Large-area selective CVD epitaxial growth of Ge on Si substrates

Abstract

Selective epitaxial growth of crystalline Ge on Si in a standard ASM Epsilon 2000 CVD reactor is investigated for the fabrication of Ge p+n diodes. At the deposition temperature of 700?C, most of the lattice mismatch-defects are trapped within first 300nm of Ge growth and good quality single crystal Ge is achieved within a layer thickness of approximately 1 ?m on window sizes up to hundreds of ?m2. For p+n junction fabrication, a sequence of pure-Ga and then pure-B depositions are utilized for the ultrashallow p-doping of As-doped Ge-islands. The I-V characterization of the diodes confirms the good quality of the Ge and ideality factors of ~ 1.1 with low saturation currents are reliably achievedDIMESElectrical Engineering, Mathematics and Computer Scienc