JPH0233787B2 - SUPATSUTARINGUSOCHODENRYOKUKYOKYUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a sputtering device that simultaneously applies high frequency power to a plurality of electrodes.

A conventional sputtering apparatus of this type has the configuration shown in FIG. In Figure 1, V is a vacuum container,
T ₁ , T ₂ , T ₃ are one electrode, for example, a target,
S is the other electrode, for example, a substrate holder. Each target has separate power supply systems 1, 2, and 3.
are equipped. For example, the power supply system 1 installed in target T ₁ is a high frequency oscillation circuit.
It consists of a series connection circuit of OSC ₁ , power amplification circuit AM ₁ , and impedance matching circuit MB ₁ . This conventional device has the following drawbacks.

Each power supply system 1, 2, and 3 has a different oscillation frequency. For this reason, a rabbit-horn beat occurs inside the vacuum vessel V,
This beat causes (1) oscillations (slow or sudden) in the discharge plasma emission intensity;

(2) Vibrations occur in the impedance matching circuit and therefore in the input power.

(3) As a result, sputtering becomes unstable, resulting in irregularities in processing such as film formation (temporal and spatial irregularities).
will occur.

This causes problems such as

Moreover, when the electrodes T ₁ , T ₂ , . . . are placed close to each other, this beat is promoted, so they have to be separated, which makes it difficult to make the device compact.

In order to solve this problem, high-frequency oscillation circuits have been made common, but even in this case, the phase difference and the floating phase difference cannot be avoided, and the degree of improvement cannot be said to be sufficient. It was hot.

An object of the present invention is to provide an apparatus which can eliminate the above-mentioned beats, phase differences, and their floating, and which can be miniaturized. Furthermore, the present invention provides a method for correctly providing and maintaining desired conditions between electrodes in operations such as thin film formation, physical etching, or chemical etching such as reactive ion etching (RIE). The purpose is to provide a device that can. The apparatus of the present invention will be explained below with reference to Examples.

FIG. 2 shows an embodiment of the invention. In this embodiment, _the power supply system ₁ , ₂₀ ,
30 share the oscillation circuit OSC. and,
Power supply system 1 is the same as before, but power supply system 2
0 and 30 are equipped with phase correction circuits FS ₂ and FS ₃ and phase detection circuits FD ₂ and FD ₃ , respectively, and the power supply system 1
Phase detection circuits FD ₂ and FD ₃ detect the phase of each output based on the phase of the output of , and a phase control loop is provided that controls the phase correction circuits FS ₂ and FS ₃ using the detected output.

In general, the desired power of each power supply system and T ₁ , T ₂ ,
It is normal for there to be differences and changes over time in the load conditions of the _T3 sections, so even if the oscillation circuit OSC is shared, simply adjusting the amplifier circuit and impedance matching circuit will cause the power supply system 1, 20, 30 It is difficult to align the phases of the outputs, and the task is troublesome. However, when adopting the above-described configuration disclosed by the present invention, the phases of the powers applied to the electrodes T ₁ , T ₂ , and T ₃ must all be made to match, or more accurately and finely adjusted to a desired phase difference. and can maintain this.

FIG. 3 shows another embodiment of the invention. In this case, the high frequency power supply systems 1 and 20 are connected to the targets T ₁ and
At T ₂ , 300 is being fed to the substrate holder S.

The apparatus with the configuration shown in Fig. 2 is called a multi-source sputtering apparatus or a simultaneous sputtering apparatus, and is capable of forming an alloy film by controlling the composition ratio using a plurality of different target substances, or by forming a plurality of homogeneous target substances. The device with the configuration shown in Fig. 3 is also called a bias sputtering system, and is used to perform high-speed film formation. Used to measure film quality improvement, etc.

FIG. 4 is a diagram explaining the second invention of the present application. Phase correction circuits FS ₂ and FS ₃ in each of the above-mentioned embodiments
Various existing methods can be used, but in many of them, a phenomenon is observed in which when the phase is corrected, the gain changes accordingly. In the case of sputtering work, fluctuations in the gain of the power supply system have a large effect on the finished product, so it is necessary to keep the gain as constant as possible. The second invention solves this problem.

Figure 4 shows that in the power supply system 4, the phase correction circuit FS,
A gain control circuit GC is attached to a part of the power supply system of the first invention described above, which is composed of the amplifier circuit AM, the impedance matching circuit MB, and the phase detection circuit FD, and the output 41 is inputted through the gain control circuit GC. 42, and maintains the gain of this system constant. Various existing methods can be used as methods for giving back.

The power supply device of the present invention is as described above,
Desired phase conditions and power conditions can be set correctly between the electrodes of the sputtering device and maintained for a long period of time. Therefore, there are the following effects.

1 In the embodiment shown in FIG. 2, when different types of targets are used, the composition ratio of the alloy film deposited on the substrate can be accurately controlled. Furthermore, when the same type of target is used, the phase can be controlled so as to obtain the maximum film deposition rate with respect to the sum of the power applied to each electrode.

2 In the embodiment shown in FIG. 3, if film adhesion and etching proceed simultaneously on the substrate, in addition to the effects described in the previous section, fluctuations in the etching speed and film quality on the substrate can be extremely suppressed. .

3. Processing accuracy and uniformity of processing will be greatly improved both temporally and spatially, and it will be possible to adjust them at will.

Therefore, the apparatus of the present invention can be used, for example, in the manufacturing process of LSIs, and can greatly demonstrate its ability to improve the quality and yield. This invention can be said to be extremely useful industrially.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a power supply device for a conventional device. FIG. 2 is a similar diagram of an embodiment of the first invention of the present application. FIG. 3 is a similar diagram of another embodiment. FIG. 4 is a block diagram for explaining the second invention of the present application. 1, 20, 30, 300,...: power supply system,
OSC, OSC ₁ ,...: Oscillator. AM, AM ₁ ...: Power amplifier. MB, MB ₁ ...: Impedance matching circuit. FD, FD ₁ ,...: Phase detection circuit. FS, FS ₁ ,
...: Phase correction circuit. T ₁ , T ₂ , T ₃ : Electrodes (targets). S: Electrode (substrate holder) V: Vacuum container.
GC: Gain control circuit.

Claims (1)

[Claims] 1. A high-frequency oscillation circuit is shared between each of a plurality of electrodes provided in a single vacuum container, and high-frequency power is supplied via a power supply system consisting of a power amplifier circuit and an impedance matching circuit. In a sputtering device that generates a vacuum discharge by applying a voltage, at least one of the power supply systems is provided with a phase correction circuit, and a phase detection circuit is provided to compare the output frequency of this system with the output frequency of another system, and this phase A power supply device for a sputtering device, characterized in that it includes a phase control loop that controls the phase correction circuit using the output of the detection circuit. 2. A first electrode in which all of the plurality of electrodes are targets.
A power supply device for a sputtering device as described in 1. 3. The power supply device for a sputtering apparatus according to claim 1, wherein the plurality of electrodes include both a target and a substrate holder. 4 A common high-frequency oscillation circuit is applied to each of the plurality of electrodes provided in a single vacuum container, and high-frequency power is applied via a power supply system consisting of a power amplifier circuit and an impedance matching circuit to cause vacuum discharge. In a sputtering device, at least one of the power supply systems is provided with a phase correction circuit, and a phase detection circuit is provided to compare the output frequency of this system with the output frequency of another system, and the output of this phase detection circuit is used to detect the phase difference. A sputtering device characterized in that it includes a phase control loop that controls a phase correction circuit, and also includes a gain control feedback circuit that includes the phase correction circuit and keeps the gain of the power supply system constant. power supply equipment. 5. A fourth electrode in which all of the plurality of electrodes are targets.
A power supply device for a sputtering device as described in 1. 6. The power supply device for a sputtering apparatus according to claim 4, wherein the plurality of electrodes include both a target and a substrate holder.