Ammonia-treated polysilicon semiconductor device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsWen-Ting Chu, Yeur-Luen Tu
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Abstract
Semiconductor devices, and methods of fabricating, having ammonia-treated polysilicon devices are provided. A substrate is provided upon which a polysilicon layer is formed. The polysilicon layer is treated with ammonia. Thereafter, portions of the polysilicon layer may be oxidized, forming poly-oxide regions. The poly-oxide regions may be used, for example, to form the poly-oxide layer of a split-gate transistor. The ammonia treatment reduces the tendency of the polysilicon to oxidize along the grain boundaries, thereby allowing smaller designs to be fabricated without bridging occurring between polysilicon structures.
Claims14
A method of forming a semiconductor structure, the method comprising:
- providing a substrate;
- forming a polysilicon layer on the substrate;
- treating the polysilicon layer with ammonia;
- forming and patterning a first mask on the polysilicon layer;
- oxidizing exposed portions of the polysilicon layer, thereby forming oxidized portions of the polysilicon layer;
- removing the first mask;
- and
- removing portions of the polysilicon layer, wherein the oxidized portions of the polysilicon layer act as a mask.
A method of forming a split-gate transistor, the method comprising:
- providing a substrate;
- forming a first polysilicon layer on the substrate;
- treating a surface of the first polysilicon layer with ammonia;
- forming and patterning a first mask on the first polysilicon layer, thereby exposing portions of the first polysilicon layer;
- oxidizing exposed portions of the first polysilicon layer, thereby forming oxidized portions of the first polysilicon layer;
- removing the first mask;
- removing portions of the first polysilicon layer, wherein the oxidized portions of the first polysilicon layer act as a mask, the remaining portion of the first polysilicon layer forming a floating gate;
- forming a dielectric layer over the floating gate, the dielectric layer forming an inter-poly oxide of the split-gate transistor;
- and
- forming a second polysilicon layer over the dielectric layer to form a control gate of the split-gate transistor.
Dependencies are inferred from the claim text.