ITRS lithography roadmap: 2015 challenges

Abstract

In the past few years, novel methods of patterning have made considerable progress. In 2011, extreme ultraviolet (EUV) lithography was the front runner to succeed optical lithography. However, although EUV tools for pilot production capability have been installed, its high volume manufacturing (HVM) readiness continues to be gated by productivity and availability improvements taking longer than expected. In the same time frame, alternative and/or complementary technologies to EUV have made progress. Directed self-assembly (DSA) has demonstrated improved defectivity and progress in integration with design and pattern process flows. Nanoimprint improved performance considerably and is pilot production capable for memory products. Maskless lithography has made progress in tool development and could have an α tool ready in the late 2015 or early 2016. But they all have to compete with multiple patterning. Quadruple patterning is already demonstrated and can pattern lines and spaces down to close to 10-nm half pitch. The other techniques have to do something better than quadruple patterning does to be chosen for implementation. DSA and NIL promise a lower cost. EUV promises a simpler and shorter process and the creation of 2-D patterns more easily with much reduced complexity compared to multiple patterning. Maskless lithography promises to make chip personalization easy and to be particularly cost effective for low-volume chip designs. Decision dates for all of the technologies are this year or next year.

Nanolithography: Status and challenges

“…Recently, significant improvement in the defect reduction on templates have been reported [40][41][42]. It has been revealed that overall process defectivity has been lessened by two orders of magnitude to 9 defects per cm 2 [43]. Another key issue of NIL that should be realized is nano-defect management (NDM) technology which includes defect inspection of templates and imprinted wafer, the resist material innovation and the defect mitigation.…”

3D Process Simulation forAdvanced Immersion Lithography

“…[1,2] The extensive and inclusive application of ArF immersion lithography with other resolution enhancement techniques (RETs) make it the most powerful, reliable and economical option from manufacturing perspective. [3] To suppress the impact of reflected light from underneath layers, the reflectivity must be precisely controlled at the interface of the resist and the bottom anti-reflective coating (BARC) layer.…”

Absorption Coefficient Measurement Advanced Method of EUV Resist by Direct-Resist Coating on a Photodiode

“…One critical issue in the EUV lithography for high volume manufacturing is development of EUV resists which has the high resolution, high sensitivity and low line-width roughness, and low outgassing, simultaneously [2,3]. Especially, the high sensitivity is strongly required to relax the specification of EUV power and maintain the highlithographic throughput.…”