PULSED-LASER DEPOSITION OF AL2O3 THIN-FILM ON SILICON

Al2O3 thin films were fabricated by pulsed laser deposition (PLD) on S i3N4Si, to improve the thermal and electrical isolation of gas sensing devices. The microstructure of the films is analyzed as a function of the deposition conditions (laser fluence, oxygen pressure, target-sub strate distance and substrate temperature). X-ray analysis shows that only a sharp peak that coincides with the corundum (116) reflection ca n be observed in all the films. But, when they are annealed at tempera tures above 1,200 degrees C, a change in the crystalline structure of some films occurs. The stoichiometry and morphology of the films with and without thermal treatment are compared using environmental scannin g electron microscopy (SEM) and EDAX analysis.