A new method to form flash memory devices in the manufacture of an integrated
circuit
device is achieved. The method comprises providing a substrate. A first film is
formed comprising a first oxide layer overlying the substrate and a floating gate
layer overlying the first oxide layer. A second film is formed comprising a second
oxide layer overlying the first film, a control gate layer overlying the second
oxide layer, and an insulating layer overlying the control gate layer. The first
and second films are patterned to form stacked gates comprising floating gates
and control gates. Ions are implanted into the substrate between the stacked gates
to form source and drain regions. A third oxide layer is then formed on the sidewalls
of the stacked gates. A plug layer is then deposited overlying the substrate and
the stacked gates and filling spaces between the stacked gates. The plug layer
is etched down to below the top surface of the stacked gates to form conductive
plugs contacting the source and drain regions and to complete the flash memory devices.
