Nano-scaled Ge FinFETs with low temperature ferroelectric HfZrO x on specific interfacial layers exhibiting 65% S.S. reduction and improved I ON

Ge n- and p-FinFETs with different interfacial layer ferroelectric HfZrO x (IL-FE-HZO) gate stacks have been demonstrated systematically by various annealing conditions for the first time. Microwave annealing (MWA) not only shows enhanced FE characteristics but also suppresses the gate leakage and Ge interdiffusion compared with conventional rapid thermal annealing (RTA). While HZO on Al 2 O 3 IL results in paraelectric behavior, HZO on GeO x IL exhibits significant FE. High I on /I off (> 107) and low subthreshold slope (S.S. ∼ 58 mV/dec.) are demonstrated by a Ge nFinFET with a gate length (L g ) of 60 nm and a FE-HZO/GeO x gate stack.