Ag-doped Lithium Alumino Silicate Photostructurable Glass For Microdevice Fabrication

Ag-doped LAS glass of composition (wt.%): 74SiO(2)-6Al(2)O(3)-15Li(2)O-5X (X= other additives) were prepared by melt-quench technique and characterized for thermal and optical properties using DTA and UV-Visible spectrometer. XRD technique was used for phase identification in the heat treated glasses. Glass samples were exposed to UV-light for conversion of Ce3+ to Ce4+ state and Ag+ intoAg(o) metallic state. DTA shows a lower crystallization temperature (T-p) at around 605 degrees C for exposed samples as compared to unexposed base glass which is at around 625 degrees C. UV-Visible spectra shows a broad band at around 305nm which indicates Ce3+ in base glass whereas in case of UV-exposed sample the reduced peak intensity indicates conversion of Ce3+ to Ce4+ ions, which also confirm formation of Ag-o in glass samples. Ag agglomeration was also confirmed from the band position at 430nm in heat treated sample, found responsible for early growth of meta-silicate phase in exposed sample. The meta-silicate phase was selectively etched for fabrication of microdevices.