Depth profiling resonance ionization mass spectrometry of Be-doped, layered III-V compound semiconductors

The accumulation of Be at the interfaces of p‐type (NBe = 2 × 1019 cm−3) GaAs/AlAs and InGaAs/InAlAs structures grown by molecular beam epitaxy (MBE) is detected by depth profiling resonance ionization mass spectrometry (DPRIMS). These results help to interpret secondary ionization mass spectrometry (SIMS) matrix effects at interfaces. The magnitude of the effect depends upon the layer sequence. DPRIMS of heterojunction bipolar transistor (HBT) structures, made of GaAs and AlGaAs layers, show transient SIMS matrix effects from layers spaced 10.0 nm apart. Mass interferences in the Be profile of the HBT structure is precluded with DPRIMS. Therefore, this method allows more accurate interpretation of dopant profiles in these types of structures.