Atomic Picture of Crystal Surfaces Terraces steps kinks

Atomic Picture of Crystal Surfaces Terraces, steps, kinks, adatoms and vacancies STM image of vicinal Si(111) STM image of Si(001)

Three Growth Modes If s > f + sf s < f + sf Film s > f + sf With misfit Substrate Layer-by-layer 3 D islanding (Frank-Van der Merwe) (Volmer-Weber) Layer-by-layer followed by 3 D islanding (Stranski-Krastanov) s: surface energy of substrate f: surface energy of film sf: interface energy of substrate-film

Stranski-Krastanov growth of Ge on Si(001) [100] pyramids huts Wetting layer ~ 2. 5 ML Ge, 475 °C, (44 nm)2 3 D islands formation ~ 3. 5 ML Ge, 475°C, (110 nm)2

MBE grown Ga. As-Alx. Ga 1 x. As superlattice Bang gap – lattice constant for alloy semiconductors

Misfit Dislocations Threading dislocation misfit dislocation

Molecular Beam Epitaxy (MBE)

Real-time monitoring of MBE using Reflection high-energy electron diffraction (RHEED) RHEED Pattern Surface reconstruction Source off RHEED intensity oscillation 3 D growth

Vapor Phase Epitaxy (VPE) Horizontal reactor Vertical reactor Barrel reactor

Liquid Phase Epitaxy (LPE)

Carrier Mobility & Concentration Measurements Hall Effect w I Doping Profile N(x) VH B x x Van der Pauw Test Pattern Depletion zone N(x) Schottky junction V C(V) = 0 A/x