Planar devices with consistent base dielectric

Abstract

Semiconductor devices, integrated chips, and methods of forming the same include forming a fill over a stack of semiconductor layers. The stack of semiconductor layers includes a first sacrificial layer and a set of alternating second sacrificial layers and channel layers. A dielectric fin is formed over the stack of semiconductor layers. The first sacrificial layer and the second sacrificial layers are etched away, leaving the channel layers supported by the dielectric fin over an exposed substrate surface. A dielectric layer is conformally deposited on the exposed substrate surface, the dielectric layer having a consistent thickness across the top surface. A conductive material is deposited over the dielectric layer.