Fabricated on a GaAs-based Semiconductor-on-Insulator Substrate Using a Spin-On Low-k Dielectric Film

Abstract

We proposed and successfully fabricated a GaAs-based semiconductor-on-insulator (SOI) metal–semiconductor-filed-effect-transistor (MESFET) using a low-temperature wafer-bonding technique with a spin-on low-k dielectric film, FOx, as a bonding layer. In this structure, the channel is isolated from the semi-insulating (SI) GaAs substrate by a FOx layer. The fabricated 1-µm-gate-length SOI MESFETs showed good pinch-off and saturation characteristics. One of the most important improvements expected for this structure is a reduction of the drain-source capacitance, CDS, which dominates the microwave switching property (on/off ratio). It was demonstrated that the CDS of the SOI MESFET is much smaller than that of the conventional GaAs MESFET. It was also confirmed that the drain current of the SOI MESFET is negligibly affected by the side-gate voltage.