SiGe channels for VT control of high-k metal gate transistors for 32 nm complementary metal oxide semiconductor technology and beyond

GLOBALFOUNDRIES 32 nm high-k metal gate technology, with SiGe channel for VT control of P-field effect transistor, is taken into production. This epitaxial channel material is being introduced into high volume manufacturing in complementary metal oxide semiconductor technology. The morphology of the SiGe channel (cSiGe) for narrow width transistors is carefully controlled by process conditions such as epitaxial growth temperature, pre bake condition or in-situ Si recess prior epitaxial deposition. A micro loading effect observed in 28 nm technology was eliminated by an in-situ recess of the silicon before epitaxial deposition. Due to the significant cost of this process step, an epitaxial batch system has been evaluated to reduce the cost of ownership dramatically. Also the cSiGe process has been optimized to minimize the thickness variation of the SiGe channel due to the strong response of VT to cSiGe thickness.