Fabrication of surface-channel charge-coupled devices with ultralow density of interface states

Abstract

Surface-channel charge-coupled devices (CCD’s) have been fabricated with ultralow density of (fast) interface states in the range 1–3×108/cm2 eV. This low interface state density is achieved by hydrogen implantation into the metal-nitride-oxide-silicon (MNOS) insulator structure of the CCD as the final fabrication step after aluminum interconnect metallization. The CCD’s are shown to have excellent operating characteristics including high transfer efficiency (∼0.99995 without bias charge), low dark current (0.25–0.50 nA/cm2 at 20°C), and high signal charge capacity (1.55×1012 e/cm2 for 10-V clock swing).