부산대학교 도서관

We present lattice matched (LM) In 0.53 Ga 0.47 As MOSHEMT and pseudomorphic (PM) In 0.75 Ga 0.25 As MOSHEMT with gate-first process as well as their related post process annealing (PPA) effects in this paper. PM In 0.75 Ga 0.25 As MOSHEMT with 7nm In 0.75 Ga 0.25 As inserted channel promotes higher DC and RF performances due to higher electron mobility with higher indium content of the channel. MOSHEMT structure is preferred to MOSFET structure since the channel layer is moved away from the oxide/semiconductor interface by using of an In 0.52 Al 0.48 As barrier layer between channel and Al 2 O 3 oxide. We obtain a high cut-off frequency ƒ T of 200GHz for a 100nm-gate-length device of PM In 0.75 Ga 0.25 As structure, which is 20GHz higher than the LM In 0.53 Ga 0.47 As MOSHEMT. The PPA process at 400°C for 1 minute in forming gas N 2 H 2 brings no difference to the DC and RF performances, showing that the detrimental effect of the interface defects is attenuated by using buried channel.