Characterization of H2-plasma-induced damage in InP substrates using optical and electrical methods

Abstract

Defect creation by H-containing plasma exposure is a critical concern in designing advanced electronic devices because of the long projection range and diffusion length of H species. This study focuses on plasma-induced damage (PID) by H-containing gas mixture to compound semiconductors such as InP. Optical and electrical characterization techniques widely implemented in Si technology were revisited in detail for the purpose of structuring robust and versatile methods. A native oxide layer consisting of InPOx and InP phases was introduced in a damaged region for the optical analysis. The presence of a thicker damaged layer was identified after H2 plasma exposure, presumably due to the deeper projection range. Impedance spectroscopy was conducted by controlling applied bias voltage (Vbias) from depletion to accumulation regime. Obtained Vbias-dependence of the real and imaginary parts shows the deviation, indicating that the present mapping is useful for the assessment of PID by H-containing processes.