Selective epitaxy growth mechanism of GaAs on circularly patterned GaAs (100) substrates by LPE and CCLPE

摘要

Selective epitaxial growth of GaAs layers on SiN_x masked Si doped semi-insulating GaAs (100) substrates were performed by current controlled liquid phase epitaxy (CCLPE). Te doped GaAs epitaxial layers were grown on circularly patterned GaAs (100) substrates at a cooling rate of 40℃/h with and without applied electric current. Surface morphology of (100) facet of the grown layer, the vertical and lateral growth rates were improved to a great extent under applied electric current. A thick layer of 337 ìm with a lateral thickness of 268 um was achieved at 6 h growth with an applied current density of 20 Acm~(-2). The epitaxial growth was realized by electromigration of the solute and supercooling by a constant rate of furnace cooling. The electromigration of solute atoms enhanced the over all epitaxial growth.