Comparative Study on Breakdown Characteristics for InGaAs Metamorphic High Electron Mobility Transistor and InGaAs/InP-Composite Channel Metamorphic High Electron Mobility Transistor

摘要

To perform a comparative study, we experimented on two differential epitaxial structures, the conventional metamorphic high-electron-mobility-transistor (MHEMT) using the InAlAs/InGaAs/InAlAs structure and the InP-composite-channel MHEMT adopting the In-AlAs/InGaAs/InP structure. Compared with the conventional MHEMT, the InP-composite-channel MHEMT shows improved breakdown performance; more than approximately 3.8V. This increased breakdown voltage can be explained by the lower impact ionization coefficient of the InP-composite-channel MHEMT than that of the conventional MHEMT. The InP-composite-channel MHEMT also shows improved Radio Frequency characteristics of S_(21) gain of approximately 4.35 dB at 50GHz, and a cutoff frequency (f_T) and a maximum frequency of oscillation (f_(max)) of approximately 124 GHz and 240 GHz, respectively, were obtained. These are due to decreases in g_o and g_m.