Realization of ultra-fine lines using sidewall structures and their application to nMOSFETs

In this paper, a new patterning technique by which ultra-fine lines can be defined using sidewall structure formation is described. In sidewall format ion, the size of sidewall can be controlled by the deposited materials, etc h rates and over-etch percentages. Sidewalls with a few hundred Angstrom wi dth and below were formed on polycrystalline silicon (poly-Si) film doped w ith POCl3 and ultra-fine poly-Si lines were defined using the sidewalls as hardmasks. The sidewall masking technique shows better uniformity in line w idth compared with e-beam lithography. Applying the sidewall masking techni que to gate formation; nanoscale nMOSFETs were fabricated. Fabricated devic es show normal operating characteristics in deep sub-0.1 mu m regime.