JPS63247361A - Sputtering device - Google Patents

Abstract

PURPOSE:To obtain the titled device for mass production capable of clean, homogeneous, and high-speed treatment, by providing bulkheads around a target electrode and a substrate holder, respectively, and inserting a partition plate between the above so as to form individual closed spaces between the plate and the electrode and also between the plate and a substrate. CONSTITUTION:A substrate 5 to be coated is attached and fixed to a substrate holder 6, and the inside of a vacuum vessel 1 is evacuated 25. Next, a partition plate 7 is inserted between the holder 6 and a target 2 and pushed up together with the holder 6 by means of a driving device 22, so that closed-region spaces are formed between the plate 7 and a bulkhead 9 and also between the plate 7 and a bulkhead 10. Subsequently, in a presputtering space, a high-frequency voltage 20 is impressed between a target electrode 3 and the plate 7, and the positive ions of formed plasma are bombarded against the target 2 surface and the impurities in the surface are sputtered out. The holder 6 is slightly lowered and the plate 7 is pulled and held into a storage space 35. Then, the holder 6 is raised to the prescribed position and a voltage is impressed on the electrode 3 so as to form the electrode 3 into a cathode, and the target 2 surface is sputtered by formed plasma, and, by allowing scattered grains to adhere to the substrate 5 surface, a thin film is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus, and particularly to a sputtering apparatus suitable for a leading model that processes a large number of substrates at high speed.

[Conventional technology]

Sputtering devices are widely used today as one of the important film forming methods, and there are various types of sputtering devices.

As described in JP-A No. 56-65981, for example, the basic configuration includes a target electrode plate and a substrate holder to which a substrate is attached in a vacuum container. By applying a voltage, ions collide with the surface of the target electrode, and part of the target member is scattered. Then, it adheres to the surface of the substrate disposed in the scattering direction, forming a thin film.

Here, if the vacuum container is opened every time film formation is completed, it is inevitable that the inside of the vacuum container, especially the target surface which is the film forming material, will be contaminated by the introduced gas or dust in the atmosphere. Therefore, although not disclosed in the prior art, a partition plate is inserted between the target electrode plate and the substrate holder, and preliminary sputtering discharge is performed between the partition plate and the target electrode, thereby improving the target surface. A cleaning method is often used. Further, as in a known example, a method of preventing contamination of the target surface by providing a closed gate valve is also expected to be effective.

On the other hand, it has also been widely adopted to perform etching cleaning of the substrate surface by applying a voltage to the substrate holder and causing plasma discharge to occur between the substrate holder and the partition plate.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, it was necessary to insert a partition plate or a gate valve into the discharge plasma formation region, which plays the most important role in the sputtering apparatus.

However, moving a shutter etc. in and out between the target electrode and the substrate holder changes the impedance of the discharge plasma during preliminary sputtering and during main sputtering, and the discharge condition must be adjusted each time to optimize it. It was necessary.

On the other hand, in order to form a homogeneous film at high speed, the distance between the target electrode and the substrate is often shortened to increase the film forming speed. Particularly when forming a film using a ceramic material, which has a slow film forming rate, the film forming time may take several tens of hours, which has a large effect. However, there are structural constraints when it comes to inserting and removing partition plates, etc., and from the standpoint of discharge stability and uniformity of gas distribution, it would be better to narrow the distance, and mass production should be considered. There was a problem with that.

An object of the present invention is to provide a sputtering apparatus that is clean, homogeneous, and capable of high-speed processing and is suitable for mass production.

[Means for solving problems]

The above purpose is to insert a partition plate between the target electrode and the substrate to determine the distance between electrodes and discharge impedance when performing preliminary sputtering, and the distance between electrodes and discharge impedance when pulling back the partition plate and perform main sputtering. This is achieved by making the lengths equal and the distance between the poles as short as possible, and by providing a partition wall outside the discharge area to equalize the exhaust conductance and pressure distribution of the discharge gas.

At this time, it is necessary to move the substrate holder or the target electrode up and down on the central axis in order to equalize the distance between the electrodes.

Further, the partition wall requires a plurality of openings for gas introduction and gas exhaust.

[Effect]

Conventionally, a partition plate is inserted to divide a space between a target electrode and a substrate holder, and serves to prevent sputtered particles from a target surface from reaching the substrate surface. However, a space partitioned by a partition plate is not necessarily a closed area, and the surrounding area is open. The same applies to the space between the partition plate and the substrate holder.

Partition walls are provided around the target electrode and the substrate holder, and a partition plate is inserted between the partition walls to form a unique closed space between the electrodes and between the substrates. As a result, bliss sputtering on the target surface and etching on the substrate surface can be performed within the closed space without spreading other contamination. It was also installed around the partition wall. By providing exhaust holes at equal intervals around the periphery, it is possible to improve the uniformity of gas distribution within the discharge region.

Next, the partition plate is pulled back to a part of the vacuum chamber, and the substrate holder is pushed up so that it is in the same position as the partition plate during the bliss sputtering. As a result, sputtering between the target electrode and the substrate holder can be performed under conditions substantially equal to those of bliss sputtering.

In other words, by making the relationship between the partition plate, which serves as an anode during bliss sputtering, and the target electrode, which serves as a cathode, as the relationship between the substrate holder, which serves as an anode during sputtering, and the cathode, most adjustments in the processes of bliss sputtering and sputtering can be made. It becomes unnecessary.

Furthermore, since there is no structure such as a partition plate in the space between the target electrode and the substrate holder, performing sputtering by pulling back the partition plate and raising the substrate holder does not adversely affect the sputtering discharge, and both The film formation rate can be increased by shortening the interelectrode separation as much as necessary for the discharge between the electrodes.

Further, by providing the partition walls in the same manner as in the case of bliss sputtering, it is possible to improve the uniformity of the gas pressure distribution and the gas flow distribution within the discharge region.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Inside the vacuum container 1, there is a target electrode 3 that mainly maintains the space between the targets 2 and serves as a cathode when sputtering discharge.
and earth shield 4. A substrate holder 6 that holds a substrate 5 on which a film is to be formed, and an openable/closable partition plate 7 that divides the space between the two into two are housed.

The target electrode 3 is fixed to a vacuum container over 8 via an electric insulator 15 having a vacuum sealing function, and a power line from a high-frequency power source 20 that supplies power for sputtering is connected to an introduction part drawn out into the atmosphere. are connected via an impedance matching device 18.

Similarly, the substrate holder 6 has 23
A bellows 24 with a mechanism that slides vertically like
and insulator 16. It is installed through. The vertical movement of the holder is performed by a drive mechanism 22 provided directly below. On the other hand, in order to remove dirt on the substrate surface by etching, the substrate holder is equipped with a DC or high frequency power source 21.
and a matching box 19 necessary for high frequencies are connected.

A shutter plate 7 that divides the space between the target electrode 3 and the substrate holder 6 into two is opened and closed by an opening and closing drive device 30. A partition wall 9 is provided around the periphery to form a closed space between the shirt shirt plate and the target electrode. On the other hand, the space with the substrate holder is also partitioned off by a partition wall 10, a mounting flange 11, and the like.

Here, 12 is an insulator for insulating the substrate holder;
13 is a vacuum sealing material such as an O-ring, and 14 is a conductive contact plate. The contact plates are arranged at equal intervals on the upper and lower end surfaces of the partition walls 9 and 10, and a gap with the partition plate 7 is maintained. Thereby, the air gap 11 between the contact plates is formed in the discharge areas 32, 33 .
It serves as an exhaust hole to exhaust the gas inside 34.

25 is a vacuum pump, 26 is a vacuum gate valve between the vacuum container and the vacuum pump, and 27 is a flange.

Next, the operation of the present invention will be described.

After attaching and fixing the substrate 5 to be deposited on the substrate holder, cover 8
is closed, and the inside of the vacuum container is evacuated using the vacuum evacuation pump 25. Next, the partition plate 7 is inserted between the substrate holder and the target, and after stopping at a predetermined position, the driving device 22 pushes both the substrate holder and the target upward, creating a closed area space 32. between the partition plate 7 and the partition walls 9 and 10. 33 is formed.

The closed spaces will be referred to as a bliss sputter space and an etching space, respectively. However, even though it is a closed space, it is not necessary to have airtightness, and it is sufficient if each space is provided with a gas inlet and an exhaust port, or a communication hole corresponding to the above-mentioned void 11 is provided.

In the bliss sputtering space 32, a voltage is applied from the high frequency power source 20 between the target electrode and the partition plate to form discharge plasma in order to clean the target surface. The positive ions of the plasma thus created collide with the target surface, knocking out impurities on the surface.

At this time, since the impedance of the discharge plasma changes depending on the gas pressure in the space 32 and the power applied, adjustment is performed using the matching box 18.

Similarly, discharge plasma is formed in the etching space 33,
The substrate surface is cleaned by bombarding the substrate surface with positive ions.

When the target surface and the substrate surface are clean, the substrate holder is lowered slightly and the partition plate 7 is drawn into and stored in the storage section 35 provided in the vacuum container 1. Then, this time, the substrate holder is raised by the driving device 22 to the position of the substrate surface near the position of the partition plate where the bliss sputtering was performed earlier. At this time, the partition walls 9 and 10 are combined without interference as shown in FIG. 2 to form a closed space 34. This space is called a sputter space.

In the sputter space 34, a voltage is applied to the target electrode 3 so that it becomes a cathode, and discharge plasma is formed between it and the substrate. The retarget surface is struck by this plasma, and the scattered sputter particles arrive at the substrate surface and adhere to it, forming a thin film.

That is, according to this embodiment, during bliss sputtering and etching discharge, the partition plate is also regarded as part of the container forming the closed area, and during sputter discharge, unnecessary partition plates and the like are removed from the main discharge area between the target rattle substrates. This is effective in improving discharge uniformity and stability due to the influence of the partition plate structure. On the other hand, by raising and lowering the substrate holder after removing the partition plate, it is possible to form a closed space in which the distance between the electrodes is adjusted to the truly required distance. Effective for uniform film formation.

〔Effect of the invention〕

According to the present invention, regardless of the method such as bliss sputter etching before sputtering, it is possible to cause the main discharge between the target rattle substrates in an optimal arrangement. Clean film formation can be performed.

(2) The distance between the electrodes can be independently adjusted to the shortest distance, thereby improving the film formation rate.

(3) The structure between the main electrodes is simple, allowing stable and homogeneous film formation.

Effects such as this can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the present invention in which a partition plate is provided between the substrate and the target layer to form a container or partition for two processing spaces, and FIG. FIG. 6 is a longitudinal cross-sectional view when the holder is raised to form a processing space between targets. DESCRIPTION OF SYMBOLS 1... Vacuum container, 2... Target plate, 3... Target electrode, 4... Earth shield, 5... Substrate, 6... Substrate holder, 7... Partition plate 58... - Bulkhead, 10... Bulkhead.

Claims (1)

[Scope of Claims] 1. A target plate serving as a base material to be deposited, a target electrode that holds the target plate and serves as a cathode during film formation, and a substrate disposed opposite to the target plate; Sputtering comprising a substrate holder that holds a substrate, a partition plate arranged to divide a processing space sandwiched between the target plate and the substrate holder into two, and a vacuum container that houses these and maintains a vacuum state. A sputtering apparatus characterized in that the front partition plate becomes a part of a container or a partition that constitutes a closed area of the processing space divided into two. 2. According to claim 1, one or both of the target electrode and the substrate holder becomes part of a container or a partition constituting a closed region of a processing space by moving up and down. A sputtering device featuring: