JPS62122219A - Ion beam etching equipment - Google Patents

Abstract

PURPOSE:To prevent the burnout of a resist film, by arranging a shielding plate of radiation heat between a filament and a substrate holder. CONSTITUTION:A shielding plate of radiation heat 19 is arranged between a filament 6 and a grid plate 2. Consequently, the component flowing toward a wafer 5 out of the heat radiated from the filament is shielded by the shielding plate of radiation heat 19, and so does not reach the wafer 5. On the other hand, ions generated in a plasma-producing chamber 1 diffuse through the gap between the side wall of a plasma-producing chamber and the shielding plate of radiation heat, and reach the grid plate 2, so that the ion flow is not shielded. Thus the ion beam for etching can be effectively taken out without any influence of shielding the radiation heat. By the effect of shielding the radiation heat, the temperature of a wafer is controlled so as to be sufficiently low.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to an ion beam etching apparatus, and particularly to an ion beam etching apparatus.

This invention relates to the structure of an ion beam etching apparatus equipped with an ion source that generates plasma by hot cathode discharge using a filament.

[Background of the invention]

In recent years, as semiconductor processes have become drier, there has been an increasing need for etching IT that uses plasma, particularly ion beams. This ion beam etching device was published by American Magazine, G.I., G.I.

Sea Science Technology Bee 2 (1) Chanuary March 1984 (J, Vac, S
ci, Technol, B2(1).

As shown in Jan.-Mar, 19841, p. 34, seven-fold structures are known. This consists of a plasma generation chamber 1, a grid plate 2, and an etching chamber 3, as shown in FIG. A filament is provided in the center of the plasma generation chamber 1.

It is heated by the power source 16. Also, filament 6
A power supply 15 is inserted between the plasma generation chamber and the plasma generation chamber, and a gas such as 8F6 is introduced from the gas inlet 10.
Low-pressure arc discharge is caused between the filament and the wall of the plasma generation chamber at a pressure on the order of Q-3 Torr. As a result, plasma is generated within the plasma generation chamber 1.

Generally, a magnetic field generating means 1 is provided outside the plasma generation chamber 1.
1 is provided to generate high-density plasma. It consists of three porous plates: two grid plates, an acceleration electrode 7, a deceleration electrode 8, and a ground electrode 9. Acceleration chamber 8
! i, 7 are biased to a positive potential by the power source 12, and the deceleration electrode 8 is biased to a negative potential by the power source 13. The ion beam is extracted by this grating plate 2. The etching chamber 3 has a substrate holder 4 at its center that supports and cools the semiconductor wafer 5, and etches the semiconductor wafer 5 with an ion beam emerging from the grating plate 2. Incidentally, the semiconductor wafer 5Kd has already been coated with a resist film which will serve as a mask for etching into a desired pattern. In this method, the radiated heat from the filament passes through the holes in the grid plate 2 and reaches the surface of the wafer 5, so even if it is cooled by the basic holder 4, the temperature of the surface of the wafer becomes considerably high. As a result, the resist film is burned, making it difficult to etch into a desired pattern.

[Purpose of the invention]

An object of the present invention is to provide an ion beam etching apparatus that does not burn the resist film.

[Summary of the invention]

The present invention includes a means of providing a radiant heat shield plate between the filament and the substrate holder.

[Embodiments of the invention]

The present invention will be explained in detail below with reference to the embodiment shown in FIG. Plasma generation chamber 1. Lattice plate 2. The etching chamber 3 and the like are constructed similarly to the embodiment shown in FIG.

Here, a disk-shaped radiation heat shield 19 is disposed between the filament 6 and the grid plate 2. As a result, the component of heat radiated from the filament 6 toward the wafer 5 is
It is shielded by the radiation heat shield 19 and does not reach the wafer 5. on the other hand.

Ions generated in the plasma generation chamber 1 diffuse through the gap between the side wall of the plasma generation chamber and the radiation heat shield and reach the grid plate 2, so that the ion flow is not blocked and is used for etching. The ion beam can be effectively increased without being affected by the radiation heat shield. Due to the effect of the radiation heat shield, the if of the wafer 5 is suppressed to a sufficiently low value.

FIG. 2 shows a second embodiment of the present invention, in which the present invention is applied to an ion source in which a plurality of radially arranged permanent magnets 20 are used instead of all cocoils 11 to generate a cusp magnetic field in the plasma chamber. This is an example of application. Here, a permanent magnet 2 for generating a cusp magnetic field is also installed on the back side of the radiation heat shield 19.
This is an example where 1 is installed.

FIG. 3 shows a third embodiment of the present invention, in which the radiation heat shield 19 is made into a cup shape and a cooling bar 6 through which cooling water flows.
This is an example of setting Eve.

FIG. 4 shows a fourth embodiment, in which a radiation heat shield is provided in the form of a baffle.

FIG. 5 shows a fifth embodiment, in which the present invention is applied to a filament 23 for neutralizing the ion beam provided between the grid plate 2 and the wafer 5. That is, a radiant heat shield 25 is also provided between the filament 23 for neutralization and the wafer 5. In this case, the radiation heat from the neutralizing filament 23 is shielded.

At this time, the ion beam is also shielded by the radiation heat shield 25 along the neutralization filament, causing non-uniformity in the ion current density reaching the wafer 5, or the substrate holder 4f'i is usually rotated around its axis. Therefore, there is no problem with etching as a result.

[Effects of the Invention] According to the present invention, radiant heat to the wafer can be effectively prevented, the temperature of the wafer can be suppressed to a sufficiently low level, and the problem of resist burnout can be solved.

[Brief explanation of drawings]

FIG. 1 is a system diagram of one embodiment of the present invention, and FIGS.
The figure is a system diagram of another embodiment of the present invention, and FIG. 6 is a conventional system diagram. 1... Plasma generation room, 2... Grid plate, 3... Etching agent Patent attorney Katsuma Ogawa ・1-゛City 1st floor Z drawing high 3rd drawing 6th drawing

Claims (1)

[Claims] 1. An ion beam etching apparatus comprising a plasma generation chamber equipped with a filament, a plurality of porous lattice plates, and an etching chamber containing a substrate holder, wherein a radiation heat shield is provided between the filament and the lattice plate. An ion beam etching system characterized by: 2. An ion beam etching apparatus according to claim 1, characterized in that a radiation heat shield is provided between the filament and the substrate holder.