JPS62299970A - Pattern correcting method - Google Patents

Abstract

PURPOSE:To obtain a defectless pattern having high accuracy by holding an excess metallic pattern locally heated to a high temp. by using a laser to bring the same into reaction with gaseous CO or gaseous CO2, thereby forming and evaporating a carbonyl compd. CONSTITUTION:The chromium and the gaseous CO4 react and the carbonyl compd. [Cr(CO)6] is formed and is evaporated away when the temp. of the metal chromium pattern 3 is increased locally up to about 250 deg.C by projecting a laser 5 (for example, Ar laser) to the excess metal chromium pattern if the pattern 2 consisting of the metal chromium formed on the glass substrate 1 and the excess metal chromium pattern 3 exist. The reaction to form the Cr(CO)6 at this time is extremely gentle and the excess chromium makes gradual reaction until said chromium is entirely removed. The residues of the chromium do not remain at all and since the removal of the defects is not by the conventional melting method, the splashing of the chromium does not arise.

Description

[Detailed Description of the Invention] 3. Part 1 of the Invention, K 1112 [Industrial Application Field 1] This invention number, L, ? I' 1114 jt! fl
! The present invention relates to a method for fabricating l1ul paths, particularly for repairing defects in wafers and photomasks.

[Background Art] In recent years, semiconductor integrated circuits have become increasingly highly integrated and highly accurate, and the photolithography process is an essential step in the production of semiconductor integrated circuits. Among these, photomask is one of the best.
Fine patterning and defect-free are required, but
Although the number of pattern defects has decreased as the process becomes drier and the number of defects due to foreign matter decreases, it is desired that this correction method is easy and that there is no defect, thereby forming a defect-free pattern.

Hereinafter, a conventional contact piece will be explained with reference to the drawings.

FIG. 3 shows a repair process for an isolated defect in a conventional photomask.

In FIG. 3(a), when the metallic chromium pattern 2 formed on the glass substrate 1 and the excess metallic chromium pattern 3 coexist, the laser 5 is irradiated to melt and evaporate the excess portion. However, if such a correction method is used, melted chromium residue 817 may remain, resulting in 1/I! (See Figure 3 (b) as the correction was not very accurate).

Further, FIG. 4 shows a correction process when redundant metal chromium patterns are adjacent to each other. In FIG. 4(a), when the surplus metal chromium pattern 3 is adjacent to the chromium pattern 2, the laser 5 is irradiated in the same way to melt and evaporate the surplus part, but the residue 7 remains. During melting, chromium 8 was scattered onto the pattern 2, and unevenness occurred on the pattern edges due to the thermal effect during melting. Furthermore, the melting caused by heat irradiation has a thermal effect on the nearby pattern 2, which has the disadvantage of weakening the adhesion strength between the glass substrate 1 and chromium.

[Problems to be Solved by the Invention] In the conventional defect repair method as shown in FIGS. 3 and 4, there is a problem in forming a defect-free pattern because of the influence of removing the surplus portion. was there.

Therefore, this invention was made in view of the drawbacks of the prior art.
This is an attempt to obtain a more accurate defect-free pattern.

Means for Solving Problem E 1 In the defect repair method of the present invention, the excessive metal pattern is locally heated to a high temperature by using a laser, and CO7
This method attempts to obtain a highly accurate defect-free pattern by reacting with 7 gas or G 02 gas to form 5L of carbonyl compound and evaporating it.

[Function] In this invention, the surplus metal pattern is not removed by melting (but is removed by evaporation as a carbonyl compound containing metal), so that the surplus part is not removed in the vicinity, and it is possible to perform high-precision defects. Corrections are possible.

[Embodiment 1 of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a pattern correction process according to an embodiment of the present invention.

In FIG. 1(a), when there is a pattern 2 made of metal chromium formed on a glass substrate 1 and an excess metal chromium pattern 3, after the surrounding atmosphere is evacuated, CO gas at about 100'C is used. Replace with In this state, the chromium pattern is not removed, but if the excess metal chromium pattern 3 is irradiated with a laser 5 (for example, an Ar laser) and the temperature is locally raised to about 250°C, the chromium and c
o gas reacts to form a carbonyl compound (Or (Co)
s ) is generated and removed by evaporation (in addition, Or
The evaporation temperature of (Go)6 is about 210°C). however,
The amount of laser irradiation at this time should be such that chromium is not melted (the melting temperature of chromium is 1000'C or higher), but the Cr (Go)G production reaction at this time is extremely slow, and there is no surplus. J Gradually reacting (first plan 1)
))) completely removed. As shown in FIG. 1(i), no residual chromium remains, and since defects are not removed by the conventional melting method, no chromium scatters.

FIG. 2 shows a pattern correction process according to another embodiment of the present invention.

If the pattern surplus part 3 is generated as in Figure 1 (see Figure 2 (a)), an organic resist pattern 6 is created on the pattern surplus part 3 (see Figure 2 (b)) and placed in plasma. The excess portion is removed by flowing wet air and irradiating the laser locally (see FIG. 2(C)). Normally, wet air alone cannot remove chromium, but by locally increasing the temperature with laser irradiation,
CO gas decomposed from organic resist in plasma, CO
2 gas reacts with the lower part 0m3, and the same <C
A carbonyl compound of r(Go)s is produced and removed by evaporation (see Figure 2(d)).

By continuously irradiating the laser, all of the excess chrome pattern can be evaporated and removed, completing the pattern defect correction (see FIG. 2(e)). The embodiment shown in FIG. 2 utilizes reverse dry etching of chromium, and although the etching speed is slow, highly accurate pattern correction can be obtained.

In both of the above embodiments, the case where the pattern surplus portion was isolated was described, but it was found that even when the pattern surplus portions were adjacent to each other, the pattern could be corrected in the same way and the chromium would not be scattered.

Further, in the above embodiment, an example of a first mask has been described, but it can also be used for semiconductor wafers, etc., and the same effect can be achieved.

Furthermore, I mentioned the case of modifying the chrome pattern,
Other metal thin films may be used as long as they can be removed by etching, and the same effect can be achieved.

Although laser light was used as a method of locally applying heat, other methods may be used and similar effects can be expected.

[Effects of the Invention] As described above, according to the present invention, since the chromium pattern is chemically converted into an evaporable substance and then removed by evaporation, the removed pattern does not remain behind compared to the conventional melting removal method. After the correction, the pattern edges are good, and the edges are not melted.
It becomes possible to repair pattern defects with high accuracy, such as eliminating the scattering of even a single layer.

In addition, since the amount of radiation can be reduced compared to the prior art melting method that uses C#I, it also has an economical advantage.

Further, in recent years, pattern repair methods using laser light have been widely used, and the present invention is also useful for repairing chromium defects using laser CvD. In other words, if the laser beam of the laser CVD repair method is used in this invention, the laser sub-method inspection function will enable more advanced ROM residual removal repair 11 (for example, 0.8 μ- or less) to i+J capability. . Naturally, it also has the function of repairing the missing part of the glue originally created by laser CVD, and more efficient use of laser CVD can be expected.

[Brief explanation of the drawing]

FIG. 1 illustrates steps illustrating a pattern modification method according to the present invention. FIG. 2 shows one step of a pattern correction method according to another embodiment of the present invention. FIG. 13 and FIG. 4 illustrate steps showing a pattern correction method according to the prior art.

Claims (4)

[Claims] (1) A method for modifying a pattern consisting of a thin film of metal or its oxide formed on a substrate, which involves locally generating heat in the portion of the pattern to be modified and causing it to react with atmospheric gas. A pattern correction method characterized in that the portion to be corrected is removed by evaporation. (2) the metal is chromium or chromium oxide,
Claims characterized in that the atmospheric gas contains carbon monoxide gas (CO gas) or carbon dioxide gas (CO_2 gas), and a carbonyl compound, which is an evaporative substance, is generated by a chemical reaction and removed. The pattern correction method described in item 1. (3) Claim 1 or 2, characterized in that the local heating is performed by a laser beam.
The pattern modification method described in section. (4) The CO gas or CO_2 gas is used with an organic resist placed in plasma and wet air flowing.
4. The pattern correction method according to claim 2, wherein the pattern correction method is performed by heating the resist.