INFLUENCE OF O-2-RIE ON SILICON SUBSTRATE - ESTIMATING PLASMA DAMAGE WITH BIPOLAR-TRANSISTOR CHARACTERISTICS

We propose a method, based on bipolar transistor HFE characteristics, for characterizing silicon damage stemming from reactive ion etching ( RIE). This method can detect shallow energy-level-defects and slight d efects, applied to investigate the influence of O2-RIE that is used in post contact hole etching process to remove the residue film on silic on substrate. It is found that O2-RIE is effective for the reduction o f contact resistance and does not deteriorate current devices in respe ct of junction leakage. However, degradation in the HFE characteristic s is caused depending on O2-RIE duration. This means that the O2-RIE i nduces silicon damage. Care must be taken in applying O2-RIE to future devices with more shallow p-n junction because silicon damage may giv e rise to junction leakage.