Selective silicon epitaxial growth at 800 °C by ultralow-pressure chemical vapor deposition using SiH4 and SiH4/H2

Abstract

This paper presents results of selective Si epitaxial growth at 800 °C on (100) silicon wafers with oxide patterns by ultralow-pressure chemical vapor deposition using pure SiH4 and SiH4/H2. Prior to deposition, the patterned wafers were in situ argon plasma sputtered at −100 V dc bias to remove native oxide. About 800 Å of Si epitaxial layer can be grown selectively on the exposed silicon windows using 3.5 mTorr of SiH4. By flowing H2 with SiH4 during deposition, selective epitaxial layers can be grown to a thickness of 1300 Å before polycrystalline silicon begins to nucleate on the SiO2 surfaces. The epitaxial films were examined by scanning electron microscopy and cross-sectional transmission electron microscopy and found to be of high structural quality. H2 was found to significantly improve the epi/substrate interface and the surface morphology of the epitaxial layers.