Frontside and backside epi contact

Abstract

Techniques are provided herein to form semiconductor devices having a frontside and backside contact in an epi region of a stacked transistor configuration. In one example, an n-channel device and a p-channel device may both be GAA transistors where the n-channel device is located vertically above the p-channel device (or vice versa). Source or drain regions are adjacent to both ends of the n-channel device and the p-channel device. Deep and narrow contacts may be formed from both the frontside and the backside of the integrated circuit through the stacked source or drain regions. The contacts may physically contact each other to form a combined contact that extends through an entirety of the stacked source or drain regions. The higher contact area provided to both source or drain regions provides a more robust ohmic contact with a lower contact resistance compared to previous contact architectures.