[split gate flash memory cell and manufacturing method thereof]
AssigneeNanya Technology Corporation
InventorsTZU-CHING TSAI, YI-NAN CHEN
Life of this patent
Estimating the term…
Abstract
A method for fabricating a buried plate of a deep trench capacitor is described. A substrate having a deep trench therein is provided. A doped layer is formed on the surface of the deep trench and a material layer is formed on the doped layer. A passivation layer is formed on the sidewall of the deep trench that is not covered by the material layer. After removing the material layer, a thermal process is conducted to drive-in the dopants in the doped layer to the substrate to form a doped region, wherein the doped region serves as a buried plate of the deep trench capacitor. The doped layer also reacts with the substrate to form an oxide layer. After removing the oxide layer, a bottle-shaped deep trench is formed.
Claims20
A fabrication method for a buried plate of a deep trench capacitor, comprising:
- providing a substrate, wherein the substrate is already formed with a deep trench;
- forming a doped layer on a surface at a bottom of the deep trench and a forming material layer on the doped layer;
- forming a passivation layer on a sidewall of the deep trench that is not covered by the material layer;
- removing the material layer;
- performing a thermal process to drive-in dopants in the doped layer to the substrate to form a doped region and concurrently inducing a reaction between the doped layer and the substrate to form an oxide layer;
- and
- removing the oxide layer.
A fabrication method for a buried plate of a deep trench capacitor, comprising:
- providing a substrate having a deep trench already formed therein;
- forming a doped layer on a bottom surface of the trench;
- forming a passivation layer on a sidewall at a top of the deep trench;
- performing a thermal process to drive-in dopants in the doped layer to the substrate to form a doped region and concurrently inducing a reaction between the doped layer and the substrate to form an oxide layer;
- and
- removing the oxide layer.
Dependencies are inferred from the claim text.