Published online by Cambridge University Press: 25 February 2011
In situ control methods of native oxide growth on Si surfaces at room temperature and during the temperature ramp-up are proposed for metal/Si contact formation, lowtemperature Si epitaxy, and very-thin thermal oxide film formation, based on analyses of factors dominating the oxide growth. Low-resistance W/Si contacts are formed by N2 gas sealed processing of HF cleaning right before W chemical vapor deposition(CVD). Highquality epitaxial Si films are grown at a low temperature of 550°C using Si2H6 molecular flow pre-showering to suppress the oxide growth caused by water or oxygen in a CVD reactor. Very thin gate oxide films with high insulating performance are realized by the preoxidation step at 300°C to form one-molecular-layer oxide for passivation and by the subsequent temperature ramp-up step in ultraclean Ar gas to prevent oxide growth and an increase of surface microroughness before the thermal oxidation step.