JP2000223423A - Semiconductor manufacturing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing equipment, where a gap is restrained from occurring between a heat block fixed to a temperature detection work and a thermocouple for eliminating the influence of gas interposed between the thermocouple and the thermal block, so as to stably measure the inner temperature of a processing chamber provided inside the semiconductor manufacturing equipment, and a processed product can be improved in quality. SOLUTION: The tip of a thermocouple 25 is embedded in a thermal block 19 fixed to a temperature detection work 16, the thermocouple 25 is housed in a protective pipe 26, and the tip of the protective pipe 26 is hermetically fixed to the thermal block 19, and the thermocouple 25 is reinforced with the protective pipe 26, so that a temperature detecting device is not required to be enhanced in strength and rigidity and can be lessened in diameter, and even if there is thermal expansion difference between the thermal block and the thermocouple, gaps are restrained from occurring between them, so that the temperature of the work 16 can be detected stably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus having a reaction chamber which is a vacuum vessel, such as a plasma CVD apparatus.
In particular, the present invention relates to an improvement in a temperature detection unit that detects a temperature inside a reaction chamber.

[0002]

2. Description of the Related Art Plasma C, one of semiconductor manufacturing apparatuses, is used.
In a processing apparatus such as a VD apparatus, it is necessary to detect a temperature during processing in a reaction chamber which is a vacuum vessel. In particular, in the plasma CVD apparatus, a substrate to be processed is charged into a reaction chamber, and a reactive gas is introduced and further heated or a plasma is generated to separate a reactive gas and form a thin film on the substrate to be processed. Perform generation processing and the like. In such processing,
Since the temperature of the substrate to be processed greatly affects the processing state such as the film forming rate, a heater is embedded in the substrate mounting table on which the substrate to be processed is mounted, and the substrate is processed through the substrate mounting table using the heater. Temperature controlled.

First, referring to FIG. 2, an outline of a plasma CVD apparatus will be described.

[0004] The vacuum vessel 1 comprises a vacuum vessel body 2 and a ceiling lid 3 for hermetically closing the vacuum vessel body 2. An upper heater 5 and a shower plate are provided on the lower surface of the ceiling lid 3 via an insulating material 4. An upper electrode (cathode) 6 that also serves as an upper electrode is provided. A process gas inlet 7 penetrating the ceiling lid 3 and the insulating material 4 and reaching the upper heater 5 is provided. The process gas inlet 7 and the ceiling lid 3 are insulated by an insulating material 8. A gas reservoir 9 is formed between the upper heater 5 and the upper electrode 6, and the gas reservoir 9 and the process gas inlet 7 are communicated with each other through a communication hole 10, and the gas reservoir 9 and the inside of the vacuum vessel 1 are formed. Are connected to each other by a shower hole 11.

A lower electrode unit 13 is provided so as to be able to move up and down through the bottom of the vacuum vessel body 2.

An elevating seat 14 is supported by a cylinder or the like (not shown) so as to be able to move up and down. A hollow column 15 is erected on the elevating column 14, and a lower heater 16 is fixed to an upper end of the column 15. A lower electrode (anode) 17 also serving as a receiving table for the substrate to be processed is fixed to the upper surface. A thermocouple 18 airtightly penetrates the elevating seat 14, and the thermocouple 18
Is buried in the lower heater 16 via a heat block 19. A bellows 20 is provided between the support 15 and the bottom surface of the vacuum vessel main body 2, and a penetrating portion of the lower electrode unit 13 is airtight.

[0007] Substrate processing in the above plasma CVD apparatus will be briefly described.

When the inside of the vacuum vessel 1 is heated to a required temperature by the upper heater 5 and the lower heater 16 and a substrate to be processed is carried in through a gate valve (not shown) and mounted on the lower electrode 17, the process is performed. A reaction gas is introduced from a gas inlet 7, and the reaction gas is dispersed and introduced into the vacuum vessel 1 through the communication hole 10, the gas reservoir 9, and the shower hole 11.

High-frequency power is applied between the upper electrode 6 and the lower electrode 17, plasma is generated, and a required thin film is generated on the substrate to be processed.

Since the temperature of the substrate during film formation strongly affects the film formation quality, the temperature of the lower heater 16 is detected by the thermocouple 18, and the temperature of the substrate to be processed is detected via the lower electrode 17. The heat generation state of the lower heater 16 is controlled by a temperature controller (not shown) based on the detection result of the thermocouple 18.

In FIG. 3, the upper end of the thermocouple 18
The penetrating portion of the lift seat 14 will be described.

The upper end of the thermocouple 18 is pressed into the heat block 19 made of aluminum alloy, and the heat block 19 is swaged to the lower heater 16 made of aluminum alloy.
A seal flange 22 is provided on the lower surface of the thermocouple 18 at the penetrating portion of the elevating seat 14, and a seal ring 23 is fitted to the seal flange 22 to hermetically seal the thermocouple 18. Thus, the heat of the lower heater 16 is detected by the thermocouple 18 via the heat block 19.

[0013]

The thermocouple 18 has an upper end supported by the lower heater 16 via the heat block 19 and a lower end supported by the seal flange 22 via the seal ring 23. Point support. For this reason, the thermocouple 18 needs to have a rigidity that is not easily deformed during handling, and the thermocouple 18 has a diameter of about 5 mm.

As described above, the lower heater 16 and the heat block 19 are made of an aluminum alloy.
Include Incoloy [Ni (72%), Fe (8%), Mn
(1%), C (0.15%), Cr (16%), Cu
(0.5%), Si (0.5%), S (0.015
%)] Is used. The aluminum alloy and Incoloy have different coefficients of thermal expansion. Therefore, when the temperature of the lower heater 16 is repeatedly increased and decreased, a gap is formed between the heat block 19 and the thermocouple 18. Since the coefficient of thermal expansion is aluminum alloy> incoloy, the gap between the heat block 19 and the thermocouple 18 at the time of temperature increase becomes larger as the diameter of the thermocouple 18 becomes larger.
This gap cannot be made zero by machining. The existence of the gap greatly affects the heat transfer, and the heat transfer coefficient changes due to the increase and decrease of the gap, and there is a problem that stable temperature measurement is difficult.

Further, the inside of the vacuum vessel 1 changes between an atmospheric pressure state and a depressurized state, and a gas may or may not be present in the gap between the heat block 19 and the thermocouple 18, and depending on the presence or absence of gas in the gap. However, the heat transfer coefficient also changed, which was one of the factors that made it difficult to measure a stable temperature.

In view of the above circumstances, the present invention suppresses the generation of a gap between a thermocouple and a heat block, and removes the influence of gas interposed between the thermocouple and the heat block, so that the present invention can be used in a processing chamber of a semiconductor manufacturing apparatus. The purpose of the present invention is to enable stable temperature measurement and to improve processing quality.

[0017]

According to the present invention, a tip of a thermocouple is buried in a heat block fixed to a temperature detection object, the thermocouple is housed in a protection pipe, and a tip of the protection pipe is attached to the protection pipe. The present invention relates to a semiconductor manufacturing apparatus having a temperature detection device hermetically fixed to the heat block, and a lower heater for heating a substrate to be processed, wherein a temperature detection target is provided in an airtight reaction chamber,
The protection pipe relates to a semiconductor manufacturing apparatus that protrudes outside the reaction chamber and communicates with the outside of the reaction chamber, and the thermocouple diameter relates to a semiconductor manufacturing apparatus that is a minimum diameter necessary for temperature detection. According to the semiconductor manufacturing apparatus in which the inside is airtight, the thermocouple is reinforced by a protection pipe, so that strength and rigidity are not required and the diameter can be reduced. Therefore, even if there is a difference in the coefficient of thermal expansion between the heat block and the thermocouple, the generation of a gap is suppressed, and stable temperature detection becomes possible.

[0018]

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

FIG. 1 shows a main part of the present embodiment.
1, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

A thermocouple 25 having a small diameter is cast into the heat block 19, and a protective pipe 26 having a hollow bottom is formed concentrically with the thermocouple 25.
And the upper end of the protection pipe 26 is connected to the heat block 1.
9 is welded to the lower surface. The thermocouple 25 passes through the bottom of the protection pipe 26, and the thermocouple 25 and the bottom of the protection pipe 26 are welded. The heat block 19 is made of the same material as the lower heater 16 or a material having a similar thermal expansion coefficient, and is fixed to the lower heater 16 by means of press fitting or the like.

The protective pipe 26 penetrates the seal flange 22 fixed to the lower surface of the elevating seat 14, and the space between the protective pipe 26 and the seal flange 22 is hermetically sealed by the seal ring 23 fitted on the seal flange 22. Seal. A through hole 27 is formed near the lower end of the protection pipe 26 to communicate the inside of the protection pipe 26 with the atmosphere.

Since the thermocouple 25 is cast into the heat block 19, the gap is extremely small. The thermocouple 25 is supported at two points, an upper end and a lower end, and is provided with the protective pipe 26. Since the thermocouple 25 is protected,
The thermocouple 25 itself does not require rigidity and strength, and the thickness of the thermocouple 25 is sufficient to be the minimum diameter required for measurement.

As described above, the thermal block 19 and the thermocouple 25 have different coefficients of thermal expansion, and
There is a possibility that a gap may be formed between the thermocouple 25 and the heat block 19 when the temperature rises or falls. However, the thermocouple 25 has a minimum thickness necessary for measurement, has a small diameter, and is generated. The gap is small.

Further, since the inside of the protection pipe 26 is open to the outside air and the inside of the protection pipe 26 is separated from the inside of the vacuum vessel 1, even if the inside of the vacuum vessel 1 repeatedly returns to the vacuum and the atmospheric pressure, The inside of the protection pipe 26 is still in the atmospheric pressure state. Thus, when the temperature is raised, when the temperature is decreased, when the inside of the vacuum vessel 1 is depressurized, and when the atmospheric pressure
The condition that air is interposed between the heat block 19 and the heat block 19 remains unchanged, and the condition of heat transfer is constant.

Since the generated gap is small and the heat transfer conditions between the heat block 19 and the thermocouple 25 do not change, the stability in the processing chamber of the semiconductor manufacturing apparatus is not limited to when the temperature is raised or lowered. Temperature measurement can be performed.

The protection pipe 26 does not necessarily have to be a bottomed pipe, but it is only necessary that the lower end of the thermocouple 25 be fixed to the protection pipe 26. Furthermore, if the inside of the protection pipe 26 is filled with an insulating material, it is not necessary to fix the lower end of the thermocouple 25 to the protection pipe 26.

Further, if the inside of the protection pipe 26 is made completely airtight, the through hole 27 does not need to be formed.

[0028]

As described above, according to the present invention, since the thermocouple is reinforced by the protective pipe, the thermocouple does not need to have strength and rigidity, and need only have a minimum thickness necessary for measurement. Therefore, the thickness of the thermocouple can be reduced, a gap generated due to a difference in thermal expansion between the heat block and the thermocouple can be suppressed, and a change in heat transfer coefficient at the time of temperature rise and temperature fall can be suppressed. And the quality of processing such as substrate film forming processing can be improved.

Further, by communicating the inside of the protection pipe with the outside air, an excellent effect such as the effect of gas present between the thermocouple and the heat block can be removed.

[Brief description of the drawings]

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

FIG. 2 is a schematic sectional view of a reaction chamber of the semiconductor manufacturing apparatus.

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

[Explanation of symbols]

 14 Lifting seat 16 Lower heater 19 Heat block 22 Seal flange 23 Seal ring 26 Protection pipe 27 Through hole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 CA12 FA03 JA10 KA17 KA18 KA39 5F045 DP03 EF05 EH05 EM02 EM10 GB05

Claims (3)

[Claims] An end of a thermocouple is embedded in a heat block fixed to a temperature detection target, the thermocouple is housed in a protection pipe, and a tip of the protection pipe is airtightly fixed to the heat block. A semiconductor manufacturing apparatus comprising a temperature detecting device. 2. The semiconductor manufacturing apparatus according to claim 1, wherein the temperature detection object is a lower heater provided in an airtight reaction chamber for heating a substrate to be processed, and the protection pipe projects outside the reaction chamber and communicates with the outside of the reaction chamber. . 3. The inside of the protection pipe is airtight.
Semiconductor manufacturing equipment.