Method and system for non-destructive distribution profiling of an element in a film
View Patent ↗A method to determine a distribution profile of an element in a film. The method comprises exciting an electron energy of an element deposited in a first film, obtaining a first spectrum associating with the electron energy, and removing a background spectrum from the first spectrum. Removing the background value generates a processed spectrum. The method further includes matching the processed spectrum to a simulated spectrum with a known simulated distribution profile for the element in a film comparable to the first film. A distribution profile is obtained for the element in the first film based on the matching of the processed spectrum to a simulated spectrum selected from the set of simulated spectra.
1. A method comprising:
obtaining a measured spectrum for a film having signals emitted by a plurality of species, each species having an emission kinetic energy, said measured spectrum covering a plurality of subregions;
obtaining an intrinsic function for a first species which has the highest emission kinetic energy at a first predetermined subregion; and
reconstructing a complete first spectrum for said first species having the highest emission kinetic energy, said complete first spectrum covers all subregions of said measured spectrum, and reconstructing is accomplished using said intrinsic function and an extrapolation method.
2. The method of claim 1 , further comprising:
using the complete first spectrum as a background spectrum to a second species which has the second highest emission kinetic energy.
3. The method of claim 2 , further comprising:
subtracting said background spectrum from said measured spectrum; and
obtaining a second intrinsic function for said second species at a second predetermined subregion; and
reconstructing a complete second spectrum for said second species having the second highest emission kinetic energy, said complete second spectrum covers all subregions of said measured spectrum, and reconstructing is accomplished using said second intrinsic function and said extrapolation method.
4. The method of claim 3 , further comprising:
optimizing a simulated intensity spectrum as a function of a simulated profile distribution for a first element associated with said first species in said film;
matching said complete first spectrum to said simulated intensity spectrum using a minimization algorithm; and
determining a distribution profile for said first element in said film based on said optimizing and matching.
5. The method of claim 4 , further comprising:
determining a centroid value for said first element in said film;
determining a dose level for said first element in said film;
correcting a dose level for said first element in said film;
predicting an electrical parameter for a device to be formed in or on said film; and
controlling an electrical parameter for a device to be formed in or on said film.
6. The method of claim 3 , further comprising:
optimizing a simulated intensity spectrum as a function of a simulated profile distribution for a second element associated with said second species in said film;
matching said complete second spectrum to said simulated intensity spectrum using a minimization algorithm; and
determining a distribution profile for said second element in said film based on said optimizing and matching.
7. The method of claim 6 , further comprising:
determining a centroid value for said second element in said film;
determining a dose level for said second element in said film;
correcting a dose level for said second element in said film; and
controlling an electrical parameter for a device to be formed in or on said film.
8. The method of claim 1 , wherein said measured spectrum is collected using a photoelectron spectroscopy system taking measurements for said film at a constant emission angle.