Selective Ge deposition on Si using thermal decomposition of GeH4

Deposition characteristics of Ge using thermal decomposition of GeH4 are studied. The deposition rate of Ge in a surface reaction region at temperatures below 410 °C is formulated as a function of the deposition temperature and GeH4 partial pressure. Selective deposition of Ge occurs reproducibly in the lower temperature range below 410 °C. The cause of the suppression of selectivity and epitaxial growth at deposition temperatures above 450 °C is confirmed as oxide contamination on the substrate.