Integration of ge-containing fins and compound semiconductor fins

Abstract

A stack of a germanium-containing layer and a dielectric cap layer is formed on an insulator layer. The stack is patterned to form germanium-containing semiconductor fins and germanium-containing mandrel structures with dielectric cap structures thereupon. A dielectric masking layer is deposited and patterned to mask the germanium-containing semiconductor fins, while physically exposing sidewalls of the germanium-containing mandrel structures. A ring-shaped compound semiconductor fin is formed around each germanium-containing mandrel structure by selective epitaxy of a compound semiconductor material. A center portion of each germanium-containing mandrel can be removed to physically expose inner sidewalls of the ring-shaped compound semiconductor fin. A high-mobility compound semiconductor layer can be formed on physically exposed surfaces of the ring-shaped compound semiconductor fin. The dielectric masking layer and fin cap dielectrics can removed to provide germanium-containing semiconductor fins and compound semiconductor fins.