Growth of High Electron Mobility Transistor Structure with InAlP Carrier Supply Layer

Abstract

This paper studies the thermal stability of InGaAs/InAlAs high electron mobility transistor (HEMT) structures with InAlAs and InAlP carrier supply layers. Although InAlAs is widely used as a carrier supply layer in conventional InP-based HEMTs, the mobility of such HEMTs gradually falls as the annealing temperature exceeds 600°C. Photoluminescence (PL) measurements and secondary ion mass spectrometry (SIMS) analysis reveal that this mobility decrease is caused by the diffusion of delta-doped Si into the InGaAs channel layer. The diffusion behavior of delta-doped Si in InAlP is examined for the first time and we clarify that the diffusion constant of Si in InAlP is about two orders of magnitude smaller than that in InAlAs. The mobility of a HEMT with InAlP carrier supply layer is unchanged throughout the entire annealing process (≦650°C). The thermal stability of the HEMT is significantly improved by using an InAlP carrier supply layer.