JP6608218B2 - Plasma etching equipment - Google Patents

Description

  The present invention relates to a plasma etching apparatus including a chamber that can be divided into two vertically.

  In the chamber of the plasma etching apparatus, a lower electrode and an upper electrode that form an electric field are arranged to face each other in the vertical direction. The lower electrode is composed of a holding table that holds the wafer in the chamber, and a wafer holding surface is formed on the upper surface of the holding table. The upper electrode has a gas supply hole for supplying a plasma etching gas. The chamber is formed with a discharge port to which a decompression unit is connected, and the interior of the chamber is evacuated by the decompression unit, so that the interior of the chamber is decompressed to a negative pressure state. In this state, a plasma etching gas is supplied from the gas supply hole and injected from the upper electrode onto the wafer. The lower electrode is connected to a high-frequency power source, a high-frequency voltage is applied between the upper electrode and the lower electrode, the plasma etching gas is turned into plasma, and the wafer is dry-etched (see, for example, Patent Document 1).

  In order to periodically maintain the gas supply hole, the holding surface of the holding table, and the like, the plasma etching apparatus is known to have a configuration in which the chamber can be opened and closed by dividing it into two. By dividing into two parts in the vertical direction instead of right and left, it becomes easy to perform maintenance of the upper electrode provided with the gas supply holes and the lower electrode composed of the holding table. Here, since the pressure inside the chamber is reduced when the plasma etching gas is turned into plasma, outside air is prevented from entering the chamber during the plasma etching. For this reason, a packing is provided on a joint surface that divides and joins the upper chamber and the lower chamber.

  As a configuration for opening and closing the chamber divided into two vertically, it is conceivable that the upper chamber and the lower chamber are connected by a hinge, and the open portion formed on the upper portion of the lower chamber is opened and closed on one side by the upper chamber.

Japanese Patent No. 5331500

  However, if the upper chamber is opened and closed on one side from the lower chamber via the hinge, the upper chamber may be shifted laterally when the upper chamber and the lower chamber are joined. As a result, there is a problem in that the packing is easily damaged, and the packing is not easily crushed due to a lateral shift, thereby reducing the airtightness of the chamber.

  The present invention has been made in view of such a point, and an object thereof is to provide a plasma etching apparatus capable of improving the airtightness of a chamber.

The plasma etching apparatus of the present invention is a plasma etching apparatus, wherein a chamber for converting an etching gas into plasma includes an upper chamber having an upper electrode, a lower chamber having a holding table for holding a wafer, and a lower chamber to an upper chamber . An opening / closing means for supporting one side and opening and closing the other side; and a packing disposed on a lower joining surface formed in the lower chamber for joining the upper chamber to the lower chamber. a pivot shaft for supporting one side of the upper chamber extends parallel to the lower bonding surface of the chamber, and a shaft-like portion for supporting the pivot axis, Ru is disposed below the chamber and lifting supporting the shaft-like part moving comprising a part, and when the upper chamber open includes an upper joint surface and a lower joint surface which is formed in the upper chamber to bond the upper chamber to the lower chamber When maintaining the parallel state, the upper chamber is lifted together with the swivel shaft by the elevating unit, the upper chamber is separated from the lower chamber, the packing is restored, and the upper chamber is closed when the upper chamber is closed. After the parallel state, the upper chamber is lowered together with the pivot shaft by the elevating unit, the upper joint surface is joined to the lower joint surface, and the packing is uniformly crushed .

  According to this configuration, since the elevating unit is provided, the upper chamber is rotated around the pivot axis to position the joint surfaces of the upper chamber and the lower chamber in parallel, and then the upper chamber is joined to the lower chamber. The chamber can be closed. At this time, the upper chamber can be moved in a direction perpendicular to the joint surface with the lower chamber to press the upper chamber against the lower chamber. This prevents the upper chamber from shifting laterally with respect to the lower chamber and prevents the bonding surfaces and the packing between the bonding surfaces from being scratched. The packing can be crushed evenly. As a result, the airtightness of the chamber when the upper chamber and the lower chamber are joined can be improved.

In the above plasma etching apparatus, comprising a damper which emits repulsive force in the direction away spaced apart and connected at one end to the upper chamber and the other end at a position from the pivot axis and connected to the lower chamber stretchable in the upper chamber from the lower chamber When the upper chamber is opened and closed, the upper chamber is raised and lowered together with the pivot shaft by the repulsive force of the damper to open and close.

  According to the present invention, since the elevating part is provided, when the upper chamber is joined to the lower chamber, the upper chamber can be pressed against the lower chamber with an equal pressure, so that the airtightness of the chamber is improved. Can do.

1 is an overall schematic diagram of a plasma etching apparatus according to an embodiment. It is a figure which shows the opening / closing operation | movement of the chamber which concerns on this Embodiment. It is the elements on larger scale of the opening-closing means which concerns on this Embodiment. It is a figure which shows the raising / lowering operation | movement of the raising / lowering part which concerns on this Embodiment.

  Hereinafter, a plasma etching apparatus according to the present embodiment will be described with reference to the accompanying drawings. FIG. 1 is an overall schematic diagram of a plasma etching apparatus according to the present embodiment.

  As shown in FIG. 1, a lower electrode 31 and an upper electrode 41 that form an electric field are disposed in the chamber 11 of the plasma etching apparatus 1 so as to face each other in the vertical direction. The lower electrode 31 includes a conductive support column 32 provided on the bottom wall 14 of the chamber 11 and a conductive holding table 33 provided on the upper end of the support column 32. A holding surface 34 for holding the wafer W is formed on the upper surface of the holding table 33. A large number of suction ports (not shown) connected to a suction source (not shown) are formed on the holding surface 34, and the wafer W is held by the negative pressure generated on the holding surface 34. The chamber 11 is divided into upper and lower parts, and an upper chamber 15 having an upper electrode 41, a lower chamber 16 having a holding table 33, and an opening / closing means for opening and closing the upper chamber 15 from the lower chamber 16 by a one-side opening and closing method. 2 is provided. The lower chamber 16 is formed in a box shape with the upper portion being an open portion, and the upper chamber 15 is formed in a lid shape capable of closing the open portion of the lower chamber 16 from above.

  The upper electrode 41 includes a conductive support 42 that penetrates the upper chamber 15 and a gas supply table 43 provided at the lower end of the support 42. A gas supply surface 44 for supplying a plasma etching gas into the chamber 11 is formed on the lower surface of the gas supply table 43. A large number of gas supply holes (not shown) are formed in the gas supply surface 44, and a gas supply part 49 is connected to the gas supply hole 4. The plasma etching gas supplied from the gas supply unit 49 is injected into the chamber 11 through a number of gas supply holes.

  In the upper electrode 41, a ball screw type elevating drive mechanism (not shown) is connected to the upper end side of the column portion 42 protruding upward from the upper chamber 15. By driving the lift drive mechanism, the upper electrode 41 is moved away from or approaches the lower electrode 31, and the height of the gas supply table 43 is adjusted with respect to the wafer W on the holding table 33.

  The lower electrode 31 is connected to a high frequency power source (not shown), while the upper electrode 41 is grounded, and a high frequency voltage is applied between them, so that the plasma etching gas is turned into plasma. Furthermore, a discharge port (not shown) is formed in the lower chamber 16 below the holding table 33, and a pressure reducing unit (not shown) is connected to the discharge port. By evacuating the inside of the chamber 11 by the decompression unit, the pressure is reduced until the inside of the chamber 11 becomes a negative pressure state.

  In the plasma etching apparatus 1 configured as described above, a plasma etching gas is jetted from the upper electrode 41 toward the wafer W in a state where the inside of the chamber 11 is at a negative pressure. In this state, a high-frequency voltage is applied between the upper electrode 41 and the lower electrode 31, and the plasma etching gas is turned into plasma. The wafer W is dry-etched by the radical chain reaction with the plasmaized gas.

  Next, the configuration and opening / closing operation of the opening / closing means 2 will be described. The opening / closing means 2 includes a turning shaft 21 that serves as an axis for opening and closing the upper chamber 15 from the lower chamber 16 on one side, and an elevating unit 22 that allows the upper chamber 15 to move up and down together with the turning shaft 21. The upper chamber 15 and the lower chamber 16 are connected by the opening / closing means 2, and the chamber 11 is opened / closed by rotating the upper chamber 15 about the turning shaft 21. When the wafer W is dry-etched, the upper chamber 15 is closed with respect to the lower chamber 16, and the upper chamber 15 is fixed to the lower chamber 16 while being pressed by the joining screw 17. Since the pressure inside the chamber 11 is reduced, a packing 63 (see FIG. 3) is provided to prevent outside air from entering the chamber 11 during plasma etching. The packing 63 is provided on a joint surface that joins the upper chamber 15 in the lower chamber 16, that is, on the upper end surface of the lower chamber 16.

  Further, the plasma etching apparatus 1 has a damper 37 used for opening / closing the chamber 11. The damper 37 includes an outer cylinder 37a and a rod 37b. One end (lower end) of the outer cylinder 37a is rotatably supported by the lower chamber 16, and the tip (upper end) of the rod 37b is rotatably supported by the upper chamber 15. Has been. The damper 37 has a hydraulic mechanism inside, for example, and is provided so that the rod 37b can be advanced and retracted. When the upper chamber 15 opens and closes the upper chamber 15, the revolving force is generated in the direction in which the upper chamber 15 is separated from the lower chamber 16. Is opened and closed by raising the repulsive force of the damper 37.

  Hereinafter, the configuration and the opening / closing operation of the opening / closing means will be described in detail with reference to FIGS. FIG. 2 is a diagram illustrating the opening / closing operation of the chamber according to the present embodiment. FIG. 3 is a partially enlarged view of the opening / closing means according to the present embodiment.

  2A and 3A show a state where the chamber 11 is opened to the open limit. 2A and 3A, the upper chamber 15 is opened to a substantially upright state. Here, the turning shaft 21 is supported via shaft support portions 23 on both sides in the direction orthogonal to the plane of FIG. 2A and FIG. 3A. A rotating body 24 is rotatably connected to the turning shaft 21. The distal end side of the rotating body 24 is fixed to the upper chamber 15, whereby the upper chamber 15 can be rotated about the turning shaft 21 as a central axis.

  In the state shown in FIGS. 2A and 3A, the pivot shaft 21 and the upper chamber 15 are disposed at the raised position by the elevating unit 22. The elevating part 22 is connected to the shaft-like part 25 linearly extending downward from the lower surface of the shaft support part 23 and the side surface of the lower chamber 16, and a support body in which a hole 61 through which the shaft-like part 25 passes is formed. 27. A bush 62 (not shown in FIG. 2A) is provided between the shaft-like portion 25 and the hole 61, and the lifting operation of the shaft-like portion 25 is guided by this bush 62. A rising stopper 29 having a shape protruding from the opening of the hole 61 is formed at the lower end of the shaft-like portion 25, and the turning shaft 21 and the upper chamber 15 are restricted from being raised by a predetermined distance or more.

  An opening limit stopper 26 that protrudes upward is formed on the distal end side of the support body 27 (on the side opposite to the lower chamber 16). The opening limit stopper 26 is formed in a protrusion shape or a rib shape, and the rotating body 24 is placed on the tip thereof to restrict the counterclockwise rotation of the rotating body 24 in the drawing. As a result, the rotation of the upper chamber 15 is restricted when the upper chamber 15 rotates around the pivot shaft 21 in a direction that opens a predetermined angle. Note that the predetermined angle may be an angle that is further rotated in the opening direction from the state in which the upper chamber 15 is vertical, whereby the state in which the upper chamber 15 is self-supporting is favorably maintained.

  FIG. 2B shows an intermediate stage of closing the upper chamber 15 from the state of FIG. 2A. At this time, the length of the rod 37b extending from the damper 37 is shorter than that in the case of FIG. 2A, and the turning shaft 21 and the upper chamber 15 are kept in the raised position by the elevating part 22.

  2C and 3B show a state immediately before the chamber 11 is completely closed. 2C and 3B, a repelling force is generated in a direction in which the upper chamber 15 is separated from the lower chamber 16 while the length of the rod 37b extending from the damper 37 (not shown in FIG. 3B) is shortened. Here, the shaft support portion 23 is formed with a closing limit stopper 28 (not shown in FIG. 2C). The closing limit stopper 28 is formed inside the shaft support portion 23, and the rotating body 24 comes into contact with the tip (upper end) thereof to restrict the clockwise rotation of the rotating body 24 in the drawing. As a result, when the upper chamber 15 is rotated in the direction of closing around the pivot axis 21, the rotation of the upper chamber 15 is restricted, and the bonding surface serving as the lower surface of the upper chamber 15 and the bonding surface (upper end surface) of the lower chamber 16. Can be positioned in parallel. At this time, the lower surface of the upper chamber 15 is in contact with the upper region of the packing 63.

  Next, with reference to FIG. 4, the raising / lowering operation | movement of the upper chamber 15 and the rotating shaft 21 by the raising / lowering part 22 of the opening / closing means 2 is demonstrated. FIG. 4 is an explanatory diagram of the lifting operation by the lifting unit according to the present embodiment.

  In FIG. 4A, as in FIGS. 2C and 3B, the joint surfaces of the upper chamber 15 and the lower chamber 16 are positioned in parallel, and the upper chamber 15 is in contact with the packing 63. At this time, a force that raises the upper chamber 15 and the turning shaft 21 is applied by the repulsive force of the damper 37 (see FIG. 2), and the upward displacement due to this force is caused by the rising stopper 29 contacting the lower surface of the support 27. Be regulated. The ascending restriction position of the upper chamber 15 by the ascending stopper 29 is set so that the joining surfaces of the upper chamber 15 and the lower chamber 16 are separated from each other and the lower surface (joining surface) of the upper chamber 15 is in contact with the packing 63. Preferably, from the viewpoint of preventing damage to the packing 63 described later, the distance between the joint surfaces of the upper chamber 15 and the lower chamber 16 should be as large as possible while the packing 63 is in contact with the lower surface of the upper chamber 15.

  When the inside of the chamber 11 is set to a negative pressure from the state shown in FIG. 4A, the upper chamber 15 is pulled downward and lowered as shown in FIG. 4B, and the joining surfaces of the upper chamber 15 and the lower chamber 16 are joined. At this time, since the shaft-like portion 25 is displaced by being guided by the hole 61 and the bush 62 in the elevating part 22, the direction in which the swivel shaft 21 and the upper chamber 15 descend is at the joint surface of the upper chamber 15 and the lower chamber 16. On the other hand, the direction is vertical. Accordingly, when the state shown in FIG. 4A is changed to the state shown in FIG. 4B, the packing 63 is uniformly crushed in the upper chamber 15 while preventing the upper chamber 15 from being displaced laterally with respect to the lower chamber 16. be able to. In this state, the airtightness of the chamber 11 is maintained by the packing 63. However, in order to improve the airtightness, the upper chamber 15 may be fixed using the joining screw 17 (see FIG. 1) if necessary. . With the chamber 11 closed as described above, the wafer W can be satisfactorily plasma etched in the plasma etching apparatus 1.

  On the other hand, when the upper chamber 15 is opened from the state shown in FIG. 4B, first, the decompression in the chamber 11 is released to the atmospheric pressure. Next, when the joining screw 17 is used, the joining screw 17 is removed. Thereafter, the upper chamber 15 is raised to the state shown in FIG. 4A by at least one force of the repulsive force upward of the damper 37, the restoring force of the packing 63, and the force by which the operator lifts the upper chamber 15. At this time, the ascending direction of the pivot shaft 21 and the upper chamber 15 is perpendicular to the joining surface of the upper chamber 15 and the lower chamber 16 for the same reason as when descending, and the lateral displacement is restricted. . Then, from the state shown in FIG. 4A, the chamber 11 is opened by rotating the upper chamber 15 around the turning shaft 21 as the rotation center.

  As described above, according to the above-described embodiment, it is possible to restrict the upper chamber 15 from shifting laterally with respect to the lower chamber 16 in the opening / closing operation of the upper chamber 15. Thereby, it is possible to prevent the joint surface of the upper chamber 15 and the lower chamber 16 and the packing 63 from being damaged. In addition, by moving the upper chamber 15 in a direction perpendicular to the joint surface with the lower chamber 16, the pressure from the upper chamber 15 is uniformly pressed on the upper end surface that becomes the joint surface of the lower chamber 16. be able to. As a result, the packing 63 can be uniformly crushed in all the extending directions, and the airtightness of the chamber 11 when the upper chamber 15 and the lower chamber 16 are joined can be improved.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, direction, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the plasma etching apparatus 1, the number of the opening / closing means 2 described above may be one, or two or more may be provided along the outer edges of the upper chamber 15 and the lower chamber 16.

  Moreover, the structure of the raising / lowering part 22 is not restricted to the structural example of illustration, For example, a shaft member is formed in the support body 27 toward an up-down direction, and the hole in which this shaft-shaped part is inserted is made into the shaft support part 23. It is also possible to guide the ascending / descending operation of the pivot shaft 21 and the upper chamber 15 by forming them.

  As described above, the present invention has an effect of improving the airtightness of the chamber, and is particularly useful in a plasma etching apparatus including a chamber that can be divided into two vertically.

DESCRIPTION OF SYMBOLS 1 Plasma etching apparatus 2 Opening-closing means 11 Chamber 15 Upper chamber 16 Lower chamber 21 Rotating shaft 22 Lifting part 33 Holding table 41 Upper electrode W Wafer

Claims (2)

A plasma etching apparatus,
A chamber that turns the etching gas into plasma,
An upper chamber comprising an upper electrode, and a lower chamber comprising a holding table for holding a wafer, and switching means for enabling open and close the other side supports the one side of the upper chamber from the lower chamber, the upper chamber A packing disposed on a lower bonding surface formed in the lower chamber to be bonded to the lower chamber ,
The opening / closing means includes
A pivot shaft for supporting one side of the upper chamber extends parallel to the lower joint surface of the lower chamber, and a shaft-like portion for supporting the revolving shaft, vertically movably supporting said lower chamber with the hinge-like portion and a lifting unit that will be disposed,
The upper chamber when Open is to maintain an upper joining surface and the lower joint surface formed on said upper chamber for bonding upper chamber to the lower part the chamber in parallel with, revolving round in the lifting unit Raising the upper chamber with the shaft, separating the upper chamber from the lower chamber, restoring the packing;
When closing the upper chamber, the upper joint surface and the lower joint surface are made parallel to each other, and then the upper chamber is moved down together with the pivot shaft by the elevating part, and the upper joint surface is moved to the lower joint surface. A plasma etching apparatus characterized in that the packing is uniformly crushed . A damper that connects one end to the upper chamber at a position spaced from the pivot and connects the other end to the lower chamber, and is capable of expanding and contracting to generate a repulsive force in a direction away from the lower chamber;
When opening and closing the upper chamber, a plasma etching apparatus according to claim 1, wherein the opening and closing by raising and lowering the upper chamber with said pivot axis with said repulsive force of the damper.

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