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.

PMOS transistors in LPCVD polycrystalline silicon-germanium films

Abstract: P-channel MOS thin-film transistors (TFTs) have been fabricated in low-pressure chemical vapor deposition (LPCVD) polycrystalline silicon-germanium (poly-SiGe) films using either a low-temperature ( >

Analysis of Polysilicon Diffusion Sources

Abstract: Diffusion of boron and arsenic from implantation doped polycrystalline silicon films into single‐crystal silicon was investigated as a function of various process parameters. The effects of interface treatment prior to poly‐Si deposition and of the poly‐Si grain size are analyzed. New data on dopant segregation are presented. Limitations of present process modeling tools are discussed and improved values for several input parameters are proposed.

“Hump” characteristics and edge effects in polysilicon thin film transistors

Abstract: Transfer characteristics of polycrystalline silicon (polysilicon) thin film transistors (TFTs) often show a “hump” in subthreshold regime. This effect, also observed in silicon-on-insulator (SOI) transistors, can be attributed to the presence of an enhanced electrical field at edges of the channel, which is related to the specific shape of the edge and its surrounding oxide. In this paper we attempt an analysis of the hump effect in polysilicon TFTs combining electrical measurements and two dimensional numerical simulations, and considering several geometries of the channel edge. The transfer characteristics showing the hump effect are analyzed in terms of a parallel of the main (“bulk”) transistor with two parasitic transistors located at the channel edges. The main and parasitic transistors have different threshold voltages and subthreshold swings and the equivalent parallel circuit reproduces very well the experimental transfer characteristics. The effect on the hump of interface states and oxide fixed...

The Nucleation of CVD Silicon on SiO2 and Si3 N 4 Substrates III . The System at Low Temperatures

Abstract: The growth of polycrystalline silicon layers on and substrates can be hampered in the early stages of growth by the presence of different species adsorbed on the surface In this article nucleation experiments with silicon on and are described in the system at temperatures between 600° and 900°C In this temperature regime (and without addition) the saturation nucleus density of silicon clusters on substrates shows a decrease in density with decreasing temperature, whereas on substrates the opposite occurs Experiments with nitrogen as a carrier gas, however, give almost the same saturation nucleus densities of silicon clusters on and substrates Additions of to the system produce a decrease in the nucleus saturation density on and substrates, and the density also decreases with decreasing temperatures below 900°C It is further shown that selective growth of silicon on partly coated silicon substrates becomes more difficult at lower growth temperatures Adsorption of different surface species (H, Cl, , and ) on and substrates is discussed and it is concluded that a strong adsorption of atomic hydrogen, notably on surfaces, may explain the difference in nucleus densities on and substrates at temperatures below 900°C

Mobility enhancement limit of excimer-laser-crystallized polycrystalline silicon thin film transistors

Abstract: The effects of various carrier scattering mechanisms on excimer-laser-crystallized polycrystalline silicon (poly-Si) thin film transistors (TFTs) fabricated using 450 °C processes on a glass substrate were studied. Good performance of a separated by ion implanted oxygen (SIMOX) metal–oxide–semiconductor field-effect transistor (MOSFET) with field-effect mobility of 670 cm2/V s and a subthreshold swing value of 0.087 V/dec was obtained using these 450 °C processes. The results showed the formation of a good silicon/silicon dioxide (SiO2) interface that is comparable to that of thermal oxide, as well as the high capability of 450 °C processes. The performance of the above SIMOX-MOSFET is superior to that of excimer-laser-crystallized poly-Si TFTs fabricated using the same 450 °C processes. This shows that poorer performance of poly-Si TFTs is caused by the poor crystalline quality of the poly-Si film. The field-effect mobility is affected little by the in-grain microdefects and surface morphology of the exc...