Study of radiation damage and contamination by magnetized inductively coupled plasma etching

Abstract

Effects of magnetic field on oxide etching characteristics in planar type radio frequency inductively coupled plasma J.Radiation damage and contamination on the silicon surfaces etched by magnetized inductively coupled C 4 F 8 plasmas were investigated. X-ray photoelectron spectroscopy ͑XPS͒, secondary ion mass spectrometry, spectroscopic ellipsometry, and transmission electron microscopy were used to characterize contamination and high resolution transmission electron microscopy, and I -V characteristics of Schottky diodes fabricated on the etched and/or annealed silicon surface were used to evaluate radiation damage. As the magnetic field applied to the inductively coupled plasmas increased from 0 to 12 G, the thickness of the residue layer formed on the silicon surface increased with the increase of SiO 2 etch rate and selectivity. XPS analysis showed that the composition of the residue layer changed from fluorine rich to carbon rich film by changing the carbon binding state from C-CF x to C-C. Dense defects distributed about 40 Å deep from the etched silicon surface were found for the 0 G condition and thicker but less dense defects were observed for higher magnetic field conditions. The electrical damage estimated from the I -V characteristics of Schottky diodes was reduced with increasing applied magnetic field strength.