CHEMICAL CHARACTERIZATION OF PLASMA-POLYMERIZED HEXAMETHYLDISILAZANE BY NUCLEAR ELASTIC RECOIL DETECTION

Chemical composition profiles of plasma-polymerized hexamethyldisilazane thin films, deposited in microwave discharges, were measured by elastic recoil detection (ERD). The main fabrication variable during film deposition was the substrate temperature, which was varied from 25 to 650 degree C. Hydrogen, carbon and silicon concentrations and profiles to a depth of roughly 1 mu m were measured by ERD. These concentrations were compared with results obtained by conventional chemical microanalysis, and agreement was found to be excellent. As in earlier work using other techniques, ERD confirmed the presence of a thin (approximately 50 nm) 'oligomeric' layer at the free surface of the films. Erosive radiation damage caused by the probing ion beam on the carbon and hydrogen profiles was observed and investigated.