Photolithography method and system based on high step slope
A photolithography system based on a high step slope may include a depositing unit configured to manufacture a sacrificial layer having high step slope on a substrate. The system may also include a coating unit configured to coat a photoresist layer on the sacrificial layer by performing a spin-on PR coating process to form a photolithographic layer. The system may further include a photolithography unit configured to perform one or more photolithography processes to the photolithographic layer. The photolithography unit may comprise a plurality of masks of compensation patterns. The compensation pattern may comprise a slope-top compensation pattern and a slope compensation pattern.
1. A photolithography system based on a high step slope, comprising:
a depositing unit configured to manufacture a sacrificial layer having high step slope on a substrate;
a coating unit configured to coat a photoresist layer on the sacrificial layer by performing a spin-on PR coating process to form a photolithographic layer; and
a photolithography unit configured to perform one or more photolithography processes to the photolithographic layer, wherein the photolithography unit comprises a plurality of masks of compensation patterns, each mask of the plurality of masks comprises a mask pattern and a compensation pattern, the mask pattern is rectangular across a top of the slope, the slope, and a bottom of the slope, the compensation pattern comprises a slope-top compensation pattern and a slope compensation pattern, the slope-top compensation pattern is rectangular corresponding to the top of the slope, having a length equal to a width of the top of the slope and a width greater than a width of the mask pattern, the slope compensation pattern comprises a plurality of triangles corresponding to the slope adjacent to the mask pattern and the slope-top compensation pattern.
2. The system according to claim 1 , wherein the slope-top compensation pattern and the mask pattern are axisym metric patterns, and the slope-top compensation pattern and the mask pattern share the same symmetry axis extending along a direction of a slope gradient.
3. The system according to claim 2 , wherein the slope compensation pattern comprises four right triangles.
4. The system according to claim 1 , wherein the slope compensation pattern comprises four right triangles located on an upper part and a lower part of the slope-top compensation pattern.
5. The system according to claim 4 , wherein a ratio of a width of the slope-top compensation pattern to a width of the mask pattern is within a range from 1.2:1 to 1:1.
6. The system according to claim 4 , wherein a ratio of a width of the slope-top compensation pattern to a width of the mask pattern is 1.1:1.
7. The system according to claim 1 , wherein a height of the high step slope is greater than 2 μm and an angle of the high step slope is within a range from 40° to 60°.
8. The system according to claim 1 , wherein the sacrificial layer is made of tetraethyl orthosilicate (TEOS) or phosphosilicate glass (PSG).
9. The system according to claim 8 , wherein a thickness of the sacrificial layer is greater than 5 μm.
10. A mask used in a photolithography system based on a high step slope, comprising:
a mask pattern; and
a compensation pattern;
wherein the mask pattern is rectangular across a top of the slope, the slope, and a bottom of the slope; and
wherein the compensation pattern comprises a slope-top compensation pattern and a slope compensation pattern, the slope-top compensation pattern is rectangular corresponding to the top of the slope, having a length equal to a width of the top of the slope and a width greater than a width of the mask pattern, the slope compensation pattern comprises a plurality of triangles corresponding to the slope adjacent to the mask pattern and the slope-top compensation pattern.
11. The mask according to claim 10 , wherein the slope-top compensation pattern and the mask pattern are axisym metric patterns, and the slope-top compensation pattern and the mask pattern share the same symmetry axis extending along a direction of a slope gradient.
12. The mask according to claim 11 , wherein the slope compensation pattern comprises four right triangles.
13. The mask according to claim 10 , wherein the slope compensation pattern comprises four right triangles, the four right triangles are located on an upper part and on a lower part of the slope-top compensation pattern.
14. The mask according to claim 13 , wherein a ratio of a width of the slope-top compensation pattern to a width of the mask pattern is within a range from 1.2:1 to 1:1.
15. The mask according to claim 13 , wherein a ratio of a width of the slope-top compensation pattern to a width of the mask pattern is 1.1:1.
16. The mask according to claim 10 , wherein a height of the high step slope is greater than 2 μm and an angle of the high step slope is within a range from 40° to 60°.