Growth and defects of GaAs and InGaAs films on porous GaAs substrates

• Published in: Thin solid films Vol. 515; no. 10; pp. 4445 - 4449
• Main Authors: Buzynin, Alexander N., Buzynin, Yury N., Belyaev, Alexander V., Luk'yanov, Albert E., Rau, Eduard I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 26.03.2007
• Subjects: Electrical properties and measurements; Epitaxy; Gallium arsenide; Porous substrates; Porous substrates; Gallium arsenide; Electrical properties and measurements; Epitaxy
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2006.07.175

We investigated the opportunities to increase the electric uniformity of GaAs and InGaAs films grown by molecular-beam epitaxy (MBE) technique on monocrystalline (single crystal) GaAs: both on porous and conventional so-called “monolithic” (without pores) GaAs (100) substrates. The basic attention was given to study the electrically active defects in films by using scanning electron microscope (SEM) with new technique which is called “Rau-detector” [E.I. Rau, A.N. Zhukov and E.B. Yakimov, Solid-State Phenomena, 1998, v. 53–54, 327.]. We compared the main properties of epitaxial GaAs and InGaAs films grown on above mentioned substrates. The films grown on porous substrates had higher structural perfection including the following advantages: ( a) smoother surface due to lateral growth mechanism; ( b) less density of structural defects (without dislocation walls), the density of pyramidal defects was ∼ 2 × 10 5 cm − 2 as compared with the density 2 × 10 7 cm − 2 in the films grown on monolithic substrates; ( c) less electrical activity of various structural defects and increased electric uniformity of grown films. The electrical activity of defects in films grown on porous substrates was essentially lowered due to gettering properties of porous substrate.