Low leakage stoichiometric SrTiO3 dielectric for advanced metal-insulator-metal capacitors

Metal-insulator-metal capacitors (MIMCAP) with stoichiometric SrTiO3 dielectric were deposited stacking two strontium titanate (STO) layers, followed by intermixing the grain determining Sr-rich STO seed layer, with the Ti-rich STO top layer. The resulted stoichiometric SrTiO3 would have a structure with less defects as demonstrated by internal photoemission experiments. Consequently, the leakage current density is lower compared to Sr-rich STO which allow further equivalent oxide thickness downscaling. Schematic of MIMCAP with stoichiometric STO dielectric formed from bottom Sr-rich STO and top Ti-rich STO after intermixing during crystallization anneal.