JPH11182699A - Gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the smooth opening/closing, and prevent generation of particles by providing an opening/closing mechanism to open/close a gate valve element to cover an opening part, and an electric motor easy to control the speed to drive the opening/closing mechanism. SOLUTION: A dry etching device 10 is provided with an etching chamber 2 and a gate valve 112 to open/close an opening part 2d. A gate valve element 60 built in the gate valve 11 is provided with a valve element plate, an O-ring fitted in a rectangular groove part at the position opposite to the circumference of the opening part 2d of the etching chamber 2, a rectangular particle suction groove, etc. The gate valve is closed in an airtight manner, and particles can be sucked. An electric motor 52 is used to drive a gate valve element 60, and the speed can be easily controlled. The vibration when the gate valve element 60 is brought into contact with the opening part 2d and particles generated therewith can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve for opening and closing an opening of a vacuum chamber used in a dry etching apparatus used for manufacturing semiconductor wafers, liquid crystal devices and the like.

[0002]

2. Description of the Related Art FIG. 7 shows a dry etching apparatus 1 used for manufacturing general semiconductor wafers and liquid crystal devices.
It is a longitudinal cross-sectional view which shows the principal part of. Dry etching equipment 1
Are an etching chamber 2 for etching the semiconductor wafer W, a load lock chamber 3 as a preparation chamber for loading the unprocessed semiconductor wafer W into the etching chamber 2, and an unloading chamber for unloading the semiconductor wafer W. And a wafer transfer robot 5 for transferring the wafer between the chambers 2 to 4.

The etching chamber 2 comprises an electrode 2a for generating a plasma Q, a process gas inlet 2b, and a table 2c for holding a semiconductor wafer W.

[0006] In FIG. 7, reference numeral 6 denotes a gate valve for opening and closing an opening 2 d provided between the etching chamber 2 and the load lock chamber 3. Gate valve 6
As shown in FIGS. 8A and 8B, a gate valve element 7 for covering the opening 2d and a drive unit 8 for opening and closing the gate valve element 7 are provided.

The gate valve element 7 includes a valve element plate 7a and an opening 2
and an O-ring 7b for hermetically closing d.
The drive unit 8 is driven by pneumatic pressure using a piston cylinder, and a speed controller is used for speed control of the opening / closing operation. The speed controller controls the operating speed of the piston cylinder by controlling high-pressure air discharged from the piston cylinder to the outside.

[0006]

The gate valve 6 used in the above-mentioned conventional dry etching apparatus has the following problems. That is, when the piston cylinder starts operating the gate valve element 7, an inertial force acts on the movable portion. In order to open and close the gate valve element 7 smoothly, this inertial force and the thrust of the piston cylinder must be absorbed. However, the speed controller cannot reduce the speed of the movable part when the piston cylinder is stopped, so that vibration occurs when the piston cylinder is stopped. Even if measures such as a shock absorber are taken, vibration cannot be sufficiently absorbed.

[0007] The vibration causes a position shift during the transfer of the semiconductor wafer W and causes a generation of particles. Particles reduce the device performance, yield, and the like, so it is necessary to reduce the number of particles.

If the O-ring 7b is attached around the opening 2d due to its viscosity, the opening of the gate valve 7 may be delayed even if the high-pressure air supplied to the piston cylinder is switched. In this case, the high-pressure air escapes from the discharge port of the piston cylinder at a delayed time, so that a speed controller that performs speed control using high-pressure air cannot perform speed control. Vibration was sometimes generated because the drive of the piston cylinder could not be stopped.

In the pneumatic drive using a piston cylinder, the coefficient of friction with the high-pressure air seal (formed of a rubber-based material) of the cylinder changes over time, and the operating speed may fluctuate. As the operating speed increases, the vibration increases. Conversely, when the operation speed is reduced, the opening / closing time is increased, and the throughput of the dry etching apparatus is reduced. Further, when a plurality of dry etching apparatuses are used, there is a problem that the tact time varies depending on the apparatuses due to the fluctuation of the opening / closing time, and it becomes impossible to secure a planned production number.

On the other hand, the O provided in the gate valve body which opens and closes
The ring 7b slides on the side of the etching chamber 2 to
The ring 7b was worn, and the generated wear debris adhered as particles to the device surface during the process, causing a reduction in device performance and a reduction in yield.

The process gas G 'activated by the ions during the dry etching is applied to the O-ring 7b.
, The O-ring 7b is deteriorated. This makes it easier for the O-ring 7b to adhere as particles to the device surface during the process, which also causes a decrease in device performance and a decrease in yield. Therefore, an object of the present invention is to provide a gate valve that can be opened and closed smoothly and that can prevent generation of particles.

[0012]

In order to solve the above-mentioned problems and achieve the object, an invention according to claim 1 is a gate valve for opening and closing an opening of a vacuum chamber, wherein the gate valve is provided to be openable and closable. A lid for covering the unit, an opening and closing mechanism for opening and closing the lid, and an electric motor for driving the opening and closing mechanism are provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the lid is provided with an O-ring for hermetic closure arranged so as to surround the opening, and an elasticity of the O-ring. A detection sensor for detecting a closed state of the opening by the lid based on the deformed state.

According to a third aspect of the present invention, there is provided a gate valve for opening and closing an opening of a vacuum chamber, comprising a lid which is provided to be openable and closable and covers the opening, and an opening and closing mechanism for opening and closing the lid. The lid body is provided with a particle suction unit for sucking particles in the vacuum chamber.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the lid is provided with a gas discharging portion for discharging gas into the vacuum chamber.
According to a fifth aspect of the present invention, in the fourth aspect, the gas is a process gas before ionization that causes a reaction in the vacuum chamber.

As a result of taking the above measures, the following operation occurs. That is, in the invention described in claim 1, since the electric motor is used to drive the opening / closing mechanism that opens and closes the lid that opens and closes the opening, the speed control becomes easy. For this reason, by reducing the speed at which the lid and the opening come into contact with each other, it is possible to reduce the vibration and the generation of particles generated with the vibration. Further, since the opening / closing speed can be easily controlled between a high speed and a low speed, the time required for opening / closing can be reduced, and the throughput can be improved. Further, in the electric motor, since the performance of the electric motor does not change with time, the opening and closing operation can always be performed in a fixed time.

According to the second aspect of the present invention, since the closed state of the opening by the lid is detected based on the deformed state of the O-ring for airtight closing, the airtight closing of the opening is reliably performed. It can be easily detected whether or not the operation is performed.

According to the third aspect of the present invention, since the lid has the verticle suction portion for sucking particles in the vacuum chamber, particles generated by contact between the lid and the opening can be reduced. can do.

According to the fourth aspect of the present invention, since the lid is provided with the gas discharging portion for discharging gas into the vacuum chamber, the O-ring can be shut off from the reaction gas in the vacuum chamber. it can.

In the invention described in claim 5, the gas is:
Since it is a process gas before ionization that causes a reaction in the vacuum chamber, it does not affect the etching process conditions.

[0021]

FIG. 1 is a front view showing a main part of a dry etching apparatus 10 to which a gate valve 11 according to an embodiment of the present invention is applied, FIG. 2 is a side view showing the gate valve 11, and FIG. 3 designates the gate valve 11 as indicated by A- in FIG.
FIG. 4 is a sectional view taken along line A and viewed in the direction of the arrow, and FIG. 4 is a view showing a gate valve body 60 incorporated in the gate valve 11. In these drawings, the same functional portions as those in FIGS. 7 and 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

The dry etching apparatus 10 includes an etching chamber 2 and an opening 2 d of the etching chamber 2.
And a gate valve 11 that opens and closes. The gate valve 11 is provided on a lower base plate 1 provided on a floor surface.
2, an upper base plate 13 provided above the lower base plate 12 and below the etching chamber 2, and columns 14, 15 for supporting the lower base plate 12 and the upper base plate 13.

The columns 14, 15 and the upper base plate 13
, Reinforcing plates 16 and 17 are fixed. Strut 14,
Linear guide rails 20 and 21 are fixed to 15 respectively, and linear guide bearings 22 and 23 and linear guide bearings 24 and 25 are slidably provided on these linear guide rails 20 and 21, respectively. . Intermediate stoppers 26 and 27 are fixed to the columns 14 and 15, respectively.

A slider 30 is fixed to the linear guide bearings 22, 24. The slider 30 has a shaft 3
1, 32 (32 is not shown) are attached. An arm 34 is rotatably supported on the shaft 31 via a bearing 33, and an arm 35 is rotatably supported on the shaft 32 via a bearing (not shown). Shaft 31
A bearing holder 36 is attached to the arm 34.
Is prevented from shifting.

The column 15 is provided with an opening sensor 37 for detecting that the slider 30 has risen. A slider 40 is fixed to the linear guide bearings 23 and 25. Cam followers 41 and 42 are attached to the slider 40. The cam followers 41 and 42 are inserted into the cam holes 34a and 35a of the arms 34 and 35, respectively. A tension spring 50 is attached to the sliders 30 and 40 and pulls each other.

A motor bracket 51 is mounted on the upper base plate 13. Motor bracket 5
An electric motor 52 and a ball screw support unit 53 are fixed to 1. The electric motor 52 is connected to a pole screw 56 via a coupling 55.

The lower side of the ball screw 56 is supported by a bearing 57 attached to the lower base plate 12.
A push rod 58 is fixed to the lower base plate 12.

A gate valve body 60 is attached to the upper ends of the arms 34 and 35 in FIG. Further, in the vicinity of the opening 2 d of the etching chamber 2, it is turned on when an O-ring 63, which will be described later, attached to the gate valve body 60 approaches the etching chamber 2 until a predetermined amount of elastic deformation occurs.
Is provided.

The gate valve body 60 has a rectangular plate 62 disposed at a position facing the periphery of the opening 2 d of the etching chamber 2 of the valve plate 61, and is fitted into the groove 62. O-ring 63 and rectangular particle suction groove 6 provided to correspond to opening 2d.
4 and a rectangular gas discharge port 65 disposed inside the particle suction groove 64.

The particle suction groove 64 is connected to a vacuum pump 70 via a pipe 61a in the valve plate 61. In FIG. 4, reference numeral 71 denotes a valve that opens and closes at a timing described later.

The gas discharge port 65 is connected to a process gas G (CF) before ionization through a pipe 61 b in the valve plate 61.
₃ and CHF ₃ ). In FIG. 4, reference numeral 73 denotes a valve that opens and closes at a timing described later.

The gate valve 11 configured as described above operates as follows. Note that the gate valve body 60 is in a state where the opening 2d is closed in advance. The vacuum bomb 70 is always in a suction state, and the gas supply device 72 is always in a supply state. At the beginning, the valves 71 and 73 are closed.

The electric motor 52 is driven by a controller (not shown). The electric motor 52 gradually increases in speed after starting to rotate. The driving force of the electric motor 52 is transmitted to the ball screw 56 via the coupling 55,
The slider 40 is raised. At this time, the slider 40
Are in contact with the intermediate stoppers 26 and 27 by the tension spring 50. Therefore, the slider 30 does not operate,
As the slider 40 moves up, the cam follower 4
1, 42 move in the cam holes 34a, 35a, respectively.

At this time, the arms 34 and 35 swing, and O
The ring 63 moves away from the etching chamber 2. When the slider 40 further moves up, the push rod 58 attached to the slider 40 comes into contact with the slider 30 and the slider 30
Push up. When the gate valve body 60 approaches the end of opening, the speed of the electric motor 52 is reduced. Then, when the opening sensor 37 detects the slider 30 and the opening 2d is opened, the electric motor 52 is stopped.

On the other hand, when closing the gate valve body 60, the electric motor 52 is operated while gradually accelerating similarly to the case of opening. At the beginning of closing, the slider 30 is set in the tension spring 50.
Is pulled by the slider 40 and lowered together.

The valve 71 is opened at the same time as receiving the operation signal for operating the gate valve element 60, and starts suction from the particle suction groove 64. Particles P generated by the sliding of the O-ring 63 and the side surface of the etching chamber 2 generated by the operation of the gate valve body 60 are sucked from the particle suction groove 64 as shown in FIG.

Before the slider 30 comes into contact with the intermediate stoppers 26 and 27, the electric motor 52 starts to decelerate. When the slider 30 comes into contact with the intermediate stoppers 26 and 27, the slider 30 stops and only the slider 40 descends. At this time, the cam followers 41 attached to the slider 40,
42 moves in the cam holes 34a and 35a, respectively.
The arms 34 and 35 swing. When the gate valve body 60 is pressed against the etching chamber 2 and the O-ring 63 is deformed by a predetermined amount, the sensor 2e is turned on and the electric motor 52 stops.

Upon receiving a stop signal indicating that the gate valve body 60 has stopped, the valve 71 is closed, and the suction of the particles P is stopped. On the other hand, etching is started in the etching chamber 2. Etching chamber 2
A process gas G is introduced into the electrode 2a and the electrode 2a
And a plasma Q is generated. When the electrode 2a is energized, the valve 73 opens, and the process gas G is released from the gas discharge port 65 as shown in FIG. Thus, the O-ring 63 can be blocked from the ionized process gas (active gas) G ′ generated during the etching, and the deterioration of the O-ring 63 can be prevented. Here, process gas G
CF ₃ and C that are not activated unless ionized
Since HF ₃ or the like is used, deterioration of the O-ring 63 can be prevented without affecting the etching process conditions.

When the etching is completed and the energization to the electrode 2a is stopped, the valve 73 is closed, and the gas emission from the gas emission port 65 is stopped. As described above, in the gate valve 10 according to the present embodiment, the gate valve body 6
Since the electric motor 52 is used to drive 0, speed control becomes easy. Therefore, the gate valve 6
By reducing the speed at which 0 and the opening 2d come into contact with each other, it is possible to reduce the generation of the vibration and the particles P generated with the vibration. Further, since the opening / closing speed can be easily controlled between a high speed and a low speed, the time required for opening / closing can be reduced, and the throughput can be improved. Further, in the electric motor 52, the change over time in the performance is smaller than that in the pneumatic drive, so that the opening and closing operation can always be performed in a fixed time.

Further, since the closed state of the opening 2d by the gate valve body 60 is detected based on the elastic deformation state of the O-ring 63, it is determined whether or not the opening 2d is airtightly closed. Can be easily detected.

The gate valve body 60 has a particle suction groove 6 for sucking particles P in the etching chamber 2.
Since the number 4 is provided, the particles P generated by the contact between the gate valve body and the opening 2d can be removed by suction and reduced.

Since the gate valve body 60 is provided with a gas discharge port 65 for releasing the process gas G into the etching chamber 2, the O-ring 63 is connected to the etching chamber 2.
From the ionized process gas G '. Further, since the gas to be released is the process gas G before ionization, it does not affect the etching process conditions.

Therefore, by using the gate valve 10 according to the present embodiment, it is possible to reduce the number of particles on the device processing surface in the process of manufacturing a semiconductor or a liquid crystal device in the etching chamber 2, thereby improving the performance and yield of the product. be able to. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the spirit of the present invention.

[0044]

According to the first aspect of the present invention, since the electric motor is used to drive the opening / closing mechanism for opening and closing the lid for opening and closing the opening, the speed control is easy. Becomes For this reason, by reducing the speed at which the lid and the opening come into contact with each other, it is possible to reduce the vibration and the generation of particles generated with the vibration. Further, since the opening / closing speed can be easily controlled between a high speed and a low speed, the time required for opening / closing can be reduced, and the throughput can be improved. Further, in the electric motor, since the performance of the electric motor does not change with time, the opening and closing operation can always be performed in a fixed time.

According to the second aspect of the present invention, since the closed state of the opening by the lid is detected based on the deformed state of the O-ring for airtight closing, the airtight closing of the opening is prevented. It can be easily detected whether or not the operation is reliably performed.

According to the third aspect of the present invention, since the lid is provided with the particle suction portion for sucking particles in the vacuum chamber, particles generated by contact between the lid and the opening are provided. Can be reduced.

According to the fourth aspect of the present invention, since the lid is provided with the gas releasing portion for releasing the gas into the vacuum chamber, the O-ring is shut off from the reaction gas in the vacuum chamber. be able to.

According to the fifth aspect of the present invention, since the gas is the process gas G before ionization that causes a reaction in the vacuum chamber, the gas does not affect the etching process conditions.

[Brief description of the drawings]

FIG. 1 is a front view showing a dry etching apparatus to which a gate valve according to an embodiment of the present invention is applied.

FIG. 2 is a side view showing the gate valve.

FIG. 3 is a cross-sectional view of the gate valve taken along line AA in FIG. 1 and viewed in a direction indicated by an arrow.

FIG. 4 is a view showing a gate valve body incorporated in the gate valve.

FIG. 5 is an explanatory diagram showing a particle suction state in the gate valve body.

FIG. 6 is an explanatory view showing an active gas cut-off state in the gate valve body.

FIG. 7 is a sectional view showing a conventional dry etching apparatus.

FIG. 8 is a view showing a gate valve body of a gate valve incorporated in the dry etching apparatus.

[Explanation of symbols]

 2 Etching chamber 2d Opening 2e Sensor 10 Dry etching device 11 Gate valve 52 Electric motor 60 Gate valve 63 O-ring 64 Particle suction groove 65 Gas outlet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Eijiro Koike 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Horikawa-cho Plant (72) Inventor Satoshi Ito 7-1, Nisshin-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Toshiba Electronics Engineering Corporation

Claims (5)

[Claims] 1. A gate valve that opens and closes an opening of a vacuum chamber, a lid that is openably and closably covers the opening, an opening and closing mechanism that opens and closes the lid, and an electric motor that drives the opening and closing mechanism. A gate valve comprising: 2. The lid according to claim 1, further comprising an O-ring for airtight closing disposed around the opening, and detecting a closed state of the opening by the lid based on an elastic deformation state of the O-ring. The gate valve according to claim 1, further comprising a detection sensor. 3. A gate valve for opening and closing an opening of a vacuum chamber, comprising: a lid that is openably and closably covering the opening; and an opening and closing mechanism that opens and closes the lid. A gate valve provided with a particle suction unit for sucking particles in the vacuum chamber. 4. The gate valve according to claim 3, wherein the lid is provided with a gas releasing portion for releasing gas into the vacuum chamber. 5. The gate valve according to claim 4, wherein the gas is a process gas before ionization that causes a reaction in the vacuum chamber.