Regular array formation of self-assembled InAs dots grown on patterned (111)B GaAs substrate by MBE

We report, for the first time, self-assembled molecular beam epitaxial (MBE) growth of InAs dots on patterned (111)B GaAs substrates by Stranski-Krastanow growth mode. (111)B GaAs substrates were patterned by using conventional optical lithography process and wet-chemical etching. Self-assembled Inns dot growth was performed on both tetrahedral etch-pit pattern and trapezoidal grooves. InAs dots were found to be selectively grown on the bottom of the tetrahedral etch-pit with appropriate growth conditions. As for the growth on trapezoidal grooves, InAs dots were found to be periodically arrayed on the middle of one side of the slope of grooves patterned along [2<(11)over bar>] direction and on the top and the bottom surface of grooves patterned along [0 (1) over bar 1] direction. The observed periodic distributions of InAs dots on the patterned substrates are presumably caused by the periodic lattice strain distributions on the patterned surface at the initial stage of highly strained layer growth.