Determination of Shallow Minority-Acceptor Concentration in Multiply Doped Silicon

A method is presented, based on photothermal ionization spectroscopy (PTIS), for determining the shallow minority‐acceptor concentration in multiply doped silicon, over the concentration range 1013/cm3–1015/cm3. The method is an extension of a model developed previously for the PTIS response in a multiply doped semiconductor, which accounts for the experimentally observed change in signature, from negative to positive, of the lower‐energy lines of the deeper acceptor as the temperature is increased. It uses a calculated curve of the dependence on the shallow‐acceptor concentration of the temperature at which the change in signature occurs, for a given line, and compares it to a determination of this temperature from actual spectra for the sample. The method is applied to the determination of boron concentration in the Si(Ga,B) system