Single-crystalline-like germanium thin films on glass substrates

Abstract

Single-crystalline-like germanium films have been demonstrated on inexpensive glass substrates (quartz). Ion Beam Assisted Deposition (IBAD) was employed to achieve biaxial crystallographic texture in MgO deposited on quartz substrates. Using intervening epitaxial oxide buffer layers, single-crystalline-like germanium films have been grown by magnetron sputtering. In-spite of significant lattice mismatch and structural mismatch, epitaxial growth was achieved in all layers. All thin films in this work were deposited by reel-to-reel processing. In-plane texture better than 5° has been measured in the germanium film. A Hall mobility value of 107 cm2/Vs was attained in 400 nm thick germanium films on glass substrates.