Comparative study of two negative CAR resists: EN-024M and NEB 31

Abstract

In this paper, two negative-tone chemically amplified resists (CAR) are evaluated. The methodology and results are compared and discussed. The resists include EN-024M from TOK, and NEB 31 from Sumitomo. Both resists show high contrast, good dry etch selectivity, and high environmental stability. EN-024M showed good coating uniformity while NEB31 showed a coating uniformity problem. This was a round "dimple" approximately one centimeter in diameter of different thickness and density at the center of the plate. We addressed the "dimple" coating problem as described in the paper. Optimum PAB and PEB temperatures and nominal to maximum doses for isolated features were determined by running a matrix of PAB and PEB temperatures along with a dose series. We evaluated the process and compared the lithographic performance in terms of dose sensitivity, dose and bake latitude, resolution, resist profile, OPC (Optical Proximity Correction) pattern fidelity, CD uniformity, environmental stability, Line Edge Roughness (LER) and etching bias and resistance.

CO2‐Based Dual‐Tone Resists for Electron Beam Lithography

“…The above performance places the CO 2 ‐PC resists among the most sensitive widely used EBL resists, such as PMMA (180 µC cm −2 ), ZEP (35 µC cm −2 ), HSQ (130 µC cm −2 , negative tone), SU‐8 (≈10 µC cm −2 , negative tone), [ 46 ] chemically modified natural polysaccharides (10 µC cm −2 , negative tone), [ 18 ] and NEB (16 µC cm −2 at 50 kV, negative tone). [ 47 ] The data of PMMA, ZEP, and HSQ were measured at the same condition with CO 2 ‐PC resists as described in Figure S17 (Supporting Information). Inspired by the above results, typical micro‐/nanoscale patterns including grating domains, concentric circles, and Siemens star structures were written into PLC 44 and PLDC 47 resists ( Figure ).…”