Silicon oxide

About: Silicon oxide is a research topic. Over the lifetime, 22220 publications have been published within this topic receiving 260986 citations.

Hall Mobility in Chemically Deposited Polycrystalline Silicon

Abstract: Hall‐mobility measurements have been performed on polycrystalline silicon films deposited on a silicon oxide surface by the thermal decomposition of silane. Samples with doping impurities added during deposition or by diffusion from a doped vapor‐deposited oxide showed similar behavior. For both n‐type and p‐type samples approximately 5 μ thick, the mobility reached a maximum value of about 40 cm2/V sec at a free carrier concentration of about 1018 cm−3 and decreased for both higher and lower carrier concentrations. The observed Hall mobility was generally higher in p‐type samples than in n‐type samples. The decrease in observed mobility with decreasing carrier concentration is attributed to the effects of high resistivity space‐charge regions surrounding grain boundaries in the polycrystalline material. The mobility was seen to increase as the film thickness increased for samples with similar doping, indicating a more ordered structure in thicker films.

Attachment of 3-(Aminopropyl)triethoxysilane on Silicon Oxide Surfaces: Dependence on Solution Temperature

Abstract: Parameters important to the self-assembly of 3-(aminopropyl)triethoxysilane (APTES) on chemically grown silicon oxide (SiO2) to form an aminopropyl silane (APS) film have been investigated using in situ infrared (IR) absorption spectroscopy. Preannealing to ∼70 °C produces significant improvements in the quality of the film: the APS film is denser, and the Si−O−Si bonds between the molecules and the SiO2 surface are more structured and ordered with only a limited number of remaining unreacted ethoxy groups. In contrast, post-annealing the functionalized SiO2 samples after room temperature reaction with APTES (i.e., ex situ annealing) does not lead to any spectral change, suggesting that post-annealing has no strong effect on the horizontal polymerization as suggested earlier. Both IR and ellipsometry data show that the higher the solution temperature, the denser and thinner the APS layer is for a given immersion time. Finally, the APS layer obtained by preannealing the solution at 70 °C exhibits a better ...

Identification of rapid changes at plasma–solid interfaces

Abstract: Recording ellipsometers and surface film balance, breath patterns, and ferric oxide powder “staining” were used to observe adsorption of normal plasma constituents onto metal oxide, silicon oxide, and polymer surfaces. Adsorbed proteins could be identified by their ability to adsorb matter from corresponding antihuman sera. Data indicate that oxidized silicon crystal surfaces adsorbed fibrinogen out of plasmas within 2 sec; within 20 sec, these films lost their ability to attract antifibrinogen and were later partially removed if intact factor XII was present in the solution. One aminated nonheparinized polymer formed films that adsorbed large amounts of fibrinogen and some gamma globulins out of plasma in the ellipsometer, and platelets out of platelet-rich plasma, as well as ferric oxide out of aqueous suspension. After taking up heparin, these polymer films appeared able to adsorb only small amounts of protein or oxide, and no detectable amounts of fibrinogen or platelets. On another aminated polymer, heparin seemed without effect. Interaction of metal surfaces with plasma may be complicated by oxidation.

Mechanisms of visible-light emission from electro-oxidized porous silicon.

Abstract: High-porosity porous silicon, after electrochemical oxidation, is a stable and highly reproducible luminescent material with a luminescence quantum efficiency as high as 3% at room temperature. Luminescence decay rates as long as several hundreds of microseconds show that radiative and nonradiative processes both have low efficiencies even at room temperature. This shows that confinement of carriers inside nanometer-sized crystallites does not have a noticeable effect on indirect-band-gap selection rules but restricts strongly the different processes for nonradiative deexcitation. An analysis of the dependence of the nonradiative-decay rates on carrier confinement in terms of the tunneling of carriers through silicon oxide barriers surrounding the confined zone accounts well for our experimental results with an average barrier thickness of 5 nm. This tunneling model is also used to explain successfully the increase in quantum efficiency with the increase of the level of oxidation.

Method for forming silicon-containing materials during a photoexcitation deposition process

Abstract: Embodiments of the invention generally provide a method for depositing films or layers using a UV source during a photoexcitation process. The films are deposited on a substrate and usually contain a material, such as silicon (e.g., epitaxy, crystalline, microcrystalline, polysilicon, or amorphous), silicon oxide, silicon nitride, silicon oxynitride, or other silicon-containing materials. The photoexcitation process may expose the substrate and/or gases to an energy beam or flux prior to, during, or subsequent a deposition process. Therefore, the photoexcitation process may be used to pre-treat or post-treat the substrate or material, to deposit the silicon-containing material, and to enhance chamber cleaning processes. Attributes of the method that are enhanced by the UV photoexcitation process include removing native oxides prior to deposition, removing volatiles from deposited films, increasing surface energy of the deposited films, increasing the excitation energy of precursors, reducing deposition time, and reducing deposition temperature.