MODEL TO EXPLAIN THE ELECTRICAL BEHAVIOR OF P-TYPE SILICON SURFACES AFTER A CHEMICAL TREATMENT

Chemical pretreatment prior to electrical measurements of silicon wafers of p-type conductivity often results in unstable and unreliable readings of resistivity or carrier concentration. In a previous publication (1) we showed that the strongest effect can be achieved by dipping the wafer into hydrofluoric acid (HF) prior to the electrical measurements. In this paper we present a model to explain the effect of resistivity shift (shift in hole concentration) by a capture of holes to the surface and the diffusion of hydrogen atoms (protons) into the silicon to compensate free charges and to rebuild the steady-state equilibrium conditions in the semiconductor. © 1979, The Electrochemical Society, Inc. All rights reserved.