Exposure mask, its manufacture method, pattern transfer method, pattern forming method, and SRAM manufacture method

1. A manufacture method for an exposure mask, comprising:

(a) forming a mask pattern having a shape that a base pattern is divided into at least two partial patterns disposed at a space narrower than a resolution limit, and acquiring a first relation between a width of the space separating the partial patterns and a size of a pattern on a substrate formed by transferring the mask pattern;

(b) determining the width of the space separating the partial patterns in accordance with the size of a pattern to be formed on the substrate and the first relation; and

(c) forming a mask pattern having at least two separated partial patterns on a mask in accordance with the width of the space determined at the step (b).

2. The manufacture method for an exposure mask according to claim 1 , wherein the mask pattern to be transferred has a shape elongated in one direction, and the mask pattern is divided in a width direction of the mask pattern in the step (a).

3. The manufacture method for an exposure mask according to claim 1 , wherein the mask pattern to be formed at the step (c) has a coupling portion coupling the separated two partial patterns with each other.

4. An exposure mask comprising:

a mask substrate; and

a mask pattern formed on the mask substrate,

wherein the mask pattern includes at least two partial patterns corresponding to a pattern to be transferred to a substrate and separated from each other at a space narrower than a resolution limit.

5. A pattern transfer method comprising:

(a) exposing a photosensitive film through an exposure mask having a mask pattern of a shape that a base pattern is divided in a first direction into at least two partial patterns disposed at a space narrower than a resolution limit; and

(b) and developing the exposed photosensitive film to form a first pattern to which the mask pattern is transferred,

wherein a size in the first direction of the first pattern is smaller than a size in the first direction of a second pattern formed by transferring the base pattern under a same exposure condition as a condition of the step (a).

6. The pattern transfer method according to claim 5 , wherein a total sum of sizes in the first direction of the partial patterns constituting the mask pattern is equal to a size in the first direction of the base pattern.

7. An exposure mask comprising:

a mask substrate; and

a mask pattern including therein an auxiliary pattern and formed on the mask substrate,

wherein a light transmission rate of an area inside the mask pattern and outside the auxiliary pattern is lower or higher than both a light transmission rate of an area inside the auxiliary pattern and a light transmission rate of an area outside the mask pattern, an outer shape of the mask pattern is a polygon having the number of apexes smaller than the number of apexes of the auxiliary pattern, and a size of the auxiliary pattern is smaller than a resolution limit.

8. The exposure mask according to claim 7 , wherein the number of apexes of the auxiliary pattern is at least six.

9. The exposure mask according to claim 7 , wherein the mask pattern has a shape elongated in a first direction and having an uniform width, the auxiliary pattern has also a shape elongated in the first direction, and the auxiliary pattern includes a narrow portion narrower than a width in a central area, at least at one end of the auxiliary pattern.

10. The exposure mask according to claim 9 , wherein the one edge of the auxiliary pattern in a longitudinal direction is constituted of one straight line from one end to the other end and the other edge is in a step-wise pattern.

11. A pattern transfer method comprising:

exposing a photosensitive film through a mask pattern including therein an auxiliary pattern, wherein a light transmission rate of an area inside the mask pattern and outside the auxiliary pattern is lower or higher than both a light transmission rate of an area inside the auxiliary pattern and a light transmission rate of an area outside the mask pattern, an outer shape of the mask pattern is a polygon having the number of apexes smaller than the number of apexes of the auxiliary pattern, and a size of the auxiliary pattern is smaller than a resolution limit; and

developing the exposed photosensitive film.

12. The pattern transfer method according to claim 11 , wherein the number of apexes of the auxiliary pattern is at least six.

13. The pattern transfer method according to claim 11 , wherein the mask pattern has a shape elongated in a first direction and having a uniform width, the auxiliary pattern has also a shape elongated in the first direction, and the auxiliary pattern includes a narrow portion narrower than a width in a central area, at least at one end of the auxiliary pattern.

14. The pattern transfer method according to claim 13 , wherein the one edge of the auxiliary pattern in a longitudinal direction is constituted of one straight line from one end to the other end and the other edge is in a step-wise pattern.

15. A pattern forming method comprising:

exposing a photosensitive film on a semiconductor wafer through a mask pattern having an opening whose width is not wider than a width of a design rule, an area inside the opening being a light shielding area; and

developing the exposed photosensitive film to form a pattern on the semiconductor wafer.

16. A manufacture method for an SRAM comprising:

exposing a photosensitive film on a semiconductor wafer through a mask pattern having an opening whose width is not wider than a width of a design rule, an area inside the opening being a light shielding area;

developing the exposed photosensitive film to form a pattern on the semiconductor wafer; and

by using the pattern as a mask, processing a surface layer of the semiconductor wafer.