EUV Direct Patterning- The next generation

The momentum behind EUV patterning is accelerating. Today, most foundries are forecasting implementation of EUV for holes and line/space by 2018-2020. Implementation of EUV in contact, via and critical metal lines could reduce cycle time by at least one month yielding significant benefits from a throughput standpoint as well as shorter learning cycles for new technology readiness.

(Fig.1) 7nm node EUV Line/Space CAR resist patterning example

TEL has developed novel patterning technologies showcased in 2017[3],[4] to transfer the EUV resist pattern into the underlying layers with improved roughness, local CD uniformity(LCDU), and bridge/line opens margin targeting the 7nm node and below.

(Fig.2) 5nm node EUV Line/Space CAR resist patterning example

TEL’s proprietary direct current superposition technology (DCS) [1,2] (see figure3) as well as directional quasi-atomic layer etching (QALE) (see figure 4) has enabled the transfer of extremely thin resist into underlying stacks without defects. DCS results in resist curing by electron beam as well as resist reinforcement through thin conformal silicon film formation, while QALE decouples the radical flux from the ion flux yielding wider process window and higher etch selectivity to the mask.
The recent introduction of the ALD/Etch fusion process is the latest in a string of innovations that will support the next generation of patterning.

(Fig.3) Direct current superposition effects on organic materials

TEL strives to work closely with their research partners to develop and explore EUV patterning technology to enable further scaling
(Angélique Raley, TEL Technology Center, America)

(Fig.4) Steps in quasi-ALE etching

[1] EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement
Kazuki Narishige, Takayuki Katsunuma, Masanobu Honda, Koichi Yatsuda Etch Process Engineering Dept., Tokyo Electron Miyagi Limited (Proc. of SPIE Vol. 8328 83280N-1)

[2] Dielectric Etch challenges and evolution, Masanobu Honda, H.Mochiki (AVS 2014)

[3] Overcoming Etch Challenges Related to EUV Based Patterning
Andrew Metz et al. (Proc. SPIE 10149, Advanced Etch Technology for Nanopatterning VI, 1014906 (27 April 2017); doi: 10.1117/12.2258153)

[4] Plasma Etch Considerations for EUV Quad-layer Patterning Stacks
Angélique Raley et al., (AVS, 2017)