DRY-ETCHING OF INP IN HELICON HBR PLASMA - MORPHOLOGY AND CHARACTERIZATION OF SURFACE DAMAGE

We report the results of InP etching using a helicon discharge plasma. The etched surface morphology and the pattern profiles were examined by scanning electron microscopy (SEM). Transmission electron microscopy (TEM) was used to observe the sidewall damage for anisotropic etching. Auger electron spectroscopy (AES) was used to obtain the elemental composition in the top 20 nm of the etched surfaces and to evaluate the contamination and desorption. We have also characterized surface and subsurface damage in InP etched substrates using photoluminescence intensity. Anisotropic submicronic etched patterns with low damage were obtained with high etch rates. However, a significant amorphisation of the sidewalls have been evidenced by TEM.