JPH0690516B2 - Mask pattern correction method - Google Patents

Description

The present invention relates to a method of correcting a mask pattern used in a photolithography technique.

[Prior Art] Conventionally, for forming a metal oxide film pattern, a metal oxide film is once deposited on the entire surface and then patterned by a normal photo-etching technique or a resist pattern is formed so as to be complementary to a desired pattern. A so-called lift-off method has been used, in which a metal oxide is formed, then a metal oxide is deposited on the entire surface, and the metal oxide on the resist is selectively removed by utilizing the difference in adhesive force when removing the resist.

[Problems to be Solved by the Invention] By the way, when a mask pattern used in a photo-etching technique is modified, a method of depositing a metal oxide film on the entire surface and photo-etching the metal oxide film is used. It has the drawback of being easily damaged. Further, the lift-off method has a drawback that the resist pattern is easily deformed during deposition of the metal oxide film. The method of selectively thermally decomposing a metal chelate on a mask substrate with a laser beam, which is described in JP-A-55-111132, also has drawbacks such as thermal strain and minute crushing of the substrate, and is conventionally effective. There was no way. An object of the present invention is to solve the above problems, and to provide a method suitable for repairing a mask blank defect.

[Means for Solving Problems] A method for correcting a mask pattern according to the present invention comprises a step of depositing a polymer film having the following repeating units on a substrate to be processed, and irradiating the film with an energy beam to selectively A step of causing the reaction to cause insolubilization, a step of developing to form a pattern of the insolubilized polymer film, and a step of oxidizing the insolubilized polymer film into a metal oxide in oxygen plasma. Is characterized by.

[Operation] A metal oxide film of Cr, Fe or the like has a low transmittance of ultraviolet rays and soft X-rays, and thus the transmission defect can be effectively corrected by this method.

[Examples] Hereinafter, the present invention will be described with reference to the illustrated examples.

In FIG. 1, it is assumed that the energy shielding line pattern 2 having the pinhole 8 is formed on the mask substrate 1. An organic polymer film 3 containing a metal such as Cr or Fe is deposited on the film of this pattern 2. For the metal-containing organic polymer film 3, for example, a polymer having the following repeating units is used.

An energy ray from an energy ray source 6, for example, an electron beam 4 of 5 to 50 kV is deflected on the polymer film 3 by a deflector 5 and irradiated on a desired portion 7 to selectively cause a reaction to insolubilize it. In this example, it is a negative organic polymer film.

This polymer film can be irradiated so that the desired portion 7 is kept at room temperature or at a low temperature that does not affect the substrate pattern even if it is heated.

Then, development processing is performed to form a metal-containing organic film pattern 9 as shown in FIG. Since the problem is not caused when the energy shield layer is thick, it is desirable to form the correction pattern larger than the pinhole 8.

Then, as shown in FIG. 3, the mask is processed in an ashing atmosphere, for example, in oxygen plasma to remove carbon in the metal-containing organic film to change it into a modified metal oxide film pattern 10.

[Effects of the Invention] As described above, the method of the present invention is naturally applicable to the formation of patterns in general, but particularly when it is used for mask pattern correction, it does not affect the substrate pattern even at room temperature or when it is heated. Since it is possible to form a pattern by chemically reacting a metal-containing organic polymer at a low temperature, it is difficult to cause defects in the repaired shape such as thermal distortion of the existing pattern and crushing of the substrate. This has the effect of being able to correct and improve the yield of mask making. In addition, since it can be modified into a metal compound having a strong adhesive force after confirming whether or not the defect repair pattern has a desired shape, re-repair can be easily performed, and the reliability of the repair is extremely high.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 and FIG.
The figure is a cross-sectional view of a mask substrate showing the steps. In the figure,
Reference numeral 1 is a mask substrate, 2 is an energy shielding layer, 3 is a metal-containing organic film layer, 4 is an energy ray, 5 is a deflector, 6 is an energy ray source, 7 is an energy ray selective irradiation portion, and 8 is a defect (pin). Hole), 9 is a metal-containing organic film pattern, and 10 is a modified metal oxide film pattern.

Claims (1)

[Claims] 1. A step of depositing a polymer film having the following repeating units on a substrate to be processed, a step of irradiating the film with an energy ray to selectively cause a reaction to insolubilize, and a process of developing to insolubilize the film. And a step of oxidizing the insolubilized polymer film into a metal oxide in an oxygen plasma.