Selective Ge deposition on Si using thermal decomposition of GeH ₄

Deposition characteristics of Ge using thermal decomposition of GeH ₄ 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.