JP2001230197A - Method for removing edge film and method for electron beam lithography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for electron beam writing and for removing edge films, which enable easy and secure connection of a ground to a substrate by generating no waste, and to provide a method for removing edge films of charge-free resist films and conductive films when a patterned substate is subjected to electron beam lithography. SOLUTION: This invention is characterized by that the ground for electron beam lithography is connected to the resist-free edge of a substrate, and be that the removal width of an edge film is changed according to the steps and film kinds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of drawing an electron beam and a method of removing an end face film relating to a ground connection of a substrate such as a semiconductor wafer and a semiconductor mask.

[0002]

2. Description of the Related Art A semiconductor mask will be described as an example.

The mask is 150 mm square and 6.2 mm thick.
After a chromium film is sputtered on the quartz substrate, a resist is applied thereon, and the pattern is selectively drawn with an electron beam, followed by development and etching.

In electron beam drawing, in order to prevent the mask from being charged, the resist film is broken and a pin is pressed against the chrome surface to ground. Therefore, there is a problem that the broken resist becomes dust and adheres to the mask surface to cause defects.

In addition, since the end face of the mask is held by a robot or a jig in the mask making step, the resist on the end face peels off and adheres to the upper surface of the mask, resulting in a defect of the mask.

In order to solve this problem, an apparatus for removing the resist on the end face of the mask has been proposed by the present applicant on February 4, 2000.
It has been proposed in a patent filed in Japan. In this proposal, a resist is dissolved in a solvent, and the resist is removed by suction in a vacuum.

However, in a Levenson-type phase shift mask in which chromium is etched and patterned and then a resist is applied again to pattern quartz, the chromium on the end face has already been etched and removed. There is a problem that the second ground cannot be taken at the same position as the time of the second electron beam drawing.

In addition, in the Levenson-type phase shift mask in which a conductive film is applied on a resist film, if the end surface of the conductive film is removed, the ground is not connected, and there is a problem that it is impossible to prevent charging.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron beam drawing method capable of easily and surely connecting a ground to a substrate without generating dust.

It is another object of the present invention to provide an end face film removing method and an electron beam drawing method for easily and surely connecting the ground to a substrate on which electron beam drawing is performed a plurality of times.

It is still another object of the present invention to provide a method of removing a resist film and an end face film of a conductive film which does not become charged even when an electron beam is drawn on a substrate after patterning.

[0012]

According to the present invention, an electron beam is drawn by connecting the ground to the resist-removed end face.

Further, the invention is characterized in that the ground connection position for electron beam drawing is located on the inner side of the substrate than the previous ground connection position.

Further, the edge film removal width of the resist is wider than the previous edge film removal width.

Further, the width of removing the end face of the conductive film is smaller than the width of removing the end face of the resist.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings, taking a semiconductor mask as an example. FIG. 1 is a diagram showing a process for producing a normal mask of the present invention.

FIG. 1A shows a state in which a resist 3 having a thickness of 0.4 μm is spin-coated on a quartz plate 1 on which a chromium film 2 having a thickness of about 0.1 μm is formed by sputtering. is there.

FIG. 1 (B) shows, for example,
FIG. 6 is a view showing a state in which the end face resist 3a is removed by the end face film removing apparatus proposed in the patent application filed on April 4, 2009. The earth pin 5 of the electron beam lithography machine is pressed against the exposed end surface chrome 2a of the chrome 2 to ground.

Since the end face resist 3a has been removed,
There is no danger of dust being generated by mask transport or pressure contact of the ground pin, and the ground connection can be reliably performed because there is no resist.

FIG. 1C is a view showing a state in which development processing has been performed after electron beam drawing. 3b is a patterned resist.

FIG. 1D shows that after the chromium 2 is etched using the patterned resist 3b as a protective film,
FIG. 4 is a view showing a state where a resist 3 is peeled off. A normal mask is completed in this step.

FIG. 2 is a diagram showing a process of forming a Levenson-type phase shift mask. The same names as those in FIG. 1 are denoted by the same reference numerals.

FIG. 2A is a step performed after FIG. 1D and shows a state in which the resist 6 is spin-coated for the second time.

FIG. 2B is a diagram showing a state in which the end face resist 6a has been removed by the end face film removing apparatus proposed in the patent filed on February 4, 2000, for example, similarly to FIG. 1B. It is.

By making the removal width 9 of the second end face resist wider than the first removal width 8 of the end face resist, the end face chromium 2c is exposed to facilitate the ground connection at the time of the next electron beam drawing.

FIG. 2C is a view showing a state in which an antistatic conductive film 7 is applied on the resist 6 for the second time. Since the chromium pattern 2b is an isolated pattern not connected to the end face chrome 2c, it is necessary to apply an antistatic conductive film on the resist film 6. Conventionally, the ground of an electron beam drawing machine is connected to the conductive film to prevent charging. Therefore, generation of refuse is inevitable.

FIG. 2 (D) shows a state in which the conductive film 7a on the end face has been removed by the end face film removing apparatus proposed in the patent filed on February 4, 2000, for example, as in FIG. 1 (B). FIG.

By making the end face removal width 10 of the conductive film smaller than the end face removal width 9 of the resist, the conductive film 7 is connected to the exposed end face chromium 2c. Can be.

Since the end face chrome 2a at the position of the earth pin 5 in FIG. 1B has been etched away, the earth pin 5 is moved further inward and connected to the newly exposed end face chrome 2c, thereby removing dust. And there is no danger of occurrence of the occurrence, and the ground connection can be reliably performed to prevent charging of the mask.

FIG. 2E is a view showing a state where the conductive film is peeled off and developed after the second electron beam drawing. 6b is a patterned resist.

FIG. 2F is a view showing a state in which the quartz 6 is etched using the resist and chromium as protective films, and then the resist 6 is removed. In this step, a Levenson-type phase shift mask is completed.

In the above description, the case of a semiconductor mask has been described. However, the present invention is not limited to this, and the present invention can be realized in the same manner for other substrates such as semiconductor wafers by changing the etching material. can do.

[0033]

As described above, the present invention has the following effects.

The end face film is removed to prevent generation of dust, and at the same time, it is possible to easily and surely connect the ground for electron beam drawing, thereby creating a highly accurate pattern free from dust defects. it can.

[Brief description of the drawings]

FIG. 1 is a view showing a process for producing a normal mask of the present invention.

FIG. 2 is a diagram showing a step of producing a Levenson-type phase shift mask of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Quartz board, 2 ... Chromium film, 3, 6 ... Resist, 5 ... Earth pin, 7 ... Conducting film, 8 ... First edge resist removal width, 9 ... Second edge resist removal width, 10 ... Conductive film Edge removal width

Claims (4)

[Claims] 1. A method of connecting an earth to an electron beam drawing substrate, wherein the electron beam is drawn by connecting the ground to the resist-removed end face. 2. A method of connecting a ground to a substrate on which electron beam drawing is performed a plurality of times, wherein the ground connection position of the electron beam drawing is inside the substrate from the previous ground connection position. Electron beam drawing method. 3. A method for removing a resist on an end face of a substrate to which a plurality of resist coatings are applied, wherein the width of the end face film removed from the resist is wider than the previous end face removal width. 4. A method for removing an end face film of a substrate on which a conductive film is applied on a resist film, wherein the width of the end face of the conductive film is smaller than the width of the end face of the resist.