摘要 |
UMOS (U-shaped trench MOSFET) semiconductor devices that have been formed using low temperature processes are described. The source region of the UMOS structure can be formed before the etch processes that are used to create the trench, allowing low-temperature materials to be incorporated into the semiconductor device from the creation of the gate oxide layer oxidation forward. Thus, the source drive-in and activation processing that are typically performed after the trench etch can be eliminated. The resulting UMOS structures contain a trench structure with both a gate insulting layer comprising a low temperature dielectric material and a gate conductor comprising a low temperature conductive material. Forming the source region before the trench etch can reduce the problems resulting from high temperature processes, and can reduce auto doping, improve threshold voltage control, reduce void creation, and enable incorporation of materials such as silicides that cannot survive high temperature processing. Other embodiments are described.
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