THE EFFECT OF OXIDATION SOURCE GAS ON EPITAXIAL AL2O3 FILMS ON SI

Epitaxial growth of Al2O3 On Si has been investigated by using ultrahi gh-vacuum chemical vapor deposition (UHV-CVD). Film thickness uniformi ty in a wafer was progressed by UHV-CVD method with a hot wall heating system, but the film surface morphology of grown films was worse than that grown by low-pressure chemical vapor deposition (LP-CVD) with a cold wall heating system. Reaction between Si surface and N2O was carr ied out by LP-CVD and UHV-CVD, and it is supposed that N2O gas etches the Si surface rather than O-2 gas at the initial growth stage in UHV- CVD. High crystalline quality of Al2O3 films was obtained at 1000 degr ees C by changing the oxidation source gas from N2O to O-2. Al2O3 film crystalline quality and electrical property were improved by using O- 2 gas.