Effects of humidity on nano-oxidation of silicon nitride thin film.
Effects of humidity on nanometer-scale oxidation of silicon nitride thin film using atomic force microscope in contact mode are studied at various values of relative humidity (RH) (30-70%). The shape of oxide protrusion is determined by the concentration of oxyanions under the tip apex and oxyanions diffusion laterally on the surface. At low RH (<or= 60%), the kinetics of silicon nitride oxidation has a logarithmic relationship to oxide height versus oxidation time. The threshold time decreased and initial oxidation rate increased simultaneously as humidity increased because a high concentration of oxyanions at the oxide/silicon nitride interface was generated. When a high sample voltage (9-10 V) is applied at high RH (>or= 60%), the effective electric field is decreased because of the electron being trapped in the oxide and oxyanions accumulating on the oxide surface.
Department of Materials Science and Engineering, National Chung Hsing University, Taichung 402, Taiwan, ROC. hfhsu@dragon.nchu.edu.tw
Hsun-Feng
HF
Hsu
Chien-Wei
CW
Lee