JPH1050627A - Vertical furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable detection of temperature at the position nearer a wafer when a vertical furnace is operated, and to prevent damage from occurring in a temperature detector. SOLUTION: A rod-like temperature detector 13 is so provided as to penetrate a furnace opening lid 8 which closes a furnace opening part placed on a board 15, the upper end of the temperature detector 13 is supported with a ceiling board 16 of the boat 15, and the temperature detector 13 is supported at two points, its lower end and upper end, so that the upper end position of the temperature detector 13 becomes stable, time-based deformation is suppressed, thus the temperature detector 13 is avoided from being damaged through interference with other components at loading of the board 15, so that the temperature detector 13 can be assigned close to a wafer 6, for improved temperature detection precision for the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical furnace equipped with devices such as a vertical diffusion device and a vertical CVD device for manufacturing semiconductor devices.

[0002]

2. Description of the Related Art An outline of a vertical furnace will be described with reference to FIG.

[0003] A soaking tube 2 is erected in a hollow heater 1,
A reaction tube 3 is provided in the heat equalizing tube 2, and the heater 1 is erected on a heater base 7. A boat 4 is moved up and down by a boat elevator (not shown) into the reaction tube 3, and is loaded and withdrawn. The boat 4 is erected on a furnace cap 8 via a boat cap 5, and the furnace cap is 8
Are supported by the boat elevator.

[0004] The boat 4 is loaded with wafers 6 in multiple stages in a horizontal posture, and while the wafers 6 are loaded in the boat 4, impurity diffusion and thin film formation are performed.

In processes such as impurity diffusion to a wafer and formation of a thin film, temperature control greatly affects the uniformity of film quality, ie, product quality and yield. Therefore, the temperature of the wafer is measured, and the measured temperature is fed back to temperature control.

Although it is not practically possible to measure the temperature during the processing of the wafer 6 directly, in a steady state, the difference between the temperature of the wafer and the ambient temperature is within about ± 0.5 ° C. As shown in FIG. 3, a plurality of rod-shaped temperature detectors 10 are inserted between the soaking tube 2 and the reaction tube 3 to detect the temperature around the wafer.

Although the temperature detectors 10 are not particularly shown, each of the temperature detectors 10 includes thermocouples 10a to 10a in a protective tube.
In this configuration, the positions of the thermocouples 10a to 10d are different in each temperature detector 10, and the detection positions in each temperature detector 10 are different. The heater 1 is divided into zones, and the temperature detectors 11a to 11
d is embedded so that the heating state of the heater 1 is detected.

The thermocouples 10a to 10a of the temperature detector 10
The detection result of d is input to a temperature control device (not shown),
The heating state of the heater 1 is zone-controlled based on the detection result.

The temperature of the wafer 6 is preferably detected at a position as close to the wafer 6 as possible. Therefore, conventionally, only when performing a performance test or the like of an apparatus such as a temperature-temperature distribution measurement in a furnace, the temperature is measured in the vicinity of the wafer in the heater 1, and based on the result, the temperature detected value by the temperature detector 10 is used. And so on.

FIG. 4 shows the structure of a vertical furnace for performing a performance test or the like. A temperature detector 13 is provided through the furnace cover 8, and the temperature detector 13 is provided with a heat-resistant protective tube 14. A plurality of thermocouples 13a to 13d are inserted therein.
The vertical positions of the thermocouples 13a to 13d are different from each other so that the temperature distribution in the reaction tube 3 can be detected.

By taking data of temperature control while performing temperature detection by the temperature detector 10 and the temperature detector 13,
A temperature deviation between the temperature detector 10 and the temperature detector 13 and a time lag at the time of temperature rise and fall are detected.
Only when the temperature is detected is corrected.

[0012]

When a performance test is performed in the above-described conventional vertical furnace, the temperature detector 13 has a configuration in which the lower end is supported by the furnace cover 8, so that the temperature detector 13 is not used. Positioning at the upper end is difficult, and repeated use at high temperatures causes the lower end support portion or the protective tube 14 itself to deform over time, resulting in a shift in the position of the tip of the temperature detector 13.

For this reason, when the boat 4 is loaded, the temperature detector 13 may come into contact with the furnace port such as the lower end of the reaction tube 3. When the vertical furnace operates, the temperature detector 13 is used.
However, since the temperature detection is performed only by the temperature detector 10, there is a problem that the accuracy of the temperature detection of the wafer 6 is reduced.

The present invention has been made in view of the above circumstances, and has as its object to enable temperature detection at a position closer to a wafer during operation of a vertical furnace and to prevent damage to the temperature detector.

[0015]

According to the present invention, there is provided a rod-shaped temperature sensor provided with a boat mounted thereon and penetrating a furnace mouth cover for closing a furnace mouth portion, and an upper end of the temperature sensor is mounted on a top plate of the boat. The temperature detector is supported at two points, a lower end and an upper end, so that the position of the upper end of the temperature detector is stabilized and deformation with time is suppressed.

[0016]

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

In FIGS. 1 and 2, the same components as those shown in FIGS. 3 and 4 are denoted by the same reference numerals.

A soaking tube 2 is erected in a hollow heater 1,
A reaction tube 3 is provided in the heat equalizing tube 2, and the heater 1 is erected on a heater base 7. A boat 15 is moved up and down by a boat elevator (not shown) into the reaction tube 3, and is loaded and withdrawn. The boat 15 is erected on a furnace cap 8 via a boat cap 5. Reference numeral 8 is supported by the boat elevator.

The boat 6 is placed on the boat 15 in a horizontal posture.
Are loaded in multiple stages, and while the wafer 6 is loaded in the boat 15, impurity diffusion and thin film formation are performed.

A plurality of the temperature detectors 10 are inserted and disposed in the heat equalizing tube 2 and the reaction tube 3, and each of the temperature detectors 10 has thermocouples 10a to 10d inserted in protective tubes. The positions of the thermocouples 10a to 10d inserted in the respective temperature detectors 10 are different, and the detection positions of the respective temperature detectors 10 are different. The heater 1 is divided into zones, and temperature detectors 11a to 11d are embedded in each zone so that the heating state of the heater 1 is detected.

The thermocouples 10a-1 of each of the temperature detectors 10
The detection result of 0d is input to a temperature control device (not shown), and the heating state of the heater 1 is zone-controlled based on the detection result.

The temperature of the wafer 6 is preferably detected at a position as close to the wafer 6 as possible. Therefore, conventionally, the temperature inside the heater 1 is measured only when a performance test or the like of the apparatus such as the temperature distribution inside the furnace is performed, and based on the result, the temperature detection value by the temperature detector 10 is corrected and the like. I have.

A part of a top plate 16 of the boat 15 is protruded, and a support hole 18 into which the upper end of the temperature detector 13 is fitted is formed in the protruding portion 17. The lower end of the temperature detector 13 penetrates a position facing the support hole 18 of the furnace roof 8, and the upper end of the temperature detector 13 fits into the support hole 18. The temperature detector 13 has an upper end on the top plate 16.
In addition, the lower end is supported by the furnace lid 8 at two points.

Therefore, the position of the upper end of the temperature detector 13 does not become unstable, and it is not necessary to pay attention to the upper end position when the temperature detector 13 is mounted. Further, since the upper end of the temperature detector 13 is restrained by the top plate 16, no misalignment occurs and the temperature detector 1
The deformation of the three supports and the protection tube 14 itself is restrained and suppressed by the temperature detector 13 being supported by the top plate 16.

Thus, the temperature detector 13 is prevented from contacting the furnace port such as the lower end of the reaction tube 3 when the boat 15 is loaded, and the mounting state of the temperature detector 13 does not change. The detector 13 can be permanently installed, and the temperature in the furnace can be detected by the temperature detector 13, that is, the temperature of the wafer 6 can be detected at a closer position, and the temperature of the wafer 6 can be controlled with high accuracy. Becomes

[0026]

As described above, according to the present invention, the temperature detector provided inside the reaction tube can be supported at two points, that is, the upper end and the lower end. It is possible to prevent damage to the temperature detector when loading the boat and to detect the temperature closer to the wafer, improving the accuracy of temperature control, improving the reliability of the equipment and improving the product quality. It has the effect.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of the boat according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view of a conventional example.

FIG. 4 is a schematic sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heater 2 Heat equalizing tube 3 Reaction tube 8 Furnace lid 10 Temperature detector 13 Temperature detector 14 Protection tube 15 Boat 16 Top plate 17 Projection 18 Support hole

Claims (1)

[Claims] The present invention is characterized in that a rod-shaped temperature detector is provided so as to penetrate a furnace lid for closing a furnace port on which a boat is mounted, and an upper end of the temperature detector is supported on a top plate of the boat. Vertical furnace.