TRANSISTOR MOS A ESPACEURS D'AIR

摘要

The transistor has a conductive gate stack comprising a lower portion close to a gate insulator (4) and an upper portion. The upper and lower portions of the stack comprise two different lengths, where the upper portion length is shorter than the lower portion length. The upper portion length is about 0.3 to 0.9 times the lower portion length. The stack is bordered with dielectric spacers delimiting vacuum spacers (10). The lower portion comprises a portion of a metal layer, and the upper portion comprises a portion of a doped semiconductor layer. The lower portion of the stack comprises a layer of a doped polysilicon layer, and the upper portion comprises a doped polycrystalline silicon-germanium layer. An independent claim is also included for a method for manufacturing a MOS transistor.