Three-dimensional cross field effect self-aligned transistors with frontside and backside power connections

Abstract

An apparatus and method for efficiently routing power signals across a semiconductor die. In various implementations, an integrated circuit uses Cross field effect transistors (FETs) with a first device, such as n-type device, having a first channel oriented in a first direction and connected to a ground reference voltage level provided by a backside metal layer. The Cross FETs also use a second device, such as the p-type device, having a second channel oriented in a second direction orthogonal to the first direction and connected to a power supply reference voltage level provided by a frontside metal layer. A micro through silicon via (TSV) traverses the silicon substrate layer in order to be placed between the backside metal layer and the source region of an n-type device. The power connections reduce on-die area, reduces semiconductor fabrication complexity, which improves wafer yield, and reduces voltage droop, which increases performance.