Evidence for the neutralization of boron in silicon using surface analysis techniques

Interactions between the shallow acceptor boron and hydrogen in single crystal, polycrystalline, and amorphous Si are investigated. Low‐temperature secondary ion mass spectrometry depth‐compositional profiles indicate a definite interaction between the boron concentration and the hydrogen penetration in single crystals and at grain boundaries. The bonding of the H is identified to be directly to the Si rather than to the B, and is confirmed by infrared measurements. Electrical neutralization of the B by hydroxyl‐group bonding is also reported at oxygen‐rich Si grain boundaries. No similar relationships between P concentration and H penetration are observed. In amorphous Si material, the B‐doping level has only a limited effect on the hydrogen penetration which seems to be controlled instead by structural diffusion mechanisms.