Electrical characteristics of Mg-doped GaAs epitaxial layers grown by molecular beam epitaxy

• Published in: Journal of crystal growth 2008-05, Vol.310 (10), p.2427-2431
• Main Authors: Park, Ho Jin, Kim, Jongho, Kim, Min Su, Kim, Do Yeob, Kim, Jong Su, Kim, Jin Soo, Son, J.S., Ryu, H.H., Cho, Guan Sik, Jeon, Minhyon, Leem, J.Y.
• Format: Article
• Language: English
• Subjects: A1. Capacitance voltage; A1. Hall effect; A1. Segregation effect; A3. Molecular beam epitaxy; B1. Magnesium; B2. Semiconducting gallium arsenide; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Iii-v semiconductors; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Physics
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2007.12.064

The electrical characteristics of magnesium (Mg)-doped GaAs epitaxial layers grown with different substrate temperatures have been investigated by Hall effect and capacitance–voltage ( C– V) measurements at room temperature. The carrier concentration obtained by Hall measurements was decreased from 1.4×10 19 to 3.4×10 16 cm −3 when increasing the substrate temperature in the range 460–540 °C, and thus the maximum attainable doping density was N A– N D=1.4×10 19 cm −3. The depth profiles of doping density, obtained by C– V measurements, show that carriers largely out-diffused toward the surface. This could be attributed to the surface segregation effect, which was predominant in the samples with a high doping density than those with a low doping density. Mg-doped GaAs layers have higher mobility than Be-doped GaAs layers around N A– N D=10 18 cm −3. Thus, it is expected that Mg could be effectively used as p-type dopants for highly doped nanostructured semiconductors.