A novel vertical DMOS transistor in SOA technology for RF-power applications

A novel SOI vertical DMOS transistor on glass for RF power applications is proposed. The device has the same advantages as conventional LDMOS transistors over bipolar transistors with respect to the linearity and efficiency for the high-power, high-frequency applications and adds the advantages of silicon-on-anything technology for the integration with high quality passive components. The gate oxide degradation due to hot carrier generation is inherently eliminated. The metalization on the wafer back includes copper electroplating. A thick copper layer on the wafer back serves as an excellent heat spreader and heat sink. Moreover, it can be used to avoid debiasing due to voltage drops over the metalization. The device performance has been investigated using DC and AC MEDICI simulations and the "Smoothie" database model for FET devices. A device with a breakdown of more than 80 V, an f/sub Tmax/ of 8 GHz, a maximum current of more than 10/sup -4/ A//spl mu/m at V/sub DS/=26 V and an R/sub ON/ of 4m/spl Omega/cm/sup 2/ is demonstrated.