JPH08134649A - Pressure control method and pressure controller of apparatus for producing semiconductor - Google Patents

Abstract

PURPOSE: To suppress soaring up of dust at the time of transportation between respective chambers and to improve the reliability of products and the yield of the products by gradually decreasing the pressure difference between a vacuum treating chamber and a load locking chamber without depending on a method for changing the opening degree of conductance valves. CONSTITUTION: The pressure values obtd. by measuring the pressures of the vacuum treating chamber 1 and/or load locking chamber 2 by pressure detectors 11, 21 and set pressure values are compared by a pressure, controller 12 at the time of controlling the pressures of the vacuum treating chamber 1 and the load locking chamber 2 connected thereto via a gate valve 3. The numerical values of the change rate and change quantity are sent to vacuum evacuation controllers 14, 24 of the vacuum treating chamber 1 and/or the load locking chamber 2 and gas controllers 13, 23 for neutralizing the pressures of the vacuum treating chamber 1 and/or the load locking chamber 2. The control of the discharge capacity of the vacuum treating chamber 1 and/or the load locking chamber 2 is executed of gas is passed to the vacuum treating chamber 1 and/or the load locking chamber 2 in accordance with the output data of the pressure controller 12, by which the pressure values are controlled to attain the set pressure values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure control method for a semiconductor manufacturing apparatus, and more particularly to a pressure control method between a vacuum processing chamber and a vacuum reserve chamber (load lock chamber) connected to the vacuum processing chamber via a gate valve. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, in vacuum transfer of a substrate to be processed between a vacuum processing chamber and a load lock chamber of a semiconductor manufacturing apparatus, the transfer is performed in a state where there is a pressure difference (10 to 30 mTorr) between the chambers. There is a problem such as dust hoisting, which may reduce the manufacturing yield.

Therefore, as a method for controlling the pressure in the vacuum processing chamber, the vacuum processing chamber is evacuated through a variable conductance valve and the opening degree of the variable conductance valve is adjusted by a pressure detector and a pressure controller. It was

[0004]

In the above-mentioned prior art, the opening degree of the conductance valve is changed by the pressure controller in order to control the pressure in the vacuum processing chamber. Since it adheres to the butterfly valve, there was an accident in which it clogged and the valve stopped operating. Therefore, regular maintenance such as disassembly and cleaning and replacement of parts was required, which reduced the operating rate of the equipment.

Further, in the pressure control method in which the degree of opening of the conductance valve is changed, the pressure value up to the set pressure overshoots, causing hunting frequently.
The production yield was reduced due to the adhesion of fine particles and the like on the substrate to be processed due to the dust being rolled up.

According to the present invention, the pressure difference between the vacuum processing chamber and the load lock chamber is gradually reduced without depending on the method of changing the opening degree of the conductance valve, and the dust is prevented from being wound up during the transfer between the chambers. The purpose is to improve device reliability and manufacturing yield.

[0007]

Means for Solving the Problems To solve the above problems, 1) the vacuum processing chamber and / or the load lock chamber are controlled in controlling the pressure of the vacuum processing chamber and the load lock chamber connected to the vacuum processing chamber via a gate valve. The pressure value measured by the pressure detector and the set pressure value are compared by the pressure controller, and the rate of change and the numerical value of the change amount are used as the vacuum exhaust controller for the vacuum processing chamber and / or the load lock chamber. And a gas controller for adjusting the pressure of the vacuum processing chamber and / or the load lock chamber, and controlling the exhaust capacity of the vacuum processing chamber and / or the load lock chamber based on the output data of the pressure controller. The pressure of the semiconductor manufacturing equipment is gradually changed from the initial pressure value over time to stably reach the set pressure value by performing gas flow in the vacuum processing chamber and / or the load lock chamber. Control method, or 2) the control of the exhaust capacity is performed by changing the rotation speed of the exhaust device, or 3) the pressure control method of the semiconductor manufacturing apparatus, or 3) the pressure of at least one of the vacuum processing chamber and the load lock chamber. A pressure detector for detecting, a pressure controller for comparing the pressure value detected by the pressure detector with a set pressure value, and calculating the rate of change and the amount of change, and based on the output data of the pressure controller, This is achieved by a pressure control device having a gas controller for adjusting pressure or an evacuation controller for adjusting the pressure of at least one of the vacuum processing chamber and the load lock chamber.

[0008]

[Operation] The pressure values measured in the vacuum processing chamber and the load lock chamber by the pressure detector are compared with the set pressure value by the pressure controller, and the rate of change and the numerical value of the amount of change are evacuated in each chamber. To the gas controller for pressure adjustment in each chamber and control the exhaust capacity based on the output data of the pressure controller.
By controlling the vacuum pump speed and flowing nitrogen gas into each chamber, the ideal proportional curve from the initial pressure value (here, the pressure is proportionally increased with time so that dust does not wind up due to overshoot or hunting). (It means a curve that shows the relationship between pressure and time that changes gradually)).

Therefore, when the substrate to be processed is transferred between the chambers and before the process, the problem of adhesion of fine particles to the substrate to be processed in the vacuum processing chamber is improved.

[0010]

EXAMPLE An example of the present invention will be described below with reference to FIG. FIG. 1 shows a vapor phase growth (CVD) apparatus as a vacuum processing apparatus.

In the figure, 1 is a vacuum processing chamber, 2 is a load lock chamber, 3 is a gate valve between the vacuum processing chamber and the load lock chamber, 11, 21 is a pressure detector, 12 is a pressure controller, 13, 23
Is a gas controller for pressure adjustment, 14, 24 is a vacuum exhaust controller, 15, 25 is a mechanical booster pump, 16, 26 is a mechanical booster pump motor, 17, 27 is a dry pump, 18, 28 is a valve, 19 is a reaction It is a gas flow controller.

A reaction gas is introduced into the vacuum processing chamber 1 through a reaction gas flow rate controller. At this time, the pressure in the vacuum processing chamber is monitored by the pressure detector 11, the pressure difference from the set pressure is compared by the pressure controller 12, and the calculated numerical values based on the arithmetic processing are sequentially stored. Is sent to the exhaust controller 14 and the pressure adjusting gas controller 13,
After controlling the exhaust capacity by changing the rotation speed of the motor 16 of the mechanical booster pump, the pressure control gas controller 13 sets the pressure in the vacuum processing chamber to the set pressure based on the value calculated by the pressure controller 12 for comparison calculation. By flowing the nitrogen gas in such a manner, the set pressure is reached and stabilized according to the ideal proportional curve shown in FIG.

Although the above-described embodiment was performed only by the control mechanism on the vacuum processing chamber side, the case where both the control mechanisms for the vacuum processing chamber and the load lock chamber are used will be described next. Based on the numerical value obtained by the comparison calculation processing by the pressure controller 12, the pressure adjusting gas controllers 13 and 23 in each chamber are operated so that the pressure values of the vacuum processing chamber and the load lock chamber become the set pressure. Nitrogen is flown into the processing chamber and the load lock chamber, and the pressure difference between the chambers is adjusted to a predetermined pressure difference, for example, 2 mTorr or less, and the gate valve 3 is opened to transfer the substrate to be processed.

FIG. 3 is a flow chart of a concrete example of comparison calculation processing by the pressure controller. The flowchart shown in the figure uses a 16-bit sequencer for a fixed period (100 ms / scan).
Run on. In the figure, APC (automatic pressure controller) is a pressure controller, MFC (mass flow controller) is a gas controller for pressure adjustment, BG (Balatron gauge: thin film capacitance pressure sensor)
Is a pressure detector.

First, it is checked in (1) whether APC is set, and if it is set in (2), the BG value is input. If it is not set, the flow ends with the MFC set value being zero in (12).

The calculation of (3) is performed based on the BG value, and the value is used as the difference. The change rates 1 and 2 are obtained by the operations in (4) and (5), and the current difference is replaced with the previous difference in (6). (7)
Then, the difference and the sum of the rate of change 1 and the rate of change 2 are calculated and used as the amount of change. In (8), divide the amount of change by the constant unique to the vacuum equipment and
C Setting change amount.

In (9), it is checked whether the MFC setting change amount is less than or equal to a constant. If it is below, double the MFC setting change amount,
If it is above, update the MFC setting value as it is (11).

[0018]

According to the present invention, the pressure difference between the vacuum processing chamber and the load lock chamber is gradually reduced according to the ideal proportional curve, or each chamber is not dependent on the method of changing the opening degree of the conductance valve. From the initial pressure value of, the set pressure value can be reached and stabilized while following the ideal proportional curve.
Pressure fluctuation in each room (overshoot, hunting, etc.)
Since it does not occur, it is possible to improve the reliability of the product and the manufacturing yield by suppressing the dust from being picked up during the transportation between the chambers.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an ideal proportional curve.

FIG. 3 is a flowchart of a specific example of comparison calculation processing by a pressure controller.

[Explanation of symbols]

 1 Vacuum processing chamber 2 Load lock chamber 3 Gate valve between vacuum processing chamber and load lock chamber 11, 21 Pressure detector 12 Pressure controller 13, 23 Pressure adjusting gas controller 14, 24 Exhaust controller 15, 25 Mechanical booster pump 16, 26 Mechanical booster pump motor 17, 27 Dry pump 18, 28 Valve 19 Reactive gas flow controller

Claims (3)

[Claims] 1. When controlling the pressure of a vacuum processing chamber and a load lock chamber connected to the vacuum processing chamber via a gate valve, the pressure of at least one of the vacuum processing chamber and the load lock chamber is measured by a pressure detector. The value and the set pressure value are compared by a pressure controller, and the rate of change and the numerical value of the amount of change are compared with the vacuum evacuation controller of at least one of the vacuum processing chamber or the load lock chamber and the vacuum processing chamber or the load lock. To a gas controller for pressure adjustment of at least one of the chambers, and controls the exhaust capacity of at least one of the vacuum processing chamber and the load lock chamber based on output data of the pressure controller, or the vacuum processing chamber Alternatively, a pressure control method for a semiconductor manufacturing apparatus is characterized in that a set pressure value is reached by flowing gas into at least one of the load lock chambers. 2. The pressure control method for a semiconductor manufacturing apparatus according to claim 1, wherein the control of the exhaust capacity is performed by changing the rotation speed of the exhaust device. 3. A pressure detector for detecting the pressure of at least one of the vacuum processing chamber and the load lock chamber is compared with a pressure value detected by the pressure detector and a set pressure value, and the rate of change and the amount of change are compared. A pressure controller for calculating, and a pressure adjusting gas controller or a vacuum exhaust controller for adjusting the pressure of at least one of the vacuum processing chamber and the load lock chamber based on the output data of the pressure controller. Pressure control device.