Relaxation Behavior of Microbubbles in Ultrasonic Field

Abstract

InAlAs was oxidized by UV and ozone process. Nanometer-order thin-oxide layers were generated in proportion to the square root of the process period, although their correlation with the period is poor compared with that of InGaAs. Oxidation initially decreased photoluminescence intensity from the InAlAs surface and then gradually increased it when the process period exceeded 15 min until it reached 4 h (crystallographic-order degradation followed by recovery). Plasma nitridation of InAlAs exhibited a gradual and monotonic decrease in photoluminescence intensity. Lattice-matched InAlAs/InGaAs metal-oxidesemiconductor high electron mobility transistors were fabricated utilizing gate oxide layers which were formed by 4 h oxidation. A transconductance of 200 mS/mm was obtained using a 1.5-mm-gate-length device, in a high-forward-gate-bias region although hysteresis was observed in the current-voltage curve.