Pattern formation method and manufacturing method of semiconductor device

1 . A pattern formation method, comprising:

causing light generated by a light source of a lithography apparatus to pass through an aperture plate and to impinge on a photomask to generate exposure light, wherein the photomask includes a plurality of octagonal shape patterns periodically arranged with a first pitch Px in a first direction and with a second pitch Py in a second direction crossing the first direction;

causing a mechanism of the aperture plate to adjust a light transmissive area of the aperture plate, wherein the aperture plate comprises a hexapole illumination system including a first pole, a second pole, a third pole, a fourth pole, a fifth pole and a sixth pole arranged in order along a circle, a distance between a center of the second pole and a center of the sixth pole is Dx, a distance between the center of the second pole and a center of the third pole is Dy, and in response to Px<Py, the light transmissive area of the aperture plate is adjusted such that Dx>Dy;

applying the exposure light to a photo resist layer formed over a substrate; and

developing the photo resist layer, wherein:

each of the plurality of octagonal shape patterns has a width Lw along the first direction, and

a width Lx of horizontal sides extending in the first direction of each of the plurality of octagonal shape patterns is smaller than the width Lw, and is different from a width Ly of vertical sides extending in the second direction of each of the plurality octagonal shape patterns.

2 . The pattern formation method of claim 1 , wherein:

the plurality of octagonal shape patterns are arranged in a staggered manner, and includes:

even number rows in which some of the plurality of octagonal shape patterns are periodically arranged with the first pitch Px along the first direction, and

odd number rows in which some of the plurality of octagonal shape patterns are periodically arranged with the first pitch Px along the first direction,

the even number rows are periodically arranged with the pitch Py along the second direction,

the odd number rows are periodically arranged with the pitch Py along the second direction,

the even number rows and the odd number rows are periodically arranged with a pitch Py/2 along the second direction, and

the odd number rows are shifted along the first direction by Px/2 with respect to the even number rows.

3 . The pattern formation method of claim 2 , wherein Px<Py and Lx>Ly.

4 . The pattern formation method of claim 3 , wherein 0.5≤Px/Py≤0.7 and 1.05≤Lx/Ly≤1.15.

5 . The pattern formation method of claim 2 , wherein Px<Py and Lx<Ly.

6 . The pattern formation method of claim 5 , wherein 0.5≤Px/Py≤0.7 and 0.85≤Lx/Ly≤0.95.

7 . The pattern formation method of claim 2 , wherein the lithography apparatus comprises a hexapole illumination system.

8 . A pattern formation method, comprising:

loading a photomask into a lithography apparatus, wherein the photomask includes a plurality of octagonal shape patterns periodically arranged with a first pitch Px in a first direction and with a second pitch Py in a second direction crossing the first direction;

applying an exposure light to a photo resist layer formed over a substrate through or via the photomask, wherein the lithography apparatus comprises an off-axis illumination system comprising an aperture plate having a mechanism that adjusts a light transmissive area of the aperture plate, the aperture plate comprises a hexapole illumination system including a first pole, a second pole, a third pole, a fourth pole, a fifth pole and a sixth pole arranged in order along a circle, a distance between a center of the second pole and a center of the sixth pole is Dx, a distance between the center of the second pole and a center of the third pole is Dy, and in response to Px<Py, the light transmissive area of the aperture plate is adjusted such that Dx>Dy; and

developing the photo resist layer, wherein:

each of the plurality of octagonal shape patterns has a width Lw along the first direction, and

a width Lx of horizontal sides extending in the first direction of each of the plurality of octagonal shape patterns is smaller than the width Lw, and is different from a width Ly of vertical sides extending in the second direction of each of the plurality of octagonal shape patterns.

9 . The pattern formation method of claim 8 , wherein:

the plurality of octagonal shape patterns includes:

even number rows in which some of the plurality of octagonal shape patterns are periodically arranged with the first pitch Px along the first direction, and

odd number rows in which some of the plurality of octagonal shape patterns are periodically arranged with the first pitch Px along the first direction,

the even number rows are periodically arranged with the pitch Py along the second direction,

the odd number rows are periodically arranged with the pitch Py along the second direction,

the even number rows and the odd number rows are periodically arranged with a pitch Py/2 along the second direction, and

the odd number rows are shifted along the first direction by Px/2 with respect to the even number rows.

10 . The pattern formation method of claim 9 , wherein:

the first pole and the fourth pole are arranged along the second direction, and

the second pole and the sixth pole, and the third pole and the fifth pole are symmetrically arranged with respect to a line connecting the first pole and the fourth pole.

11 . The pattern formation method of claim 10 , wherein Px<Py, Lx>Ly and Dx>Dy.

12 . The pattern formation method of claim 11 , wherein 0.5≤Px/Py≤0.7, 1.05≤Lx/Ly≤1.15 and 1.5≤Dx/Dy≤1.7.

13 . The pattern formation method of claim 10 , wherein Px>Py, Lx<Ly and Dx<Dy.

14 . The pattern formation method of claim 10 , wherein a light intensity of the first pole and the fourth pole is greater than a light intensity of the second pole, the third pole, the fifth pole and the sixth pole.

15 . A pattern formation method, comprising:

providing a pattern layout including a plurality of octagonal shape patterns periodically arranged in a staggered matrix, wherein in the staggered matrix, a plurality of pattern rows in which some of the plurality of octagonal shape patterns are periodically arranged with a first pitch Px along a first direction and the plurality of pattern rows are periodically arranged with a half of a second pitch Py in a second direction crossing the first direction;

manufacturing a photomask using mask data comprising the plurality of octagonal shape patterns;

exposing, by using a lithography apparatus comprising an aperture plate having a mechanism that adjusts a light transmissive area of the aperture plate, a photo resist layer formed over a substrate with an exposure light through or via the photomask, wherein the aperture plate comprises a hexapole illumination system including a first pole, a second pole, a third pole, a fourth pole, a fifth pole and a sixth pole arranged in order along a circle, a distance between a center of the second pole and a center of the sixth pole is Dx, a distance between the center of the second pole and a center of the third pole is Dy, and in response to Px<Py, the light transmissive area of the aperture plate is adjusted such that Dx>Dy; and

developing the photo resist layer, wherein:

Px is different from Py,

each of the plurality of octagonal shape patterns has at least four sides, and a width Lw along the first direction, and

a width Lx of horizontal sides extending in the first direction of each of the plurality of octagonal shape patterns is smaller than the width Lw, and is different from a width Ly of vertical sides extending in the second direction of each of the plurality of octagonal shape patterns, and the width Lx and the width Ly satisfy Lx>Ly when Px<Py, and Lx<Ly when Px<Py.

16 . The pattern formation method of claim 15 , wherein Px<Py, Lx>Ly and Dx>Dy.

17 . The pattern formation method of claim 16 , wherein 0.5≤Px/Py≤0.7, 1.05≤Lx/Ly≤1.15, and 1.5≤Dx/Dy≤1.7.

18 . The pattern formation method of claim 15 , wherein

a light intensity of at least one of the first to sixth poles is different from a light intensity of another of the first to sixth poles.

19 . The pattern formation method of claim 14 , wherein the plurality of octagonal shape patterns are for a plurality of storage node patterns of a dynamic random access memory.

20 . The pattern formation method of claim 15 , wherein a light intensity of the first pole and the fourth pole is greater than a light intensity of the second pole, the third pole, the fifth pole, and the sixth pole.