Characteristics of Gate-All-Around Junctionless Poly-Si TFTs With an Ultrathin Channel

Abstract

This letter demonstrates for the first time junctionless (JL) gate-all-around (GAA) poly-Si thin-film transistors (TFTs) with ultrathin channels (2 nm). The subthreshold swing is 61 mV/decade and the ON/OFF current ratio is close to 10 8 because of the excellent gate controllability and ultrathin channel. The JL-GAA TFTs have a low drain-induced barrier lowering value of 6 mV/V, indicating greater suppression of the shortchannel effect than in JL-planar TFTs. The cumulative distribution of electrical parameters in JL-GAA is small. Therefore, the proposed JL-GAA TFTs of excellent device characteristics along with simple fabrication are highly promising for future system-on-panel and system-on-chip applications.Index Terms-Gate-all-around (GAA), junctionless (JL), thin-film transistor, ultrathin channel.

Surface potential calculation and drain current model for junctionless double-gate polysilicon TFTs

“…4 The cross-section of channel with 2-nm-thick nano-belt structure 4 can be approximately modeled by the double-gate structure. In addition, the gate length (L) of the device is 1 μm.…”

“…This behavior can be explained by the surface scattering at higher gate bias. 4 As a result, the effective mobility is expressed as μ e f f = μ 0 /(1 + χ V 2 gs ), where μ 0 is the maximum mobility and χ is the scattering factor.…”

“…Thus, it can skip junction formation issues and greatly simplify fabrication. Recently, the JL poly-Si TFTs [1][2][3][4] have been shown as attractive devices because they possess excellent turn-on and output characteristics, an improved subthreshold swing, a large ON-current, a high ON/OFF-current ratio, etc. Also, it is feasible to apply JL scheme for large-area electronics as well as 3D stackable poly-Si based electronics.…”

Silicon-on-insulator (SOI) junctionless transistors

“…The signifi cant improvement in the current drive is ascribed to the inherently high carrier concentration contained in the channel of the JL device. These results provide evidence of the great potential of the JL poly-Si TFTs for manufacturing future 3D and fl at-panel electronic products (Lin et al , 2012;Chen et al , 2013). P-type junctionless transistors made in polycrystalline germanium have an advantage over poly-Si transistors because of higher carrier mobility, and thus higher current drive.…”

Complementary resistive switching behavior induced by varying forming current compliance in resistance random access memory

“…Technological development of on-display devices, logic IC, batteries, and memory is crucial for advanced portable electronic product applications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Among these devices, a reliable, fast-working, and energy-saving nonvolatile memory is extremely important, especially for portable applications. Resistance random access memory (RRAM) has great potential to serve as the next-generation nonvolatile memory device due to its simple structure, low power consumption, rapid operation, and high density integration capability.…”