Evaluation of the practical use of GHOST technique for various e-beam resists

In this paper we present results of the application of the GHOST technique to the practical use with 10 keV system. Three commercial e-beam resists which include ZEP7000, PBS, and EBR9 HS31 are selected for comparisons. The background dose equalization by the GHOST technique was found to be effective in reducing the proximity effect. It is generally assumed that exposure contrast degradation due to secondary exposure with largely defocused beam for the GHOST technique, especially at boundary between pattern pixel and nonpattern pixel, leads to poor CD uniformity. Thus, we examined CD uniformity variations as a function of with and without the GHOST technique for three e-beam resists. And we also reported the comparison of proximity effect correction quality for three resists by looking at CD linearity in order to investigate relationship between proximity effect and resist contrast.