Takayuki Nagasawa

Conductive layer for charge dissipation during electron-beam exposures

Electron beam resists develop a surface potential during exposure, which can lead to image placement errors of up to several nanometers [1] and result in poor CD uniformity and image quality. To address this problem, we have synthesized a conductive polymer that can be coated onto a resist. Our conductive discharge layer (CDL) is water-soluble and is easily removed during subsequent processing steps. Having established that our material has a low enough resistance for full charge dissipation, we have carried out extensive tests to evaluate the impact of the layer on lithographic performance. We will report these findings, which include measurements of the effect of the CDL on the resolution, roughness, and speed of the resist.