Selective polycrystalline and epitaxial growth by silicon molecular beam epitaxy

Abstract Silicon molecular beam epitaxy (MBE) on Si(001) substrates patterned with oxide has been studied. The transition between polycrystalline silicon deposition on the oxide and in situ etching of the oxide was compared, using a thermodynamic model. Islanding was found at the transition, which appears to reduce the maximum oxide etching rate. Patterned substrates prepared by the LOCOS (localized oxidation of silicon) process were etched in situ to give a level surface. Selective polycrystalline and epitaxial growth was then used to produce wafers suitable for CMOS processing. The structure of these layers is discussed in detail.