Near-field scanning optical nanolithography using amorphous silicon photoresists

Near-field scanning optical microscopy (NSOM) patterning of hydrogenated am orphous silicon (a-Si:H) has been explored. Our sample preparation techniqu e produces films that are stable over several days. The etching process use d is highly selective, allowing the unexposed aSi:H to be completely remove d while patterns with line heights equal to the original film thickness rem ain in exposed regions. We are able to generate patterns with and without t he use of light. We have found that the probe dither amplitude greatly affe cts the linewidth and height of patterns generated without light. We also f ind that the exposure required for the NSOM to optically generate patterns agrees with threshold dosages determined by far-field exposure studies. Fea ture sizes of approximately 100 nm, comparable to the probe diameter, were obtained. (C) 1999 American Institute of Physics. [S0003-6951(99)04001-2].