Optical method for determining the doping depth profile in silicon

1. A method of processing a sample, comprising the steps of:

introducing dopant into a sample thereby producing a doped sample;

producing a completely healed sample including a doping density profile in response to introducing the dopant into the sample; and

measuring the doping density profile of the completely healed sample by performing reflectometry using light generated within the visible wavelength spectrum.

2. A method of processing a sample as set forth in claim 1 , wherein the step of introducing dopant into the sample is performed with ion implantation.

3. A method of processing a sample as set forth in claim 1 , wherein the step of introducing dopant into the sample is performed using diffusion.

4. A method of processing a sample as set forth in claim 1 , wherein the step of introducing dopant into the sample is performed by depositing a layer of doped crystal silicon on a semiconductor wafer.

5. A method of processing a sample as set forth in claim 1 , wherein the healed sample is produced in response to an annealing step.

6. A method of processing a sample as set forth in claim 1 , wherein the healed sample does not include an abrupt interface.

7. A method of processing a sample as set forth in claim 1 , wherein the healed sample has a consistent crystal lattice structure.

8. A method of processing a sample as set forth in claim 1 , wherein the visible wavelength spectrum is from about 3 eV to about 5 eV.

9. A method of processing a sample as set forth in claim 1 , further comprising the step of controlling the manufacture of a semiconductor product in response to measuring the doping density profile.

10. A method of processing a sample, comprising the steps of:

producing a processed sample by introducing dopant into the sample in a manner that does not produce an interface in the sample, the sample including a doping density profile in response to introducing dopant into the sample; and

determining the doping density profile using reflectometry of the processed sample after complete annealing, wherein the reflectometry is performed using light generated in the visible light spectrum.

11. A method of manufacturing an integrated circuit as set forth in claim 10 , wherein the visible light spectrum is from about 3 eV to about 5 eV.

12. A method of determining a doping density profile, comprising the steps of:

producing a sample, the sample comprising a first region of undoped crystal silicon including a first crystal lattice structure covering a second region of undoped crystal silicon including a second crystal lattice structure;

introducing dopant into the sample thereby damaging the first crystal lattice structure, the sample including a doping density profile in response to introducing the dopant;

producing a completely healed sample by healing the first crystal lattice structure to closely match the second crystal lattice structure such that there is little or no amorphous silicon present; and

determining the doping density profile by irradiating the healed sample with light that can be focused to less than 1 millimeter.

13. A method of determining a doping density profile as set forth in claim 12 , wherein the doping density profile is characterized by an abrupt change in doping concentration between the first region and the second region.

14. A method of determining a doping density profile as set forth in claim 12 , wherein the doping density profile is characterized by a gradual change in doping concentration between the first region and the second region.

15. A method of determining a doping density profile as set forth in claim 12 , wherein the light that can be focused on the sample includes light within the visible wavelength spectrum.

16. A method of determining a doping density profile as set forth in claim 12 , wherein the light that can be focused on the sample includes light including wavelength between about 3 eV to about 5 eV.

17. A method of processing a semiconductor sample, the semiconductor sample comprising optical properties as a function of dopant density, the semiconductor sample including at least two regions without a distinct interface between said at least two regions, the method comprising the steps of:

generating at least one predicted behavior curve associated with changes in the optical properties as a function of dopant density, the predicted behavior curve including at least one expected optical measurement and a depth profile;

generating at least one measured optical measurement by emitting light within the visible wavelength spectrum onto the sample after the sample is completely healed; and

determining the dopant density by comparing the predicted behavior curve to the at least one measured optical measurement.

18. A method of processing a semiconductor sample including optical properties, comprising the steps of:

introducing dopant into the semiconductor sample;

producing a sample with a doping density profile in response to introducing the dopant into the semiconductor sample;

directing light within a visible wavelength spectrum at the sample after the sample is completely healed;

measuring a change in the optical properties of the completely healed sample, in response to directing light in the visible wavelength spectrum at the completely healed sample, the change in the optical properties of the completely healed sample resulting from introducing the dopant into the sample; and

determining the doping depth profile in response to measuring the change in the optical properties of the completely healed sample.

19. A method of processing a semiconductor sample including optical properties, as set forth in claim 18 , wherein the visible wavelength spectrum is from about 3 e.V. to about 5 e.V.