Device based evaluation of electron projection lithography

Abstract

As we move technology further and further down the geometry scale we are coming upon imaging situations where our use of existing optical lithography is being questioned due to the lack of process margin in manufacturing lines. This is especially apparent in the imaging of contacts where memory devices, that generally have the densest arrays of these features, may no longer be able to print the desired features. To overcome this it is necessary to either modify the design, a very expensive and time consuming process, or find an imaging process capable of printing the desired features. Electron Projection Lithography (EPL) provides an option to print very small features with a large process margin.In this paper we detail the performance of both memory and logic based designs in an EPL process. We detail the manufacture and results of stencil mask manufacture. Data is also presented showing the imaging results (DOF, exposure latitude, pattern transfer) of features down to 50nm imaged on Nikon's EB1A tool.