Oxidation of si Why spend a whole lecture on oxidation of Si? Ge has high ue, Wh, Ge stable but no oxide GaAs has high ue and direct band Why sio? Sio, is stable down to 10 9 Torr. T>900C Sio can be etched with hf which leaves si unaffected Sio, is a diffusion barrier for B. p. as SiO, is good insulator, p>106 Q2cm, E. 8 eV Sio, has high dielectric breakdown field, 500 V/um SiO2 growth on Si= clean Si/ Sio, interface Oxide because DSi through Sio,<< DOxy through Sio2 Sept.19,2003 3.155J/6.152JOxidation of Si Why spend a whole lecture on oxidation of Si? Ge has high me, mh , Ge stable… … but no oxide GaAs has high m and direct band… … no oxide e Why SiO2? SiO2 is stable down to 10-9 Torr , T > 900°C SiO2 can be etched with HF which leaves Si unaffected SiO2 is a diffusion barrier for B, P, As SiO2 is good insulator, r > 1016 Wcm, Eg = 8 eV! O2 SiO2 has high dielectric breakdown field, 500 V/mm SiO2 growth on Si fi clean Si / SiO2 interface because DSi through SiO2 << DOxy through SiO2 SiO2 Si dtOxide Sept. 19, 2003 3.155J/6.152J 1