JPS5918638A - Dry etching apparatus - Google Patents

Abstract

PURPOSE:To execute the etching with high accuracy by revolving a rotating magnet arranged opposing to a holder of a work to be processed, thereby effectuating magnetic flux to the entire part of holder and uniformly converting an active gas into plasma. CONSTITUTION:When an axis 9 is rotated by a motor 13, an arm 15 rotates, an axis 17 revolves around the axis 19 and the axis 17 rotates because of engagement between a gear 18 and a gear 20. Thereby, a magnet 4 mounted to the axis 17 revolves, while it is rotating, on the surface parallel to the holder 2 and the magnetic flux of magnet 4 uniformly works to the entire part of holder 2 owing to an eccentrical rotation. Thereby, an active gas supplied to a vacuum reservior 1 between the holder 2 and flat plate electrode 3 is uniformly converted to plasma and thereby wafers 5 can be etched with high accuracy. The magnetic flux of magnet is not required to be uniform, a circular holder may also be used for circular wafer and area of holder can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dry etching apparatus for etching a workpiece by converting active gas into plasma.

[Technical background of the invention and its problems]

In recent years, dry etching, which is superior to wet etching of semiconductor wafers in terms of processing accuracy, has come to be widely used as a means of patterning semiconductor elements with high precision. This dry etching is
The active gas is turned into plasma by electrons generated by applying a high frequency power source between the holder and the electrode to which the workpiece is attached, and thereby the workpiece is etched.

By the way, in such etching processing, it has been considered to improve the etching efficiency by applying a magnetic field to the holder using a magnet to enhance the plasma formation of the active gas.

However, if the magnetic field is not uniformly applied to the holder, the plasma of the active gas will be non-uniform, resulting in a drawback that the uniformity of the etching process will be hindered. Therefore, it is conceivable to move the magnet linearly in order to apply a uniform magnetic field to the holder. However, if the magnet is simply moved linearly, the direction of the magnetic flux generated from the magnet will only change linearly, so the magnetic field applied to the holder will not be uniform enough, resulting in uneven etching. Sometimes it happens.

[Purpose of the invention]

The present invention provides a dry etching device that can apply a sufficiently uniform magnetic field to a holder using a magnet, thereby etching a workpiece attached to the holder with high precision. There is a particular thing.

[Summary of the invention]

A magnet is placed opposite the other surface of a holder that has a workpiece attached to one surface, and this magnet is rotated and revolved by a drive mechanism, thereby applying a uniform magnetic field to the holder. It is made so that it can be given.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a vacuum container. This vacuum container 1 has a suction port, an inflow port, and a force (not shown)! The inside of the vacuum container 1 is evacuated through the suction port, and active gas is supplied from the inflow port.

A disk-shaped holder 2 is held horizontally within the vacuum container 1. Below this holder 2: On the surface side, a flat plate electrode 3 having a diameter smaller than that of the holder 2 is arranged facing, and on the upper surface side, it has almost the same diameter as the flat plate electrode 3, and the center is magnetized with an N pole, and the periphery is magnetized. Magnets 4 whose portions are magnetized to have S poles are arranged to face each other. A semiconductor wafer 5 having approximately the same diameter as the magnet 4 is attached to the lower surface of the holder 2 as a workpiece, for example, with an adhesive. The holder 2 and the plate electrode 3 are connected to a high frequency power source 6, and electrons are generated between them to turn the active gas into plasma. Also,
The magnet 4 is caused to revolve while rotating by a drive mechanism 7. That is, a support portion 8 is formed in the vacuum container 1, and a first rotating shaft 9 is rotatably and airtightly supported through the support portion 8 via a bearing 10 and a sealing material 11.

One end of the first rotating shaft 9 protruding outside the vacuum chamber 1 is fitted with a first gear 12, and the second rotating shaft 13 of the motor 13 is suddenly fitted onto the first gear 12. gears 14 are in mesh with each other.An arm 15 has one end attached to the other end of the first rotating shaft 9 located inside the vacuum vessel 1.A receiving end is attached to the other end of the arm 15. A hole 16 is formed, and a second rotating shaft 17 is rotatably inserted into this receiving hole 16.The lower end of this second rotating shaft 17 is the upper surface of the magnet 4,
It is fixed at a position eccentric from the center of the magnet 4 by a dimension a, and a third gear 18 is fitted to the upper end. A protrusion 19 is formed in the middle of the second rotation shaft 12, and this protrusion 19 allows the second rotation shaft 17 to be axially connected to the fourth gear 20 fixed to the support portion 8. They fit together.

Note that the first rotating shaft 9 is rotatably inserted through a through hole formed in the fourth gear 20 .

According to the dry etching device configured in this way,
The motor 13 is operated to rotate the rotating shaft 13h for a second time.
When the signal is transmitted from the gear 14 to the first gear 12 and rotates the first rotating shaft 9, the arm 15 rotates together with the first rotating shaft 9. This rotation of the arm 15 causes the second rotation shaft 17 to revolve around the first rotation shaft 9. Further, when the second rotating shaft 17 revolves, the third gear 18 rotates due to the meshing of the third gear 18 and the fourth gear 20, so the second rotating shaft 17 rotates. Therefore, the magnet 4 attached to the second rotating shaft 17 revolves while rotating on a plane parallel to the holder 2, and the rotation is caused by the second rotating shaft 17 being eccentrically attached to the magnet 4. Since the magnet 4 rotates eccentrically, the magnetic flux generated from the magnet 4 acts uniformly over the entire surface of the holder 2.

Therefore, the active gas supplied to the vacuum container 1 is uniformly converted into plasma between the holder 2 and the flat electrode 3, so that the semiconductor wafer 5 can be etched uniformly and with high precision accordingly. I can do it. Moreover, even if the magnetic flux generated from the magnet 4 is not uniform due to non-uniformity of the material of the magnet 4, the magnetic flux can be uniformly applied to the holder 2 by the magnet 4 revolving while rotating. This also increases the accuracy of etching.

Furthermore, since the magnet 4 revolves while rotating, the holding body 2
Even if the holding body 2 is made into a disk shape, the magnetic flux can be applied uniformly to the entire surface of the holding body 2. That is, since the semiconductor wafer 5 is generally disk-shaped, the holder 2 can be shaped to correspond to the semiconductor wafer 5. This means that the overall area of the holder 2 can be made smaller than, for example, when the holder 2 is made rectangular as in conventional devices that move magnets linearly. This will increase rigidity.

〔Effect of the invention〕

As described above, in this invention, the magnet placed opposite the holder that holds the workpiece is rotated and revolved, so that the magnetic flux generated from this magnet is uniformly distributed over the entire surface of the holder. can be made to act.

Therefore, since the active gas can be uniformly turned into plasma, the etching process can be performed on the workpiece with high precision.

[Brief explanation of drawings]

The drawing is a schematic diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Vacuum container, 2... Holder, 3... Flat electrode, 4... Magnet, 5... Semiconductor element (workpiece), 7
...Drive mechanism.

Claims (2)

[Claims] (1) A vacuum container, a holder held in the vacuum container with a workpiece attached to one surface, an electrode placed opposite to one surface of the holder, and an electrode placed opposite to the other surface of the holder. What is claimed is: 1. A dry etching device comprising: a magnet disposed as a substrate; and a drive mechanism for causing the magnet to revolve while rotating on a plane parallel to the holder. (2) The dry etching apparatus according to claim 1, wherein the magnet rotates eccentrically.