STUDY OF RADIATION-DAMAGE AND CONTAMINATION BY MAGNETIZED INDUCTIVELY-COUPLED PLASMA-ETCHING

Radiation damage and contamination on the silicon surfaces etched by m agnetized inductively coupled C4F8 plasmas were investigated. X-ray ph otoelectron spectroscopy (XPS), secondary ion mass spectrometry, spect roscopic ellipsometry, and transmission electron microscopy were used to characterize contamination and high resolution transmission electro n microscopy, and I-V characteristics of Schottky diodes fabricated on the etched and/or annealed silicon surface were used to evaluate radi ation 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 SiO2 etch rate and selectivity. XPS analysis showed that the composition of the residue layer changed from fluorine rich to carbon rich film by chang ing the carbon binding state from C-CFx to C-C. Dense defects distribu ted about 40 Angstrom 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 incr easing applied magnetic field strength. (C) 1996 American Vacuum Socie ty.