Potential applications of negative tone development in advanced lithography

• Published in: Microelectronic engineering Vol. 88; no. 8; pp. 1917 - 1922
• Main Authors: De Simone, Danilo, Tenaglia, Enrico, Piazza, Paolo, Vaccaro, Alessandro, Bollin, Maddalena, Capetti, Gianfranco, Piacentini, Paolo, Canestrari, Paolo
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2011; Elsevier
• Subjects: Applied sciences; Contacts; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Illumination; Imaging devices; Light water reactors; Lithography; Masks; Materials science; Methods of nanofabrication; Microelectronic fabrication (materials and surfaces technology); Nanolithography; Negative tone development; NTD; Patterning; Physics; Resists; Roughness; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surface treatments; Trenches; Negative tone development; Contacts; Trenches; NTD; Water; Immersion method; Scanner; High resolution; Roughness; Critical field; Numerical aperture; Microelectronic fabrication; Illumination; Photolithography; Image contrast; Patterning; Trench technology; Lithography; Double exposure method; Interconnection; Line width; Integrated circuit; Positive resist; Miniaturization; Via hole
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2011.01.064

Advanced lithography requires resolution enhancement techniques (customized illumination mode, litho friendly design), and alternative process flow schemes (double exposure, double patterning) in order to meet the requirements of the ITRS technology roadmap and to extend the applications of a full-field scanner with a 1.35 numerical aperture (NA) that represents the physical limit of water-based immersion ArF lithography. Today, one of the most interesting alternative processes uses the patterning inversion through a negative tone development (NTD) process step. Traditionally, the patterning (contacts or trenches) is done by using a dark field mask in combination with positive tone resist and positive tone development (PTD). By using a solvent-based developer (NTD) and a bright field mask, the same features can be transferred into a positive resist with the benefit of better image contrast and, consequently, better line width roughness (LWR) and resolution. In this work we have explored the potential applications of NTD for trenches and contact holes for the 45nm technology node requirements and beyond. The NTD process is a promising option considering the impact on process window, LWR, CD uniformity and defectivity. The experimental result of this alternative approach to print critical dark field levels in an advanced lithography boundary has been explored.