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.

Method of fabricating a polysilicon transistor with a high carrier mobility

Abstract: A method for making a TFT comprises forming an amorphous silicon layer having a smooth upper surface. An insulating layer is then formed on the smooth surface at or below the critical temperature for the instantaneous crystallization of amorphous. This slowly converts the amorphous silicon to polycrystalline silicon while retaining the smooth surface. TFTs incorporating the invention have a relatively high field effect (surface) mobility.

Thickness dependence of properties of excimer laser crystallized nano-polycrystalline silicon

Abstract: Excimer laser crystallization is used to produce layered nanocrystalline silicon from hydrogenated amorphous silicon, using a partial melting process. Three types of hydrogenated amorphous silicon samples, 100, 300, and 500 nm thick, were laser treated in order to investigate the changes to the structural, optical, and electrical properties as a function of amorphous silicon thickness with excimer laser crystallization. The resulting nanocrystalline thin films were characterized using Raman spectroscopy, optical absorption measurements, atomic force microscopy, forward recoil spectrometry, and current–voltage measurements. The relationship of crystalline volume and laser energy density was established, along with the behavior of the optical gap and its relationship to hydrogen content. Surface roughness effects are discussed in the context of photovoltaic applications. The effect of increased mobility on photoconductivity after excimer laser crystallization is also examined.

Effective density‐of‐states distributions for accurate modeling of polycrystalline‐silicon thin‐film transistors

Abstract: The effective density‐of‐states (DOS) distributions in unhydrogenated and hydrogenated polycrystalline silicon (poly‐Si) thin films have been determined from field‐effect conductance measurements of n‐ and p‐channel thin‐film transistors (TFTs) fabricated in these films. These results are compared with those obtained through device simulation as well as with trap‐state densities obtained by Levinson’s method. Variations in TFT fabrication process conditions and device architecture are shown to significantly impact the DOS distribution and to correspondingly affect device performance. Hydrogenated low‐temperature‐processed (600 °C) films have relatively high midgap‐state and valence‐band tail‐state densities and Fermi levels located above midgap, in contrast to high‐temperature‐processed (950 °C) films that have low midgap‐state densities and Fermi levels located below midgap. The field‐effect conductance analysis method provides realistic gap‐state density information and can thereby facilitate the accura...

Semiconductor thin film, method of producing the same, apparatus for producing the same, semiconductor device and method of producing the same

Abstract: A semiconductor device having a high field effect mobility is produced by increasing the particle diameter of a silicon thin film of a polycrystalline silicon thin film transistor. On a transparent insulating substrate (201) is formed an insulating film of a two-layer structure comprising a lower insulating film (202) contacting with the transparent insulating substrate (201) and having a heat conductivity larger than that of an upper insulating film (203) that is formed thereon. The upper insulating film (203) is patterned into a plurality of stripes. Then, an amorphous silicon thin film (204) is formed on the patterned insulating film. Thereafter, the amorphous silicon thin film (204) is transformed into a polycrystalline silicon thin film (210) by scanning the amorphous silicon thin film (204) with a laser beam in parallel with the stripes of the upper insulating film (203).

Micromachining and Micropackaging of Transducers

Abstract: I. Overview. Silicon micromachining and its application to high performance integrated sensors (K.D. Wise). Epoxy encapsulants, adhesives and specialty polymers for microelectronic applications (D.R. Owen, R.M. Zone). II. Micropackaging and Encapsulation. Packaging considerations for the microdielectrometer and related chemical sensors (S.D. Senturia, D.R. Day). Bonding techniques for microsensors (W.H. Ko et al.). Corrosion protection for implantable integrated sensors by CO 2 laser processing for glass and silicon (Y. Naruse et al.). Electrical contacts to implantable integrated sensors by CO 2 laser-drilled bias through glass (L. Bowman et al.). Packaging of an intracranial pressure telemetering unit for chronic implantation (T. Spear et al.). III. Etching Techniques. Orientations of the third kind: the coming of age of (110) silicon (D.L. Kendall,G.R. de Guel). The use of a certain fluorocarbon surfactant and fluorocarbon conformal coating improves KOH silicon etching quality (B. Block, M. Sierakowsky). Ellipsometric study of bias-dependent etching and the etch-stop mechanism for silicon in aqueous KOH (E.D. Palik et al.). Submicron accuracies in anisotropic etched silicon piece parts - a case study (T.L. Poteat). Deep etching of silicon using plasma (C.D. Fung, J.R. Linkowski). IV. Microstructures. Microfabrication technology for microsensors (L.T. Romankiw). Polycrystalline silicon microstructures (R.T. Howe). Micromachining technology for flexible sensor arrays (P.W. Barth). Planar processed, integrated displacement sensors (H. Guckel et al.). Electrochemical shaping of three dimensional continuously modulated surface contours (U. Langau et al.). V. Applications. A microtransducer for air flow and differential pressure sensing applications (G.B. Hocker et al.). V-groove capillary for low flow control and measurement (M.G. Guvenc). Fabrication of biomedical sensors using thin and thick film microelectronic technology (M.R. Neuman, C.-C. Liu). Microelectronic microelectrode glucose sensor at low potentials (L.-T. Chan et al.). Potential applications of micromachining to semiconductor chemical sensors (P.W. Cheung).