Gas Source Techniques for Molecular Beam Epitaxy of Highly Mismatched Ge Alloys

作者：Stephenson Chad A^*; Gillett Kunnath Miriam; O'Brien William A; Kudrawiec Robert; Wistey Mark A

来源：Crystals, 2016, 6(12): 159.

DOI：10.3390/cryst6120159

• germanium
• germanium carbide
• molecular beam epitaxy

Ge and its alloys are attractive candidates for a laser compatible with silicon integrated circuits. Dilute germanium carbide (Ge1-xCx) offers a particularly interesting prospect. By using a precursor gas with a Ge4C core, C can be preferentially incorporated in substitutional sites, suppressing interstitial and C cluster defects. We present a method of reproducible and upscalable gas synthesis of tetrakis(germyl) methane, or (H3Ge)(4)C, followed by the design of a hybrid gas/solid-source molecular beam epitaxy system and subsequent growth of defect-free Ge1-xCx by molecular beam epitaxy (MBE). Secondary ion mass spectroscopy, transmission electron microscopy and contactless electroreflectance confirm the presence of carbon with very high crystal quality resulting in a decrease in the direct bandgap energy. This technique has broad applicability to growth of highly mismatched alloys by MBE.

• 出版日期2016-12