Nanoimprint lithography steppers for volume fabrication of leading-edge semiconductor integrated circuits

Abstract

This article discusses the transition of a form of nanoimprint lithography technology, known as Jet and Flash Imprint Lithography (J-FIL), from research to a commercial fabrication infrastructure for leading-edge semiconductor integrated circuits (ICs). Leading-edge semiconductor lithography has some of the most aggressive technology requirements, and has been a key driver in the 50-year history of semiconductor scaling. Introducing a new, disruptive capability into this arena is therefore a case study in a “high-risk-high-reward” opportunity. This article first discusses relevant literature in nanopatterning including advanced lithography options that have been explored by the IC fabrication industry, novel research ideas being explored, and literature in nanoimprint lithography. The article then focuses on the J-FIL process, and the interdisciplinary nature of risk, involving nanoscale precision systems, mechanics, materials, material delivery systems, contamination control, and process engineering. Next, the article discusses the strategic decisions that were made in the early phases of the project including: (i) choosing a step and repeat process approach; (ii) identifying the first target IC market for J-FIL; (iii) defining the product scope and the appropriate collaborations to share the risk-reward landscape; and (iv) properly leveraging existing infrastructure, including minimizing disruption to the widely accepted practices in photolithography. Finally, the paper discusses the commercial J-FIL stepper system and associated infrastructure, and the resulting advances in the key lithographic process metrics such as critical dimension control, overlay, throughput, process defects, and electrical yield over the past 5 years. This article concludes with the current state of the art in J-FIL technology for IC fabrication, including description of the high volume manufacturing stepper tools created for advanced memory manufacturing.

Roadmap to Gigahertz Organic Transistors

“…At these channel lengths, the transit frequency is essentially unaffected by the charge‐carrier mobility and is instead determined mainly by the contact resistance, which will need to be smaller than ≈10 Ω cm. 2)In the event that the transit frequency is limited not by the ratio between the transconductance and the gate capacitance, but by the saturation of the charge‐carrier velocity in the semiconductor ( f T = v sat /(2 πL )), the channel length may have to be even smaller than indicated above. For example, if the carrier velocity were to saturate at 10 5 cm s −1 , a transit frequency of 1 GHz might require a channel length below 100 nm. 3)Regarding the question of how to fabricate nanoscale organic TFTs on flexible, large‐area substrates with sufficient yield and uniformity in a scalable and cost‐effective manner, a number of techniques have been developed over the past few years; one of these is nanoimprint lithography, which has been used to demonstrate functional organic TFTs with channel lengths as small as 70 nm and which can be combined with self‐alignment techniques to define nanoscale gate‐to‐contact overlaps …”

Wafer‐Scale Nanoimprint Lithography Process Towards Complementary Silicon Nanowire Field‐Effect Transistors for Biosensor Applications

“…Since then many variants using thermal or UV curing of the resist were described. Nowadays NIL is widely used for nanostructuring in academic setting as well as in some industrial processes . We used a 6 inch silicon mould with 200 nm deep structures based on our design, which was fabricated by the Institut für Mikroelektronik (ims chips) Stuttgart, Germany.…”

Multilevel nanoimprint lithography with a binary mould for plasmonic colour printing

“…31 A similar effect was observed when a mould with various pattern densities was used in the NIL process. 33 Although inhomogeneous imprint depth oen caused unwanted artefact appearing in the NIL pattern transfer process 34,35 we, on the other hand, nd that this feature is an advantage when producing plasmonic colour as such it permits control over the vertical dimension and add another degree of freedom for colour tuning.…”