GAS PHASE AND PARTICLE DIAGNOSTIC OF HMDSO PLASMAS BY INFRARED ABSORPTION SPECTROSCOPY

摘要

FTIR spectroscopy has been applied to a radio-frequency discharge in hexamethyldisiloxane (HMDSO) diluted with oxygen and helium, as typically used for industrial SiO_x deposition. By measuring the infrared absorption of the HMDSO molecule, the gas consumption during processing can be monitored, allowing process optimization. Additional information on various infrared active radicals formed within the plasma, such as CO, CO_2 and aldehydes, helps to elucidate the plasma chemistry in HMDSO plasmas. Besides information on the formation of gaseous components in the plasma, infrared transmission spectra give at the same time important data on the nature of the particle contamination.