JPH01107527A - Forming method for pattern - Google Patents

Abstract

PURPOSE:To form a fine rectangular pattern in which two-dimensional effect due to the diffraction of a light is eliminated by employing two different masks, and exposing the mask patterns of the masks by crossing them. CONSTITUTION:Negative type photosensitive resin is formed on a semiconductor substrate, and exposed with ultraviolet ray with photomasks 100, 200. Linear mask patterns (shielding parts) 101, 201 are exposed in a crossing state, and, in this case, the alignment of the mask patterns may be or may not be performed according to the step. When they are exposed with the masks 100, 200, photosensitive resin 300 is exposed. That is, the pattern of an unexposed part 400 not exposed with the mask patterns 101, 210 is formed on the resin 300. Since the crossing parts are of the mask regions of the linear portions with two different masks, two-dimensional effect is not generated by the diffraction of a light and, since the masks are individually exposed, the deterioration of the shape due to the two-dimensional effect is not generated, thereby obtaining a preferable rectangular pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pattern forming method, and more particularly to a pattern forming method during the manufacture of semiconductor integrated circuits.

2. Description of the Related Art As the density of semiconductor integrated circuits increases, it has become difficult to form fine patterns. Particularly in the light exposure method using ultraviolet rays, as shown in FIG. If we look at the output intensity profile B of the light 1 incident on the glass mask 2 having the light shielding part 4 using the mask dimensions as a parameter, we can see that as the dimension of the mask pattern 10 becomes smaller, the amount of light that surrounds the glass mask directly below becomes smaller. It can be seen that the strength increases. B3 is the light intensity when mu is large, B2 is the light intensity when mu is small, and B is the light intensity when mu is further reduced. This is due to a light diffraction phenomenon, and becomes noticeable when the dimension becomes 1 μm or less. The actual glass mask pattern 10 is mainly a rectangular pattern, as shown in FIG. 4a, for example. When this fine mask pattern is exposed to light and developed on the photosensitive resin on the semiconductor substrate 20, the remaining resin becomes a rounded photosensitive resin pattern 30 as shown in FIG. 4, and the area becomes smaller. this is·
This is due to a two-dimensional effect in which the light diffraction phenomenon explained in FIG. 3 is further emphasized at the corners of the mask.

Problems to be Solved by the Invention As described above, in the conventional method, the edges of a rectangular mask pattern are transferred as a rounded pattern due to the two-dimensional effect caused by light diffraction, and dimensional fluctuations are prevented. This causes a negative effect on the characteristics of the formed semiconductor device. The present invention aims to prevent such dimensional variations in pattern transfer.

Means for Solving the Problems The present invention is a method of exposing by using two different masks and crossing each other's mask patterns in order to eliminate the influence of the two-dimensional effect, and a rectangular pattern is also obtained. It's a good thing.

Effect: According to the method of the present invention, two different masks are used, and the intersection of the two masks is a straight line mask area, so light diffraction does not cause a two-dimensional effect, and each mask is Since they are exposed separately, shape deterioration due to two-dimensional effects does not occur, and a good rectangular pattern can be obtained.

EXAMPLE An example of the present invention will be described below. Although not shown in FIG. 1, it is assumed that a negative photosensitive resin is formed on a semiconductor substrate.

First, using photomasks 100 and 200 shown in FIG.
Each is exposed to ultraviolet light. 101.degree. 201 is a linear mask pattern (light-shielding portion), and 101.201 is exposed in a crossed state. In this case, the alignment of the mask patterns may or may not be performed through a process. mask 10
0.200, the photosensitive resin 300 is exposed as shown in FIG. 2a. That is, a pattern of unexposed portions 400 that are not exposed by mask patterns 101 and 201 is formed on photosensitive resin 300. Since this rectangular pattern 400 is an intersection of linear patterns, a conventional rectangular end region does not exist in each mask pattern.

Next, when a development process is performed, a rectangular photosensitive resin pattern 301 corresponding to the unexposed area 400 is transferred and formed on the semiconductor substrate 20 as shown in the figure. Note that the photosensitive resin is not limited to a negative type, and a positive type can be used as well.

Effects of the Invention According to the present invention, it is possible to form a fine rectangular pattern that eliminates the influence of two-dimensional effects due to light diffraction, and it is industrially useful as a method for obtaining a pattern faithful to a designed pattern. It is.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of a photomask pattern according to an embodiment of the present invention, Fig. 2 is a process plan view of a photosensitive resin pattern forming method using the pattern of Fig. 1, and Fig. 3 is a schematic plan view of a photomask pattern using the same mask. FIG. 4 is a schematic plan view of a photomask pattern and a photosensitive resin pattern in a conventional method. 20... Semiconductor substrate, 100.200...
... Photomask, 101, 201 ... Mask pattern, 301 ... Photosensitive resin pattern.

Claims (2)

[Claims] (1) A photosensitive resin is formed on a semiconductor substrate, and by exposing and developing the photosensitive resin using two different mask patterns, a single rectangular photosensitive resin pattern is left. A pattern forming method. (2) The pattern forming method according to claim 1, wherein two different patterns are exposed so as to partially intersect.