Calibration Relationships for Optically Measuring the Concentrations of Boron, Gallium, and Indium in Silicon.
Abstract
New, more effective calibration relationships have been experimentally determined which enable FTIR absorption spectroscopy to accurately measure the impurity concentrations of In, Ga, and B in silicon. The peak areas of the Group III acceptor related spectra, are shown to behave linearly with concentration 1/3 or concentration 2/3, rather than simply being proportional to concentration as was previously assumed. These calibration relationships were determined for optical measurements made on samples cooled to 5K for In and Ga, and to 5-8K for B. The relationships for some lines of Ga and In were tested and found to still be accurate for sample temperatures up to 9K. From the high resolution optical measurements made in this study, previously unobserved acceptor related spectral lines were seen. These new lines were observed in the P3/2 spectra of In, Ga, Al, and B. Also a 5p' was observed in the P1/2 spectra of Ga. A feature in each acceptor's P3/2 spectrum is defined as EI, the ground state binding energy, and the spin-orbit splitting of the silicon valence bands was measured. All the IR induced excited states of In, Ga, Al, and B were measured. After renumbering of the B lines 5 - 11, a more complete correspondence between all the Group III excited state lines was shown than any published previously.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1982
- Accession Number
- ADA125670
Entities
People
- John Joseph Rome
Organizations
- Air Force Institute of Technology