Silicon Atomic-Layer Doped Hf₀.₇Zr₀.₃O₂ Films: Toward Low Coercive Field (0.64 MV/cm) and High Endurance (>10¹² Cycles)

The impacts of Si doping in Hf <tex-math notation="LaTeX">0.7</tex-math> Zr <tex-math notation="LaTeX">0.3</tex-math> O <tex-math notation="LaTeX">₂</tex-math> films are studied in this work. Compared with the standard Hf <tex-math notation="LaTeX">0.5</tex-math> Zr <tex-math notation="LaTeX">0.5</tex-math> O <tex-math notation="LaTeX">₂</tex-math> (HZO) films, the samples with Si-doped Hf <tex-math notation="LaTeX">0.7</tex-math> Zr <tex-math notation="LaTeX">0.3</tex-math> O <tex-math notation="LaTeX">₂</tex-math> film show higher relative permittivities and lower leakages. More importantly, a high breakdown electric field ( E <tex-math notation="LaTeX">BD</tex-math> 4.3 MV/cm) and a low coercive field ( E <tex-math notation="LaTeX">c</tex-math> 0.64 MV/cm) have been achieved experimentally. In this way, E <tex-math notation="LaTeX">c</tex-math> / E <tex-math notation="LaTeX">BD</tex-math> could be reduced from 32% to 15%, and this benefits the endurance property effectively. Specifically, compared with the HZO samples, better endurance and weaker fatigue ( <tex-math notation="LaTeX">$>$</tex-math> 10 <tex-math notation="LaTeX">¹²</tex-math> cycles at 2.5 MV/cm) have been observed in Si-doped Hf <tex-math notation="LaTeX">0.7</tex-math> Zr <tex-math notation="LaTeX">0.3</tex-math> O <tex-math notation="LaTeX">₂</tex-math> devices. The average switching time with three electrode sizes is smaller than that of the standard HZO group. Our data strongly indicate that Si doping in Hf <tex-math notation="LaTeX">0.7</tex-math> Zr <tex-math notation="LaTeX">0.3</tex-math> O <tex-math notation="LaTeX">₂</tex-math> film is a feasible way to fabricate ferroelectric devices with better performances and robust reliabilities.