Method of manufacturing a flash memory cell having inter-poly-dielectric isolation
AssigneeAgere Systems Guardian Corp.
InventorsPatrick J. Kelley, Ranbir Singh, Larry B. Fritzinger, Cynthia C. Lee, John Simon Molloy
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Abstract
A method of forming round corners for a gate oxide between a floating gate and a control gate of a memory cell comprises the steps of forming the floating gate over a tunnel oxide; forming a mask over the floating gate; forming rounded end caps adjacent distal ends of the mask; transferring the rounding of the end caps to top corners of the floating gate; forming the gate oxide over the floating gate; and, forming the control gate over the gate oxide. A memory cell having a rounded corner interface between the floating gate and control gate is also provided.
Claims16
A method of forming a memory cell, comprising the steps of:
- forming a mask over a floating gate layer;
- forming rounded end caps adjacent distal ends of the mask;
- transferring a profile of the rounded end caps to the floating gate layer, thus forming a floating gate having rounded top corners;
- and
- forming a gate oxide over the floating gate, the gate oxide having rounded top corners.
A method of forming a floating gate having rounded top corners for a memory cell, comprising the steps of:
- forming a floating gate layer;
- forming a mask layer over the floating gate layer;
- reducing the mask layer to form a mask;
- forming a cap layer over the mask and the floating gate layer;
- reducing the cap layer to form rounded end caps adjacent distal ends of the mask;
- forming the floating gate;
- and,
- transferring rounding of the end caps to the floating gate to form rounded top corners on the floating gate, the transferring rounding step concurrent with the floating gate forming step.
Dependencies are inferred from the claim text.