Novel Germanium n-MOSFETs With Raised Source/Drain on Selectively Grown Ge on Si for Monolithic Integration

We demonstrate novel Ge n-MOSFETs with raised source/drain (S/D) fabricated on high-quality single-crystal Ge selectively grown heteroepitaxially on Si. For the raised S/D, an implant-free in situ doping technique has been employed for low-resistance, abrupt, and shallow n+/p junctions. The novel n-MOSFETs show an excellent on/off ratio (4 × 103) with very high on current (3.23 μA/μm) and relatively high electron mobility on (100) Ge among the Ge n-MOSFETs. These results show promise toward monolithic integration of Ge MOSFETs with a Si VLSI platform.