Spatial variation of TSV capacitance and method of stabilization with Al2O3-induced negative fixed charge at the silicon-liner interface

摘要

Stable TSV capacitance is desired to control spatial TSV performance variation due to non-uniform hot-spot heating. Thin Al2O3 is inserted between PETEOS liner and Si substrate to induce negative fixed charge (Qf = −7.44×10¹¹cm⁻²). This causes flat-band voltage shift (ΔVFB = +7.37V) and the TSV is operated in the stable accumulation region within the operating voltage of interest (0–5 V). The leakage current density of this combination is reduced by 10X with annealing in forming gas at 300°C.