The effect of heavy metal contamination in SIMOX on radiation hardness of MOS transistors

It is shown that heavy metal contamination introduced during implantation of oxygen into silicon results in a reduction of SIMOX (separation by implanted oxygen) oxide radiation hardness. Radiation-induced back-channel leakage currents in MOS transistors processed in SIMOX films containing various levels of heavy metals, as measured by surface photovoltage (SPV), are a strong function of heavy metal concentration. It is concluded that SPV measurements of as-implanted SIMOX wafers can be used as a rapid, nondestructive quality control inspection technique to predict the radiation hardness of the SIMOX oxide prior to processing.<
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