JPS6310500A - Cyclotron plasma generator - 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] [Industrial Application Field] The present invention is a method for converting gas, liquid or solid into plasma, forming a film,
The present invention relates to a plasma generation device used for etching, sputtering, surface processing, surface modification, etc., and particularly relates to a cyclotron plasma generation device that uses both electron microtron resonance and ion cyclotron resonance.

[Prior Art] Conventionally, there are two types of cyclotron plasma generation devices: devices using ion cyclotron resonance and devices using electron cyclotron resonance. The former is published in Japanese Unexamined Patent Application Publication No. 1973-
It is also possible to selectively heat only certain ions in the plasma, as disclosed in Japanese Patent Application Laid-open No. 53-7199 and Japanese Patent Application Laid-open No. 53-96.
As disclosed in Kosei No. 938 and Japanese Unexamined Patent Publication No. 56-155535, the ionization efficiency is high and high-speed film formation is possible.

[Problems to be solved by the invention] However, in the device using electron cyclotron resonance, as with other plasma generation methods, the ion temperature is low;
It is difficult to select the ions involved in film formation, and it is also difficult to control, for example, the internal characteristics of the formed film. On the other hand, devices using ion cyclotron resonance have problems in that it is difficult to provide a large-area reaction field and the ionization efficiency is low.

The present invention was devised in view of these problems, and an object of the present invention is to provide a cyclotron plasma generation device that can be used at a high ion temperature and has improved ionization efficiency.

[Means for solving the problem] The means taken to achieve the above object will be explained with reference to FIG. 1, which corresponds to an embodiment of the present invention. This is a cyclotron plasma generation device that has a magnet 2 that forms a microwave, a microwave supply means 3 that simultaneously supplies microwaves into the plasma generation chamber 1, and a high frequency supply means 4 that supplies high frequency waves into the plasma generation chamber 1. This measure is being taken.

[Function] Electrons within the plasma generation chamber 1 are subjected to Lorentz force by the magnetic field of the magnet 2, and perform cyclotron motion.

When the cyclotron frequency of the electrons at this time matches the frequency of the microwave supplied into the plasma generation chamber 1 from the microwave supply means 3, electron cyclotron resonance occurs, thereby making it possible to efficiently generate plasma. . On the other hand, when a high frequency wave is supplied from the high frequency supply means 4 into the plasma generation chamber, specific ions or protons are caused to undergo ion cyclotron resonance depending on the frequency of the high frequency wave.

[Example 1] Figure 1 shows an example of the present invention, and numeral 1 in the figure is a plasma generation chamber. The inside of the plasma generation chamber 1 is a vacuum system, and a magnet 2 for preforming a magnetic field inside the plasma generation chamber 1 is provided outside thereof. The magnet 2 may be an electromagnet or a permanent magnet.

A microwave supply means 3 and an ion source supply pipe 5 are connected to the rear of the plasma generation chamber 1 . The microwave supply means 3 in this embodiment is a waveguide and supplies microwaves into the plasma generation chamber 1 through a window 6 made of a material such as quartz that allows microwaves to pass through. . Further, the ion source supplied from the ion source supply pipe 5 into the plasma generation chamber 1 varies depending on the purpose of the cyclotron plasma generation apparatus, but for example, nitrogen, oxygen, argon, etc. are used. The supplied ion source is turned into plasma in the plasma generation chamber 1, and after being used for the intended purpose, an exhaust system (not shown) is used together with the reaction product gas etc. Exhausted from within the vacuum system.

The high frequency supply means 4 in this embodiment is a pair of high frequency electrodes provided within the plasma generation chamber 1.

Here, the frequency of the microwave supplied from the microwave supply means 3 is ν, the magnetic flux density of the magnetic field formed in the plasma generation chamber 1 by the magnet 2 is B, and the frequency of the ion source supplied from the ion source supply means 5 is If the electron charge is e and the electron mass is m, then from the Lorentz equation, ν=e −B / 2πm. Therefore, the commonly used frequency is 2,45
When using GHz microwave, the magnetic flux density of the magnetic field is 87
It turns out that 5 Gauss is preferable for generating good electron cyclotron resonance. Also, to get good ion cyclotron resonance with this magnetic field, if you make protons resonate.

When a high frequency of 1.3 MHz is supplied and carbon ions resonate, the high frequency is 0.11 MHz.
Preferably, two frequencies are provided.

FIG. 2 shows another embodiment of the present invention, in which a high frequency coil is wound around the outside of the plasma generation chamber 1 as the high frequency supply means 4. In FIG. The rest of the structure in this embodiment is the same as that explained in FIG. 1, and the same reference numerals as in FIG. 1 represent the same members in the figure.

This has the advantage that high frequency waves can be easily supplied to the entire interior of the plasma generation chamber 1.

FIG. 3 also shows another embodiment of the present invention, in which a waveguide serving as a microwave supply means 3 and a high frequency supply means 4 is provided at the rear of the plasma generation chamber 1 to supply microwaves and high frequencies in a superimposed manner. The other structures in this embodiment are the same as those described in FIG. 1, and the same reference numerals in FIG. 1 represent the same members.

In this way, the microwave supply means 3 and the high frequency supply means 4 can be provided by one member, and the structure can be simplified.

In the above embodiments, a waveguide is used as the microwave supply means 3, but a coaxial cable or a combination of these with a horn antenna, slot antenna, or spiral antenna may also be used. can.

[Effects of the Invention] As explained above, the present invention provides a cyclotron plasma generator capable of increasing ion temperature and increasing ion efficiency by combining electron cyclotron resonance and ion cyclotron resonance. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams of other embodiments of the present invention. 1: Plasma generation chamber, 2: Magnet, 3: Microwave supply means, 4: High frequency supply means, 5: Ion source supply tube. 6: Window section.

Claims (1)

[Claims] 1) A cyclotron plasma generation device having a magnet that forms a magnetic field within a plasma generation chamber, a microwave supply means that supplies microwaves into the plasma generation chamber, and a high frequency supply means that supplies high frequency waves within the plasma generation chamber.