JPH02310364A - Sputtering device - Google Patents

Abstract

PURPOSE:To perform good quality sputtering for the substance to be sputtered by varying the delay time until a shutter is opened after electric discharge in a target is started in accordance with the degree of contamination on the surface of the target. CONSTITUTION:The substance to be sputtered is placed on a holding base 5 and the inside of a vacuum vessel 1 is exhausted through an exhaust port 14. When a shutter driving control unit 11 receives the signal of the degree of vacuum capable of performing sputtering from a vacuum gauge 7, a signal for closing a shutter 3 is sent to a solenoid 6 for driving the shutter. Then when voltage is impressed to a target 2 and the holding base 5 from a DC voltage power source 8 and discharge is started, simultaneously a delay time control unit 10 is initialized. The unit 10 sent a signal for announcing the elapse of delay time in accordance with the degree of contamination on the surface of the target 2 to the unit 11. The shutter 3 is opened via the solenoid 6 for driving the shutter. Thereby sputtering is performed which is good quality and is stable in the sputtering velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus that is equipped with an automatic shutter opening/closing mechanism and whose main purpose is to sputter a substance using a sputtering method.

[Conventional technology]

Sputtering equipment that forms thin films using conventional sputtering methods is often equipped with a manual shutter, which is rarely equipped with an automatically driven shutter, but these are mainly used to adjust the amount of sputtering. It was just attached. An example of using an automatically driven shutter to eliminate the influence of instability factors at the start of discharge to the target is disclosed in Japanese Patent Laid-Open No. 62-26.
It is described in Publication No. 3961. In this invention, a shutter is automatically driven after a certain period of time has elapsed after the target is charged, and sputtering is performed between the target and the thin film forming substance. However, this invention relates to a device with multiple targets, and the number of targets is one, and in order to eliminate the influence of instability factors at the start of charging, there is a delay time after the target is charged until the shutter is automatically driven. The user selects the delay time by considering the degree of contamination of the target surface, and the device automatically sets the delay time using the elapsed time since the previous sputtering, which is correlated with the degree of contamination of the target surface. was not taken into account.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, no consideration is given to eliminating the influence of instability factors at the initial stage of discharge in a single target.

An object of the present invention is to provide a sputtering material that allows the user to set the delay time from the start of sputtering to the shutter drive to the optimal time to eliminate unstable factors, or that allows the device to automatically set the delay time. Our goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the sputtering apparatus is equipped with a shutter plate that is driven at a relatively high speed, a power source that charges the target, and a delay circuit that drives the shutter plate after a certain period of time has elapsed after the start of discharge.

Furthermore, the sputtering apparatus is equipped with a delay time setting timer and a delay circuit interlocked with the timer in order to manually set the delay time from the start of discharge until the shutter is driven.

Furthermore, in order to automatically set the delay time from the start of discharge until the shutter is activated, there is a long timer that measures the elapsed time after the previous sputtering, which is related to the degree of contamination of the target surface, and a delay that works with the timer. It is equipped with a circuit.

[Effect]

In the present invention, if a long time (configurable) has not elapsed since the previous sputtering, the discharge starts with the shutter closed, and after a short time (configurable), the shutter opens and sputtering starts on the material to be sputtered. Therefore, initial instability factors such as sample damage due to transient currents and high-energy sputtered particles generated when voltage is applied can be eliminated. Also, if a long time has passed since the last sputtering, pre-discharge is performed between the target and the shutter for a slightly longer time (configurable) than if no elapsed time has elapsed, then the shutter is opened and the sputtered material is discharged. Since sputtering is started, contamination of the material to be sputtered due to sputtering of target surface contaminants, which is a factor of initial instability that increases with time, can be prevented.

〔Example〕

FIG. 1 is a system diagram of a sputtering apparatus based on an embodiment of the present invention. In the vacuum chamber 1, a target 2 and a sputtering material holding table 5 are installed. This holding stand 5
A shutter 3 is installed between the target 2 and the target 2 and is opened and closed by a shutter drive solenoid 6 that can be opened and closed. The inside of the vacuum container 1 is evacuated through an exhaust port 4, and the degree of vacuum inside the container is measured with a vacuum gauge 7. The delay time control unit 10 is initialized at the same time when a voltage is applied to the DC voltage power supply 8 and discharge starts, and sends a signal to the shutter drive control unit 11 after a predetermined delay time has elapsed. The shutter drive control unit 11 outputs a signal to close the shutter when receiving a signal from the vacuum gauge 7 that the degree of vacuum for sputtering has been reached, and then receives a signal from the delay time control unit 10 notifying the elapse of the delay time. by giving a signal to open the shutter.

Good quality sputtering is performed on the material to be sputtered.

Furthermore, the shutter drive control unit 11 issues a signal to open the shutter even when it receives a signal from the vacuum gauge 7 that the degree of vacuum has worsened to the point where sputtering is not possible, thereby preventing damage if the operation is stopped before discharging. To allow sputtering material to be easily taken in and out from inside a vacuum container 1. An opening/closing signal sent from the shutter drive control unit 11 switches the output of the solenoid power supply 9, and the solenoid 6 is driven to open and close the shutter.

Next, the time sequence based on this embodiment will be explained using FIG. 2. When evacuation of the vacuum container is started and a vacuum level that allows sputtering is reached (Tl), the shutter is closed. Thereafter, when the degree of vacuum becomes stable (Tl), discharge starts. After the predetermined delay time (Ts-Tz) has elapsed (T8)
The shutter opens, sputtering of the material to be sputtered starts, and ends at the end of target discharge (T4). In order to take out the material to be sputtered, the inside of the vacuum chamber leaks.

The delay time can be any one of a constant fixed time, a user-set time, and an automatic device-set time. The third example of the delay time control unit 10 that notifies the elapse of the delay time is as follows.
Shown in Figures (a) to (Q).

When the delay time is always constant, the delay time control unit 10
' is constituted by a delay circuit 12 whose delay time is always constant. The delay circuit 12 is initialized in synchronization with the application of high voltage to the DC high voltage power supply 8, and sends a delay time elapsed signal to the shutter drive control unit 11 after a certain period of time has elapsed. When the delay time is set by the user, the delay time control unit 10' is comprised of a delay time input switch 13 and a delay circuit 12' whose delay time is variable. Delay circuit 1
2' is initialized in synchronization with the application of high voltage to the DC high voltage power supply 8, and sends a delay time elapsed signal to the shutter drive control unit 11 after the time input in advance with the delay time input switch has elapsed. When the device automatically sets the delay time, the delay time control unit 10' includes a long timer 14 and a delay circuit 12' whose delay time is variable.
Consisted of. In synchronization with the application of high voltage to the DC voltage power supply 8, the long timer 14 is reset, and at the same time as it starts counting, the delay time of the delay circuit 12'' is switched in accordance with the time that was being counted up to that point. In other words, if the time being counted is relatively short, the delay time is set to a very short time necessary to eliminate the effects of transient currents and voltage application; The delay time is set to a short period of time necessary to eliminate the effects of contamination on the target surface, which increases in time. After the set time has elapsed,
The delay circuit 12' sends a delay time elapsed signal to the shutter drive control unit 11.

FIG. 4 is a diagram showing another embodiment of the present invention, and since the shutter 3 does not become an obstacle when setting the material to be sputtered on the material holding table 5, the signal from the vacuum gauge 7 in FIG. In place of the shutter drive control unit 11 receiving the
This is an example using a shutter drive control unit 110 that issues a shutter opening/closing signal using a signal received from a DC voltage power source 8. The time sequence of this embodiment will be explained using FIG. 5. After the conditions for sputtering are established, when high voltage is applied to the DC voltage power supply 8 (tz), the target 2
At the same time as the discharge starts, a signal is sent to the shutter drive control unit 110 to close the shutter. When a predetermined delay time (ta-tz) has elapsed, the shutter drive control unit 110 is activated from the delay time control unit 10.
A signal is sent to the shutter to open the shutter (ta), and sputtering to the material to be sputtered starts, and ends at the end of target discharge (t4) (shutter (a drive)). Alternatively, it is also possible to close the shutter from the beginning (shaladder (b drive)). That is, after the start of target discharge (tz), a predetermined delay time (ta-tz)
When (ta) has elapsed, the shutter opens and sputtering of the material to be sputtered begins. At the end of target discharge (t4), a signal is sent from the DC voltage power source 8 to the shutter drive control unit 110, and the shutter is closed.

〔Effect of the invention〕

The present invention is constructed as described in one or more ways and provides the advantages described below.

By driving the shutter with a time delay in conjunction with the discharge switch, it is possible to perform sputtering with high quality and a stable sputtering speed.

Furthermore, if the one-hour delay drive is always performed at a constant time, the operation of the device becomes easier. Furthermore, when the sputtering apparatus automatically sets the time for time delay driving, the sputtering apparatus can be operated easily, the sputtering apparatus can be used in an optimal state, and the target can be used economically.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a sputtering apparatus according to the present invention, FIG. 2 is a diagram showing a time sequence of shutter driving according to the present invention, and FIGS. 3(a) to (c) are diagrams for explaining a delay circuit according to the present invention. The system diagram, FIGS. 4 and 5 are diagrams showing other embodiments of the present invention. 2...Target, 3...Shutter, 6...Shutter drive solenoid, 1o...Delay time control unit, 11...Shutter drive control unit.

Claims (1)

[Claims] 1. A holding table that holds a material to be sputtered in a vacuum container;
In a sputtering apparatus comprising a target and a target electrode arranged opposite to the holding table, and a shutter plate that can be automatically taken in and out between the holding table and the target, depending on the degree of contamination of the target surface, A sputtering device characterized in that the delay time from the start of discharge at a target until the shutter opens is variable. 2. The sputtering apparatus includes a long-time timer that recognizes the elapsed time since the previous sputtering, which is an indicator of the degree of contamination of the target surface, and a sputtering apparatus that automatically sets a delay time in accordance with the elapsed time.