JPH02247380A - High frequency bias sputtering device and method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a high frequency bias sputtering apparatus and method for forming a thin layer on a substrate.

[Conventional technology]

Conventionally, in order to form a stable film in a bias sputtering device that shares a Tameshu Kai oscillator and applies a 1% oscillation oscillator to the target electrode and the Kiyoshi electromagnetic wave, For example, as disclosed in Japanese Patent Laid-Open No. 59-205477, a method has been adopted in which the phase of high-frequency power applied to the inner electrode is controlled to maintain a constant phase difference.

[Problem to be solved by the invention]

Kaminichi's conventional technology is a method that controls the phase difference of the high-frequency power applied to the inner electrode to be constant, and no consideration is given to maintaining the bias voltage of the substrate electrode at a predetermined level. However, there was a problem in that the thickness of the thin film formed on the substrate varied each time because the base of the sputter etch changed due to fluctuations in the bias voltage of the substrate electrode.

An object of the present invention is to provide a high-frequency modified bias sputtering apparatus and a method thereof that allow good rewriting of the thickness of the formed section.

〔assignment! Means to solve]

In order to achieve the above object, a bias potential detection and comparison means is provided which detects the bias voltage of the fi temporary electrode, compares it with that of the construction setting, and outputs a gL number corresponding to the detected bias voltage.

A phase g adjustment means for adjusting the phase of the high frequency power applied to the substrate electrode based on the output signal was provided to maintain the bias voltage of the substrate electrode at a predetermined value.

[Effect]

The bias voltage detection and comparison means detects the waveform of the high frequency power applied to the substrate electrode, and calculates the half width g of the two-wave shape.
L (hereinafter referred to as bias voltage). Next, this bias voltage is compared with a preset reference voltage, and a control voltage corresponding to the amount is output. (When the bias voltage is m feet negative, the control voltage becomes Or.) Phase! IIl! I! One means is to determine the phase! according to the control voltage from the bias voltage detection and comparison means. &i41 The phase of high-frequency power from a high-frequency source is changed in the adjusting means and applied to the two-substrate electrode.

As a result, the bias voltage of the substrate electrode is always maintained at a predetermined value, and a thin film having a predetermined thickness is formed on the substrate.

〔Example〕

Hereinafter, practical examples of the high frequency bias sputtering according to the present invention will be explained with reference to FIGS. 1 to 8.

First, FIG. 1 is a schematic diagram showing one embodiment of the high frequency bias sputtering apparatus of the present invention.

1 is a vacuum chamber, 2 & target electrode, 3 is a target,
4 is a substrate electrode, and 5 is a substrate. 6 is a shared high M1B,
It is a flea generator. Reference numeral 7.8 is a high frequency power source which receives the polarization of the shared high frequency excavator 60 and outputs predetermined high frequency power respectively. 9 is a high frequency phase control unit, and 10 is a bias voltage detection comparison unit.

In the above configuration, the vacuum 1111 is
(not shown) and gas introduction means (not shown).
After introducing a discharge sustaining gas (argon gas; Ar) to a predetermined pressure, a predetermined high frequency power is applied from the high frequency power source 7.8 to the target electrode 2 and the substrate electrode 4 to start the discharge. , the target 5 is sputtered to form the substrate 5.
Deposit a thin film on.

Here, the high-frequency power source 7.8 shares the ai6MliMm device 6, and the high-frequency power applied to the target electrode 2 and the substrate electrode 4 has a completely same frequency, so there is no power interference due to a deviation of one frequency. (A stable discharge can be obtained.

What is the high frequency power output from the high frequency power supply 8? The phase of the substrate electrode 4 can be changed arbitrarily by the aJ frequency phase control unit.
is applied to That is, the phase of the high frequency power F2020 applied to the substrate electrode 4 and the phase of the high frequency power W10 applied to the target electrode 2 can be adjusted arbitrarily.

The second factor is that 150W is applied to the target electrode 2, 2ElF'1 and the substrate electrode 4, and the internal pressure of the vacuum 1w1 is 0.7p.
a With K set, use the high frequency phase adjustment unit 9 to adjust the phase of the High 8 Osaka Electric Power F2 applied to the substrate electrode 4.
It! is applied to the target electrode 2. ! , are experimentally determined bias voltages of the target electrode 2 and substrate electrode 4 when shifted by 0° to 180° with respect to the phase of the frequency power W1.

Further, the film formation rate on the substrate 5 and the bias voltage of the substrate electrode 4 at this time have a relationship 6R as shown in diagram aK5. Increase the bias voltage to the negative side (then the sputter etching violets on the substrate will increase, so the apparent film formation rate will decrease).

Here, when private time bias sputtering is performed under the above discharge conditions with the high frequency phase control unit 9 not operating and the phase difference kept constant, the bias voltage CVnc) of the substrate electrode 4 is I! Changes as shown in Figure 4,
It gradually decreases over time.

In addition, the setting state of the substrate 5 to the substrate electrode 4, the vacuum chamber 1
Due to the surface condition of the inner wall, fluctuations in the vacuum base pressure, etc.
The bias voltage (Vnc) of the substrate electrode 4 varies within the range shown in the fifth column.

If the above conditions are different, the bias voltage CVn of the substrate electrode 4
Due to the variation in c), the film formation rate changes as shown in Figure 5, and the thickness of the thin film formed on the substrate 5 varies.

Therefore, in order to reduce the variation in the thickness of the film to be formed, it is essential to always maintain the bias voltage CVnc of the substrate electrode 4 constant. By constantly monitoring the bias voltage (CVnc) of 4ik4 during film formation and adjusting the phase of the high frequency modified power V20 applied to the substrate electrode 4 according to the calculation, a constant bias voltage (Vnc) of the substrate electrode 4 is maintained at all times. ).

Therefore, the bias potential detection/comparison unit 10 and the high frequency phase adjustment unit 9 according to the present invention shown in FIG. 1 will be specifically explained with reference to FIG. 6. That is, waveform detection $11
monitors the waveform of high frequency power #72 applied to the substrate electrode 4 as shown in Figure 7. Bias potential detection section 12
The bias voltage (Vnc) is reduced from the half-width value of the amplification signal having the above waveform. This bias potential has a ratio of 1
In the second section 15, it is compared with the reference voltage 4 outputted from the "C reference voltage generator 1B14," and a control voltage VC corresponding to the voltage difference is output.

This control voltage is input to the high frequency phase control unit 9, and as shown in FIG. The phase of the power supply F2) is shifted by Δψ.

As a result, the high frequency power W2 applied to the substrate mold &4 is out of phase with the high frequency power FIK applied to the target electrode 2. Here, the high school student F1 is the high school student F2
2, the bias voltage of the target electrode 2 hardly changes as shown in FIG. On the other hand, the bias potential of the substrate electrode 4 (CVnc) is set to a predetermined value in response to the phase shift.

With the above configuration and operation, a predetermined bias potential CVnc) is always generated on the substrate electrode 4, and it becomes possible to obtain the thickness of the film formed on the substrate 5 with a predetermined thickness with good reproducibility.

〔Effect of the invention〕

As explained above, according to the present invention, the bias voltage of the substrate electrode can be maintained at a predetermined value, so that the shape and speed of the film formed on the substrate are stabilized.

This has the effect that a film of a predetermined thickness can be obtained with good reproducibility.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing one embodiment of the present invention;
The figure shows the experimental relationship between the phase shift violet of high-frequency power applied to the substrate electric current to the target electrode and the VOC of the target electrode and the substrate electrode. Fig. 4 is a diagram showing the time change of the substrate electrode bias voltage according to the experiment, and Fig. 5 is a diagram showing the experimental relationship between the out-of-phase power of the local power and the relative rapid reaction. Figure 1012 shows the bias '1 pressure detection comparison unit shown in 1- in detail, Figure 7 shows the modification shown in Figure 6. The figure showing -911 of the waveform of the Shusaka electric power detected by the detection sister, and the λδ diagram are examples of the phase shift violet of the waveform of the input and output high frequency electric power of the high frequency phase control unit 4 shown in the sixth example. FIG. 1...^Empty tank 2...Target electrode 4...Substrate electrode 6...High frequency oscillator 7.
... High frequency power supply 8 ... High frequency power supply 9 ... High frequency phase control unit 10 ... Bias voltage detection ratio unit (Fig. 1) Repeating box H length i times (Fig.

Claims (1)

[Claims] 1. A high-frequency oscillator; a first high-frequency power source that applies high-frequency power to a target electrode using high-frequency waves oscillated by the high-frequency oscillator; a second high-frequency power supply applied to the substrate electrode; a bias voltage detection means for detecting the bias voltage of the substrate electrode and outputting a control voltage according to the detected bias voltage; A high frequency bias sputtering apparatus comprising: a phase control means for changing the phase of high frequency power applied from the second high frequency power supply to the substrate electrode based on a control voltage, and forming a thin film on a substrate. 2. The high frequency bias sputtering apparatus according to claim 1, wherein the bias voltage detection means is configured to output a control voltage according to the difference between the detected bias voltage and a preset reference voltage. . 3. Using the first and second high-frequency power supplies that share a high-frequency oscillator, high-frequency power is applied to the target electrode from the first high-frequency power supply, and the bias voltage of the substrate electrode is detected by the bias voltage detection means. A high frequency bias sputtering method characterized by forming a thin film on a substrate by changing the phase of high frequency power applied to the substrate electrode from a second high frequency power supply based on a control voltage corresponding to a bias voltage.