JPS63271922A - Heat treatment device - Google Patents

Abstract

PURPOSE:To obtain the title heat treatment device having excellent temperature uniformity on wafers and also generating a few defects by a method wherein a cylindrical heating structure arranged surrounding a sample stand and a lamp heating mechanism arranged in the direction vertical to the sample stand are provided. CONSTITUTION:An Si wafer 3 is retained by a sample stand 2 in a cylindrical quartz chamber 1a, the Si wafer 3 is heated up by the halogen lamp 4 provided on the vertical upper part of the sample stand 2, and also the wafer is heated up by the heater 6 cylindrically surrounding the chamber 1a. The inner surface of a cooler 7 constitutes a reflection mirror, the mirror reflects heat rays, it is useful for the temperature rise of the Si wafer and also the escape of heat to outside is prevented. Also, the non-uniformity of temperature due to a convection can be prevented. As a result, a uniform temperature distribution can be obtained, and the generation of defects on the wafer can also be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat treatment apparatus that has good temperature uniformity at high temperatures and less thermal shock to the object to be treated.

Conventional Technology In the semiconductor industry, heat treatment has traditionally been carried out in a horizontally elongated electric furnace using a reciprocal tube.

However, for purposes such as forming a shallow impurity diffusion layer, there is a need to perform heat treatment at a temperature of about 900° C. to 1060° C. in a short time, and lamp annealing equipment using a halogen lamp or the like is being considered.

Special applications in semiconductor integrated circuit processes may require heat treatment at a temperature of 1150° C. to 1300° C., which is much higher than conventional heat treatment. In this case, conventional electric furnaces have problems such as the lifespan of the heater, deformation of the quartz tube, and deterioration in strength, and are also impractical in terms of power consumption. For this reason, lamp annealing equipment has generally been used for high temperature heat treatment exceeding 1100°C.

FIG. 3 shows a conventional lamp annealing device. Sl is placed on a support stand 2 installed in a quartz chamber 1.
A wafer 3 is placed and heated with light from a halogen lamp 4. The inside of the chamber 1 is normally filled with an inert gas such as N2 or hydrogen.

Problems to be Solved by the Invention However, in the structure described above, if heat treatment is performed at 1000°C or higher for several minutes, a slip line that can be visually confirmed at the periphery of the Si wafer 3 will be generated, and in the worst case, the wafer 3 will be damaged. There was a problem that it could not withstand the strain and would break. Furthermore, since the temperature distribution within the three surfaces of the Si wafer is non-uniform, there is a problem in that when a semiconductor device is completed, a good product can only be obtained near the center of the wafer.

The reasons for this are: (1) Si weto heats up to 100oC in a short period of time.
Exposure to temperature rises or falls above (rapid heating and cooling).

(2) Since the temperature of the Si wafer is directly raised by the lamp, the temperature difference between the areas where the wafer and the support are in good contact and the areas where it is not becomes large, which causes distortion in the wafer and causes slip lines and cracks. to occur.

It is thought that these two points have a strong effect.

In view of this, the present invention aims to provide a processing device that has good temperature uniformity on the wafer even during high-temperature heat treatment of 1,100°C or higher, and has fewer defects such as slip lines and cracks. It is something to do.

Means for Solving the Problems The present invention includes a sample stand, a cylindrical heating mechanism arranged to surround the sample stand, and a lamp heating mechanism installed vertically above the sample stand. By using a heat treatment apparatus, the above problem is solved.

In the present invention, the temperature of the wetted material is raised in advance to around 900°C using a cylindrical heating mechanism surrounding the sample stage, and then the temperature is increased from 1100°C to 1°C using a lamp heating mechanism.
Because heat treatment is performed by raising the temperature to 000℃,
Since a uniform temperature distribution can always be obtained and heat removal and slow cooling can be performed in the same manner as in conventional electric furnaces, it is possible to eliminate defects on wafers that occur in conventional equipment. Furthermore, by reducing the pressure inside the chamber, convection is reduced and non-uniformity in temperature distribution is further reduced.

EXAMPLE An example of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional perspective view of a high-temperature heat treatment apparatus in a first embodiment of the present invention. The structure is such that a Si Weno 3 is held in a cylindrical quartz chamber 1a by a sample stage 2 made of quartz or SiC. Visible light and infrared light emitted from the lamp 4 pass through the quartz window 6 to the Sl
It is irradiated onto Ueno-3, absorbed by Si, and converted into heat. The Sl Ueno 3 is heated by a nitrogen lamp 4 provided vertically above the sample stage 2, and also by a heater 6 surrounding the chamber 11L in a cylindrical shape. The inner surface of the cooler 7 is a reflective mirror that reflects heat rays and
It helps raise the temperature of the sea urchin 3 and prevents heat from leaking to the outside. The chamber 1a is supplied with N2. A large amount of inert gas and a reducing gas such as N2 are introduced as necessary. In addition, the pressure inside the chamber 1& is controlled by controlling the exhaust speed of the exhaust port 9. Normally, the pressure inside the chamber 1& is controlled by controlling the exhaust speed of the exhaust port 9.
The number 1 is kept from Q'rorr. This device was applied to heat treatment when forming a buried oxide film by implanting oxygen ions. Oxygen ion implantation was performed at an energy of 200 KeV, 1.6 to 2.5 x 1018 doses/i, and a substrate temperature of about 600°C. The sample was placed in the apparatus, the first step was at 1250°C for 60 minutes in 10 Torr N2, and the second step was at 1250°C in 10 Torr N2, and the second step was at 1250°C in 10 Torr N2.
Same in gas (after heat treatment at 1250℃ for 60 minutes,
The temperature was lowered in N2 gas.

The standby temperature is 900℃, and the temperature rise and fall is approximately 0℃.
Heat removal and slow cooling were performed for 1/min. There are no slip lines in the Ueno/periphery that were observed in conventional equipment, and the dislocation density in the surface Si layer has increased from about 1 to 2 digits, compared to the conventional approximately 1 O ltr&.
An order of magnitude decrease was observed.

FIG. 2 is a cross-sectional perspective view of a high-temperature heat treatment apparatus in a second embodiment of the present invention. A wafer 3 is held by a quartz sample stage 2 in a cylindrical quartz chamber 1b. The wafer 3 is heated by heat rays emitted from a halogen lamp 4 installed vertically and passing through a quartz window 5. Further, the wafer 3 is heated by the heater 6 from around the chamber 1b except for the quartz window 6 portion. The pressure inside the chamber is controlled by pumping speed control to improve the uniformity of temperature distribution within the wafer. This arrangement places the sample stage 2 in the quartz chamber 1b.
It can be placed on top, making the insertion mechanism easy.

Using this device, a sample into which oxygen ions were implanted was heated to 1260°C.
As a result of heat treatment, no slip lines were observed.

Effects of the Invention By using the heating device of the present invention, it is possible to perform heat treatment of wafers with good uniformity even at high temperatures of about 1100°C to 1300°C and by gradual cooling with heat removal.This device can be used for heat treatment of Si into which oxygen ions are implanted. For example, it is possible to form an SOI structure without slip lines around the wafer and having a buried oxide film with low dislocation density. Although the apparatus of the present invention is designed with particular consideration given to temperature uniformity at temperatures of 1000° C. or higher, it goes without saying that good characteristics of the apparatus of the present invention can be obtained even when used at temperatures lower than 1000°C.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view showing a first embodiment of a heat treatment apparatus according to the present invention, FIG. 2 is a cross-sectional perspective view showing a second embodiment of a heat treatment apparatus according to the present invention, and FIG. 3 is a conventional high-temperature heat treatment. FIG. 2 is a cross-sectional view of the device. 1! L, 1b...Quartz chamber, 2...
・Sample stage, 3...Si wafer, 4...
Halloken lamp, 6...Quartz window, 6...
・Heater, 9...Exhaust port.

Claims (1)

[Claims] A heat treatment apparatus comprising a sample stage, a cylindrical heating mechanism arranged to surround the sample stage, and a lamp heating mechanism installed vertically above the sample stage.