Heat dissipation and series resistance reduction of pa and rf switch in slt by backside thick metal

Abstract

Methods of forming a SOI PA and RF switch device having a thin BOX layer in the PA power cell region and a thick metal layer directly under the thin BOX layer and the resulting device are provided. Embodiments include providing a SOI structure having a substrate, BOX, device and metallization layers; bonding a handling layer to the metallization layer; removing the substrate; forming a passivation oxide layer over the BOX; forming first and second trenches through the passivation, BOX, and device layers down to the metallization layer; forming a third trench through the passivation layer and a portion of the BOX above a PA power cell region of the SOI structure, a thin portion of the BOX remaining; forming a first backside contact in the first trench; and forming a second backside contact in the second and third trenches and over a portion of the passivation oxide layer.