THE PLASMA PROPERTIES OF LASER-ABLATED SIO2

The optical emission from laser-produced plasmas generated by 1.06-mu-m irradiation of SiO2 targets at a flux of 7 X 10(10) W cm-2 was recorded and analyzed between 250 and 800 nm. The ionization states of Si and O were mapped as a function of both time from the incident laser pulse and location from the front surface of the target. Electron temperatures were calculated using the relative emission intensities of Si(II) and O(II) ionization states (T(e)=3.4 eV), and an electron number density was determined from the Stark-broadened linewidths of five Si(II) emission lines. The ablated material was collected on Si substrates to examine the particulate nature of the plasma. Thin films were grown in the process and properties of these films were examined using IR reflectance and transmittance spectroscopy, scanning electron microscope analyses, and Auger electron spectroscopy.