KR19990079137A - How to fix defects in masks - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defect correction method of a mask for removing a defect pattern on a photo mask, wherein the photoresist film is formed to sufficiently cover the defect pattern and its side regions. The photoresist film in the remaining regions except for the side region of the defect pattern is removed to reveal the defect pattern, and the ion pattern is removed using the ion beam. By such a defect correction method of the mask, the damage pattern generated by the photoresist film can be minimized, thereby minimizing damage occurring on the lower surface of the substrate.

Description

A METHOD OF REPAIRING MASK DEFECT

The present invention relates to a method for correcting a defect of a mask, and more particularly, to a method for correcting a defect of a mask capable of minimizing damage to a lower substrate.

In mass production of semiconductor products, the importance of its original mask is increasing day by day. In order to satisfy the highly integrated and finer circuit line width during mask fabrication, a variety of process technologies are emerging, but the technology for repairing defects on the mask is completely dependent on the equipment technology. In the future, masking will be difficult if no new defect removal techniques are available.

Current defect elimination techniques include laser correction techniques using optics and correction techniques using focused ion beams (FIB). There is a limit to correct the defect of the circuit

FIB correction technology also has a difficulty in using the ions to correct defects as a problem of damaging the substrate by the ions. The mask structure is composed of a mask pattern which is a light blocking film and a substrate to be transmitted. In most cases, the defect remains as a mask pattern when a defect exists. At this time, the ion beam is removed using an ion beam, and the selectivity during ion etching is very low, thereby damaging the substrate at the same time as removing the mask pattern, which affects the light transmittance.

1A to 1B are flowcharts showing processes of a conventional mask defect correction method.

Referring to FIG. 1A, mask patterns 4 having a defect pattern 6 are formed on a substrate 2. The defect pattern 6 is etched by an ion beam. Referring to FIG. 1B, as a result of etching using an ion beam, a problem (reference numeral 7) occurs in the lower substrate of the edge surface of the defect pattern 6.

The present invention has been proposed to solve the above-mentioned problems, and an object of the present invention is to provide a defect correction method of a mask that can minimize damage occurring on the lower substrate of an edge surface of a defect pattern.

1A and 1B are flowcharts sequentially showing processes of a defect correction method of a conventional mask;

2a to 2d are flow charts sequentially showing processes of a method for correcting a defect of a mask according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

1, 10: substrate 4, 12: mask pattern

6, 14: defect pattern 15: photoresist film

(Configuration)

According to the present invention for achieving the above object, a mask defect correction method for removing a defect pattern on a photo mask having a substrate and mask patterns formed on the substrate, by forming a photo resist film on the mask patterns A first step for the resist film to sufficiently cover the defect pattern and the side region thereof; A second step of removing the photoresist film in a region other than the side region of the defect pattern to expose a surface of the defect pattern; And a third step of removing the defect pattern using an ion beam.

In a preferred embodiment of this method, the photoresist film is negative.

In a preferred embodiment of the method, the second step comprises the steps of: irradiating ultraviolet light on the back side of the substrate to use the mask patterns as a mask; Developing the exposed mask patterns.

(Action)

Referring to FIG. 2C, a defect correction method of a mask for removing a defect pattern on a novel photo mask according to an embodiment of the present invention is formed such that the photoresist film sufficiently covers the defect pattern and the side region thereof. The photoresist film in the remaining regions except for the side region of the defect pattern is removed to reveal the defect pattern, and the ion pattern is removed using the ion beam. By such a defect correction method of the mask, damage to the substrate under the edge surface of the defect pattern can be minimized by protecting the edge surface of the defect pattern by the photoresist film pattern.

(Example)

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 2A to 2D.

2A through 2D are flowcharts sequentially illustrating processes of a defect correction method of a mask according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, mask patterns 12 are formed on the substrate 10. The defect pattern 14 may be generated when the mask patterns 12 are formed. A negative photoresist film 15 is formed on the substrate 10 including the mask patterns 12 and the defect pattern 14. In order to use the mask patterns 12 as a mask, ultraviolet exposure is performed on the back surface of the substrate 10. In FIG. 2B, when developed after exposure, the negative photoresist film 15 is formed between the mask patterns 12 on the substrate 10 and the defect pattern 14.

Referring to FIG. 2C, the defect pattern 14 is etched by an ion beam. During the ion beam etching, the substrate 10 under the surface of the defect pattern 14 is protected by the photoresist layer 15. As shown in Fig. 2D, the photoresist film 15 is removed.

The present invention solves the problem of damage to the substrate under the defect pattern edge surface in the defect correction method of the conventional mask, by forming a photoresist film to protect the substrate of the defect pattern, it occurs in the lower edge substrate of the defect pattern There is an effect that can minimize the damage that is caused.

Claims (3)

In the mask defect correction method of removing the defect pattern 14 on the photo mask having the substrate 10 and the mask patterns 12 formed on the substrate 10, Forming a photoresist film (15) on the mask patterns (12) so that the photoresist film (15) fully covers the defect pattern (14) and its side regions; A second step of removing the photoresist film (15) in the remaining regions other than the side region of the defect pattern (14) to expose the surface of the defect pattern (14); And a third step of removing the defect pattern 14 by using an ion beam, wherein the surface of the substrate 10 on the side surface of the defect pattern 14 is prevented from being damaged by the ion beam. How to fix mask defects. The method of claim 1, And the photoresist film (15) is negative. The method of claim 2, The second step includes irradiating ultraviolet rays on the back surface of the substrate (10) to use the mask patterns (12) as a mask; Developing the exposed mask patterns (12).