JPS62223756A - Ion beam processing apparatus - Google Patents

Abstract

PURPOSE:To increase the speed of processing of a large area and to enhance the accuracy of processing of a small area by placing a movable diaphragm having through holes of different diameters arranged in an ion beam path and by selecting one of the through holes according to the area of a film deposited. CONSTITUTION:Ion beams from an ion source 1 are condensed with condensers 2, deflected with an upper deflector 3 and passed through one of plural through holes of different diameters in a movable diaphragm 4. The ion beams are then passed through an astigmatic compensating lens 5 to form a perfectly round ion beam spot and the ion beams are image-formed on a sample 9 through object lenses 6. In case of a large area of processing, a through hole of a large diameter is selected to increase the diameter of ion beams, so high-speed processing is enabled. In case of as small area of processing, a through hole of a small diameter is selected to reduce the diameter of ion beams, so fine processing is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ion beam processing apparatus that performs fine processing of a sample surface while scanning and irradiating an ion beam. The type of processing includes, for example, the removal of unnecessary adhesion from photomasks and reticles (hereinafter simply referred to as masks) for semiconductor chip manufacturing.
Mask repair is performed when sputtering a black defect (hereinafter referred to as a black defect) by ion beam irradiation, or when an organic compound vapor is supplied to a batan defect (hereinafter referred to as a white defect) and the organic compound is baked in by ion beam irradiation. (hereinafter, this processing is simply referred to as film deposition).

[Summary of the invention]

The present invention uses a movable aperture in which a plurality of through holes or apertures having different diameters are arranged in the ion beam path in an ion beam processing apparatus that processes a sample surface by scanning and irradiating an ion beam. By doing so, the aperture diameter is increased in proportion to the processing area (for example, in the case of film deposition, this corresponds to the white defect area), and the ionic current can be controlled. When the processing area is large, a large-diameter aperture is used and the ion beam diameter is increased to enable processing by high-speed ion beam scanning.When the processing area is small, a small-diameter aperture is used to enable processing with a thin ion beam with high precision. I made it.

[Conventional technology]

Conventionally, the ion beam emitted from a liquid metal ion source (for example, gallium is used as the ion material) is narrowed down with a fixed aperture, focused into a spot with an objective lens, and irradiated with a rask scan using a scanning electrode to process the sample surface. For example, ion beam processing equipment that performs film deposition is known. When applying a mask film, an ion beam spot diameter of about 0.1 μφ is used. In this case, the diameter is 50 to 100μ
An aperture of approximately φ is used. The ion current is about 100 pA at an accelerating current of 20 keV, and the speed for membrane attachment is 5 μ x 5
It takes about 5 minutes for a processing area of μ.

[Problem that the invention seeks to solve]

However, the white defect area that requires repair varies in size depending on the cause of the defect. For example, when attaching a film of 50μ x 50μ square, with conventional equipment, the area increases by 1
It will take 500 minutes, which is 00 times longer. This has the problem of not only being impractical but also significantly lowering the operating rate of the ion beam processing apparatus.

[Means for Solving the Problems] The present invention aims to solve the problems of the prior art described above. They also focused on the fact that if the ion beam spot diameter is increased while keeping the ion beam current density constant, the energy applied to the sample surface per unit time will increase in proportion to the square of the spot diameter, and the rate of film deposition will increase accordingly. I found the following solution.

In other words, in ion beam processing equipment, a movable diaphragm with a plurality of through holes with different diameters arranged is interposed in the ion beam path, and a large diameter diaphragm is selected to correspond to an increase in the processing area, thereby increasing the ion beam current density. This makes it possible to increase the ion beam spot diameter while keeping it constant.

[Effect]

For example, a plurality of apertures with diameters of 50 μφ, 160 μφ, and 500 μφ are arranged. Then, the ion beam spot diameter increases in proportion to the aperture, and the ion beam spot area increases in proportion to the square of the aperture. i.e. l:10
:100 ratio. At this time, since the ion current density does not change, the ion current increases in proportion to the ion beam spot area, and the speed of membrane deposition can be increased accordingly.

〔Example〕

Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

1 is an ion source that emits an ion beam; 0, for example, a gallium liquid metal ion source is used. A condenser lens 2 condenses the ion beam emitted from the ion source 1. Reference numeral 3 denotes an upper deflection plate which largely refracts the ion beam that has passed through the condenser lens 2 by applying a voltage. This is to perform blanking of the ion beam as necessary. 4 is a movable aperture that can be moved in a direction perpendicular to the ion beam path. The movable aperture 4 is provided with a plurality of through-hole apertures having different diameters, for example 50 μφ, 160 μφ and 500 μφ. The movable aperture 4 is moved as necessary to insert a through hole having a desired diameter into the ion beam path. The ion beam passes through the selected through-hole, thereby narrowing down the ion beam amount and adjusting the ion beam spot diameter. For large machining areas, diameter 500μ
High-speed processing is performed by selecting an aperture of φ and increasing the ion beam diameter. However, in this case, fine processing is not possible due to the large beam diameter, and in the case of a small processing area, the diameter is 50μφ.
The aperture was selected to reduce the ion beam diameter and enable microfabrication.

Reference numeral 5 denotes an astigmatism correction lens, which corrects the astigmatism of the ion beam that has passed through the movable aperture 4 to obtain a perfectly circular ion beam spot. Reference numeral 6 denotes an objective lens for forming an image of a spot of the astigmatism-corrected ion beam on the surface of the sample 9. Reference numeral 7 denotes a scanning electrode consisting of X and 72 sets of electrodes. The defective portion of the sample mask is repaired by scanning the ion beam spot on the XY plane of the sample. Reference numeral 8 is a gas gun that irradiates the white defective portion of the mask with an organic compound gas such as pyrene. At the same time, the white defective portion is irradiated with an ion beam while scanning to carbonize or polymerize the pyrene and form a film. Although not shown, a secondary ion detector is arranged on the surface of the sample 9 to detect secondary ions emitted from the sample mask bomb and obtain a mask slam image from the planar distribution of the secondary ions. While looking at the image of the baton, we search for defective parts and process the film.

〔Effect of the invention〕

As described above, according to the present invention, a plurality of apertures having different diameters are movably interposed in the ion beam path, so that the ion beam spot diameter can be adjusted. As a result, when processing a large area, an ion beam with a large spot diameter can be used to perform high-speed processing.

Furthermore, in the case of small area processing, fine processing is possible using an ion beam with a small spot diameter.

[Brief explanation of drawings]

The drawing is an exploded perspective view of the ion beam processing device. l...Ion source 2... Condenser lens 3... Upper deflection plate 4...Movable aperture 5... Stigma correction lens 6...Objective lens 7...Scanning electrode 8...gas gun 9...sample that's all Applicant: Seiko Electronics Industries Co., Ltd. the law of nature\ There are 81 changes in the fan face. Ion beam fJO dust collector Procedural amendment (flag) June 11, 1986

Claims (1)

[Claims] means for irradiating an ion beam emitted from an ion source onto a sample surface while condensing it with an objective lens and scanning it with a scanning electrode;
In an ion beam local coating device that combines a gas gun that blows raw material gas onto the sample surface, a movable diaphragm with a plurality of through holes with different diameters is interposed in the ion beam path, and the coating area is adjusted according to the coating area. An ion beam processing device characterized by being able to change the hole diameter of a movable aperture.