A method of making embedded non-volatile memory devices includes forming a
first mask layer overlying a polycrystalline silicon layer in a cell
region and a peripheral region on a semiconductor substrate wherein the
first mask layer has a plurality of openings in the cell region. Portions
of the polycrystalline silicon layer exposed in the plurality of openings
can be oxidized to form a plurality of poly-oxide regions, and the first
mask layer can then be removed. The polycrystalline silicon layer not
covered by the plurality of poly-oxide regions can be etched to form a
plurality of floating gates, wherein etching the polycrystalline silicon
layer is accompanied by a sputtering. A dielectric layer can then be
formed, as well as a second mask layer in both the cell region and the
peripheral region. The second mask layer in the cell region is partially
etched back after a photoresist layer is formed over the second mask
layer in the peripheral region. The dielectric layer is partially etched
to form multiple thicknesses of the dielectric layer. The second mask
layer is removed and a plurality of control gates are formed partially
overlying the plurality of floating gates in the cell region.