JP2002323146A - Pressure controller and semiconductor manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly control amount of exhaust. SOLUTION: In a valve element 182, provided in a pressure controller and a flange 100, by forming the flange 100 into flanges 162, 262 with curved surface part having a curved surface, exhausted amount is smoothly controlled. The valve element and the flange are provided with a heating means for substantially preventing reaction gas from depositing and adhering to the valve element and the flange.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing technique, and more particularly to a pressure control device for performing pressure control by evacuation and a semiconductor manufacturing device.

[0002]

2. Description of the Related Art For example, in a process of manufacturing a semiconductor thin film, there are many steps of evacuating. When a semiconductor substrate, particularly an amorphous-silicon (hereinafter a-Si) thin film is etched by a dry etching method, there is a step of performing etching using an SF ₆ / Cl ₂ -based reaction gas compatible with a Freon-less process. In this step, the inside of the vacuum chamber is evacuated to a desired degree of vacuum by a vacuum pump connected via a valve body, thereby forming a reaction gas atmosphere under reduced pressure, and using the thermal energy to form a substrate thin film. That is, the a-Si film is etched. After that, open the inside of the vacuum chamber, that is, increase the valve opening angle of the valve body,
The reaction gas is removed and purified by evacuating to a high vacuum that can be reached by a vacuum pump. The a-Si film after the completion of the etching step is transferred to the outside of the vacuum chamber by a substrate transfer device using a permanent magnet or the like.

FIG. 1 is a view schematically showing a configuration example of a conventional valve element of this type and a pipe. In particular, FIG.
Valve body 8 rotatably provided in this pipe 16
FIG. Referring to FIG.
6 shows the relationship between the valve body 6 and the valve body 82 and the operating principle.

In FIG. 1, a valve element 82 has a substantially disk shape. The valve element 82 is configured to be rotatable about a rotation shaft 84.

With such a structure, when the peripheral portion of the valve element 82 comes closest to the pipe 16, the opening area is reduced and the valve element 82 is closed.

When the valve element 82 rotates about the rotation shaft 84 from the above-mentioned closed state, the opening area increases in accordance with the rotation angle.

Further, the structure of the peripheral portion of the valve element 82 is
It is more preferable to have the disk portion 10 and the curved surface portion 12 (see FIG. 2B). Next, this configuration and operation will be specifically described based on the disclosed contents.

[0008] An example of the structure of this type of valve element is disclosed in the literature:
No. 0-132141. FIG. 2 is a configuration diagram illustrating a configuration example of a conventionally used valve body and piping.

FIG. 2A is a perspective view showing the whole of the valve element 82 and the pipe 16. According to this conventional configuration, the opening area of the exhaust gas flow path 14 defined by the inner wall of the pipe is adjusted by rotating the plate-shaped valve element 82 around the rotation shaft 84 in the pipe 16. The displacement of the vacuum pump is adjusted according to the ratio of the opening area to control the internal pressure in the vacuum chamber.

FIG. 2B is a perspective view of the valve element 82 disclosed in this document. This valve element 82 has two distinctive structures. The first is a disk portion 10 having a disk shape, and the second is a curved surface portion 12 having a curvature. The disk portion 10 has a shape corresponding to the pipe 16, and the disk portion 10 has a maximum diameter capable of rotating the inside of the pipe with the axis in the pipe diameter direction as a rotation axis 84.
In addition, the curved surface has a shape having a curvature that can rotate inside the pipe.

Next, the operation of the valve will be described with reference to FIG.

FIG. 3A shows a pipe 16 and the pipe 16.
FIG. 7 is a longitudinal sectional view of a main part of a pressure control device including a valve body 82 rotatably provided in the pressure control device. FIG. 3 (a)
Shows a state in which the valve element 82 is at a rotational position where the opening area of the exhaust gas flow path 14 is minimized. In this state, the disk portion 10 of the valve element 82 is at the closest distance to the pipe 16. Therefore, by the disk portion 10 of the valve element 82,
The opening area is adjusted to the minimum. That is, when the disk portion 10 as the internal structure of the valve element is closest to the pipe 16, the opening area is minimized, and the internal pressure in the vacuum chamber can be maximized.

Next, FIG. 3B shows a state in which the valve body 82 is rotated from the rotational position of the valve body 82 shown in FIG.
FIG. 4 is a cross-sectional view showing a state in which the rotary shaft is rotated at a rotational position where the opening area of the exhaust gas flow path 14 is slightly enlarged. In this state, the curved surface portion 12 on the peripheral side of the valve element is closest to the pipe 16 to adjust the opening area of the exhaust gas flow path 14. That is, when the curved surface portion 12 which is a component of the valve element 82 is closest to the pipe 16, the pressure in the vacuum chamber is controlled by the opening area of the exhaust gas flow path 14 determined by the pipe 16 and the curved surface portion 12. are doing.

In the above-described structure, a ring-shaped ring portion may be provided along the inside of the pipe 16 on a surface substantially in the pipe diameter direction.

FIG. 14A is a perspective view showing a main part of a pressure control device having another conventional structure. FIG. 14 (a)
FIG. 14B is an enlarged view of the circle A of FIG.

A ring portion 360 is provided on the side wall of the pipe 16 substantially in parallel with a plane including the pipe diameter direction.

FIG. 4 is a cross-sectional view showing a main part of a pressure control device having another conventional structure. In the conventional configuration shown in FIG. 4, the pipe 16, a valve element 82 rotatably provided on the pipe 16, and an exhaust gas flow provided on the inner wall of the pipe 16 and cooperating with the valve element 82. And a ring portion 360 for opening and closing the road. In the longitudinal section of the pipe 16, the ring portion has a rectangular shape.

Referring to FIG. 4, the relationship between the pipe 16 and the valve body 82 will be described.

FIG. 4 is a view showing a state in which the opening area is minimized, that is, a closed state. The valve body 82 and the pipe 16 are substantially connected by the ring portion 360.

With such a configuration, the opening area becomes substantially zero in the closed state. Then, when the valve element 82 rotates from the closed state about the rotation shaft 84 as a center axis, the closed state changes to the open state according to this rotation. The opening area gradually increases in accordance with the magnitude of this rotation (rotation angle, that is, valve opening angle).

[0021]

However, such a conventional pressure control device using a valve body has a problem that the flow rate of the gas flowing through the gas flow path is limited in a range where the rotation angle of the valve body, that is, the valve opening angle is small. Fine adjustment could not be performed and coarse adjustment was performed. It is difficult to accurately control the internal pressure of the vacuum chamber due to the difficulty in finely adjusting the gas flow rate during an etching process or the like in semiconductor manufacturing.

In the case of a conventional pressure control device including this valve body, when a plasma reaction or the like is performed in a vacuum chamber, a reaction product generated by this reaction adheres to the valve body or the like. Due to the accumulation of reaction products on the valve body, the accuracy of the pressure control in the vacuum chamber may be deteriorated, as well as the change over time of the displacement and the malfunction of the pressure control device. Technical challenges arise.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and therefore, the present invention provides a smooth exhaust by adjusting the displacement characteristics using a flange cooperating with a valve element. An object of the present invention is to provide a pressure control device capable of obtaining a quantity characteristic.

Another object of the present invention is to provide a semiconductor device which is capable of producing a good etching thin film by providing a pressure control device for giving a smooth displacement characteristic, thereby improving the production yield. It is to provide a manufacturing apparatus.

[0025]

Therefore, according to the pressure control device of the present invention, a tubular shape is formed on a wall surface of a tubular body defining a gas flow path in a ring shape and substantially perpendicular to the gas flow path. A flange provided parallel to the cross-section of the body,
In order to open and close the gas flow path in cooperation with the flange, a valve body rotatably provided around an axis parallel to the cross section as a rotation axis is provided.

The ring-shaped flange has a first ring half and a second ring half. The first and second
The ring half has a first member having a contact surface that is in contact with the valve body and closes the gas flow path, and an opposing surface provided on the contact surface side and facing the valve body. And a second member formed. The opposing surface is a curved surface that sequentially increases the closest distance between the opposing surface and the valve element as the valve element rotates from the closed state to the open state of the gas flow path.

According to this configuration, since the facing surface of the flange facing the valve body is a curved surface, it is possible to adjust the closest distance between the valve body and the flange in a range where the valve opening angle is small.
It can be performed with higher accuracy than before. Therefore, according to this configuration, the displacement can be adjusted with high accuracy.

Preferably, the curved portion of the second member is a part of an elliptical surface or a part of a spherical surface.

In this case, a more preferable form is obtained in a range where the valve opening angle is small. That is, the increase in the closest distance between the valve element and the flange becomes smoother, and the displacement control can be performed more reliably.

[0030] Preferably, the lengths of the second members of the flanges of the first and second ring halves may be different from each other.

As described above, according to the configuration in which the lengths of the second members of the first and second ring halves are different from each other, in the range where the valve opening angle is small, the distance between the valve body and the flange caused by the rotation of the valve body is increased. The increase in the closest approach distance is small. Therefore, the exhaust amount can be adjusted with high accuracy by adjusting the valve opening angle of the valve element. Moreover, in this configuration, since the lengths of the second members are different from each other, in the range where the valve opening angle is small, the increase in the closest approach distance between the valve body and the flange becomes smoother. Therefore, the displacement can be adjusted more precisely.

Preferably, the heating means includes a valve body,
It is good also as composition provided in each with a flange.

As the heating means, specifically,
A sheath heater or the like may be provided.

As described above, by providing the heating means on the valve body and the flange, the adhesion of reactants to the valve body and the flange can be reduced. Therefore, the life of the pressure control device is extended. That is, the pressure control device can maintain a stable state with high accuracy for a long period of time.

[0035]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pressure control device according to an embodiment of the present invention. It should be noted that the drawings used in this description merely schematically show the shapes, sizes, and arrangements of the components so that the present invention can be understood. In each drawing, the same components are denoted by the same reference numerals, and overlapping description may be omitted. The numerical conditions and the like described in this embodiment are merely examples of the present invention, and therefore, the present invention is not limited to the following embodiments. In the following description, an example in which the pressure control device of the present invention is applied to a semiconductor etching device will be described.

First Embodiment FIG. 5 is a block diagram showing a configuration of a semiconductor manufacturing apparatus, particularly, a semiconductor etching apparatus. Referring to FIG. 5, an outline of a pressure control device according to an embodiment of the present invention will be briefly described.

<Structure of Semiconductor Etching Apparatus> In the semiconductor etching apparatus of this embodiment, a vacuum chamber 30 provided with a sample table 46 for mounting a semiconductor sample 52 is provided.
And a bias power applying mechanism 50 for applying bias power to the sample table 46. Further, a substrate transport mechanism 48 for transporting the semiconductor sample 52 into and out of the vacuum chamber 30 is provided. The apparatus comprises a pressure gauge 32 connected to the vacuum chamber 30 for measuring the pressure in the vacuum chamber 30. The apparatus further includes a source gas supply unit 34 for supplying a source gas into the vacuum chamber 30 via a gas supply path, and is provided on the gas supply path and connected to the source gas supply unit 34. Gas flow control device 36 for controlling the flow rate of source gas
And a source gas supply valve 38 which is provided in a gas supply path between the vacuum chamber 30 and the gas flow control device 36 and controls the supply of the source gas in accordance with the reaction in the vacuum chamber 30. I have. The apparatus further includes a main exhaust valve 40 interposed in an exhaust gas flow path between the vacuum chamber 30 and the vacuum pump 44 for operating a degree of vacuum according to a reaction in the vacuum chamber 30; A pressure control device 42 interposed in an exhaust gas flow path between the vacuum pump 40 and the vacuum pump 44 for controlling the exhaust amount of the reaction gas in the vacuum chamber 30, and a vacuum for obtaining a degree of vacuum in the vacuum chamber 30. A pump 44 is provided.

<Operation of Semiconductor Etching Apparatus> First, a semiconductor sample 52 to be manufactured is placed on a sample table 46 using a substrate transfer mechanism 48, for example, an apparatus using a permanent magnet or the like. The semiconductor sample 52 mounted on the sample stage 46 is shown by a broken line. And the raw material gas supply unit 34
Is opened and the source gas supply valve 38 is opened to supply or inject the reaction gas into the vacuum chamber 30. Then, the gas flow controller 36 is operated to control the flow rate of the source gas to be injected.

Next, the pressure in the vacuum chamber 30 is controlled by operating the vacuum pump 44 and the pressure controller 42 while checking the pressure gauge 32 for monitoring the pressure in the vacuum chamber 30.

When the target pressure is reached, that is, when the pressure reaches, for example, 55 Pa in this embodiment, the bias power applying mechanism 50 is operated to apply the bias power to the semiconductor sample 52 placed on the sample stage 46. In this embodiment, specifically, an appropriate power of, for example, 1 kW to 5 kW is applied.

Next, when the target applied power is reached, the sample is etched to the target film thickness while monitoring the etching time for etching the semiconductor sample 52 from that point.

When the target etching time has been reached, the application of bias power is stopped, that is, turned off.

Next, after maintaining the inside of the vacuum chamber 30 at a low pressure and removing the reaction gas, the semiconductor sample 52 is transferred from the inside of the vacuum chamber 30 to the outside using the substrate transfer mechanism 48 or the like. The operations of the control device 42, the source gas supply valve 38, and the source gas supply unit 34 are stopped or turned off.

By performing such a series of operations, the etching process of the semiconductor sample can be completed.

Next, the pressure control device according to the present invention used here will be specifically described.

<Structure of Pressure Control Apparatus> FIG. 6 is a plan view of a main part of a pressure control apparatus used in the above-described semiconductor manufacturing apparatus. This pressure control device is mainly composed of two parts for performing pressure control. One is a plate-shaped valve body having a tubular body, that is, a rotary shaft 184 extending in the pipe radial direction in the pipe 16 and rotating or rotating around the rotary shaft 184 (however, FIG. Body not shown). The other is a flange 100 provided in a ring shape on a wall surface or a side wall of a tubular body that defines a gas flow path, that is, an exhaust gas flow path 14, that is, a pipe 16. This flange has two further characteristic structures. One is the first
Ring half 164, the other being the second ring half 2
64. These first and second ring halves 164,
The H.264 is provided along the pipe 16 at symmetrical positions with the rotation axis 184 as a symmetry axis. In addition, each ring half 164, 264 comprises a first member 160, 260 and a second member 162, 262, respectively.

In this configuration example, a space that depends on the closest distance between the valve body and the flange, that is, the space between the valve body and the flange, is defined as the opening 70.

Next, FIG. 7 shows a perspective view of a valve body used in this pressure control device. Essentially, there is no change from the conventional valve body.

The valve body 182 has a disk portion 110 and a curved surface portion 1.
12 and a rotating shaft 184. The disc portion 110 of the valve element 182 is connected to the valve element 182 and the flange 100.
With a structure that does not affect the closest distance to
Any shape may be used as long as the rotation in 6 is not hindered. Here, the disk portion 110 has a disk shape.

The curved surface portion 112 of the valve element 182 is
This is to derive the closest approach distance to the flange 100.
Therefore, the curved surface portion 112 has such a shape that the closest approach distance is sequentially increased as the rotation angle of the valve body 182, that is, the valve opening angle is increased.

Here, the peripheral portions 110a and 112a of the disk portion 110 and the curved surface portion 112 have a configuration using a disk shape having a curved surface.

The position of the rotating shaft 184 of the valve body 182 is determined by the center or center of gravity (S, in the figure, X) of the disk having the disk portion 110 and the center or center of gravity (T, The center axis is a rotation axis 184 that includes a midpoint j (indicated by ◎) of a line segment connecting the two, and extends a straight line orthogonal to the pipe diameter direction i (indicated by a dotted arrow). And

The disk portion 110 and the curved surface portion 112 of the valve element 182 are disposed on the left and right with the rotation shaft 184 as the center axis. The left and right parts are identical, but upside down.

When the valve body having such a structure is used, the characteristic effect of the displacement is the same on the left and right.

Next, FIG. 8A is a perspective view of the pressure control device in order to facilitate understanding of the entire pressure control device. As described above, the exhaust gas flows in the direction defined by the arrow B in the interior defined or partitioned by the pipe 16. The flow path through which the exhaust gas flows is referred to as an exhaust gas flow path 14. In order to define the exhaust gas passage 14, the exhaust gas passage 14 includes the flange 100 (the first ring half 164 and the second ring half 264) and the valve body 182. Further, the valve element 182 is located at the center of the valve element 182 (here, including the longitudinal center axis O of the pipe 16 and the center of gravity of the valve element 182 (because the valve element here is a point-symmetric solid)). And a rotation axis 184 extending in the pipe diameter direction as a central axis. And this valve element 182
Rotates around the central axis 184.

FIG. 8 (b) is an enlarged view of a portion surrounded by a circle A in the vicinity of the first ring half 164 which is a part of the flange 100 provided on the wall surface of the pipe 16 in the entire configuration of the pressure control device described above. ). This enlarged view is a perspective view of a sectional shape obtained by cutting the above-described pipe 16 along a plane including the central axis O. In FIG. 8B, the hatched portion on the left side is a pipe 16. A first ring half 164, which is a part of the flange 100, is provided along the side wall of the pipe 16 in an annular shape. The first ring half 164 is further divided into a first member 160 and a second member 162. The first member 160 has a rectangular shape in a cross-sectional view and has a half-ring shape because it is along the pipe 16. The other second member 16
2 has an L-shape in cross section and is along the pipe 16 like the former, so that it also has a semi-ring shape. The second member 162 is provided on the contact surface of the first member 160 with the valve body.
That is, the first and second members 160 and 162 are vertically connected along the central axis O of the pipe 16 and are continuously arranged.

The other part of the flange 100, that is, the structure of the second ring half 264 is similar to that of the first ring half 16.
4 has a point-symmetric structure with respect to the intersection of the rotation axis 184 of the valve body 182 and the central axis O of the pipe 16. First and second
The ring halves 164 and 264 are vertically connected along the central axis O of the pipe 16, that is, the first member and the second member are continuously connected in the reverse order along the gas flow direction.

<Operation of Pressure Control Apparatus> Next, the operation of the pressure control apparatus 42 will be described in detail with reference to FIG. FIGS. 9A and 9B are views showing the main part of the II section when the valve element 182 is attached to the configuration of FIG. Arrows R shown in FIGS. 9A and 9B are:
This is a reference line of rotation taken in the pipe radial direction of the pipe 16 from the axis of the rotation shaft 184 of the valve element 182.

Hereinafter, the tilt angle generated by the rotation of the valve body 182 from the reference line R will be described as the valve opening angle θ.

This sectional view 9 (a) shows the inclination angle θ = 0 of the valve body.
At (°), (b) shows the case at θ = θ ₀ . FIG. 9A shows that, when the valve opening angle θ = 0 °, the closest approach distance between the first and second ring halves 164 and 264 forming the valve body 182 and the flange 100 is minimum here. That is, a form in which the gas flow path 14 is closed by substantially contacting is shown. In other words, the form in which the valve body and the first member are in contact with each other is shown. When the closest distance becomes the minimum, the size of the opening 70 that depends on the closest distance becomes the smallest state, that is, the closed state. By maintaining such a state, the flow rate of the exhaust gas flowing through the exhaust gas passage 14 inside the pipe 16 can be adjusted to a minimum, in this case, substantially zero.

By arranging the valve element and the flange in this manner, the exhaust of the vacuum pump 44 can be prevented at a maximum, and the internal pressure of the vacuum chamber 30 can be maintained at a maximum.

Next, FIG. 9B shows a state in which the valve body 182 has rotated θ ₀ about the rotation shaft 184 in the counterclockwise direction from the above-mentioned state of θ = 0 °. In this state, the valve body 182 and the first member 160 of the first ring half 164 and the first member 260 of the second ring half 264 are released from contact with each other. Curved surface 112 and second member 16 of first and second ring halves
The distance between 2, 262 is the closest approach distance.
That is, it shows a state in which the pressure control device has changed from the closed state to the open state. Then, these second members 16
By making the surfaces facing the valve bodies 182 of the two and 262, that is, the facing surfaces be curved surfaces, the above-described closest approach distance is gradually increased in accordance with the rotation angle of the valve body 182.

As described above, the flange 100 and the valve body 182
The size of the opening 70 depending on the closest distance can be sequentially adjusted in the range near θ = 0 ° in cooperation with the above. Therefore, it is possible to finely adjust the displacement of the vacuum pump 44 within this adjustment range. As described above, since the exhaust amount can be sequentially and finely adjusted, it is possible to control the internal pressure in the vacuum chamber 30 without substantially causing an error.

In the first embodiment described above, in the configuration in which the flanges are the first and second ring half-structures, that is, the first and second members 160, 260 and 162, 262, the opening is small. , The fine adjustment of the displacement becomes possible. Therefore, the internal pressure in the vacuum chamber can be controlled smoothly, and the semiconductor can be etched with high accuracy.

Second Embodiment In the above-described first embodiment, the first member and the second member of the flange have different shapes, but the first and second ring halves 164 and 264 have a different shape. , The shape and size of the first member are the same. That is, they are congruent, and similarly, between the first and second ring halves, the shape and size of the second member are the same. That is, both are congruent. However, between the first and second ring halves 164 and 264, the first member can have a congruent shape and the second member can have a different shape and size. That is, the first member and the second member may have the following structures.

FIG. 10 is a cross-sectional view of the main part of the pressure control device according to the second embodiment, taken along a parallel plane including the center of the pipe diameter along the pipe. It is a figure corresponding to a). The lengths Y1 and Y2 of the second members 162 and 262 along the pipe are defined by the first and second ring halves 16.
4, 264. That is, Y1
A configuration of ≠ Y2 (Y1, Y2 are positive real numbers) is adopted.

Further, the second members (162, 26) appearing in a cross section in a parallel plane including the center of the pipe diameter along the pipe 16
2) may be configured to be a part of an elliptical surface or a spherical surface when viewed from the valve body.

Next, the displacement characteristics of a specific embodiment of the present invention and a comparative example of a conventional configuration will be considered. Note that the shape and size of the valve body are the same.

(1) No flange 100 is provided. That is, the case of only the pipe 16 (Comparative Example 1).

(2) The second member 16 of the flange 100 cut along a parallel plane including the center of the pipe diameter along the pipe 16
A case where the cross-sectional shapes of 2, 262 are combined by a rectangular straight line. That is, it corresponds to the conventional flange (Comparative Example 2).

(3) When the L-shape of the second members 162 and 262 uses a part of an elliptical surface, here X ²
/ A ² + Y ² / b ² = 1 (where X, Y, a, and b are real numbers within a range that can constitute the pipe, the flange, and the valve element)
(Example 1).

However, in this embodiment, a = 7.5.
h, b = 5h (h is a half of the thickness of the valve body 182. However, the thickness of the valve body 182 passes through the center of the valve body,
The length is in the direction along the tube axis direction orthogonal to the rotation shaft 184. ).

(4) When a part of the spherical surface is used. In this embodiment, in the above elliptic curve, a = 5h, b =
5h (Example 2).

In any of the above four configurations, Y1 = 3h and Y2 = 2h. Here, h = 2
The simulation was performed at 0 mm. The pipe diameter was set to 10 h, the maximum diameter of the valve element in the pipe diameter direction was set to 9.9 h, and the maximum thickness of the second member of the flange in the pipe diameter direction was set to 0.1 h. However, it goes without saying that a, b, Y1, and Y2 may be arbitrary real numbers independent of h as long as this configuration is possible.

FIG. 11 shows the displacement characteristics with respect to the difference in the flange shape.

FIG. 11 shows the flange 100 (160, 162, 260, 262) and the valve element 18 using these structures.
3 is a graph showing an opening ratio of an opening 70 with respect to No. 2, that is, an exhaust amount characteristic. The horizontal axis shows the valve opening angle θ of the valve body 182,
The range from 0 ° to 40 ° in units of (°) is graduated every 10 °. The vertical axis indicates the opening ratio (opening area /
Total opening area) in the range of 0% to 10% in units of (%)
The scale is shown for each percentage.

According to the simulation result of FIG.
For example, when the valve opening angle is 20 °, 6% is obtained without a flange (curve A) and 6% with a straight flange, that is, a flange having a conventional rectangular shape (curve B).
%, 4% for an elliptical flange, ie, a flange having a part of an elliptical surface (curve C), a spherical flange, ie, a flange having a part of a spherical surface (curve D)
Then, it increases sharply to 2%.

As described above, the opening ratio sharply increases as the valve opening angle increases. As can be understood from the displacement characteristics shown in FIG. 11, the size of the valve opening angle determines the size of the opening area. Therefore, in the range where the valve opening angle is small, the smaller the increase in the opening area, the lower the pressure. Suitable for fine adjustment of the control device.

Further, the opening ratio without flange (curve A) is such that even if the valve opening angle is 0 °, the above-mentioned area ratio is 1.
It is about 7% and does not become substantially 0%. This is because the pipe 16 and the valve element 182 do not substantially contact each other because the flange 100 is not provided.

The opening area of the linear flange (curve B), elliptical flange (curve C) and spherical flange (curve D) is substantially 0% when the valve opening angle is 0 °.
become. This is because the pipe 16 and the valve body 182
This is because they are substantially in contact with each other through 00.

In addition, the opening ratios of the flangeless shape (curve A) and the straight flange (curve B) match at a valve opening angle larger than about 12 °. Under these conditions, the valve body and the flange do not cooperate to control the displacement. That is, the valve element 182 is not substantially affected by the flange 100.

When the valve opening angle is from 0 ° to 8 °, the elliptical flange (curve C) is excellent, and from 8 ° to 40 °.
Up to this, a spherical flange (curve D) is excellent.

As described above, by selecting the shape of the flange, particularly the shape of the second member of the flange according to the valve opening angle,
Fine adjustment of the pressure control device in the range where the valve opening angle is small can be achieved.

As described above, it is difficult to adjust the displacement with high accuracy by using a rectangular straight flange. However, by using the pressure control device of the present invention, in the range where the valve opening angle is small, The displacement can be adjusted with high accuracy. Therefore, the internal pressure in the vacuum chamber 30 can be accurately controlled by using the pressure control device of the present invention. Then, it becomes possible to manufacture a good etching thin film, and it is possible to provide a semiconductor manufacturing apparatus capable of improving the yield.

Third Embodiment In addition to the above-described first and second embodiments, a heating means may be provided on the flange and the valve body.

FIG. 12 is a plan view of the pressure control device. In this configuration, the pipe 16, the exhaust gas flow path 14 defined by the pipe 16, a flange (not shown) having first and second ring halves, and a valve body 182 that rotates inside the pipe
(Not shown), and a rotation shaft 184 provided inside the valve body for rotating the valve body 182. Further, a motor 90 for rotating the rotation shaft 184 is used.
And the rotating shaft 184 and the flanges 160, 162,
260 (not shown), 262;
2 is provided.

FIG. 13 is a sectional view taken along the line II-II of FIG. A flange 160 provided inside the pipe 16,
A cavity is provided inside 62, 260, 262. The shape of the cavity may be spherical or rectangular. In this embodiment, a cylindrical body is used. The above-mentioned heater 92, that is, a heating means may be provided in this cavity.

A cavity is provided inside the rotating shaft 184. The above-mentioned heater 92, that is, a heating means may be provided in this cavity.

Thus, the valve body 182 and the first and second ring halves 164 and 264 are heated. Therefore, when the reaction gas generated by the plasma reaction or the like in the vacuum chamber passes through the pressure control device 42, the valve body 182
And the first and second ring halves 164, 264 and the like.

The heater used here may be a Teflon (registered trademark) heater, a sheathed heater, or the like.

The temperature of the heater at which the effect of preventing the adhesion of the reaction product is obtained is in the range of 20 ° C. to 300 ° C., preferably 50 ° C. to 150 ° C., and more preferably 80 ° C. to 100 ° C. The temperature range is ° C. Thus, the valve body 182 and the flange 1 are heated by the heater.
The reaction products adhering to 00 are substantially reduced.

As described above, the reaction gas causes the valve body 182 and the first and second ring halves 164, 26
4 is substantially prevented. Therefore, the valve element 182 and the first and second curved surface flanges 1
60, 162, 260, 262, deterioration with time is reduced,
The life of the pressure control device is extended. Then, the displacement characteristics of the pressure control device 42 can be maintained in a highly accurate state.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the embodiments, and can be variously modified without departing from the gist of the present invention.

For example, in the description of the above-described embodiment, a case where the present invention is applied to a Freon-less low-pressure etching apparatus is shown as an example. It can be widely applied to devices and the like.

[0095]

As is apparent from the above description, according to the pressure control device and the semiconductor manufacturing apparatus of the present invention, it is possible to smoothly and precisely adjust the displacement in the range where the valve opening angle is small. Therefore, the effect that the pressure control of the internal pressure of the vacuum chamber can be performed with high accuracy can be obtained.

Further, by selecting the shape of the flange, particularly the shape of the second member of the flange according to the valve opening angle, fine adjustment of the pressure control device in a range where the valve opening angle is small can be achieved.

Further, it is possible to form a good etching thin film, and it is possible to obtain an effect of improving the yield.

Further, since the valve body and the flange are heated, the amount of the reaction gas attached decreases. As a result, the occurrence of deterioration with time is improved, and the life of the device is extended. In addition, running costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conventional pressure control device.

FIG. 2 is a schematic diagram of a conventional pressure control device.

FIG. 3 is a sectional view of a conventional pressure control device.

FIG. 4 is a sectional view of a conventional pressure control device.

FIG. 5 is a configuration block diagram of a semiconductor etching apparatus.

FIG. 6 is a plan view of the pressure control device according to the first embodiment.

FIG. 7 is a perspective view of a valve body according to the first embodiment.

FIG. 8 is a diagram illustrating a pressure control device according to the first embodiment.

FIG. 9 is a cross-sectional view of the pressure control device according to the first embodiment.

FIG. 10 is a cross-sectional view illustrating a second embodiment.

FIG. 11 is a diagram showing a relationship between a valve opening angle and (opening area / total opening area).

FIG. 12 is a diagram showing a third embodiment.

FIG. 13 is a sectional view of a pressure control device according to a third embodiment.

FIG. 14 is a diagram showing a conventional pressure control device.

[Explanation of symbols]

 10, 110: Disk part 12, 112: Curved part 14: Exhaust gas flow path 16: Piping 30: Vacuum chamber 32: Pressure gauge 34: Source gas supply part 36: Gas flow control device 38: Source gas supply valve 40: Main Exhaust valve 42: Pressure controller 44: Vacuum pump 46: Sample table 48: Substrate transfer mechanism 50: Bias power application mechanism 52: Semiconductor sample 70: Opening 82, 182: Valve body 84, 184: Rotating shaft 90: Motor 92 : Heater 100: Flange 160: First member of first ring half 162: Second member of first ring half 164: First ring half 260: First member of second ring half 262: Second ring Half second member 264: Second ring half 360: Ring portion

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiaki Oguchi 5-8-1, Yotsuya, Fuchu-shi, Tokyo Inside Anelva Co., Ltd. (72) Nobuyuki Takahashi 5-81-1, Yotsuya, Fuchu-shi, Tokyo Anelva Incorporated F term (reference) 3H052 AA02 BA11 CA01 DA02 EA09 EA16 3H076 AA21 BB33 CC41 CC94

Claims (9)

[Claims] 1. A flange provided in a ring shape on a wall surface of a tubular body defining a gas flow path and parallel to a cross section of the tubular body substantially perpendicular to the gas flow path; A valve body rotatably provided about an axis parallel to the cross section as a rotation axis in order to open and close the gas flow path in cooperation with the first ring half. A first member having a contact surface for contacting the valve body and closing the gas flow path, wherein the first and second ring halves have a contact surface for closing the gas flow path; A second member provided on a contact surface side and having a facing surface facing the valve body, wherein the facing surface is configured such that the valve body moves from a closed state to an open state of the gas flow path. As it rotates, the curved surface gradually increases the closest distance between the opposed surface and the valve body. Pressure control device according to symptoms. 2. The pressure control device according to claim 1, wherein the first and second members of the first ring half and the first and second members of the second ring half are arranged in a gas flow direction. Characterized in that they are arranged in the reverse order along the line. 3. The pressure control device according to claim 1, wherein the curved surface is a part of an elliptical curved surface. 4. The pressure control device according to claim 1, wherein the curved surface is a part of a spherical surface. 5. The pressure control device according to claim 1, wherein a length of a facing surface of a second member facing the first member in a direction along a rotation direction of the valve body. ,
The length of the opposing surface of the second member is the same or different. 6. The pressure control device according to claim 1, wherein heating means is provided on at least one of the valve body and the flange. 7. The pressure control device according to claim 1, wherein the tubular body is interposed between a vacuum chamber and a source gas supply unit. apparatus. 8. The pressure control device according to claim 1, wherein the tubular body is interposed between a vacuum pump and a vacuum chamber. 9. A semiconductor manufacturing apparatus comprising the pressure control device according to claim 1, wherein the pressure control device is provided between a vacuum pump and a vacuum chamber. .