Assessment of carbon concentrations in polycrystalline and monocrystalline gallium arsenide using SSMS, FTIR, and CPAA

For the assessment of C concentration [C] in GaAs with SSMS, FTIR, and CPAA new results are presented. Using a SSMS relative sensitivity coefficient RSC=[C]SSMS/[C]CPAA=3.1±0.1 an improved FTIR calibration factor f=[C]/(integrated absorption)=(7.1±0.2)×1015 cm−1 for the infrared absorption due to the local vibrational mode of C on As sites in the GaAs lattice (582 cm−1) at 77 K has been derived.