Progress and process improvements for multiple electron-beam direct write

Abstract

Massively parallel electron beam direct write (MP-EBDW) lithography is a cost-effective patterning solution, complementary to optical lithography, for a variety of applications ranging from 200 to 14 nm. This paper will present last process/integration results to achieve targets for both 28 and 45 nm nodes. For 28 nm node, we mainly focus on line-width roughness (LWR) mitigation by playing with stack, new resist platform and bias design strategy. The lines roughness was reduced by using thicker spin-on-carbon (SOC) hardmask (−14%) or non-chemically amplified (non-CAR) resist with bias writing strategy implementation (−20%). Etch transfer into trilayer has been demonstrated by preserving pattern fidelity and profiles for both CAR and non-CAR resists. For 45 nm node, we demonstrate the electron-beam process integration within optical CMOS flows. Resists based on KrF platform show a full compatibility with multiple stacks to fit with conventional optical flow used for critical layers. Electron-beam resist performances have been optimized to fit the specifications in terms of resolution, energy latitude, LWR and stack compatibility. The patterning process overview showing the latest achievements is mature enough to enable starting the multi-beam technology pre-production mode.

Advanced Fabrication of Mechanical Metamaterials Based on Micro/Nanoscale Technology

“…[ 183 ] To overcome the shortcoming in throughput caused by the point‐by‐point serial process, the multiple e‐beam direct‐write (MEBDW) lithography, a parallel process using more than 10 000 e‐beams, has been developed. [ 184 ] The transfer and scattering of electrons are the main limitations of EBL. Some emerging lithographic techniques, such as XRL and FIBL, are developed to overcome these limitations.…”