PIP capacitor for split-gate flash process
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Ker Yeh, Hung-Cheng Sung, Di-Son Kuo, Chia-Ta Hsieh, Yai-Fen Lin
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Abstract
A PIP (Poly-Interpoly-Poly) capacitor with high capacitance is provided in a split-gate flash memory cell. A method is also disclosed to form the same PIP capacitor where the bottom and top plates of the capacitor are formed simultaneously with the floating gate and control gate, respectively, of the split-gate flash memory cell. Furthermore, the thin interpoly oxide of the cell, rather than the thick poly-oxide over the floating gate is used as the insulator between the plates of the capacitor. The resulting capacitor yields high storage capacity through high capacitance per unit area.
Claims6
A PIP (Poly-Interpoly-Poly) capacitor with high capacitance integrated with a split-gate flash memory cell comprising:
- a semiconductor substrate having a split gate region and a capacitor region, and a first gate dielectric layer formed on said split gate region and said capacitor region;
- a first polysilicon layer forming the floating gate of said memory cell in said split gate region, and the first electrode of said PIP capacitor in said capacitor region;
- a poly-oxide layer formed on said floating gate;
- a second polysilicon layer forming the control gate of said memory cell in said split gate region, and the second electrode of said PIP capacitor in said capacitor region;
- a second gate dielectric layer beneath said control gate and over said poly-oxide on said floating gate and over said substrate in said split gate region, said second gate dielectric and said poly-oxide forming an inter-gate dielectric layer;
- said second gate dielectric layer as the insulator layer between said first electrode and said second electrode of said PIP capacitor.
Dependencies are inferred from the claim text.