JPS59170267A - High frequency sputtering device - Google Patents

Abstract

PURPOSE:To provide a titled device which increases the number of sputters and improves the utilizing efficiency of a target by using a high frequency radiation for excitation of a specific frequency or above in making an electric field mode into a high mode and providing a concentrical strong electric field and high plasma density. CONSTITUTION:The inside of a vacuum vessel 1 is evacuated to a vacuum by an evacuating system 2 and is substd. with the gas from a gaseous Ar bomb 6. The radiation of >=915MHz from a microwave generator 8 is applied from an antenna 15 on the inside of the vacuum vessel to make the electric field mode on the surface of a target 18 into the concentrical strong electric field of approximately a TE01 mode. A voltage is applied from a DC power source 19 on the target 18 to increase plasma density, thus sputtering on a base plate 29. The number of sputters is thus increased and the utilizing efficiency over the entire surface of the target 18 is improved. The water molecules in the vessel 1 are excited to improve the efficiency of a hydraulic pump.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a high frequency sputtering apparatus, and in particular to the use of a high frequency (microwave) of 915 MI (z or more) as a rare gas excitation source during sputtering. It is characterized by:

(oY next technology) In conventional sputtering equipment, D
The main sources were C glow discharge and high frequency discharge in the 13.56 MHz band. However, these conventional methods generally have the drawback of slow sputtering speed.

In contrast, magnetron-type sputtering equipment, which has become increasingly popular in recent years, uses magnetic force to direct the plasma density without changing the operating frequency, achieving high-speed sputtering. However, since the sputter distribution on the Q-target is donut-shaped, there is often a problem of poor target utilization efficiency.

More recently, microwaves (2,45
An ion source using a radio frequency (GHz) has been developed, and it is now at the stage where it can be effectively used as an ion etching device using a reactive gas. However, this sputtering method in the microwave band has not yet been adopted.

(Purpose of the Invention) Therefore, the present invention uses microwaves for excitation of rare gas and adopts an electric field mode based on the TEo mode on the target surface, thereby achieving a high sputtering rate and high target utilization efficiency. It provides 41 sputtering devices. Hereinafter, embodiments will be explained in detail with reference to the drawings.

(Embodiment) Fig. 1 shows the configuration of an embodiment of the present invention, in which 1 is a vacuum tank, 2 is an exhaust system, for example, a baffle; 3; an oil diffusion popper 4; a rotary pump 5; It is configured. Reference numeral 6 denotes a cylinder of rare gas, for example Ar. After the inside of the vacuum chamber I is once brought to a high vacuum by the exhaust system 2, Ar is introduced into the vacuum chamber 1 through the balloon 7, and the required degree of vacuum is reached, for example 1.
Maintain it at around 0-3 to 10' Torr. 8 is a microphone O-wave generator, which includes an oscillator 9, a circulator 10.
Isolator 11, attenuator 12, power meter 1
3, a divider 14, etc., and a microwave radiation antenna 15 is provided in a part of the vacuum chamber 1.

Reference numeral 16 denotes a dummy antenna, which serves to absorb surplus energy 7 of the microwave energy radiated from the antenna 15 and release it to the outside. Alternatively, it becomes a human power monitor. Radiation antenna 15, dummy antenna 1
Step 6 is to prevent adhesion of sputtered materials. Instead, a ceramic cover 17 is provided. IElj target, 1
9 is a DC power supply, 20 is a substrate on which a thin film is formed, 2
Reference numeral 1 denotes an electric field moat regulator which is disposed between the Hegenot 18 and the substrate 20 and adjusts the electric field and power to the maximum value, and a magnetic force from an electromagnet 23 is applied to the electric field moat regulator to stabilize the plasma. 22 is glossy.

In the above configuration, for example, 91'5 MHz or 2.45 GHz is used as the microwave for excitation of rare particles, and the electric field mode is set to TEo, moat, TE11 mode, etc. on the target surface. Figure 2 shows the electromagnetic field distribution at this time, and it is possible to generate a concentric strong electric field on the target surface. In addition, 24 is an electric field, 2
5 indicates a magnetic field. This electric field increases the plasma density, and the bombardment of the ions causes target particles, j 18
is sputtered to form a thin film on the substrate 20.

FIG. 3 shows a comparison of sputtering speeds between method A of the present invention and conventional method B. According to this, it can be seen that the sputtering speed is significantly improved.

(Effects of the Invention) The present invention, which uses microwaves for excitation of rare gas, has the following effects.

Since the electric field mode on the target surface is approximately TEo1 mode, it is possible to generate a strong concentric electric field, which improves the plasma density and provides high-speed sputtering similar to that of conventional magnetron type sputtering equipment. be able to. At the same time, secondary electrons generated during one sputtering process can be removed with greater efficiency than the magnetron method, and a rise in temperature of the substrate can be eliminated. 1. The electric field intensity distribution formed on the target surface is not donut-shaped like in the magnetron method, but is concentric, so the entire surface of the target surface is sputtered almost evenly, which increases the target utilization efficiency. It gets much better. Furthermore, an advantage of the high excitation frequency is that water molecules present in the vacuum chamber can be excited, and therefore, the partial pressure thereof can be lowered. For example, in a conventional sputtering system that uses an oil diffusion pump in the exhaust system, the partial pressure of water molecules is 9 x 10-7 Torr.
r, whereas when using microwaves,
2.5X10'Torr, can be lowered with 'i'. This can be achieved using an oil diffusion pump to the same extent as an evacuation system using a cryopump in a conventional device.

Generally, when sputtering targets consisting of components with different vapor pressures, a compositional mismatch between the target and the film is a problem, but according to the present invention, the film formation rate can be precisely controlled without reducing the kinetic energy of the evaporated molecules. As a result, compositional deviations can be minimized and suppressed. Specifically, the composition deviation is 1% for each element compared to the target.
It can be done within.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing the electromagnetic field distribution (TF:, o. mode) on the target surface, and FIG. 3 is a diagram showing the sputtering method according to the invention method. FIG. 3 is a diagram showing a comparison of speed with that of a conventional example. 1...Vacuum chamber, 2...Exhaust system, 6...To Ganobon, 8......
・Microwave generator, 15-...Microwave radiation antenna, 16-...Dummy antenna,
]8...Target, 20...
...Substrate, 21...Electric field mode adjustment ua
%23...External electromagnet. Figure 1 Figure 3 Figure 2 Figure 3 Consumption power fWl

Claims (1)

[Claims] 915M in a vacuum chamber equipped with a gas loss system and gas introduction means.
It is equipped with a high frequency radiation source of l1z or higher and a mode adjuster that mechanically or electrically adjusts the electric field mode, and uses the high frequency to excite the rare gas and adjusts the electric field mode at the target surface to approximately TEo, A high frequency sputtering device characterized by a mote.