JPH1062281A - Pressure detector of film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure detector wherein no sub-product deposits even when used in detecting pressure of a CVD device and highly accurate pressure detection is possible. SOLUTION: The pressure detector comprises a pressure take-out pipe 11 connected to a reactant gas supply pipe 1 which is a part to be sensed and a diaphragm sensor 12 attached to the tip of the pressure take-out pipe 11. The pressure detector includes a pipe temperature sensor 14 for detecting a temperature of the pipe 11, a pipe heater 13 for heating the pipe 11, a sensing part temperature sensor 19 for detecting a temperature of the diaphragm sensor 12, a built-in heater for heating the diaphragm sensor 12 and a temperature adjuster 20 for individually driving the pipe heater 13 based on a sensed output from the pipe temperature sensor 14 and the built-in heater of the diaphragm sensor 12 based on a sensed output from the sensing part temperature sensor 19 so that difference in temperature between the pressure take-out pipe 11 and the diaphragm sensor 12 may be controlled to be a predetermined value or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure detector for use in a film forming apparatus such as a CVD apparatus, and more particularly to a pressure detector which extracts a pressure of a detected part by a pressure extraction pipe and detects the pressure by a pressure detection part such as a diaphragm sensor. In addition, the present invention relates to a pressure detector that heats a pressure extraction pipe, a diaphragm sensor, and the like to prevent adhesion of by-products.

[0002]

2. Description of the Related Art In a film forming apparatus, for example, a CVD apparatus, a reaction gas is introduced while maintaining the inside of a processing furnace at a predetermined degree of vacuum, and a thin film such as polysilicon is formed on the surface of a work such as a substrate. . In such a CVD apparatus, pressure as well as temperature and concentration are important control elements, and the pressure inside the furnace and the pressure of the reaction gas introduced into the furnace can be detected by a pressure detector and controlled to an appropriate value. Is being done.

Conventionally, as the above-mentioned pressure detector, FIG.
The following are known. In FIG. 2, reference numeral 1 denotes a reaction gas supply pipe (detected portion) connected to a processing furnace (not shown). The reaction gas supply pipe 1 has a main valve 2 interposed therebetween. A pressure detector 10 is provided. The pressure detector 10 is configured by connecting a pressure extraction pipe 11 in the middle of the reaction gas supply pipe 1 and attaching a diaphragm sensor (pressure detection unit) 12 to the tip of the pressure extraction pipe 11. Reference numeral 18 denotes an air valve provided on the pressure extraction pipe 11.

[0004] The pressure extraction pipe 11 is provided with a pipe heater 13 for heating the pipe 11 and a pipe temperature sensor 14 for detecting the temperature of the pipe 11. The pipe heater 13 and the pipe temperature sensor 14 are connected to a temperature controller 20, and the pipe temperature sensor 14 outputs a temperature detection signal of the pipe 11 to the temperature controller 20. Is controlled by the temperature controller 20 based on

[0005] The diaphragm sensor 12 has a diaphragm that is elastically deformed by the pressure introduced through the pressure extraction pipe 11, and has a built-in heater. The diaphragm sensor 12 is connected to the above-mentioned temperature controller 20, converts the deformation of the diaphragm into an electric signal and outputs the electric signal to the temperature controller 20, and the heating heater is connected to the above-mentioned pipe 11
Is heated by the temperature controller 20 based on the temperature of the diaphragm.

[0006] The pressure detector 10 includes a pressure extraction pipe 11.
The diaphragm and the like are heated by the piping heater 13 and the diaphragm sensor 12 by the built-in heater to prevent by-products from adhering to the piping 11 and the diaphragm. Since the detection accuracy of the diaphragm sensor 12 is affected by the temperature of the diaphragm, etc.
The temperature controller 20 corrects the diaphragm detection signal based on the detection output of the pipe temperature sensor 14 and the like.

[0007]

However, in the conventional pressure detector 10 described above, the pipe temperature sensor 1
In order to control both the pipe heater 13 and the heater with the built-in diaphragm sensor 12 based on the temperature of the pressure extraction pipe 11 detected by the diaphragm sensor 1,
In some cases, the temperature of No. 2 does not match the temperature of the pressure extraction pipe and fluctuates from the control target value, causing a problem that a detection error due to this temperature fluctuation occurs. The present invention has been made in view of the above problems, and has as its object to provide a pressure detector capable of preventing occurrence of an error due to temperature fluctuation of a diaphragm sensor and capable of detecting pressure with high accuracy.

[0008]

In order to achieve the above object, the present invention relates to a method for connecting a pressure extraction pipe to a detected portion of a film forming apparatus, attaching a pressure detection section to the pressure extraction pipe, In a pressure detector of a film forming apparatus provided with a pipe heater for heating a pipe and a detector heater for heating the pressure detector, a pipe temperature sensor for detecting the temperature of the pressure extraction pipe, and the pressure detector Temperature of the pressure extraction pipe and the pressure detection by controlling the pipe heating heater and the detection section heater based on the detection outputs of the detection section temperature sensor and the pipe temperature sensor. And a temperature controller for maintaining a temperature difference from the temperature of the section at a predetermined value or less.

The film forming apparatus to which the pressure detector according to the present invention is applied is represented by a CVD apparatus, but can be applied to other film forming apparatuses, for example, an epitaxial growth apparatus. Examples of the detected part of the film forming apparatus include a processing furnace, a reaction gas supply pipe for supplying a reaction gas to the processing furnace, and a discharge pipe for discharging a gas from the processing furnace. Is done.

Although a pressure sensor such as a diaphragm sensor is used as the pressure detecting unit, the present invention is particularly effective for a pressure detecting unit that detects a pressure by replacing the pressure with a deformation of a member. The pipe heater and the detector heater are typified by an electric heater that generates Joule heat, but other heating means such as an infrared lamp can be used. A well-known thermocouple or the like is used for the pipe temperature sensor and the detection unit temperature sensor, and each of them is separately and independently connected to the temperature controller.

As the temperature controller, a machine controller such as a CVD device or a controller dedicated to a pressure detecting device is used. This temperature controller controls each heater so that the temperature difference between the temperature of the pressure extraction pipe and the temperature of the pressure detection unit is equal to or less than a predetermined value, and desirably, the temperatures match.

In the pressure detector of the film forming apparatus according to the present invention, the pressure extraction pipe is heated by a pipe heater controlled based on the detection output of the pipe temperature sensor, and the pressure detection section is detected by the detection section temperature sensor. The temperature is heated by the detector heater controlled based on the output, and the temperature difference between the pressure extraction pipe and the pressure detector is maintained at a predetermined value or less. For this reason, the temperature of not only the pressure extraction pipe but also the pressure detection section can be accurately managed, and the occurrence of errors due to temperature fluctuations can be prevented.
Pressure can be detected with high accuracy.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a pressure detector of a film forming apparatus according to one embodiment of the present invention. Note that the same parts as those of the conventional pressure detector of FIG. 2 described above are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the diaphragm sensor 1
A detection unit temperature sensor 19 for detecting the temperature of the diaphragm or the like is provided at 2. The detection unit temperature sensor 19 is formed of a thermocouple or the like, and is connected to the temperature controller 20.

In this embodiment, the temperature of the pressure extraction pipe 11 is detected by a pipe temperature sensor 14;
Temperature sensor 19 for detecting the temperature of diaphragm sensor 12
Is detected by Then, the temperature controller 20 controls the drive of the pipe heater 13 based on the detection output of the pipe temperature sensor 14, and controls the drive of the built-in heater of the diaphragm sensor 12 based on the detection output of the detection unit temperature sensor 19.
The pressure extraction pipe 11 and the diaphragm sensor 12 are heated. For this reason, by-products can be prevented from adhering to the pressure extraction pipe 11 and the diaphragm sensor 12.

The temperature controller 20 determines that the temperature difference between the pressure extraction pipe 11 and the diaphragm 12 is a predetermined value, for example, 5
The temperature of the piping heater 13 and the built-in heater of the diaphragm sensor 12 are controlled so as to be equal to or lower than ° C. For this reason, the pressure extraction pipe 11 and the diaphragm sensor 12 can be maintained at substantially the same temperature, and the temperature of the diaphragm sensor 12 can be accurately managed, so that the temperature does not fluctuate. Therefore, the pressure can be detected with high accuracy without occurrence of an error due to temperature fluctuation.

That is, the diaphragm sensor 12 is deformed by the pressure introduced through the pressure extraction pipe 11, and outputs the deformation of the diaphragm as a pressure value. Therefore, the diaphragm sensor 12 is easily affected by the temperature at which the diaphragm is thermally deformed. However, since the temperature is accurately managed, the correction in the temperature controller 20 can be performed accurately, and the pressure can be detected with high accuracy.

[0018]

As described above, according to the pressure detector of the film forming apparatus according to the present invention, the temperature sensor and the heater are individually provided in the pressure detecting section and the pressure extracting pipe for guiding the pressure to the pressure detecting section. The pressure detection unit and the pressure extraction pipe are separately and independently heated by a heater based on the respective sensors, and the temperature difference between the pressure detection unit and the pressure extraction pipe is controlled to be equal to or less than a predetermined value. In addition, by-products can be prevented from adhering to the pressure detection unit and the pressure extraction pipe, and a pressure detection error caused by a temperature change in the pressure detection unit can be prevented, so that the pressure can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a pressure detector of a film forming apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a pressure detector of a conventional film forming apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reaction gas supply pipe (detection part) 10 Pressure detector 11 Pressure extraction pipe 12 Diaphragm sensor (pressure detection part, detection part heating heater) 13 Pipe heating heater 14 Pipe temperature sensor 19 Detection part temperature sensor 20 Temperature controller

Claims (1)

[Claims] 1. A pressure extraction pipe is connected to a detected section of a film forming apparatus, a pressure detection section is attached to the pressure extraction pipe, and a pipe heater for heating the pressure extraction pipe and the pressure detection section are heated. In a pressure detector of a film forming apparatus provided with a detection unit heater, a pipe temperature sensor for detecting a temperature of the pressure extraction pipe,
A detector temperature sensor for detecting the temperature of the pressure detector,
The pipe heater and the detector heater are controlled based on the detection outputs of the detector temperature sensor and the pipe temperature sensor, and the temperature difference between the temperature of the pressure extraction pipe and the temperature of the pressure detector is equal to or less than a predetermined value. And a temperature controller for holding the pressure in the film forming apparatus.