JP2002113355A - Plasma processing method and plasma processing apparatus - Google Patents

Abstract

(57) [Problem] In dry etching, a method of processing the surface of a substrate to be processed using ions or radicals generated by generating plasma in a vacuum vessel, wherein the substrate is continuously processed. Then, reaction products and the like are deposited and deposited in the vacuum vessel. As a result, the operation of the sliding portion of the valve body of the APC becomes unstable, and it becomes difficult to stably process the substrate to be processed. For this reason, maintenance of the apparatus is required, and an object of the present invention is to clarify the timing of such maintenance. SOLUTION: An automatic pressure adjusting means (APC) for moving a valve body 10 on an exhaust port of a vacuum vessel to control an exhaust flow rate in the vacuum vessel to adjust a pressure in the vacuum vessel, and a valve body 10 for evacuating the vacuum vessel. Detecting means 21 for detecting the position when the mouth is closed
Clarifies the optimal maintenance time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing method and apparatus for performing plasma processing such as etching on an object to be processed (substrate to be processed) in a vacuum.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional plasma processing apparatus.
The plasma processing apparatus includes a vacuum vessel 1, a main vacuum pump 2 such as a turbo molecular pump connected to an exhaust port 3 of the vacuum vessel 1, an auxiliary pump 24 such as a dry pump or a rotary pump, and a vacuum gauge 25. , Mass flow controller (MFC) 26, valve 27, and gas ejection section 8
A regulator (not shown), a substrate holder 5 in the vacuum vessel 1 on which the substrate 4 to be processed is placed, and a plasma source 6 for generating inductively coupled plasma (ICP), VHF high-frequency plasma, and the like. , A high frequency power supply 7 to the plasma source 6 and an automatic matching unit 28. Further, the valve element 10 that moves on the exhaust port 3, a column 13 that holds the valve element 10, a bellows 19 that covers the column 13, a connection plate 14 that connects the column 13, and a ball screw 15 that moves the valve element 10 up and down And the pulley 1 for rotating the ball screw 15
7 and a timing belt 16 for synchronously rotating the two pulleys 17 and an automatic pressure adjusting means (APC) comprising a motor 18 for rotating the timing belt 16 also constitute this plasma processing apparatus.

When the valve body 10 of the APC moves up and down, the exhaust port 3 provided on the bottom surface (the surface on which the vacuum pump is mounted) of the vacuum vessel 1 is connected to the APC.
The size of the open portion of the space surrounded by the valve body 10 is changed. Thus, the exhaust resistance of the gas in the vacuum vessel 1 changes, and the pressure in the vacuum vessel 1 is adjusted by changing the gas density in the vacuum vessel 1.

At this time, the center of the exhaust port 3, the substrate 4, the substrate holder 5, the gas blowing portion 8, and the valve body 10 of the APC coincide with each other. 4 is an isotropic flow. The structure for moving the valve body 10 of the APC up and down is as shown in FIG.
The valve element 10 of the PC is a motor 18 such as an AC servomotor.
The two ball screws 15 are driven synchronously via transmission elements such as a pulley 17 and a timing belt 16, and connected via a connecting plate 14 connected thereto and two columns 13 provided on a valve body. The mechanism is movable up and down.

In the plasma processing apparatus configured as described above, the reaction gas is supplied to the evacuated vacuum vessel 1 by the reaction gas supply means, and the amount of exhaust of the vacuum vessel 1 is controlled by the APC so that the desired pressure is obtained. Plasma is generated in the vacuum vessel 1 by high-frequency application means, and plasma processing such as dry etching is performed on the substrate 4 to be processed.

[0006]

SUMMARY OF THE INVENTION Dry etching is
In this method, plasma is generated in a vacuum vessel, and the surface of the substrate to be processed is processed using ions and radicals generated inside the vacuum vessel. Reaction products and the like adhere to and accumulate on the surface. As a result, the operation of the valve body of the APC or its sliding portion becomes unstable, the pressure of the reaction gas in the vacuum vessel cannot be kept constant, and the plasma processing of the substrate to be processed can be performed stably. It becomes difficult. For this reason, maintenance of the apparatus is required. This maintenance has conventionally been empirically determined based on the number of substrates to be processed and the number of operating days of the apparatus. Further, once maintenance is performed, it takes a long time to bring the apparatus into a movable state, and the productivity of the apparatus has been significantly reduced. An object of the present invention is to clarify the timing of such maintenance by monitoring the amount of reaction products, and to stably perform processing of a substrate to be processed while keeping the required number of maintenance to a minimum.

[0007]

In order to achieve this object, a plasma processing apparatus according to the present invention comprises an automatic pressure adjusting means (APC) for controlling an exhaust flow rate in a vacuum vessel and adjusting a pressure in the vacuum vessel. A detection means is provided for detecting the position of the valve body when the valve body provided in the APC closes the exhaust port of the vacuum vessel.

An automatic pressure adjusting means (A) for moving the valve body on the exhaust port of the vacuum vessel (on the center axis of the substrate to be processed) to control the exhaust flow rate in the vacuum vessel and adjust the pressure in the vacuum vessel.
PC) and detecting means for detecting the sliding resistance when the valve element moves.

This makes it possible to clarify the maintenance time of the APC and to stably process the object to be processed (substrate to be processed).

[0010]

1 and 2 show an embodiment of the present invention.

FIG. 1 shows a schematic configuration of an APC of a plasma processing apparatus for realizing a plasma processing method and apparatus according to a first embodiment of the present invention. Except for the configuration of the APC, the configuration is the same as that of the plasma processing apparatus shown in FIG.

In FIG. 1, an APC valve element 10 is an AC
The rotation of a motor 18 such as a servomotor is driven by synchronizing two ball screws 15 via transmission elements such as a pulley 17 and a timing belt 16, and a connection plate 14 connected to the two ball screws 15 and two valves provided on a valve body. The mechanism is driven in the up-down direction via the support column 13.

A dog 20 is attached to a portion of the APC that moves together with the valve body, and a sensor 21 such as a laser displacement sensor is provided so that the position of the dog can be detected.

Although the pulley 17 and the timing belt 16 are used as the transmission elements here, other transmission elements such as gears can be used. In addition, as for the columns provided on the valve body, two examples are given, but more columns may be used.

In the plasma processing apparatus configured as described above, when performing the plasma processing on the substrate to be processed, the APC
The position of the valve body 10 in a fully closed state (a state in which the APC valve body is in contact with the exhaust port of the vacuum vessel) is monitored every time by detecting the dog 20 with the sensor 21, and the reaction product A certain value (predetermined value) of the detection position of the dog 20 due to the adhesion of
At this time, the maintenance means of the APC is displayed by displaying the maintenance time of the APC on the display means. This makes it possible to prevent the APC from malfunctioning.

(Embodiment 2) FIG. 2 shows a schematic configuration of an APC of a plasma processing apparatus for realizing a plasma processing method and apparatus according to Embodiment 2 of the present invention. Except for the configuration of the APC, the configuration is the same as that of the plasma processing apparatus shown in FIG.

The APC valve element 10 drives the rotation of a motor 18 such as an AC servo motor by synchronizing two ball screws 22 via transmission elements such as a pulley 17 and a timing belt 16 as in FIG. It is a mechanism driven vertically by a connecting plate 14 connected thereto and two columns 13 provided on a valve body.

The motor 1 driving the valve body of the APC
Either one having a torque detection function is used as 8 or a torque detector 23 is provided in the drive unit.

Here, a pulley and a timing belt are used as transmission elements, but other transmission elements such as gears can be used. In addition, as for the columns provided on the valve body, two examples are given, but more columns may be used.

In the plasma processing apparatus configured as described above, when performing the plasma processing on the substrate to be processed, the APC
The sliding resistance, that is, the torque during the movement of the valve body is detected, and when the value becomes equal to or more than a predetermined value, the maintenance time of the APC is displayed on the display means to perform the maintenance of the APC. Thus, even when the plasma processing apparatus is operating, it is possible to display the maintenance time of the APC, and it is possible to prevent the APC from malfunctioning.

[0021]

As described above, according to the present invention, the position of the valve body of the APC of the plasma processing apparatus and the load on the driving motor are monitored, and maintenance is performed when the monitored value exceeds a desired value. By displaying the time,
The maintenance time of the plasma processing apparatus can be accurately grasped, and the malfunction of the APC can be prevented. Thus, the plasma processing of the substrate to be processed can be stably performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an APC according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an APC according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a schematic configuration of a vacuum processing apparatus according to an embodiment of the present invention and a conventional example.

FIG. 4 is a schematic configuration diagram showing a conventional APC.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 3 Exhaust port 4 Substrate to be processed 10 Valve body of APC 13 Support 14 Connection plate 15 Ball screw 16 Timing belt 17 Pulley 18 Motor 19 Bellows 20 Dog 21 Sensor 23 Torque detector

Continued on the front page F term (reference) 4G075 AA30 AA52 AA57 AA61 AA65 BC06 CA05 CA65 EB01 EB42 ED03 ED06 ED08 ED11 ED13 EE23 5F004 AA16 BA20 BB11 BC02 CA02 CB01

Claims (4)

[Claims] In a plasma processing method for generating plasma in a vacuum chamber and performing plasma processing on an object to be processed, an automatic pressure adjusting means (APC) controls an exhaust flow rate in the vacuum chamber to reduce a pressure in the vacuum chamber. A plasma processing method, comprising: adjusting; and detecting a position of the valve element when the valve element provided in the APC closes an exhaust port of the vacuum vessel. 2. A plasma processing method for generating plasma in a vacuum vessel and performing plasma processing on an object to be processed, wherein a valve element provided in an automatic pressure adjusting means (APC) is moved on an exhaust port of the vacuum vessel to produce a vacuum. A plasma processing method comprising: controlling a flow rate of exhaust gas in a container to adjust a pressure in the vacuum container; and detecting a sliding resistance when the valve body moves. 3. A plasma processing apparatus for generating plasma in a vacuum vessel and performing plasma processing on an object to be processed, wherein the automatic pressure adjusting means (APC) controls an exhaust flow rate in the vacuum vessel and adjusts a pressure in the vacuum vessel. And a detecting means for detecting a position of the valve body when the valve body provided in the APC closes an exhaust port of the vacuum vessel. 4. In a plasma processing apparatus for generating plasma in a vacuum vessel and performing plasma processing on an object to be processed, a valve body is moved on an exhaust port of the vacuum vessel to control an exhaust flow rate in the vacuum vessel, A plasma processing apparatus comprising: automatic pressure adjusting means (APC) for adjusting the internal pressure; and detecting means for detecting sliding resistance during movement of the valve element.