Novel Single Metal Gate CMOS Integration with Effective Workfunction Modulation by a Differential Spacer: Manipulation of Oxygen Vacancy

Abstract

We demonstrate a novel simplified CMOS integration process utilizing a single metal gate electrode and a differential spacer scheme. Workfunction modulation by use of an oxide spacer contiguous to the pFET in combination with a capping layer was shown to achieve near band-edge Vth in a gate first scheme. Low temperature deposited oxide spacers have a high O-H content which when released into the gate stack, passivates the O vacancies in the HfO 2 thereby lowering pFET Vt. Circuit functionalities (SRAM) and Vth integrity up to five metal levels are demonstrated showing that near band-edge CMOS circuits can be obtained.