High Performance Quantum Well InGaAs-On-Si MOSFETs With sub-20 nm Gate Length For RF Applications

We demonstrate RF-compatible quantum well InGaAs MOSFETs integrated on Si substrates, with $L_{\mathrm{G}}$ down to 14 nm and a Si CMOS compatible RMG fabrication flow. Devices exhibit simultaneously extrapolated $f_{\mathrm{t}}$ and $f_{\max}$ of 370 and 310 GHz, respectively, the highest reported combined $f_{\mathrm{t}}/f_{\max}$ for III-V MOSFETs on Si. This is enabled by the scaled $L_{\mathrm{G}},\ g_{\mathrm{m}}$ of $1.75\ \text{mS}/\mu \mathrm{n}$, 8 nm source and drain spacers and raised source and drain extensions maintaining low access resistance. The use of the InP/In0.75Ga0.25As/InP quantum well offers three times higher electron mobility and a 60% increase of $g_{\mathrm{m}}$, compared to reference devices.