Electrical properties of hydrogen‐implanted Si annealed under high hydrostatic pressure

Abstract

AbstractCzochralski p‐type Si: B was implanted with H2‐ions at energy of 130 keV and a dose of 4 × 1016 cm‐3. The specimens were annealed at 720 K/10 h in argon ambient under a hydrostatic pressure of 1.2 GPa. Reference specimens were annealed under atmospheric pressure. Schottky‐barrier diodes were fabricated and then capacitance‐voltage (C‐V) measurements and C‐V profiling in the temperature range 80‐370 K were performed to characterise the samples. It has been found that the implantation followed by high temperature annealing is effective in producing deep as well as shallow acceptor levels in the Si energy gap. The deep acceptor is a dominant defect that acts as a strong compensating centre in the n‐type material. The latter was formed as a result of a conversion of the initially p‐type material due to creating thermal donors (TDs) during heat treatment. Unusual properties in C‐V curves and complex carrier profiles were attributed to the presence of the deep‐level defect. Moreover, it has been found that the generation and thermal activation energy of TDs showed a substantial dependence on the hydrostatic pressure. It is interpreted that high‐pressure gives rise to thermal donors that are distinctly different from those that form during annealing under normal pressure.