Lithography systems and methods of manufacturing using thereof
Multi-beam lithography systems and methods of manufacturing semiconductor devices using the same are disclosed. For example, the method utilizes non-coincidence of boundaries of electrical fields emanating from chrome on glass or phase shifted mask features distributed over two masks for the optimization of lithographic process windows, side lobe suppression, or pattern orientation dependent process window optimization employing one mask with polarization rotating film on the backside.
1. A method of forming a semiconductor device, the method comprising:
forming an integrated circuit by forming a pattern comprising a first feature and a neighboring second feature on a semiconductor body, the integrated circuit being formed by simultaneously exposing a first mask and a second mask, wherein the first and the second features are formed at the same time during the simultaneous exposure, wherein a distance between the first and the second features is near a resolution limit of a optical system performing the exposing, wherein the first mask comprises transparent regions bounded by opaque regions, wherein the second mask comprises transparent regions bounded by phase shift regions, wherein boundaries of the pattern are formed by a superposition of a first light exposed by the transparent regions of the first mask with a second light exposed by the phase shift regions of the second mask, wherein center portions of the pattern are formed by a superposition of the first light exposed by the transparent regions of the first mask with a third light exposed by the transparent regions of the second mask, and wherein the second light is configured to destructively interfere with the first light.
2. The method of claim 1 , wherein the pattern is formed by a superposition of electric fields.
3. The method of claim 1 , wherein boundaries of the phase shift regions to the transparent regions of the second mask are misaligned relative to the boundaries of the transparent regions to the opaque regions of the first mask.
4. The method of claim 3 , wherein the boundaries are misaligned to enhance an image slope along boundaries of the pattern formed.
5. The method of claim 1 , wherein a dimension of one of the phase shift regions of the second mask is larger than a corresponding opaque region of the first mask.
6. The method of claim 1 , wherein the first mask is a binary mask and the second mask is an attenuated phase shift mask.
7. The method of claim 1 , wherein the first mask is oriented on a first plane and the second mask is oriented on a second plane, wherein the first plane and the second plane are not co-planar.
8. A method of forming a semiconductor device, the method comprising:
simultaneously exposing a first mask and a binary mask, the first mask comprising target features, and the binary mask comprising assist holes, wherein the target features are formed at the same time during the simultaneous exposing, wherein a distance between the target features is near a resolution limit of a optical system performing the simultaneous exposing, wherein the assist holes are aligned relative to target features for preventing side lobes formed during exposure of the target features, wherein the first mask and the binary mask are aligned on planes that are different during the simultaneous exposure; and
forming the target features by a superposition of a first light exposed by the first mask with a second light exposed by the binary mask, wherein the first light and the second light are phase shifted by 180 degrees, wherein center portions of the target features are formed by the first light, and wherein the second light passing through the assist holes destructively interferes with the first light thereby preventing side lobes formation.
9. The method of claim 8 , wherein dimensions of the assist holes are adjusted to reduce side lobe formation.
10. The method of claim 8 , wherein the second light is optimized for side lobe suppression.
11. The method of claim 10 , wherein the optimization of the second light includes changing exposure dose, exposure intensity, polarization, and phase difference.
12. The method of claim 8 , wherein the first mask and the binary mask are oriented along planes that are perpendicular to each other during the simultaneous exposure.
13. A method of forming a semiconductor device, the method comprising:
exposing a first region of a first mask comprising a plurality of first features, the plurality of first features optimally exposed by a first process window, wherein all first features of the plurality of first features are formed at the same time during the exposing, and wherein a distance between the plurality of first features is near a resolution limit of a optical system performing the simultaneous exposing;
simultaneously exposing a second region of a second mask comprising a plurality of second features, the plurality of second features optimally exposed by a second process window, wherein the first mask and the second mask are aligned on different planes when simultaneously exposing the first and the second regions; and
forming a pattern on a semiconductor body by interference of light from the first mask and the second mask, wherein center portions of the pattern are formed by a superposition of a first light exposed by transparent regions of the first mask, wherein edges of the pattern are formed by a superposition of the first light exposed by transparent regions of the first mask with a second light exposed by the second mask, and wherein the second light is configured to destructively interfere with the first light.
14. The method of claim 13 , wherein the first features comprise horizontal features and the second features comprise vertical features.
15. The method of claim 13 , wherein the light from the first mask and the second mask are coherent.
16. The method of claim 13 , wherein the second mask further comprises a back side polarizing rotation film.
17. The method of claim 16 , wherein the back side polarizing rotation film rotates on a plane of polarization by 90 degrees.
18. The method of claim 13 , wherein the first features comprise features to be printed on the semiconductor body.
19. The method of claim 18 , wherein the second features comprise sub-resolution scatter bars that are not printed.
20. The method of claim 19 , wherein the sub-resolution scatter bars are not constrained for space by the first features.
21. The method of claim 19 , wherein the sub-resolution scatter bars are embedded in opaque regions.
22. The method of claim 13 , wherein the first mask and the second mask are oriented along planes that are perpendicular to each other when simultaneously exposing the first and the second regions.
23. A method of forming a semiconductor device by forming a pattern on a semiconductor body, the method comprising:
simultaneously exposing a first mask and a second mask, the first mask comprising transparent regions bounded by opaque regions, the second mask comprising transparent regions bounded by phase shift regions, wherein boundaries of the pattern are formed by a superposition of a first light exposed by the transparent regions of the first mask with a second light exposed by the phase shift regions of the second mask, wherein the first light and the second light are not different diffractive orders of a light beam, wherein center portions of the pattern are formed by a superposition of the first light exposed by the transparent regions of the first mask with a third light exposed by the transparent regions of the second mask, and wherein the second light is configured to destructively interfere with the first light, wherein the first mask comprises a first feature and a neighboring second feature, wherein the first and the second features are formed at the same time during the simultaneous exposure, wherein a distance between the first and the second features is near a resolution limit of a optical system performing the exposing.