Charged-particle-beam transfer masks and methods of making

Abstract

Charged-particle-beam pattern-transfer methods, apparatus, and masks are disclosed that reduce the effects of resist-heating, avoid the so-called stencil problem, and exhibit high throughput. A circuit pattern is divided into low-resolution and high-resolution features that are defined by respective mask patterns in different areas of a mask or on different masks. The respective mask patterns are projected overlappingly onto the substrate. In another embodiment, a mask pattern defines low-resolution circuit features and a portion of high-resolution features. A second mask pattern defines a substantial portion of the high-resolution circuit features. The first and second mask patterns are projected onto the substrate with the charged-particle beam at first and second doses. The first dose, corresponding to the low-resolution circuit features, is larger than the second dose, and the first and second doses are independently selectable.

Dependencies are inferred from the claim text.