Stable microcrystalline silicon thin-film transistors produced by the layer-by-layer technique

Abstract

International audienceMicrocrystalline siliconthin films prepared by the layer-by-layer technique in a standard radio-frequency glow discharge reactor were used as the active layer of top-gate thin-film transistors(TFTs). Crystalline fractions above 90% were achieved for silicon films as thin as 40 nm and resulted in TFTs with smaller threshold voltages than amorphous siliconTFTs, but similar field effect mobilities of around 0.6 cm2/V s. The most striking property of these microcrystalline silicontransistors was their high electrical stability when submitted to bias-stress tests. We suggest that the excellent stability of these TFTs, prepared in a conventional plasma reactor, is due to the stability of the μc-Si:H films. These TFTs can be used in applications that require high stability for which a-Si:HTFTs cannot be used, such as multiplexed row and column drivers in flat-panel display applications, and active matrix addressing of polymer light-emitting diodes

Analytical Threshold Voltage Model Considering Quantum Size Effects for Nanocrystalline Silicon Thin Film Transistors

“…• C) making nc-Si attractive for fabrication of relatively high quality and inexpensive TFTs compared to those of amorphous and poly-Si [5,6].…”

High mobility, bottom gate, nanocrystalline silicon thin film transistors incorporating a nitrogenated incubation layer

“…However, to date, only top gate (TG) TFTs have been produced with field effect mobilities greater than a-Si:H devices. Bottom gate (BG) TFTs, on the other hand, tend to yield devices with field effect mobilities that are below 1 cm 2 V À1 s À1 [5,6].…”

“…To achieve the conversion of such a thick layer of crystalline silicon to silicon nitride, a À50 kV bias was applied to the crystalline silicon to raise the nitrogen ion bombardment energy. Meanwhile, a layer-by-layer growth methodology has previously been reported for the growth of nc-Si [5,17]. In this process, a thin layer of a-Si:H is deposited by rf-PECVD before being exposed to a hydrogen plasma which converts the amorphous material into nc-Si though a chemical annealing process [18,19].…”

Raman spectroscopy of heavily doped polycrystalline and microcrystalline silicon

“…The same fields of application are envisaged for as-deposited microcrystalline (sometimes also called nanocrystalline) silicon (µc-Si) [3]. However, the terms for the two materials (poly-Si and µc-Si) are often used synonymical (see e.g.…”