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:
computing a set of statistical coefficients characteristic of a set of spectra, said set of statistical coefficients organized in a database as a function of selected parameters that define a reference film;
simulating a background spectrum for a sample film using said database and a known parameter for said sample film; and
subtracting said background spectrum from a measured spectrum for said sample film to generate a processed spectrum for said sample film.
2. The method of claim 1 , further comprising:
optimizing a simulated intensity spectrum as a function of a simulated profile distribution for an element in said sample film;
matching said processed spectrum to said simulated intensity spectrum using a minimization algorithm; and
determining a distribution profile for said element in said film based on said optimizing and matching.
3. The method of claim 2 , further comprising:
determining a centroid value for said element in said sample film;
determining a dose level for said element in said sample film;
correcting a dose level for said element in said sample film; and
controlling an electrical parameter for a device to be formed in or on said sample film.
4. The method of claim 1 , wherein simulating said background spectrum for said sample film further comprising:
determining whether said known parameter of said sample film matches one of said selected parameters for said statistical coefficients computed from said spectra;
selecting one or more appropriate statistical coefficients associated with said known parameter when said known parameter matches one of said selected parameters or interpolating from said selected parameters to compute one or more appropriate statistical coefficients for said known parameter; and
using said appropriate statistical coefficients to simulate said background spectrum.