JPS6157625B2 - - 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 coating tool 4, making it extremely difficult to correct minute pattern defects. 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 creates a defect-filling material in a small area that is free from conventional defects by locally generating a defect-filling material by irradiation with a laser beam or the like, which will not be eluted by cleaning or peeled off from the substrate. The purpose is to provide a method for correcting pattern 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. In this embodiment, first, as shown in FIG. 4A, a metal layer 6 such as gold Au is formed on a pattern 2 made of a metal thin film such as chromium Cr. Next, as shown in FIG. 4B, the entire surface of the glass substrate 1, including the surface of the metal layer 6 on the pattern 2, is coated for 300 min by vacuum evaporation, plasma CVD, sputtering, etc.
The polycrystalline silicon layer 7 is formed at a relatively low temperature below ℃.
is applied to a thickness of approximately 0.1 to 1.0 μm. Next, as shown in FIG. 4C, a high-density laser beam with a diameter of 5 μm or less is applied from above the polycrystalline silicon layer 7 to the portion where the pattern defect 3 exists, as shown by the broken line arrow L in the figure. The irradiation is performed in a focused manner, thereby raising the temperature locally to a temperature higher than the eutectic point of gold and silicon, thereby forming a eutectic alloy portion 8 within the pattern defect portion 3. At this time, the glass substrate 1 and the eutectic alloy part 8
The adhesive strength with the above-mentioned laser beam increases as the temperature rises due to the laser beam irradiation. Then, by removing the unnecessary unalloyed polycrystalline silicon layer 7 other than the pattern defect portion 3, a desired mask pattern with pattern defects corrected can be obtained as shown in FIG. 4D. This polycrystalline silicon layer 7 may be removed by, for example, gas plasma, and since the removal rate of the eutectic alloy portion 8 is low, only the eutectic alloy portion 8 that compensates for the pattern defective portion 3 remains, leaving a fine structure. Pattern defects can be corrected.

In the above embodiment, the polycrystalline silicon layer 7 is used to fill the pattern defect 3, but the polycrystalline silicon layer 7 is eutectic with the material constituting the pattern of the mask or the material deposited thereon (A _u in the embodiment). Any material may be used as long as it can be deposited at a temperature below the point, is heated by irradiation with a high-density energy beam such as a laser beam, forms a eutectic alloy, and has a lower etching rate than before the alloy. Further, in the embodiment, a laser beam is used as the irradiation beam, but the beam is not limited to a laser beam as long as it can provide high-density energy. Further, although an example has been shown in which C _r is used for the mask pattern 2 and A _u is deposited thereon, the present invention is not limited to this in relation to the substance filling the pattern defect portion 3 as described above.

As detailed above, in the present invention, a eutectic alloy is formed on the light shielding member constituting the mask pattern, including the inside of the pattern missing defect, with the first substance constituting at least the surface portion of the light shielding member at a predetermined temperature. forming a coating layer made of a second substance that forms a defective portion of the pattern, and irradiating the coating layer at the defective portion of the pattern with a high-density energy beam; Since the eutectic alloy is generated by heating the relevant part and repairing pattern defects, the irradiation beam can be focused sufficiently narrowly, making it possible to repair defects in fine patterns.
The positioning of the irradiation can also be precisely performed by mechanical operation, and since the repaired areas are made of eutectic alloy, they have sufficient resistance 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 (transparent) substrate, 2 is a pattern, 3 is a defective part, and 6 is a metal (first substance)
7 is a polycrystalline silicon layer (covering layer), and 8 is a eutectic alloy portion. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A first substance forming at least a surface portion of the light shielding member, including the inside of the missing defect, on a light shielding member forming a mask pattern having a missing defect and formed on a transparent substrate. A first step of forming a coating layer made of a second substance that forms a eutectic alloy at a predetermined temperature below the predetermined temperature, irradiating the coating layer at the defective portion of the mask pattern with a high-density energy beam; A pattern of a mask comprising: a second step of raising the temperature of the region to the predetermined temperature or higher to generate the eutectic alloy; and a third step of removing the coating layer other than the eutectic alloyed region. How to fix defects. 2. A method for correcting pattern defects in a mask according to claim 1, characterized in that a laser beam focused to a high-density energy beam is used. 3 Claim 1 characterized in that gold is used as the first substance and polycrystalline silicon is used as the second substance.
The method for correcting pattern defects in a mask according to item 1 or 2.