JPS63219137A - Plasma treatment device - Google Patents

Abstract

PURPOSE:To suppress the generation of dust in a treatment chamber as well as to let a wafer pressing means to accurately press the orientation flat part of a wafer by a method wherein the alignment means of a lower electrode unit is provided outside a treatment chamber, and a rotation-preventing means is provided on the wafer pressing means. CONSTITUTION:A closed ring 12 is raised by a closed-ring driving unit 13 when a wafer 3 is set on a sample stand 2, the closed ring 12 is closely contacted to the cover plate 21 of a treatment chamber and vacuum-isolated from the outside. The lower electrode unit 1 is raised using a plurality of guide rollers 14 as a guide, and a wafer pressing means 15 is pushed up using a guide link 18 as a guide. The wafer pressing means 15, having the shape similar to the outer circumference of the wafer 3, is raised by the guide of a plurality of rotation stop rods 17, and the wafer pressing part 15a is raised to the position having the prescribed electrode interval while it is pressing the wafer 3 at a correct position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a plasma processing apparatus, and particularly to a plasma processing apparatus used in a film forming process of a semiconductor wafer.

[Conventional technology]

FIG. 5 shows a conventional plasma processing apparatus disclosed in, for example, Japanese Unexamined Patent Publication No. 110432/1983, and in the figure,
A sample stage (2) constitutes a part of the lower electrode unit (1). The wafer (3) is held down by a wafer holding device (4) having a wafer holding portion (4a). (5) is a stopper for the wafer holding tool (4). A plurality of centering tools (7) are arranged in the automatic centering means (6) of the wafer holding tool (4), and guide the wafer holding tool (4). (7a) is an alignment cam of the alignment tool (7), with which the guide roller (8) engages.

(9) is a mounting bracket for the alignment tool (7).

With the above configuration, when the lower electrode unit (1) is raised to perform plasma processing on the wafer (3), the alignment cam (
7a) and the guide roller (8), the sample stage (2)
At the same time as the centering tool (7) is aligned, the centering tool (7)
4) Guide. As a result, Ueno (3) and wafer holding part (4a) are aligned, and plasma processing of Ueno (31) is performed.

[Problem that the invention seeks to solve]

Since the conventional plasma processing apparatus is configured as described above, the wafer 1 holder (4) rotates slightly during repeated operations, so the wafer 1 holder (4) holds the wafer (3).
) could not be aligned with the orientation flat part (hereinafter referred to as orientation flat part). In addition, since alignment of the sample stage (2) is performed within the processing chamber, there are problems such as dust generation.

This invention was made to solve the above problem, and by preventing the rotation of the wafer holder, the inner peripheral shape of the wafer holding part of the wafer holder matches the outer shape of the wafer including the orientation flat part. It is an object of the present invention to provide a plasma processing apparatus in which dust generation can be suppressed by providing an alignment mechanism for a sample stage outside the processing chamber.

[Means for solving problems]

In the plasma processing apparatus according to the present invention, the shape of the wafer holding part of the wafer holding tool is matched with the outer shape of the evaporator (including the orientation flat part), and a plurality of anti-rotation rods are provided to prevent rotation of the wafer holding tool. In addition, for aligning the sample stage, the lower i
A plurality of guide rollers are disposed at the bottom of the processing chamber of the IIl bipolar unit.

[For production]

In this invention, since the centering means for the sample stage is provided outside the processing chamber, dust generation inside the processing chamber is suppressed. Also,
Since the wafer holder is guided by a rotation stopper, rotational deviation will not occur even if the wafer holder is shaped in consideration of the orientation flat portion of the wafer.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In these figures, symbols (1) to (3) are the same as or corresponding to the same symbols in FIG. 5. (3a)
is the orientation flat portion of the wafer (3). upper electrode unit)
(10) is supported by the upper vacuum vessel (11).

The sealing ring (12) vacuum-isolates the processing chamber from the outside, and is driven by a sealing ring drive unit (13).

(14) is a guide roller serving as centering means for the lower polarization unit (1). The wafer holding part (15a) of the wafer holding tool (15) matches the outer shape of the wafer including the orientation flat part. (15b) is a guide groove. A plurality of detent bars (17) attached to a stopper (16) attached to the lower part of the upper vacuum container (11) are connected to the wafer holding tool (1).
5) is engaged with the guide groove (15b). A guide link (18) for centering the wafer holder (15) is rotatably supported by a pin (20) on a mounting bracket (19). (21) is a processing chamber cover plate.

Next, the operation will be explained. The wafer (3) is placed on the sample stage (2
), the sealing ring drive unit (13
) causes the sealing ring (12) to rise and close to the processing chamber cover plate (2).
1) It is pressed against the outside and vacuum isolated.

Next, the lower electrode unit (1) is raised using the guide roller (14) as a guide, and the wafer presser (15) is pushed up using the guide link (1B) as a guide. (17) and rises, while the wafer holding part (15a) presses the wafer (3) at the correct position and rises to a position with a predetermined electrode spacing. Guide link (18) and wafer holder (15)
The guide operates smoothly because the tip of the guide link (18) is tapered and there is a gap between it and the mounting bracket (19) that allows slight rotation. Further, the guides of the wafer holder (15) and the stopper bar (17) are made to operate smoothly by using the guide holes of the wafer holder (15) as guide grooves (15b).

In addition, in the above embodiment, the guide link (18) is connected to the mounting bracket (19) only by the bottle (20), and the guide link (18) is slightly separated from the sample stage (2) only by n1. However, a twisting spring or the like may be incorporated to forcibly separate the guide link (18) from the sample stage (2). Furthermore, various means for aligning the Ueno presser (15) and the sample stage (2) are conceivable.

〔Effect of the invention〕

As described above, according to the present invention, the lower electrode unit (
Since the centering means of 1) is arranged outside the processing chamber and the wafer holder (15) is provided with a rotation prevention means,
Dust generation in the processing chamber is suppressed, and the wafer/holding part (15a) is correctly attached to the orientation flat part (3a) of the wafer (3).
It can be held down with

[Brief explanation of drawings]

FIG. 1 is a front sectional view of one embodiment of the present invention, and FIGS.
The figure is a partially enlarged view of the one in Figure 1, Figure 2 is a bottom view of the wafer holder, Figure 3 is a plan view of the wafer, Figure 4 is a partially sectional front view of the guide link section, and Figure 5. 1 is a front sectional view of a conventional plasma processing apparatus. (1)...lower electrode unit, (2)...sample stage, (3
)...Wafer, (3a)...Orientation flat part, (14)...
Guide roller, (15)・Fist holder, (15a)
...Wafer holding part, (15b) +I guide groove, (16
)...stopper, (17)...rotation rod, (19)...
・Mounting bracket. In each figure, the same reference numerals indicate the same or corresponding parts. Akira 2 illustration child 3 illustration Akira 4 illustration 1 Akira 5 ward

Claims (1)

[Claims] In plasma processing equipment that uses plasma to press and fix a semiconductor wafer to the sample stage of the lower electrode unit using its own weight, the wafer is automatically aligned using multiple guide rollers installed at the bottom of the processing chamber. the lower electrode unit, the wafer holder having a wafer holding part having a shape similar to the outer peripheral shape of the wafer, and a plurality of wafer holders for preventing rotational deviation in the wafer holder when the lower electrode unit is raised. A plasma processing apparatus characterized by comprising a rotation stopper rod.