Lattice-matched In/sub 0.29/Al/sub 0.71/As/In/sub 0.3/Ga/sub 0.7/As doped-channel FETs

摘要

Lattice-matched and dislocation-free In/sub 0.29/Al/sub 0.71/As/In/sub 0.3/Ga/sub 0.7/As heterostructures with an improved Schottky barrier height have been realized on GaAs substrates. Through measurements of the temperature-dependent Hall effect as well as TEM analysis, we have verified the effectiveness of dislocation filtering from this metamorphic buffer, which is favorable for device application. Based on the doped-channel approach, we demonstrated a high current capability and high device performance of M-DCFETs. A g/sub m/ of 220 mS/mm and an I/sub ds/ of 400 mA/mm were obtained from a 1 /spl mu/m-long gate device. An f/sub T/ of 22 GHz and an f/sub max/ of 51 GHz were also achieved from the same gate dimension. In addition, we conducted reliability testing, and found that a better performance was preserved for M-DCFETs. Metamorphic buffers provide, therefore, a very promising alternative way to achieve high performance of devices without the critical thickness limitation.