MOVPE growth of homoepitaxial germanium

• Published in: Journal of crystal growth 2008-07, Vol.310 (14), p.3282-3286
• Main Authors: Bosi, M., Attolini, G., Ferrari, C., Frigeri, C., Rimada Herrera, J.C., Gombia, E., Pelosi, C., Peng, R.W.
• Format: Article
• Language: English
• Subjects: A1. Characterisation; A2. Metal-organic vapour phase epitaxy; B2. Semiconducting germanium; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Vapor phase epitaxy; growth from vapor phase
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2008.04.009

n-Type Ge epitaxial layers were deposited on p-type Ge substrates by means of metal-organic vapour phase epitaxy (MOVPE) at temperatures ranging from 500 to 600 °C using isobutylgermane (iBuGe) as metal-organic precursor and hydrogen as carrier gas. The samples were grown at different iBuGe partial pressure conditions and were characterised by means of atomic force microscopy (AFM), high-resolution X-ray diffraction (HR-XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The layers grown with iBuGe partial pressure of 3.3×10 −6 bar at 550 °C show a good crystallographic structure, flat surface and a good interface with the substrate, while for lower partial pressures a series of pits was evidenced on the layer. The pit density was found to be dependent on the growth rate. n-Ge/p-Ge diodes, obtained with standard photolitographic techniques, show rectification ratios higher than 10 5 and ideality factors in the 1.008–1.010 range.