Active-matrix organic LED (AMOLED) is one of the most promising contenders for next-generation displays. However, the VT-shift issue in thin-film transistors (TFT) has to be addressed to enable wide deployment [1]. Voltage programming and current programming are well-known VT-shift-compensation techniques for analog driving. However, they all need more than 4 TFTs per pixel, which increases the...

We describe possible applications of pixelized micro-well detectors (PMWDs) as three-dimensional charged particle trackers in advanced gamma-ray telescope concepts. A micro-well detector consists of an array of individual micro-patterned gas proportional counters opposite a planar drift electrode. When combined with pixelized thin film transistor (TFT) array readouts, large gas volumes may be i...

Hydrogenated polymorphous Silicon allows to fabricate TFTs with very interesting characteristics including better threshold voltage stability than a-Si TFTs, lower leakage current than μc-Si:H TFTs and excellent uniformity. Investigation of threshold voltage shift mechanisms of pm-Si:H TFTs has shown a specific semiconductor material degradation with different activation energies compared to a-...

We previously demonstrated highly stable backchannel cut and back-channel passivated amorphous silicon thin-film transistors (a-Si:H TFTs) made at 300C on 2.9-inch x 2.9-inch clear plastic substrates [1]. Mechanical stress in the TFT stack causes the substrate to expand or contract, which easily results in misalignment between consecutive device layers [2,3]. Therefore we developed three selfal...

We have investigated the microwave-detected photoconductivity responses from the amorphous In–Ga–Zn–O (a-IGZO) thin films. The time constant extracted by the slope of the slow part of the reflectivity signals are correlated with TFT performances. We have evaluated the influences of the sputtering conditions on the quality of a-IGZO thin film, as well as the influences of gate insulation films a...

This report describes a crystallization method we developed for amorphous (a)-Si film by using 405-nm laser diodes (LDs). The proposed method has been used to fabricate bottom gate (BG) microcrystalline (μc)-Si TFTs for the first time. A μc-Si film with high crystallinity was produced and high-performance BG μc-Si TFTs with a field effect mobility of 3.6 cm2/Vs and a current on/off ratio exceed...

CMOS poly-Si thin-film transistors (TFTs) were fabricated through crystallization and GILD processes by a novel selected area laser assisted (SALA) system. The system enables a local area irradiation of small beams of a pulsed solid-state laser of frequency tripled Nd:YAG. The novel TFT process eliminated 3 doping mask steps of the conventional process. On-off current ratios for both types of p...

In this paper, we study the electrical properties and current-temperature stress (CTS) induced electrical instability of half Corbino and fork-shaped hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) fabricated on the same substrate. The influence on overall electrical properties of the threshold voltage shift of half Corbino a-Si:H TFT is discussed in comparison to fork-shap...

Amorphous InGaZnO (a-IGZO) TFTs attracted more demands due to the transparency and high mobility. Since TFTs are always exposed to both positive and negative gate bias, the alternating pulse bias stress tests are required to ensure stable TFT characteristics. In this paper, the effects of alternating pulse bias stress on the threshold voltage shift (ΔVth) of a-IGZO TFTs with respect to the chan...

Polysilicon Thin Film Transistors (TFT) are of great interest in the field of large area microelectronics, especially because of their application as active elements in Flat Panel Displays. Different deposition techniques are in tough competition with the objective to obtain device-quality polysilicon thin films at low temperature. In this paper we present the preliminary results obtained with ...