can be transmitted, but the support leg 6c has a main body made of silicon carbide, and the supporting leg 6c is made of silicon carbide chemically. It is formed by coating by vapor deposition. Also with this configuration, there is no temperature gradient at the contact portion between the silicon wafer and the support leg 6c, so that the silicon wafer does not slip.

[0012]

According to the present invention, in a heat treatment apparatus for directly heating a semiconductor wafer by heat radiation, the portion of the supporting member that is in contact with the semiconductor wafer absorbs radiant heat and is heated at a rate equivalent to that of the semiconductor wafer. Since the heat treatment apparatus is made of a material, the heat treatment of the semiconductor wafer can be performed without slippage at the contact portion with the support member.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is a diagram showing the radiation intensity of a halogen lamp.

FIG. 3 is a graph showing the transmittance of quartz.

FIG. 4 is a diagram showing the absorption rate of silicon.

FIG. 5 is a diagram showing a conventional silicon wafer slip.

FIG. 6 is a perspective view showing a second embodiment.

[Explanation of symbols]

1 ... Silicon wafer 2 ... Lamp heater 3
... Container 3a ... Support legs 4 ... Halogen lamp 5
... Slip 6 ... Conveyor 6a ... Grip 6
b ... Ring part 6c ... Support leg

Claims (5)

[Claims] 1. A heat treatment apparatus for semiconductor wafers by radiant heat, wherein a supporting member for supporting a semiconductor wafer is provided in a container, a heat source is arranged outside the container, and the semiconductor wafer is heated by radiant heat radiated from the heat source. In the portion of the supporting member that comes into contact with the semiconductor wafer, the ratio of increasing the temperature by absorbing the radiant heat is formed by a material equivalent to the semiconductor wafer, of the semiconductor wafer by radiant heat Heat treatment equipment. 2. The heat treatment apparatus for a semiconductor wafer by radiant heat according to claim 1, wherein the carrier member formed to be removable from the container is provided with the support member for supporting the semiconductor wafer. 3. The heat treatment of a semiconductor wafer by radiant heat according to claim 1, wherein the semiconductor wafer is a silicon wafer, and a portion of the supporting member that comes into contact with the silicon wafer is formed of silicon or silicon carbide. apparatus. 4. The radiant heat according to claim 1, 2 or 3, wherein the semiconductor wafer is a silicon wafer, and a portion of the supporting member that comes into contact with the silicon wafer is coated by chemical vapor deposition of silicon or silicon carbide. Heat treatment equipment for semiconductor wafers. 5. A semiconductor produced by radiant heat, wherein the whole or substantially the whole of the supporting member is replaced with a portion of the supporting member which comes into contact with the semiconductor wafer, as in claim 1, 2, 3 or 4. Wafer heat treatment equipment.