JPS5943992B2 - Ion processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ion etching, ion cleaning, and other ion processing apparatus using an electron cyclotron resonance type ion source.

Conventionally, this type of device generates a magnetic field in the ionization chamber by an excitation solenoid on the outer periphery, while introducing microwaves through a waveguide to generate cyclotron resonance of electrons in the chamber to generate plasma. Plasma ions are extracted by an extraction electrode in front of the plasma to generate an ion shower in the reaction chamber in front of the plasma, and wafers and other substrates in the chamber are irradiated with the ion shower to perform ion etching and other ion processing on the wafers and other substrates. Methods of this type are known, but such methods have the disadvantage that when the substrate is an insulator, the substrate is rapidly charged in a time unit of microseconds, thus making ion irradiation impossible. The purpose of the present invention is to obtain an apparatus free from such inconveniences, and while a magnetic field is generated in the ionization chamber by an excitation solenoid on the outer periphery, microwaves are introduced through a waveguide into the chamber. Cyclotron resonance of electrons is generated to generate plasma, and the ions of the plasma are extracted by an extraction electrode in front of the plasma to create an ion shower in the reaction chamber in front of it, which is then irradiated onto wafers and other substrates in the chamber. In a method in which ion etching, ion cleaning, or other ion processing is performed on the ionization chamber, a cup made of ceramic or other insulating material extending into the ionization chamber is provided on the negative potential electrode of the extraction electrode. Plasma with a negative potential is generated in the cup, electrons of the plasma are extracted by an electrode with a ground potential in the extraction electrode to generate an electron shower, and the above-described substrate is irradiated with this along with the ion shower. Become.

An example of implementing the present invention will be explained with reference to the attached drawings.

In the drawing, 1 indicates a cylindrical ionization chamber with a relatively large diameter.
While excitation is generated in the chamber 1 by an excitation solenoid 2 on the outer periphery, microwaves generated by a magnetron are introduced from the back side of the chamber 1 through a waveguide 3 having a relatively small diameter. Plasma was generated by causing electron cyclotron resonance. The ions of the plasma are extracted by the extraction electrode 4 in front of the plasma, and are drawn out into the reaction chamber 5 in front of the extraction electrode 4.
An ion shower is generated within the chamber 5, and the shower irradiates the wafer or other substrate 7 on the turntable 6 in the chamber 5, so that it is subjected to ion processing such as ion etching or ion cleaning. In the drawing, reference numeral 8 indicates an exhaust port connected to a vacuum pump, and reference numeral 9 indicates an air supply port that introduces a reaction gas into the chamber 1. Note that the extraction electrode 4 described above has a positive potential, for example, +
It is composed of a first electrode 4a with a voltage of 1 volt, a second electrode 4b with a negative potential in front of it, for example -V2 volts, and a third electrode 4c with a ground potential in front of it, and according to the first electrode 4a. The above-mentioned plasma in the chamber 1 is maintained at a positive potential close to +V/volt, for example, +V/volt, and the second electrode 4b mainly performs an extraction function, and the third electrode 4c It mainly performs a deceleration effect, and the above is not particularly different from conventional ones. According to the present invention, at least one cup 10 made of alumina or other ceramic is provided in the chamber 1 from the second electrode 4b to generate a negative potential plasma in the cup 10. Electrons from the plasma are extracted by the third electrode 4c to form an electron shower, and the above-described substrate 7 is irradiated with this electron shower together with the above-described ion shower.

To be more specific, a plurality of cups 10, for example, 12 cups as shown in the figure, are arranged on the electrode 4b as necessary, and each cup 10 produces the above-mentioned electron cyclotron resonance in the chamber 1. The electron cyclotron resonance generates a plasma within the cup 10, but this plasma has a negative potential close to the potential of the electrode 4b, that is, 12 volts, that is, 2' volts. The electrons of the plasma are drawn forward by the third electrode 4c in front of it to form an electronic shower. This is shown schematically in FIG. 3, where 1 represents an ion and e represents an electron. The electronic shower irradiates the substrate 7 with the ion shower described above, so that even if the substrate 7 is an insulator, there is no charge as in the case of only the ion shower, and the ion shower is incident on the substrate 7. Ion treatment is performed.

In this way, according to the present invention, a plasma with a positive potential is generated in the ionization chamber and an ion shower is extracted from it, and a plasma with a negative potential is generated in the cup and an electron shower is extracted from it, and both act on the substrate. Even if the substrate is an insulator, it can be subjected to ion treatment by the ion shower, and has the advantage of not having the above-mentioned disadvantages of the conventional method.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of one example of the device of the present invention, FIG. 2 is a cross-sectional view taken along the line 2, and FIG. 3 is a diagram illustrating its operation. 1... Ionization control, 2... Excitation solenoid, 3... Waveguide, 4... Extraction electrode, 4a, 4b, 4c... ...first, second and third electrodes, 5
...Reaction chamber, 7...Substrate,
10...Katsupu.

Claims (1)

[Claims] 1 A magnetic field is generated in the ionization chamber by an excitation solenoid on the outer periphery, while microwaves are introduced through a waveguide to generate cyclotron resonance of electrons in the chamber to generate plasma, and the ions of the plasma are A method in which an ion shower is produced in the reaction chamber in front of the extraction electrode by a front extraction electrode, and the ion shower is illuminated onto a wafer or other substrate in the chamber to perform ion etching, ion cleaning, or other ion processing. In this method, a cup made of ceramic or other insulating material extending into the ionization chamber is provided on the negative potential electrode of the extraction electrode, a plasma having a negative potential is generated in the cup, and the electrons of the plasma are extracted from the extraction electrode. An ion processing device comprising an ion processing device which generates an electronic shower by extracting it with an electrode at a ground potential, and irradiates the substrate with the electron shower together with the ion shower.