Self-aligned metal source/drain InxGa1−xAs n-MOSFETs using Ni-InGaAs alloy

We have found that a Ni-InGaAs alloy is promising material for the self-aligned metal source/drain (S/D) of InGaAs MOSFETs. The Ni-InGaAs alloy has a low sheet resistance of around 25 Ω/square and a low Schottky barrier height (SBH) for n-InGaAs. We also introduce the SBH engineering by modulating the In content in In_xGa_1-xAs. The value of SBH is reduced with increasing the In content with maintaining the low sheet resistance for different In contents. We propose a novel fabrication process of self-aligned metal S/D MOSFETs using Ni-InGaAs, and demonstrate the successful operation of the metal S/D In_xGa_1-xAs MOSFETs, for the first time. The MOSFETs have realized R_SD lower by 1/5 than that in PN junction devices and the high peak mobility of 2000 and 1810 cm²/Vs in the In content of 0.7 and 0.8, respectively.