ISOLATION BETWEEN NONVOLATILE MEMORY CELLS BY MEANS OF LOW- DIELECTRIC- CONSTANT DIELECTRICS AND AIR GAPS AND CORRESPONDING MANUFACTURING METHOD

摘要

High - density semiconductor memory is provided with enhancements to gate - coupling and electrical isolation between discrete devices in non-volatile memory. The intermediate dielectric (438) between control gates (442) and charge storage regions (436) is varied in the row direction, with different dielectric constants for the varied materials to provide adequate inter-gate coupling while protecting from fringing fields and parasitic capacitances. Dielectric caps (451,453) are provided between memory cells and have a dielectric constant smaller than the one of the intermediate dielectric (438). Electrical isolation is further provided, at least in part, by air gaps that are formed in the column (bit line) direction and/or air gaps that are formed in the row (word line) direction.