Methods for reducing semiconductor substrate strain variation
Embodiments of the disclosure provide methods and system for correcting lithographic film stress/strain variations on a semiconductor substrate using laser energy treatment process. In one embodiment, a method for correcting film stress/strain variations on a substrate includes performing a measurement process in a metrology tool on a substrate to obtain a substrate distortion or an overlay error map, determining dose of laser energy in a computing system to correct film stress/strain variations or substrate distortion based on the overlay error map, and providing a laser energy treatment recipe to a laser energy apparatus based on the dose of laser energy determined to correct substrate distortion or film stress/strain variations.
1. A method for correcting film stress/strain variations on a substrate comprising:
performing a measurement process in a metrology tool on a substrate to obtain a substrate distortion or an overlay error map;
determining dose of laser energy in a computing system to correct film stress/strain variations or substrate distortion based on the overlay error map; and
providing a laser energy treatment recipe to a laser energy apparatus based on the dose of laser energy determined to correct substrate distortion or film stress/strain variations.
2. The method of claim 1 , further comprising:
performing a laser energy treatment process on the substrate using the determined laser energy treatment recipe.
3. The method of claim 1 , wherein computing dose of laser energy further comprises:
comparing the overlay error map or substrate distortion with database library stored in the computing system.
4. The method of claim 3 , wherein the database library includes a correlation of a stress change in a film layer to laser energy dose.
5. The method of claim 4 , wherein the film layer disposed on a surface of the substrate is an amorphous carbon hardmask layer or an organic material with or without a thin capping layer.
6. The method of claim 5 , wherein the thin capping layer a dielectric layer.
7. The method of claim 2 , wherein performing the laser energy treatment process on the substrate further comprises:
altering a film stress locally or globally in a film layer disposed on the substrate.
8. The method of claim 2 , wherein performing the laser energy treatment process on the substrate further comprises:
correcting film stress/strain variations or substrate distortion found on the substrate.
9. The method of claim 2 , further comprising:
coating a photoresist layer on the substrate and performing a lithographic exposure process after the laser energy treatment process.
10. The method of claim 2 , wherein performing the laser energy treatment process on the substrate further comprises
providing a plurality of laser energy pulses at a wavelength between about 193 nm and about 2 μm.
11. The method of claim 2 , wherein computing dose of laser energy for treating the substrate in a computing system further comprises:
determining discrete locations of the substrate to be treated.
12. The method of claim 1 , wherein the laser energy treatment recipe is determined in response to a film stress, substrate curvature, in plane distortion or pattern shift detected on the substrate.
13. The method of claim 1 , wherein the substrate distortion measured on the substrate is determined by measuring a film stress of a film layer disposed on the substrate.
14. The method of claim 1 , wherein the computing system is incorporated in the metrology tool or in the laser energy apparatus.
15. The method of claim 1 , wherein the computing system is in data communication with the metrology tool or the laser energy apparatus.
16. A method for correcting film stress/strain variations on a substrate comprising:
measuring a film stress hysteresis behavior as a function of laser wavelength or dose for the film layers deposited on a substrate;
creating a correlation to the film stress hysteresis behavior with a database library to determine a laser energy treatment recipe to be performed in a laser energy apparatus; and
performing a laser energy treatment process on selected discrete locations of the film layer using the determined laser energy treatment recipe.
17. The method of claim 16 , wherein performing the laser energy treatment process further comprises:
locally altering a residual stress of the film layer to induce an in-plane strain which changes locally to a substrate geometry making up dies or map of dies on the substrate.
18. The method of claim 17 , wherein the film stress is altered to correct substrate distortion prior to a lithography process to reduce film stress/strain variations.
19. The method of claim 16 , wherein measuring the film stress of the film layer further comprises:
determining a overlay error map for the substrate.
20. A method for correcting film stress/strain variations on a substrate comprising:
measuring a film stress, substrate curvature or in-plane distortion or pattern shift of a film layer disposed on a substrate;
determining an overlay error map or substrate distortion based on the measured film stress on the film layer;
determining a laser energy treatment recipe based on the measured film stress on the substrate; and
laser treating the film layer using the determined laser energy treatment recipe to locally change the film stress of the film layer.