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11.
Jesús Rodríguez Kristen Kobylus Abernathy 《Journal of Mathematical Analysis and Applications》2012,385(1):49-59
Our goal in this paper is to provide sufficient conditions for the existence of solutions to discrete, nonlinear systems subject to multipoint boundary conditions. The criteria we present depends on the size of the nonlinearity and the set of solutions to the corresponding linear, homogeneous boundary value problems. Our analysis is based on the Lyapunov–Schmidt Procedure and Brouwer?s Fixed Point Theorem. The results presented extend the previous work of D. Etheridge and J. Rodríguez (1996, 1998) [5], [6] and J. Rodríguez and P. Taylor (2007) [18], [19]. 相似文献
12.
Inductively Coupled Plasma Etching in ICl- and IBr-Based Chemistries. Part I: GaAs, GaSb, and AlGaAs
Y. B. Hahn D. C. Hays H. Cho K. B. Jung E. S. Lambers C. R. Abernathy S. J. Pearton W. S. Hobson R. J. Shul 《Plasma Chemistry and Plasma Processing》2000,20(3):405-415
High-density plasma etching of GaAs, GaSb, and AlGaAs was performed inICl/Ar and IBr/Ar chemistries using an Inductively Coupled Plasma (ICP)source. GaSb and AlGaAs showed maxima in their etch rates for both plamachemistries as a function of interhalogen percentage, while GaAs showedincreased etch rates with plasma composition in both chemistries. Etchrates of all materials increased substantially with increasing rf chuckpower, but rapidly decreased with chamber pressure. Selectivities >10 forGaAs and GaSb over AlGaAs were obtained in both chemistries. The etchedsurfaces of GaAs showed smooth morphology, which were somewhat better withICl/Ar than with IBr/Ar discharge. Auger Electron Spectroscopy analysisrevealed equirate of removal of group III and V components or thecorresponding etch products, maintaining the stoichiometry of the etchedsurface. 相似文献
13.
S. J. Pearton W. S. Hobson C. R. Abernathy F. Ren T. R. Fullowan A. Katz A. P. Perley 《Plasma Chemistry and Plasma Processing》1993,13(2):311-332
Electron cyclotron resonance (ECR) BCl3 discharges with additional rf biasing of the sample position have been used to etch a variety of III–V semiconductors. GaAs and AlxGa1–xAs (x = 0–1) etch at equal rates in BCl3 or BCl3/Ar discharges, whereas SF6 addition produces high selectivities for etching GaAs over AlGaAs. These selectivities are in excess of 600 for dc biases of –150 V, and fall to 6 for biases of –300 V. If the dc biases are kept to – 100 V, there is no measurable degradation of the optical properties of the GaAs and AlGaAs. The AlF3 formed on the AlGaAs surface during exposure to BCl3/SF6 plasmas can be removed by sequential rinsing in dilute NH4OH and water. In-based materials (InP, InAs, InSb, InGaAs) etch at slow rates with relatively rough morphologies in BCl3 plasmas. 相似文献
14.
J. W. Lee J. Hong E. S. Lambers C. R. Abernathy S. J. Pearton W. S. Hobson F. Ren 《Plasma Chemistry and Plasma Processing》1997,17(2):155-167
BCl3/Ar discharges provide rapid, smooth pattern transfer in GaAs, AlGaAs, GaP, and GaSb over a wide range of plasma conditions.
At high BCl3-to-Ar ratio there is significant surface roughening on GaSb, which is correlated with the presence of B- and Cl-containing
residues detected by Auger electron spectroscopy. BCl3/N2 discharges provide similar etch rates to BCl3/Ar, but when used with photoresist masks lead to rough morphologies on the semiconductor materials due to enhanced dissociation
and redeposition of the resist. Etch rates with electron cyclotron resonance discharges are up to two orders of magnitude
higher than for rf-only conditions. 相似文献
15.
16.
J. W. Lee J. Hong E. S. Lambers C. R. Abernathy S. J. Pearton W. S. Hobson F. Ren 《Plasma Chemistry and Plasma Processing》1997,17(2):169-179
BCl3/Ar and BCl3/N2 plasma chemistries were compared for patterning of InP, InAs, InSb, InGaAs, InGaAsP, and AlInAs. Under electron cyclotron
resonance conditions etch rates in excess of 1 μm/min can be achieved at room temperature with low additional rf chuck power
(150 W). The etch rates are similar for both chemistries, with smoother surface morphologies for BCl3/Ar. However, the surfaces are still approximately an order of magnitude rougher (as quantified by atomic force microscopy)
than those obtained under the same conditions with Cl2/Ar. InP surfaces etched at high BCl3-to-Ar ratios have measurable concentrations of boron-and chlorine-containing residues. 相似文献
17.
WYETH Paul 《中国科学:化学》2010,(3)
Silks represent some of the most precious ancient and historic textile artefacts in collections worldwide.Their optimum preservation demands an appreciation of their characteristics.One important concern,especially with regard to ancient Chinese silks,is whether the fabrics have been degummed.Silks with remnant sericin gum coating the fibroin fibres would require different conservation protocol.In previous research on aged silks,the presence of sericin has been inferred from amino acid analysis of hydrolysa... 相似文献
18.
J. Hong E. S. Lambers C. R. Abernathy S. J. Pearton R. J. Shul W. S. Hobson 《固体与材料科学评论》1998,23(4):323-396
Current and future generations of sophisticated compound semiconductor devices require the ability for submicron scale patterning. The situation is being complicated because some of the new devices are based on a wider diversity of materials to be etched. Conventional RIE (reactive ion etching) has been prevalent across the industry so far, but has limitations for materials with high bond strengths or multiple elements. In this article, we suggest high-density plasmas such as ECR (electron cyclotron resonance) and ICP (inductively coupled plasma), for the etching of ternary compound semiconductors (InGaP, AlInP, AlGaP) that are employed for electronic devices such as heterojunction bipolar transistors (HBTs) or high electron mobility transistors (HEMTs), and photonic devices such as light-emitting diodes (LEDs) and lasers. Operating at lower pressure, high-density plasma sources are expected to meet target goals determined in terms of etch rate, surface morphology, surface stoichiometry, selectivity, etc. The etching mechanisms that are described in this article can also be applied to other III-V (GaAs-based, InP-based) as well as III-Nitride, because the InGaAlP system shares many of the same properties. 相似文献
19.
B.S. Kang S. Kim F. Ren K. Ip Y.W. Heo B.P. Gila C.R. Abernathy D.P. Norton S.J. Pearton 《Applied Physics A: Materials Science & Processing》2005,80(2):259-261
Bulk Pt/ZnO Schottky rectifiers show gas sensitivities for CO of 4% and 8%, respectively, at 150 °C for 1 and 10% CO in N2. The current or voltage changes are time dependent, with an activation energy of 40.7 kJmol-1. Over a limited range of partial pressures of CO (PCO) in the ambient gas, the on-state resistance R of the sensor at fixed bias voltage decreased according to R=(RO+A(PCO)0.5)-1, where A is a constant and RO is the resistance in N2. Since these devices are also sensitive to H2 and C2H4, the ZnO rectifiers appear promising for a range of gas-sensing applications. PACS 81.05.Dz; 73.61.Ga; 72.80.Ey 相似文献
20.
[formula: see text] Iron salts efficiently catalyze the Doyle-Kirmse reaction of allyl sulfides with (trimethylsilyl)diazomethane and ethyl diazoacetate in dichloroethane at 83 degrees C. Competitive dimerization is less of a problem with (trimethylsilyl)diazomethane than with ethyl diazoacetate. Good results are obtained using only 1.5 equiv of (trimethylsilyl)diazomethane, even without slow addition. Phosphine ligands affect the kinetics, but not the diastereoselectivity. Dppe and BINAP lead to higher yields than dppp, but no enantioselection was detected with R-(+)-BINAP. 相似文献