| 摘要 |
A method for forming an ultra-short channel device with an inverse-T gate lightly-doped drain (ITLDD) structure is disclosed. The method includes forming a silicon layer (14) over a semiconductor substrate (10), and forming a dielectric layer (16) on the silicon layer. Next, a sacrificial region (18) is formed on the dielectric layer to define a gate region. A portion of the sacrificial region is oxidized to form a oxide layer (22) in the sacrificial region and along sidewalls and top surface of the sacrificial region, wherein at least a portion of the sacrificial region is unoxidized. The dielectric layer and a portion of the silicon layer are then removed using the oxide layer as a mask, thereby forming a step in the silicon layer. After removing the oxide layer, the silicon layer is removed using the unoxidized sacrificial region and the dielectric layer as a mask, thereby resulting in an inverse-T structure in the silicon layer. Finally, the substrate is implanted though the inverse-T structure, thereby forming the inverse-T gate lightly-doped drain (ITLDD) structure.
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