Tunneling current modulation by Ge incorporation into Si oxide films for flash memory applications

摘要

Current-voltage characteristic for a Ge-incorporated Si oxide was investigated. Current enhancement was observed for the electric field larger than 10MV/cm. Such a current enhancement only under high electric field is expected to improve programming performance without deteriorating reading performance. From secondary ion mass spectrometry and hard x-ray photoelectron spectroscopy analyses and current simulation, it is concluded that the Ge impurity in Ge~(4+) state around the tunnel oxide/substrate interface enhances the current by trap-assisted tunneling. The programming current enhancement induced by the Ge incorporation is expected to be one of the promising solutions for the next-generation flash memory.