JPH0566968U - Dry etching equipment - Google Patents

Abstract

(57) [Summary] [Purpose] An etching device intended to suppress fluctuations in the uniformity of the etching rate within the wafer surface. [Structure] The cover is moved up and down in response to the decrease of the etching cover 3 in the etching chamber, and the positional relationship between the wafer 2 and the surface of the cover 3 is automatically adjusted so as to be always constant. [Effect] With this mechanism, the shape of the plasma becomes constant regardless of the degree of decrease of the cover 3, and the in-plane uniformity of the etching rate does not change.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a structure inside an etching chamber in a dry etching apparatus.

[0002]

[Prior Art]

 Conventionally, this type of dry etching apparatus has a structure as shown in FIG. 2 as a cross-sectional view. During etching, the wafer 2 is placed at a predetermined position on the fixed stage 10 and the chamber is evacuated to a vacuum for etching gas. Is applied at a certain constant pressure, RF having a high voltage is applied to the electrode 10 to generate plasma, and the wafer is etched by ions and radicals in the plasma. Since the etching rate greatly depends on the plasma state, the shape of the inside of the etching chamber, which affects the shape of the plasma, was also an important factor in increasing the in-plane uniformity of the etching rate of the wafer.

[0003]

[Problems to be solved by the device]

 By the way, in the conventional etching apparatus described above, the etching cover 3 is gradually thinned by the plasma as the etching process is repeated.

That is, the relative position between the wafer 2 and the surface of the etching cover 3 changes. As a result, the shape of the plasma changes depending on whether the cover is new or when it is worn down, and this has the drawback that the uniformity of the etching rate within the wafer surface changes.

[0005]

[Means for Solving the Problems]

 The etching apparatus of this invention has a wafer stage with a fixed height, a sensor for detecting the height of the etching cover including the etching cover attached to a movable table, and the position of the cover automatically set to a predetermined position. And a controller unit for correction.

Alternatively, the height of the table on which the etching cover is installed may be fixed and the wafer stage may be adjusted up and down.

[0007]

[Action]

 According to the above configuration, the cover is pulled up to a predetermined position before etching is started, and etching is started each time with the same positional relationship with the wafer. Stable etching can be performed without performing.

[0008]

【Example】

 The present invention will be described below with reference to the drawings. 1 is a sectional view of an etching apparatus according to an embodiment of the present invention. In the figure, 1 is an upper electrode, 2 is a wafer, 3 is an etching cover, 4 is a movable stage, 5 is a stage drive unit, 6 is a drive shaft, 7 is a bellows seal, 8 is a position detecting laser, and 9 is a light receiving sensor. Is.

Next, the operation of the above etching apparatus will be described. First, the drive unit 5 is moved in advance to find the most uniform cover position, and then the positions and angles of 8, 9 are adjusted so that the light emitted from the laser 8 is incident on the light receiving unit 9. .

After that, if the stage 4 is adjusted so that the light is incident on the light receiving portion 9 before the etching is started, there is an advantage that etching can always be performed in the same plasma state and stable etching can be performed.

Although the wafer stage is fixed and the table having the etching cover is moved up and down in the above embodiment, the wafer stage may be moved up and down.

[0012]

[Effect of the device]

 As described above, this invention has an effect that stable etching can be achieved by making the cover of the etching apparatus movable and always keeping the relative position to the wafer the same.

[Brief description of drawings]

FIG. 1 is a sectional view of an etching apparatus of the present invention.

FIG. 2 is a sectional view of a conventional etching apparatus.

[Explanation of symbols]

 4 Drive Stage 5 Drive Section 8 Laser for Position Detection 9 Photosensor 10 Fixed Stage

Claims (2)

[Scope of utility model registration request] 1. A wafer stage having a fixed height, a movable table having an etching cover, a sensor for accurately reading the position of the etching cover surface, and a controller for determining the position of the table in cooperation with the sensor. Dry etching equipment. 2. A dry etching having a fixed height table having an etching cover, a movable wafer stage, a sensor for reading the position of the surface of the etching cover, and a controller for interlocking with the sensor to determine the position of the wafer stage. apparatus.