JPS6142261B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to photolithography.
The present invention relates to a method for correcting pattern defects in masks used for such purposes.

FIG. 1 is an enlarged plan view showing a defective portion of an example of a mask, and FIG. 2 is a sectional view taken along the - line in FIG. In the figure, 1 is a glass substrate, 2 is a pattern formed in a desired shape with a metal thin film, etc. on the glass substrate 1, and 3 is a defect (missing metal thin film) that occurs in a part of the pattern 2. If such a defective portion 3 remains, it will impair its function as a mask, so a method has been adopted in which the defective portion 3 is compensated for and corrected using an opaque material.

FIG. 3 is a cross-sectional view showing how pattern defects on a mask are corrected by a conventional method. ] 5 is attached directly to the defective part 3. This resin 5
has appropriate adhesion strength to the substrate 1, and also has light scattering and emissive properties, so that it can maintain the same masking function as a defect-free metal thin film portion.

However, in the conventional repair method described above, the correction is performed manually, and the minimum area that can be corrected is limited by the cross-sectional area of the tip of the resin application tool 4, making it extremely difficult to correct minute pattern defects. Ta. Furthermore, masks repaired by such a method have the disadvantage that the resin in the repaired portions tends to be eluted or peeled off each time the mask is washed, requiring the above-mentioned repair work to be repeated.

This invention eliminates the conventional problem by locally generating a defect-filling material that will not be eluted by cleaning or peeled off from the substrate using methods such as ion beam irradiation and plasma etching. It is an object of the present invention to provide a method for correcting pattern defects of a minute area without defects.

FIGS. 4A to 4D are cross-sectional views showing the situation at each process step in an embodiment of the present invention, in which parts equivalent to those in the conventional example are designated by the same reference numerals, and their explanations will be omitted. Since the present invention uses plasma etching technology, first, as shown in FIG. 4A, a plasma etching-resistant layer 6 having resistance to plasma etching is formed on the surface of the pattern 2 having the defective portion 3. The method for forming the plasma etching resistant layer 6 is to include a substance whose oxide film is resistant to plasma etching, such as antimony Sb or tungsten W, in the material forming the pattern 2 when forming the pattern 2; It can be formed at the same time as pattern 2 by reverse etching using plasma, or it can be formed on the surface after pattern 2 is formed.
Form an oxide layer of Sb, W, etc. Next, the fourth
As shown in FIG. B, a covering layer 7 made of the same material as the material forming the pattern 2 is formed over the entire surface of the glass substrate 1 including the pattern 2. This coating layer 7 also contains a substance such as Sb.W that is resistant to plasma etching in its entire layer or its surface. Next, as shown in FIG. 4C, a narrowly focused oxygen ion beam is irradiated from above the coating layer 7 onto the part where the pattern defect 3 originally existed, as shown by the broken line arrow in the figure, to oxidize the area. A membrane layer 8 is formed. Then, if the entire surface of the coating layer 7 including the oxide film layer 8 is subjected to plasma etching,
Since the oxide film layer 8 and the plasma etching resistant layer 6 are resistant to plasma etching, a desired mask pattern with pattern defects 3 corrected can be obtained as shown in FIG. 4D.

In the above description, the mask used in photolithography has been described, but it goes without saying that the present invention can be used to correct defects in other general fine patterns.

As detailed above, in the present invention, the first plasma etching resistant layer is formed on the surface of the mask pattern, and the entire upper surface of the mask can be plasma etched from thereon, and the layer can be eluted or peeled off by cleaning the mask. A second plasma etching-resistant layer is formed on the surface of the covering layer at the defective part of the pattern of the mask, and then the remaining covering layer is removed by plasma etching. The second plasma etching-resistant layer can be formed mechanically with high precision using light, ion beams, etc., and is suitable for modifying fine patterns. Furthermore, the repaired areas are resistant to mask cleaning.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an enlarged pattern defect of an example of a mask, Fig. 2 is a cross-sectional view taken along the - line in Fig. 1, and Fig. 3 shows how the pattern defect of the mask is corrected by a conventional method. Cross-sectional views and FIGS. 4A to 4D are cross-sectional views showing the situation at each process step in an embodiment of the present invention. In the figure, 1 is a glass substrate, 2 is a pattern,
3 is a defective portion, 6 is a (first) plasma etching resistant layer, 7 is a covering layer, and 8 is an oxide film layer (second plasma etching resistant layer). Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A first step of forming a first plasma etching resistant layer having resistance to plasma etching on a pattern member having a missing mask defect; a second step of forming a coating layer made of a substance that can be plasma etched and does not dissolve or peel off from the mask when the mask is cleaned, on the surface of the mask including the missing defects in the pattern; A third step of forming a second plasma etching resistant layer on the surface of the covering layer at the missing defect site, and plasma etching is performed from the upper surface of the mask that has undergone the first to third steps to eliminate the missing defect in the pattern. A method for correcting pattern defects in a mask, comprising a fourth step of removing the covering layer in areas other than the portions. 2. A first plasma etching resistant layer is formed by using a substance that becomes resistant to plasma etching through oxidation on at least the surface portion of the pattern member, and oxidizing the surface after forming the pattern. A method for correcting pattern defects in a mask according to claim 1. 3. Using a material that becomes resistant to plasma etching when irradiated with a predetermined ion beam on at least the surface portion of the coating layer, 3. A method for correcting pattern defects in a mask as claimed in claim 1 or 2, characterized in that a plasma etching resistant layer (2) is formed. 4 Using the same material as the pattern member for the covering layer,
A second plasma etching-resistant layer is formed by using a material that becomes resistant to plasma etching through oxidation on at least the surface portion of the coating layer, and by irradiating with an oxygen ion beam narrowed to the required thickness. 3. A method of correcting pattern defects in a mask according to claim 2, characterized in that the method comprises forming a mask pattern defect.