Takahiro Yasue

Thermally Robust Multi-layer Non-Volatile Polymer Resistive Memory

The feasibility of the charge-transfer based polymer resistive memory as a future data storage device was tested using a thermally robust polyimide and PCBM composite film, available by low-cost solution processing. The prototype device with a simple 4F cross-point cell structure demonstrated basic non-volatile memory functions (> 1000 write/erase cycles and 1-week data retention in an ambient without encapsulation). Not only bi-polar but also uni-polar operation scheme with multi-level programming worked for the device. The cells on both the top and the bottom layers of a stacked device with additional heat budget of > 300 degC for 1 hour exhibited no degradation on the performance

Patterning with EUVL: the road to 22nm node

EUV resists have been developed to be able to print sub-30nm L/S features with EUV ADT having 0.25NA. However, a lithographic performance especially line width roughness (LWR) of EUV resist is not comparable to that of DUV resist. Shot noise effect has been regarded as a main reason for this poor performance of EUV resist [1-2]. Polymer bound PAG with sensitizer is considered as one of solutions to overcome this problem. The champion resist based on polymer bound PAG shows good performance at 30nm L/S and 27nm L/S patterns, although LWR is still worse than target. Additional processes such as smoothing process, chemical treatment process and surfactant rinse process are evaluated. Surfactant rinse process which can improve LWR and pattern collapse simultaneously is regarded as a best solution. A new resist which can overcome out-of band radiation problem is required for EUV lithography. A resist which is totally transparent at DUV or a resist which is very opaque at DUV wavelength is expected to be a solution for OOB problem of EUV lithography.

EUV sensitive photo-acid generator sans chromophore

Recent advances in EUVL lithography is mainly centered on improving the RLS trade-off by employing new resist platforms, bulkier PAGs, EUV sensitizers etc. Among the several new kinds of PAGs proposed till date, the focus of development was mainly on the acid strength, compatibility with resin etc., whilst always retaining the mono, Di or tri phenyl chromophore of the PAG. Herein we report on the use of chromophore-less PAG for the patterning of EUVL resists. Resist performance using model acrylate and PHS based resist was studied. The patterned resists were characterized using SEM. Thermal stability of the PAG was compared with model chromophore containing PAG.