High-temperature threshold characteristics of a symmetrically graded δ -doped InAlAs Inx Ga1-x AsGaAs (x=0.5→0.65→0.5) metamorphic high electron mobility transistor (MHEMT) have been investigated. The thermal threshold coefficients, defined as Vth T, are superiorly low at 0.9 mVK from 300 to 420 K and at -0.75 mVK from 420 to 500 K. An interesting polarity change of the thermal threshold coefficient was observed around 420 K due to the variation of thermal modulation effects. The present MHEMT device, with stabilized thermal threshold variations and superior high-temperature linearity characteristics, is promising for high-temperature circuit applications.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)