Effects of process variations on the current in Schottky Barrier Source-Gated Transistors

IEEE Trans. Electron Devices

Trainor

Young

et al. 2012

Self Cite

-Source-gated transistors (SGTs) have potentially very high output impedance and low saturation voltages, which make them ideal as building blocks for high performance analog circuits fabricated in thin-film technologies. The quality of the saturation is greatly influenced by the design of the field-relief structure incorporated into the source electrode. Starting from measurements on self-aligned polysilicon structures, we show through numerical simulations how the field plate design can be improved. A simple source field plate around 1µm long situated several tens of nm above the semiconductor can increase the low-voltage intrinsic gain by more than two orders of magnitude and offers adequate tolerance to process variations in a moderately scaled thin-film SGT.

Section: B Simulation Of Sgt Operationsupporting

confidence: 87%

Field Plate Optimization in Low-Power High-Gain Source-Gated Transistors

IEEE Trans. Electron Devices

Trainor

Young

et al. 2012

Self Cite

“…Practical concerns might exist regarding increased parasitic capacitance and reduced speed as a result of this overlap. However, as we have shown in the past [15], in SGTs operating in high-mobility semiconductors and at high electric fields the majority of the current enters the device in less than 1 um of source length at the drain-end of the source. This current crowding effect means that the source/gate overlap need not be a lot larger than this value, in order to minimize capacitance and at the same time exploit the whole of the injection area.…”

Section: B Electrical Characteristics and Source Geometrymentioning

confidence: 86%

Source-Gated Transistors for Power- and Area-Efficient AMOLED Pixel Circuits

Guo

2014

J. Display Technol.

Self Cite

In this work, the source-gated transistor (SGT) structure is proposed for implementation of the driving transistor in active-matrix organic light-emitting diode (AMOLED) display pixel circuits. The benefits of using the SGT were evaluated through numerical device simulations based on the well-developed low temperature polycrystalline silicon (LTPS) and indium-gallium-zinc-oxide (IGZO) material models. The simulation results prove that significant reductions of the layout area and the power consumption can be achieved for both LTPS and IGZO technologies by using the SGT device structure, which in turn proves that the SGT device structure is potentially an ideal choice for achieving efficient AMOLED pixel circuits.Index Terms-Active-matrix, organic light emitting diode (OLED), thin-film transistor, polycrystalline silicon, amorphous metal oxide semiconductor.

“…Since the high-field region under the source covers a short area opposite the drain, we expect current in this regime to be independent of the length of the source, S [14]. However, the current will be sensitive to changes in source barrier height, ϕ B .…”

Section: High-and Low-field Behaviour Of the Sgtmentioning

confidence: 99%

Low-Field Behavior of Source-Gated Transistors

Shannon

IEEE Trans. Electron Devices

Georgakopoulos

et al. 2013

-A physical description for low-field behavior of a Schottky source-gated transistor (SGT) is outlined where carriers crossing the source barrier by thermionic emission are restricted by JFET action in the pinch-off region at the drain end of the source. This mode of operation leads to transistor characteristics with low saturation voltage and high output impedance without the need for field relief at the edge of the Schottky source barrier and explains many characteristics of the SGT observed experimentally. Two-dimensional device simulations with and without barrier lowering due to the Schottky effect show that transistors can be designed so that the current is independent of source length and thickness variations in the semiconductor. This feature, together with the fact that the current in an SGT is independent of source-drain separation, hypothesizes the fabrication of uniform current sources and other large-area analog circuit blocks with repeatable performance even in imprecise technologies such as high-speed printing.