TSR Quantum Dots and their Application to Nanometer-size Memory Devices

This paper describes a novel semiconductor quantum dot (QD) grown in a tetrahedralshaped recess (TSR) formed on a (111)B GaAs substrate from the material science and device application points of view. After describing the fabrication procedure for TSRs, the growth of InGaAs QDs and their optical properties are explained. Then, this paper shows that an indium-rich InGaAs QD is spontaneously formed at the bottom of each TSR. Next, the mechanism of QD formation is discussed in detail. Then, we . explain how magneto-photoluminescence experiments have revealed that the QDs have the optical properties peculiar to zero-dimensional confinement. Next, we present experimental results indicating the excellent growth controllability of the QDs. This paper ends with a description of two possible applications of QDs in electronic memory devices.