Overview of Modern Lithography Techniques and a MEMS-Based Approach to High Throughput Rate Electron Beam Lithography

Abstract

The ever-increasing drive to fabricate Integrated Circuits (ICs) with smaller feature sizes is stretching the capabilities of today’s optical lithography methods. Current research is focused on alternative lithographic techniques to create new platforms that more easily scale to sub-50 nm feature size and beyond. This paper presents an overview of alternative lithography technologies being investigated, analyzes them, and determines critical tradeoffs with respect to necessary production throughput rates. An alternative approach for sub-50 nm lithography that utilizes recent developments in smart materials and Micro-Electro-Mechanical Systems (MEMS) is then presented as a result of this analysis. Specifically, MEMS fabricated arrays of electron beam emitters offer the resolution and scalability of Multi-column Electron Beam Lithography (MEBL), while overcoming limitations in production rate, and optical complexity. The critical tradeoffs between significant variables are developed to determine the feasibility and define the design space of the approach presented. A highly parallel, multi-column EBL system with a production rate from 10-60 wafers/h at 50 nm resolution is shown to be feasible with near-term evolution in technology. This solution exploits converging technologies and represents a new leverage point where the application of MEMS technology creates significant innovation and new opportunities.