Si-doped HZO and ZrO2 for hysteresis free high-k dielectric

Thin high-k dielectrics play a crucial role in achieving low leakage and high capacitance dynamic random-access memory (DRAM) cells. Various high-k materials, such as amorphous HfO2, have shown significant improvements over SiO2. In this study, a novel coreactant, HOOH, is shown to have successfully facilitated the doping of Si into thermal atomic layer deposition ZrO2, which converts an unstable antiferroelectric tetragonal phase after postdeposition anneal into a nonswitching dielectric. Si-doped HZO and Si-doped ZrO2 thin films exhibited a high-k value (∼45) without hysteresis with ±1.5 V operation consistent with a tetragonal phase with a high coercive field. Moreover, the dielectric constant is insensitive to oxide thickness, and an equivalent oxide thickness of 3.5 Å has been achieved in sub-5 nm thickness. The study reveals the potential of high-k Si-doped antiferroelectric HZO in high-performance DRAM or decoupling capacitors.