Low-temperature poly-Si nanowire junctionless devices with gate-all-around TiN/Al2O3 stack structure using an implant-free technique.

In this work, we present a gate-all-around (GAA) low-temperature poly-Si nanowire (NW) junctionless device with TiN/Al.

A junctionless SONOS nonvolatile memory device constructed with in situ-doped polycrystalline silicon nanowires.

In this paper, a silicon-oxide-nitride-silicon nonvolatile memory constructed on an n+-poly-Si nanowire [NW] structure featuring a junctionless [JL] configuration is presented. The JL structure is fulfilled by employing only one in situ heavily phosphorous-doped poly-Si layer to simultaneously serve as source/drain regions and NW channels, thus greatly simplifying the manufacturing process and alleviating the requirement of precise control of the doping profile. Owing to the higher carrier concentration in the channel, the developed JL NW device exhibits significantly enhanced programming speed and larger memory window than its counterpart with conventional undoped-NW-channel. Moreover, it also displays acceptable erase and data retention properties. Hence, the desirable memory characteristics along with the much simplified fabrication process make the JL NW memory structure a promising candidate for future system-on-panel and three-dimensional ultrahigh density memory applications.

A study on low temperature transport properties of independent double-gated poly-Si nanowire transistors.

Employing mix-and-match lithography of I-line stepper and e-beam direct writing, independent double-gated poly-Si nanowire thin film transistors with channel lengths ranging from 70 nm to 5 µm were fabricated and characterized. Electrical measurements performed under cryogenic ambient displayed intriguing characteristics in terms of length dependent abrupt switching behavior for one of the single-gated modes. Through simulation and experimental verification, the root cause for this phenomenon was identified to be the non-uniformly distributed dopants introduced by ion implantation.

Novel poly-silicon nanowire field effect transistor for biosensing application.

A simple and low-cost method to fabricate poly-silicon nanowire field effect transistor (poly-Si NW FET) for biosensing application was demonstrated. The poly-silicon nanowire (poly-Si NW) channel was fabricated by employing the poly-silicon (poly-Si) sidewall spacer technique, which approach was comparable with current commercial semiconductor process and forsaken expensive E-beam lithography tools. The electronic properties of the poly-Si NW FET in aqueous solution were found to be similar to those of single-crystal silicon nanowire field effect transistors reported in the literature. A model biotin and avidin/streptavidin sensing system was used to demonstrate the biosensing capacity of poly-Si NW FET. The changes of I(D)-V(G) curves were consistent with an n-type FET affected by a nearby negatively (streptavidin) and positively (avidin) charged molecules, respectively. Specific electric changes were observed for streptavidin and avidin sensing when nanowire surface of poly-Si NW FET was modified with biotin and streptavidin at sub pM to nM range could be distinguished. With its excellent electric properties and the potential for mass commercial production, poly-Si NW FET can be a very useful transducer for a variety of biosensing applications.

Ultrasensitive detection of dopamine using a polysilicon nanowire field-effect transistor.

An unprecedented high sensitive sensing of neurotransmitter dopamine at fM level was demonstrated using a poly-crystalline silicon nanowire field-effect transistor (poly-SiNW FET) fabricated by employing a simple and low-cost poly-Si sidewall spacer technique, which was compatible with current commercial semiconductor processes for large-scale standard manufacture.

Fabry-perot-type antireflective coating for deep-ultraviolet binary photomask applications.

We demonstrate an antireflective coating structure, which is based on the three-layer metal interference called the Fabry-Perot structure, for a deep-ultraviolet binary mask. The antireflective coating structure is composed of a metal-oxide-metal stack. By addition of different optimized structures, reflectances of less than 1.5% at both 248 and 193 nm have been achieved. At the three-layer Fabry-Perot structure, the bottom chrome layer provides suitable absorption. By controlling the thickness of the intermediate silicon oxide layer, we can tune the minimum-reflection regime to the desired exposure wavelength. The top metal layer can prevent charge accumulation during e-beam writing.