JP2001029772A - Substrate treating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct amt. of deviation of zero point to appropriately control pressure in a vacuum chamber and to prevent defect of treatment of a base caused by change in pressure from being generated by a method wherein a low pressure condition in the vacuum chamber is measured by means of a low pressure side vacuum gauge and in this instance, the measured value by means of the vacuum gauge for control is compared with the set value to detect the deviation of zero point. SOLUTION: In an apparatus for treating a substrate in a vacuum chamber 1, while inner pressure of the vacuum chamber 1 is measured by means of a low pressure side vacuum gauge 5 until the inner pressure of the vacuum chamber 1 is lowered to e.g. 0.01 Pa or lower, the inside of the vacuum chamber 1 is evacuated through an exhaust pipe 3 by means of a vacuum pump 2. In addition, the inner pressure of the vacuum chamber 1 is measured by means of a vacuum gauge 4 for control and this measured value is compared with a set value stored in advance. As the result, when the difference between the measured value and the set value is at most an allowable value, gas is introduced into the inside of the vacuum chamber 1 from a gas inlet pipe 6 and the inner pressure of the vacuum chamber 1 is controlled to a target value by controlling a variable valve 7. Treatment of the substrate is always appropriately performed thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a substrate processing apparatus for performing a process for forming a semiconductor or the like on a substrate in a vacuum chamber controlled to maintain a constant pressure.

[0002]

2. Description of the Related Art Conventionally, a substrate processing apparatus has been widely used, for example, in a semiconductor manufacturing process, and has a vacuum chamber capable of maintaining a vacuum inside. A substrate for forming a semiconductor is arranged on the vacuum chamber, and a gas such as an active gas introduced into the vacuum chamber is evacuated by a vacuum pump to the vacuum chamber, and the inside of the vacuum chamber is controlled to be maintained at a constant pressure. It is configured.

The substrate processing apparatus further includes a pressure control vacuum gauge capable of accurately measuring the internal pressure even when the inside of the vacuum chamber is filled with plasma or active gas, and an accurate pressure gauge in plasma or active gas. It has a vacuum gauge that cannot measure, but can measure the lower pressure side.
The operation steps of the pressure control in the vacuum chamber when the semiconductor is manufactured by such a substrate processing apparatus will be described below.

FIG. 4 is a flow chart showing an operation process (procedure) when a vacuum is filled with a certain kind of gas in a conventional substrate processing apparatus to perform pressure control. As shown in FIG. 4, first, the introduction of gas from the gas introduction pipe is stopped, and the inside of the vacuum chamber is evacuated to a certain degree of vacuum by a vacuum pump while detecting pressure with a low pressure side vacuum gauge (step 40). ). Since the low pressure gauge used at this time cannot accurately measure the pressure depending on the type of gas introduced, the measurement range is on the high pressure side, but the pressure measurement is performed using a control gauge that is not affected by the gas type. Perform (Step 41)
While introducing gas into the vacuum chamber from the gas introduction pipe (step 42), a variable valve that is attached to an exhaust pipe connecting the vacuum chamber and the vacuum pump and has a variable exhaust area is provided with a control vacuum. The pressure in the vacuum chamber is controlled to be maintained at a constant pressure P1 by changing the displacement from the vacuum chamber based on the pressure signal from the gauge (step 43).

[0005] In accordance with the above operation steps, pressure control in the vacuum chamber at the time of semiconductor manufacturing is performed.

[0006]

However, in the conventional procedure as described above, the only pressure control sensor is a control vacuum gauge. For example, the zero point of the control vacuum gauge is set to the high pressure side. In this case, the zero point cannot be detected, and the pressure control is performed on the higher pressure side than the target pressure.

[0007] As a result, when a workpiece is processed in the vacuum chamber, a processing defect occurs.
In addition, such a defect detection of a workpiece such as a semiconductor processed in a vacuum chamber can often be found by inspection after processing in another process is completed, so that there is a problem that more loss is caused. I was The present invention solves the above-mentioned conventional problems, and issues a warning before a pressure control in a vacuum chamber to a zero point shift of a control vacuum gauge to which an output value is provided for the pressure control. While being able to
A substrate processing apparatus capable of correcting a shift amount of a pressure in a vacuum chamber caused by a zero point shift of a control vacuum gauge and preventing a work defect of a work due to a pressure change during a processing step. I will provide a.

[0008]

In order to solve the above-mentioned problems, a substrate processing apparatus according to the present invention comprises a vacuum chamber in which a control vacuum gauge for which an output value is provided for pressure control by gas introduction is provided. The output value of the control vacuum gauge when the pressure is sufficiently lower than the measurement limit on the pressure side is stored as the output value at the normal pressure 0 point, and is stored before the pressure control in the vacuum chamber by gas introduction. In addition, the measurement on the low pressure side in the vacuum chamber is more accurate than the control vacuum gauge,
Detecting that the inside of the vacuum chamber is at a pressure sufficiently lower than the measurement limit of the control vacuum gauge, comparing the output value of the control vacuum gauge at this time with the output value of the normal zero point stored in advance, The present invention is characterized in that the actual pressure in the vacuum chamber is controlled in a normal state in which a correction is made for the shift amount by detecting a shift of zero point of the control vacuum gauge.

As described above, before the pressure control in the vacuum chamber, a warning can be given to the zero point shift of the control vacuum gauge to which the output value is provided for the pressure control, and the control vacuum gauge can be issued. Even if there is a pressure shift in the vacuum chamber caused by the zero point shift, it is possible to correct the shift amount and prevent a processing defect of the work due to a pressure change during the processing step.

[0010]

A substrate processing apparatus according to a first aspect of the present invention includes a vacuum chamber capable of holding the inside at a low pressure, a vacuum pump for evacuating the inside of the vacuum chamber for holding the low pressure, and An exhaust pipe that connects a vacuum chamber and a vacuum pump for the exhaust and that can vary the exhaust speed of the vacuum pump, and a gas introduction pipe that introduces a gas at a constant flow rate into the vacuum chamber. Controlling the vacuum chamber to maintain a constant pressure in the vacuum chamber while exhausting a gas body introduced from the gas introduction pipe into the vacuum chamber through the exhaust pipe with the vacuum pump; In a substrate processing apparatus for processing a substrate inside a chamber, when controlling the pressure by introducing a gas inside the vacuum chamber, the internal pressure is not affected by the type of the gas inside the chamber. Measure and provide a measured output value for the pressure control for the control vacuum gauge, while being affected by the type of the gas body, while measuring the low pressure side in the vacuum chamber from the control vacuum gauge A low-pressure side vacuum gauge that does not perform high-precision, and performs pressure control in the vacuum chamber based on a measurement output signal from the control vacuum gauge, while controlling the pressure in the vacuum chamber by the low-pressure side vacuum gauge. Is detected to be sufficiently lower than the measurement range of the control vacuum gauge, and a zero point shift of the control vacuum gauge is performed based on the measurement output value from the control vacuum gauge at this time. Is configured to be detected.

According to a second aspect of the present invention, there is provided a substrate processing apparatus according to the first aspect, wherein the inside of the vacuum chamber according to the first aspect is at a sufficiently lower pressure than a measurement limit on a low pressure side of the control vacuum gauge. Is stored as an output value at a normal pressure of 0, and before the pressure control by introducing a gas body into the vacuum chamber, the vacuum chamber is controlled by the low pressure side vacuum gauge to control vacuum. It is detected that the pressure is sufficiently lower than the measurement limit of the gauge, and the output value of the control vacuum gauge at this time is compared with the output value at the normal zero point stored in advance, and the comparison detects the output value. The pressure in the vacuum chamber is controlled in a normal state in which the deviation of the control vacuum gauge at the zero point is corrected.

According to the above configuration, the inside of the vacuum chamber is
The output value of the control vacuum gauge when the pressure is sufficiently lower than the measurement limit on the low pressure side of the control vacuum gauge to which the output value is provided for the pressure control by the gas introduction is the normal zero point output. Before the pressure control in the vacuum chamber by gas introduction, the measurement on the low pressure side in the vacuum chamber is performed by the low pressure side vacuum gauge which is more accurate than the control vacuum gauge. It detects that the pressure is sufficiently lower than the measurement limit of the control vacuum gauge, compares the output value of the control vacuum gauge at this time with the output value of the normal zero point stored in advance, and determines the control vacuum gauge. , The actual pressure in the vacuum chamber is controlled in a normal state in which the amount of the shift is corrected.

Hereinafter, a substrate processing apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings.
The substrate processing apparatus of the present embodiment has, as a basic configuration,
It has a vacuum chamber that can keep the inside vacuum, and a pressure control vacuum gauge that can accurately measure pressure even when the vacuum chamber is filled with plasma or active gas, and a vacuum gauge for plasma or active gas. Although a pressure gauge cannot be measured accurately, a vacuum gauge capable of measuring a lower pressure side is provided. (Embodiment 1) A substrate processing apparatus according to Embodiment 1 of the present invention will be described.

FIG. 1 is a perspective view showing a schematic configuration of the substrate processing apparatus according to the first embodiment. In FIG. 1, reference numeral 1 denotes a vacuum chamber capable of maintaining the inside at a low pressure, 2 denotes a vacuum pump capable of evacuating the inside of the vacuum chamber 1 to a low pressure of 1 × 10 ⁻² or less, and 3 denotes a vacuum chamber 1 And an exhaust pipe 4 connecting the vacuum pump 2 and a capacitance manometer type control vacuum gauge hardly affected by the type of gaseous substance. A voltage proportional to the pressure value between 0 and 13.3 Pa is set to 0 to 0. Output at 10V. 5 is a control vacuum gauge 4
This is a low pressure side vacuum gauge capable of measuring at a lower pressure side as compared with the above, and can notify by a contact output when the inside of the vacuum chamber 1 becomes 0.01 Pa or less. Reference numeral 6 denotes a gas introduction tube which can introduce, for example, an active gas as a gas into the vacuum chamber 1 at a constant flow rate. The gas introduction pipe 6 is closed by a valve or the like so that the inside of the vacuum chamber 1 can be kept at a low pressure except when the gas is introduced. Reference numeral 7 denotes a variable valve which is located in the middle of the exhaust pipe 3 and can change the exhaust area of the exhaust pipe 3 to change the exhaust speed of the vacuum pump 2. Inside this device, a normal output voltage of the low pressure side vacuum gauge 5 when the low pressure side vacuum gauge 5 sets and outputs is stored.

The operation of the pressure control device in the substrate processing apparatus configured as described above will be described below with reference to an operation flowchart. Here, the pressure value indicated by the control vacuum gauge 4 when the pressure inside the vacuum chamber 1 is sufficiently lower than the measurable range of the control vacuum gauge 4 is set to P _0, and the pressure inside the vacuum chamber 1 is set to P _0. the pressure of the purpose of trying to control the P _1.

FIG. 2 shows a substrate processing apparatus according to the first embodiment.
FIG. 7 is an operation flowchart showing operation steps of the present embodiment. As shown in Figure 2
First, in steps 8 and 9, the vacuum chamber 1
Without introducing gas into the vacuum chamber with the vacuum pump 2
Exhaust until the pressure inside 1 becomes 0.01 Pa or less
You. The low pressure side vacuum gauge 5 is used for measuring the pressure.
In step 10, the output voltage of the control vacuum gauge 4 is read.
The pressure P inside the vacuum chamber 1_TwoConvert to
You. In step 11, the pressure P_TwoAnd the positive memorized inside
The pressure P of the control vacuum gauge 4 at all times₀Compare with The result
Result, pressure P_TwoAnd pressure P₀Is less than or equal to the allowable value a,
In step 12, gas introduction into the vacuum chamber 1 is started.
At step 13, the variable valve 7 is controlled to
Member 1 has pressure P ₁Pressure control so that
After performing the force control for a certain period of time, the operation flow ends.

However, if the difference between the pressure P ₂ and the pressure P _{0 in} step 11 is larger than the allowable value a,
The alarm output of step 14 is performed. The operation flow ends without performing the pressure control. Here, it is needless to say that the output voltage of the control vacuum gauge 4 does not need to be proportional to the degree of vacuum, and may be output based on a known law. Further, the pressure range of the control vacuum gauge 4 is not limited to 0 to 13.3 Pa. Furthermore, there is no problem if the contact output of the low pressure side vacuum gauge 5 is sufficiently smaller than the maximum measurement range of the control vacuum gauge 4, and it is not necessary to limit the contact output to 0.01 Pa. (Embodiment 2) Hereinafter, the operation of the substrate processing apparatus of Embodiment 2 having the same configuration as that of Embodiment 1 will be described with reference to FIG.

FIG. 3 is an operation flowchart showing operation steps in the substrate processing apparatus according to the second embodiment. As shown in FIG. 3, the same steps 15-17 as in the first embodiment, reads the current pressure value P ₂ by the control vacuum gauge 4 and evacuation. In step 18, the difference between the pressure P ₂ and the pressure value P ₀ of the control vacuum gauge 4 stored in the normal state stored therein is stored as ΔP. In step 19, gas introduction into the vacuum chamber 1 is started, and in step 20, the variable valve 7 is controlled so that the pressure in the vacuum chamber 1 becomes equal to the pressure (P ₁ + ΔP). Is performed for a predetermined time, and then the operation flow ends.

Note that the substrate processing apparatus according to each of the above-described embodiments performs processing for forming a semiconductor on a substrate disposed in a vacuum chamber when manufacturing a semiconductor, as in the description of the prior art. In addition to the case, for example, when performing processing for forming elements such as electrodes and semiconductors on a liquid crystal substrate constituting a liquid crystal panel used for a liquid crystal display device, or for various substrates in a vacuum chamber The same applies to the case of performing various processes.

[0020]

As described above, according to the present invention, the inside of the vacuum chamber is sufficiently lower than the measurement limit on the low pressure side of the control vacuum gauge whose output value is provided for pressure control by gas introduction. The output value of the control vacuum gauge at the time of pressure is stored as a normal zero point output value, and before the pressure control in the vacuum chamber by gas introduction, the measurement on the low pressure side in the vacuum chamber is performed. The low-pressure side vacuum gauge, which is more accurate than the control vacuum gauge, detects that the inside of the vacuum chamber is at a pressure sufficiently lower than the measurement limit of the control vacuum gauge. By comparing the output value of the normal zero point stored in advance with the zero point deviation of the control vacuum gauge and detecting the deviation of the zero point, the actual value in the vacuum chamber is corrected in a normal state in which the deviation amount is corrected. Pressure can be controlled.

Therefore, before the pressure control in the vacuum chamber, a warning can be issued for the zero point shift of the control vacuum gauge to which the output value is provided for the pressure control, and
Even if there is a pressure shift in the vacuum chamber caused by a zero point shift of the control vacuum gauge, it is possible to correct the shift amount and prevent processing defects of the work due to a pressure change during the processing process.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of a substrate processing apparatus according to a first embodiment of the present invention.

FIG. 2 is an operation flowchart showing operation steps in the substrate processing apparatus of the first embodiment.

FIG. 3 is an operation flowchart showing operation steps in the substrate processing apparatus according to the second embodiment of the present invention;

FIG. 4 is an operation flowchart showing operation steps in a conventional substrate processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Vacuum pump 3 Exhaust pipe 4 Control vacuum gauge 5 Low pressure side vacuum gauge 6 Gas introduction pipe 7 Variable valve 8-20 Transition state of operation flow diagram

Claims (2)

[Claims] 1. A vacuum chamber capable of holding the inside at a low pressure, a vacuum pump for evacuating the inside of the vacuum chamber for maintaining the low pressure, and a connection between the vacuum chamber and the vacuum pump for the evacuation. An exhaust pipe with a variable exhaust rate at the vacuum pump, and a gas introduction pipe for introducing a gas at a constant flow rate into the vacuum chamber,
The vacuum chamber is controlled to maintain a constant pressure inside the vacuum chamber while exhausting a gas body introduced from the gas introduction pipe into the vacuum chamber through the exhaust pipe by the vacuum pump. In the substrate processing apparatus for processing a substrate, the pressure is controlled by introducing a gas in the vacuum chamber, and the internal pressure is measured without being affected by the type of the gas in the vacuum chamber. A control vacuum gauge provided for use in the vacuum chamber, and a low pressure side vacuum gauge which is affected by the type of the gaseous body and measures the low pressure side in the vacuum chamber with higher accuracy than the control vacuum gauge. The pressure in the vacuum chamber is controlled by the low pressure side vacuum gauge while controlling the pressure in the vacuum chamber based on a measurement output signal from the control vacuum gauge. Detecting that the pressure is sufficiently lower than the measurement range of the control vacuum gauge, and detecting a zero point shift of the control vacuum gauge based on a measurement output value from the control vacuum gauge at this time. A substrate processing apparatus characterized in that: 2. The measured output value of the control vacuum gauge when the pressure inside the vacuum chamber is sufficiently lower than the measurement limit on the low pressure side of the control vacuum gauge, is the output value at a normal pressure of zero. Before the pressure control by introducing the gas into the vacuum chamber, the low pressure side vacuum gauge detects that the pressure in the vacuum chamber is sufficiently lower than the measurement limit of the control vacuum gauge. In this case, the output value of the control vacuum gauge is compared with the output value at the normal zero point stored in advance, and a correction is made for the deviation of the zero point of the control vacuum gauge detected by the comparison. 2. The substrate processing apparatus according to claim 1, wherein the pressure in the vacuum chamber is controlled in a normal state.