Application of direct-write electron-beam lithography for deep-submicron fabrication

Lithography is one of the most important techniques in the IC fabrication and has been extensively used in processing. The high resolution and accuracy of electron beam lithography is most appropriate for making mask of optical and X-ray lithography as well as direct writing on wafer. Two types of resist, ZEP-520 positive resist and SAL-601 negative resist, were prepared for used in the electron beam lithography. Three different patterns, which include isolated line, contact hole and line & space patterns were exposed on the tungsten, oxide, and metal substrates, respectively. The 0.15 mu m resolution of lithography patterns was achieved. For the etching of polysilicon and oxide, well defined profile of polysilicon gate with 0.1 mu m width and well-defined tapered profiles of oxide contact hole have been obtained successfully.