JPH03266429A - Ion beam etching device - Google Patents

Abstract

PURPOSE:To prevent pollutants from adhering to work surface by a method wherein the work processed surface is arranged not to oppose to an ion gun while a magnetic field device bending ion beams to irradiate the work processed surface is provided. CONSTITUTION:The position of a work holder 22 is changed so that the normal direction D2 of the processed surface of a work 24 may be almost orthogonal to the direction D1 of ion beams 26 acceleratingly irradiated with an accelerating grid 16. Next, in order to irradiate the work processed surface 24a with the acceleratingly irradiated ion beams 26, a device to generate magnetic fields 20 in the perpendicular direction to the paper surface is provided, thereby enabling the ion beams 26 to be bent. At this time, pollutants 18, being neutral elements, are to be scattered around in the direction D1 without being influenced by the magnetic field 20. Through these procedures, the pollutants 18 can be prevented from adhering to the work processed surface 24a.

Description

[Detailed Description of the Invention] [Summary] Regarding an ion beam etching device, for the purpose of preventing contamination elements from adhering to the workpiece surface, the processing surface of the workpiece, which is the object to be irradiated, is The workpiece is arranged so as not to face the ion gun, and the workpiece is configured to include a magnetic field device that bends the ion beam irradiated from the ion gun so as to irradiate the processing surface of the workpiece.

[Industrial application field]

The present invention relates to an ion beam etching apparatus.

[Prior art] Ion beam etching equipment is used for dry processing of various device materials such as bubble memory devices, silicon ultrahigh-speed devices, GaAs ICs, multi-chip packages, MCT infrared detection elements, surface acoustic wave filters, thin film magnetic heads, and MR elements. It is used as an effective means of microfabrication.

BACKGROUND ART In recent years, electronic devices have become smaller, and their patterns have become finer down to submicron levels. With this miniaturization, it is desired to eliminate insulation defects between patterns and manufacture with high yield.

[Problem to be solved by the invention]

However, in conventional ion beam etching equipment, the grid for accelerating ions and other jig parts are affected by ion irradiation and emit neutron contamination elements, which are exposed to the surface of the workpiece being irradiated. This causes problems such as short circuits between patterns.

Therefore, the present invention aims to prevent contaminating elements from adhering to the work surface.

[Means to solve the problem]

In view of the above object, the present invention arranges the workpiece, which is an object to be irradiated, so that its processed surface does not face the ion gun with respect to the ion irradiation direction of the ion gun, and directs the ion beam irradiated from the ion gun to the ion gun. An ion beam etching apparatus is provided, characterized in that it is equipped with a magnetic field device that bends the ion beam to irradiate the surface of a workpiece.

[Function] If the machined surface of the workpiece is tilted so that its normal line does not face the ion irradiation direction of the ion gun, the contaminating elements accompanying the firing from the ion gun will scatter in the ion irradiation direction, so that the workpiece processing surface It will not stick to the surface. On the other hand, the ion beam can be bent in the direction of the work surface to be irradiated by the magnetic field device, and since the contaminating elements are not ionized, they are not affected by the bending action and travel straight, so they do not adhere to the work surface to be processed.

〔Example〕

The present invention will be described in more detail below based on embodiments shown in the accompanying drawings. FIG. 2 shows a conventional ion beam etching apparatus in which argon gas 1 is placed inside a screen grid 14.
2 is introduced and heated to a high temperature by the filament 1o, the argon gas 12 is supplied with energy from the filament 10 and is excited, loses electrons and becomes a positive ion.

The screen grid 14 is further surrounded by an acceleration grid 16 disposed on the outside thereof, and the screen grid 14 is given a positive potential, the acceleration grid 16 is given a negative potential, and argon gas is applied between the two grids. The ions are accelerated and fly in a straight line. The processing surface 24a of the work 24 is supported by the work holder 22 in a direction perpendicular to the center line D1 of the ion beam group so as to receive the ion beam 26 generally from the front.

However, in the above method, when the ion beam 26 passes through the acceleration grid 16, the grid material 18 is scraped off.
For example, molybdenum adheres to the processed surface 24a of the workpiece 24, causing problems such as poor insulation of the pattern on the processed surface 24a. The present invention provides an apparatus shown in FIG. 1 in order to prevent contaminating elements 18 such as grid material from adhering to the workpiece processing surface 24a.

The difference from the conventional case is that the position of the workpiece holder 22 is changed so that the normal direction D2 of the workpiece processing surface 24a of the workpiece 24 is approximately perpendicular to the direction D1 of the ion beam accelerated and irradiated by the acceleration grid 16. There is. In order to irradiate the processed surface 24a of the workpiece with the accelerated ion beam 26, a device is provided which generates a magnetic field 20 in a direction perpendicular to the plane of the paper as shown in the figure, thereby making it possible to bend the ion beam 26. In this case, since the contamination element 18 is a neutral element, it will not be affected by the magnetic field 20 and will fly away in the direction of Dl. Therefore, adhesion to the processed surface 24a can be avoided.

In the above case, the radius of curvature r (
The relationship between m)=PO41, acceleration voltage V (v), and magnetic flux density B (Wb/n()) is shown. Definitions of the following symbols are also shown.

m: Argon ion mass (kg) = 6.636xlO-" (kg) e: Argon ion charge (C) = 1.60207 The following two equations are derived from the force balance equation.

a+vz=eV - (a) By eliminating V from equations (a) and (b), the following relational expression is obtained.

Substituting the values of m and e into Equation 20 (c) yields the following equation.

Therefore, for example, if the radius r is 0.5 m and the acceleration voltage ■ is set to 800 ■, the magnetic flux density B is 5.15X10-
"Wb/rrf" is required, and if the acceleration voltage V is the same, and the radius r is 1.0 m, the magnetic flux density B may be half of the above value, that is, 2.57X10-"Wb/rrf.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to reduce as much as possible the adhesion of contaminant elements emitted from the ion gun to the workpiece surface.

[Brief explanation of drawings]

FIG. 1 is a diagram of an ion beam etching apparatus according to the present invention, and FIG. 2 is a diagram of a conventional ion beam etching apparatus. 10... filament, 12... argon gas, 1
4...Screen grid, 16...Acceleration grid, 18...Contamination element, 20
...Magnetic field, 24...Work, 24a.
...Processed surface, 26...Ion beam.

Claims (1)

[Claims] 1. With respect to the ion irradiation direction (D1) of the ion gun (10, 12, 14, 16),
), the workpiece is arranged so that the processed surface (24a) of the workpiece is not opposed to the ion gun, and a magnetic field device (20) is configured to bend the ion beam (26) irradiated from the ion gun so as to irradiate the processed surface (24a) of the workpiece. An ion beam etching device characterized by: