High-performance SiGe pMODFETs grown by UHV-CVD

The fabrication and characterization of 0.1 /spl mu/m-gate-length SiGe pMODFETs fabricated on UHV-CVD-grown heterostructures with various novel layer structure configurations are reported. We have fabricated Ge-Si/sub 0.4/Ge/sub 0.6/ pMODFETs with peak extrinsic transconductance (g/sub max/) values as high as 488 mS/mm at room temperature. These devices also displayed a unity current gain cutoff frequency (f/sub T/) of 42 GHz and maximum frequency of oscillation (f/sub max/) of 86 GHz. We have also investigated the performance of Si/sub 0.2/Ge/sub 0.8/-Si/sub 0.7/Ge/sub 0.3/ pMODFETs on silicon-on-sapphire (SOS) substrates. These devices exhibited DC transconductances as high as g/sub max/=377 mS/mm, and had values of f/sub T/=49 GHz and f/sub max/=95 GHz. The first high-frequency noise characterization of SiGe MODFETs has also been performed. Si/sub 0.2/Ge/sub 0.8/-Si/sub 0.65/Ge/sub 0.35/ pMODFETs grown on high-p Si substrates produced minimum noise figures of 1.1 dB (2.9 dB) with an associated gain (G/sub a/) of 18 dB (7.6 dB) at 3 GHz (18 GHz).