Method and apparatus for performing optical proximity and photomask correction
View Patent ↗An approach is provided for enabling simulation of photomask contour shapes, performing verification on the simulated photomask shapes, and correcting errors in OPC correction or bad fracturing methods to perform photomask proximity correction in real time before physically writing of the photomask. Embodiments include performing optical proximity correction of a photomask of a semiconductor layout to generate a corrected photomask, simulating the corrected photomask to generate one or more simulated contour shapes within a simulated photomask, verifying the simulated contour shapes to determine errors associated with the simulated photomask, and correcting the errors in the simulated contour shapes of the simulated photomask to generate a final photomask.
1. A method comprising:
performing optical proximity correction of a photomask of a semiconductor layout to generate a corrected photomask;
generating simulated contour shapes based on simulating a masking process of the corrected photomask;
verifying the simulated contour shapes, by a processor, to determine errors associated with the simulated photomask; and
correcting the errors in the simulated contour shapes of the simulated photomask to generate a final photomask,
wherein the verifying the simulated contour shapes is based on at least one of a process variation band, a mask error enhancement factor, a depth of focus, and one or more hotspots; and
wherein the simulation of the masking process takes into account at least one of e-beam forward and backward scattering, development, baking, and etching of the corrected photomask.
2. A method according to claim 1 , comprising correcting the errors in the simulated contour shapes by modifying a mask shot configuration.
3. A method according to claim 2 , further comprising modifying the mask shot configuration based on at least one of adjusting variable e-beam shapes and including overlapping shots.
4. A method according to claim 1 , further comprising performing lithography simulation on the corrected contour shapes of the final photomask prior to lithography based on the final photomask.
5. An apparatus comprising:
at least one processor; and
at least one memory including computer program code for one or more programs,
the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to:
perform optical proximity correction of a photomask of a semiconductor layout to generate a corrected photomask;
generate simulated contour shapes based on simulating a masking process of the corrected photomask;
verify the simulated contour shapes to determine errors associated with the simulated photomask; and
correct the errors in the simulated contour shapes of the simulated photomask to generate a final photomask,
wherein the apparatus is further caused to verify the simulated contour shapes based on at least one of a process variation band, a mask error enhancement factor, a depth of focus, and one or more hotspots; and
wherein the simulation of the masking process takes into account at least one of e-beam forward and backward scattering, development, baking, and etching of the corrected photomask.
6. An apparatus of claim 5 , wherein the apparatus is further caused to correct the errors in the simulated contour shapes by modifying a mask shot configuration.
7. An apparatus of claim 6 , wherein the apparatus is further caused to modify the mask shot configuration based on at least one of adjusting variable e-beam shapes and including overlapping shots.
8. An apparatus of claim 5 , wherein the apparatus is further caused to perform lithography simulation on the corrected contour shapes of the final photomask prior to lithography based on the final photomask.
9. A non-transitory computer-readable storage medium carrying one or more sequences of instructions which, when executed by one or more processors, cause an apparatus to:
perform optical proximity correction of a photomask of a semiconductor layout to generate a corrected photomask;
generate simulated contour shapes based on simulating a masking process of the corrected photomask;
verify the simulated contour shapes to determine errors associated with the simulated photomask; and
correct the errors in the simulated contour shapes of the simulated photomask to generate a final photomask,
wherein the apparatus is caused to verify the simulated contour shapes based on at least one of a process variation band, a mask error enhancement factor, a depth of focus, and one or more hotspots; and
wherein the simulation of the masking process takes into account at least one of e-beam forward and backward scattering, development, baking, and etching of the corrected photomask.
10. A computer-readable storage medium of claim 9 , wherein the apparatus is caused to correct the errors in the simulated contour shapes by modifying a mask shot configuration.
11. A computer-readable storage medium of claim 10 , wherein the apparatus is caused to further modify the mask shot configuration based on at least one of adjusting variable e-beam shapes and including overlapping shots.