Polycrystalline silicon

About: Polycrystalline silicon is a research topic. Over the lifetime, 19554 publications have been published within this topic receiving 198222 citations. The topic is also known as: polysilicon & poly-Si.

High-speed, short-channel polycrystalline silicon thin-film transistors

Abstract: Results are presented on the performance of low-temperature, short-channel polycrystalline silicon (poly-Si) thin-film transistors (TFTs), with channel length down to 0.5 μm, and scaled gate oxide thickness down to 20 nm. Good TFT switching characteristics were obtained, and the uniformity of short-channel TFTs was shown to have a standard deviation of better then 10%, even for channel widths as small as 4 μm. The 0.5 μm TFTs have been incorporated into a 15-stage complementary pair metal-oxide-Si transistor ring oscillator, which, at a supply voltage of 3 V, operated with a delay/stage of ∼0.1 ns.

Enhanced conduction and minimized charge trapping in electrically alterable read‐only memories using off‐stoichiometric silicon dioxide films

Abstract: An electrically alterable read‐only memory using silicon dioxide and silicon‐rich silicon dioxide layers capable of being cycled ≳107 times by minimizing electron charge trapping in the SiO2 layers of the device by incorporation of small amounts of silicon is discussed in detail. Charge transfer to and from a floating polycrystalline silicon layer from a control gate electrode is accomplished by means of a modified dual‐electron‐injector‐structure stack. This modified stack has the intervening silicon dioxide layer, which is sandwiched between silicon‐rich silicon dioxide injectors, replaced by a slightly off‐stoichiometric oxide containing between 1 and 6% excess atomic silicon above the normal 33% found in silicon dioxide. The operation of the electrically alterable device structures in terms of write/erase voltages, cyclability, breakdown, and retention is related to current‐voltage characteristics obtained from capacitors. A physical model based on direct tunneling between Si islands in the off‐stoichiometric oxide layer is proposed to account for the observed increase in the moderate electric field conductance and decrease in charge trapping in these oxide layers incorporated into devices and capacitors. This model and the observed current‐voltage characteristics are used to predict device operation for a variety of conditions.

Method of applying optical coatings of silicon compounds by cathode sputtering, and a sputtering cathode for the practice of the method

Abstract: Method of applying optical coatings of silicon compounds to substrates by reactive cathode sputtering of siliceous target materials. To solve the problem of improving the utilization of the target material and eliminating the blowout of particles from the target, the target of the invention is a polycrystalline silicon casting of at least 99% silicon containing dopants from the group, boron, antimony, phosphorus and arseic, and it is sputtered by direct current in an atomsphere containing the reaction gas.

Homogeneous nanocrystalline cubic silicon carbide films prepared by inductively coupled plasma chemical vapor deposition

Abstract: Silicon carbide films with different carbon concentrations xC have been synthesized by inductively coupled plasma chemical vapor deposition from a SiH4/CH4/H2 gas mixture at a low substrate temperature of 500 °C. The characteristics of the films were studied by x-ray photoelectron spectroscopy, x-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared absorption spectroscopy, and Raman spectroscopy. Our experimental results show that, at xC = 49 at.%, the film is made up of homogeneous nanocrystalline cubic silicon carbide without any phase of silicon, graphite, or diamond crystallites/clusters. The average size of SiC crystallites is approximately 6 nm. At a lower value of xC, polycrystalline silicon and amorphous silicon carbide coexist in the films. At a higher value of xC, amorphous carbon and silicon carbide coexist in the films.

Large-grain polycrystalline silicon films with low intragranular defect density by low-temperature solid-phase crystallization without underlying oxide

Abstract: The solid-phase crystallization of an amorphous silicon film to polycrystalline silicon by a low-temperature (⩽600 °C) furnace anneal has been investigated in a suspended cantilever structure without underlying silicon oxide by transmission electron microscopy and Raman spectroscopy. The grain size of polysilicon increases up to ∼3.0 μm and the density of intragranular defects decreases one order of magnitude in the samples without underlying oxide, compared with those with underlying oxide. The main reasons for the high quality of the suspended structures are thought to be due to the lower stress in the films during crystallization and a reduced grain nucleation rate.