Preparation of SrTiO3 Thin Films by Ecr and Thermal Mocvd

1993 ◽  
Vol 310 ◽  
Author(s):  
P-Y. Lesaicherre ◽  
H. Yamaguchi ◽  
T. Sakuma ◽  
Y. Miyasaka ◽  
M. Yoshida ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Reaction ◽  
Columnar Structure ◽  
Thermal Cvd ◽  
Diffusion Limited ◽  
Maximum Dielectric Constant ◽  
And Diffusion ◽  
Ti Content ◽  
Limited Process ◽  
Sem Analyses

AbstractSrTiO3 thin films were prepared by ECR and thermal MOCVD. In thermal-CVD mode, Sr content and Ti content were at a maximum at 0.56 Torr. Results showed that SrO deposition is a surface reaction limited process between 500 and 650°C, whereas TiO2 deposition is surface reaction limited between 500 and 600 °C, and diffusion limited above 600 °C. At a low pressure of 8 mTorr, ECR oxygen plasma was found to help decompose Ti(i-OC3H7)4. In ECR-CVD mode, the deposition temperature could be lowered to 400 °C. TEM and SEM analyses showed that SrTiO3 thin films have a columnar structure. The size of the grains depends on film thickness, and their shape on film composition (Sr/Ti ). Films prepared by thermal-CVD had a lateral step coverage of 50 %. 40 nm SrTiO3 thin films (Sr/Ti = 1.0) prepared by thermal-CVD on Pt/TaOx/Si and annealed for 2 hours in O2 had a maximum dielectric constant of 139 (Cs = 31 fF/μm2 and teq = 1.1 nm) and a leakage current density of 6x10−8 A/cm2 at 1.0 V.

Low Energy Ion Bombardment and Microstructural Evolution in Thin Films

1989 ◽  
Vol 157 ◽  
Author(s):  
Chih M. Yang ◽  
Harry A. Atwater
Keyword(s):  
Thin Films ◽  
Ion Bombardment ◽  
Island Growth ◽  
New Approach ◽  
Enhanced Diffusion ◽  
Rate Laws ◽  
Island Evolution ◽  
Diffusion Limited ◽  
Kinetics Of ◽  
And Diffusion

ABSTRACTA new approach to modeling the evolution of islands in thin films by growth and coarsening during ion bombardment is described. Solution of a continuity equation and matter conservation relation, coupled with interface-limited and diffusion-limited rate laws for island growth and coarsening allows the kinetics of island evolution to be modeled. Results from the model indicate distinct kinetic paths for island evolution during ion bombardment as a result of growth, enhanced diffusion, island dissociation and monomer sputtering.

A large portion of the astrocyte proteome is dedicated to perivascular endfeet, including critical components of the electron transport chain

2021 ◽  
pp. 0271678X2110041
Author(s):  
Jesse A Stokum ◽  
Bosung Shim ◽  
Weiliang Huang ◽  
Maureen Kane ◽  
Jesse A Smith ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Transport Chain ◽  
Glycogen Storage ◽  
Subcellular Compartment ◽  
Diffusion Limited ◽  
Transport Chain ◽  
Critical Components ◽  
And Diffusion ◽  
Ubiquitous Presence ◽  
Astrocyte Endfeet

The perivascular astrocyte endfoot is a specialized and diffusion-limited subcellular compartment that fully ensheathes the cerebral vasculature. Despite their ubiquitous presence, a detailed understanding of endfoot physiology remains elusive, in part due to a limited understanding of the proteins that distinguish the endfoot from the greater astrocyte body. Here, we developed a technique to isolate astrocyte endfeet from brain tissue, which was used to study the endfoot proteome in comparison to the astrocyte somata. In our approach, brain microvessels, which retain their endfoot processes, were isolated from mouse brain and dissociated, whereupon endfeet were recovered using an antibody-based column astrocyte isolation kit. Our findings expand the known set of proteins enriched at the endfoot from 10 to 516, which comprised more than 1/5th of the entire detected astrocyte proteome. Numerous critical electron transport chain proteins were expressed only at the endfeet, while enzymes involved in glycogen storage were distributed to the somata, indicating subcellular metabolic compartmentalization. The endfoot proteome also included numerous proteins that, while known to have important contributions to blood-brain barrier function, were not previously known to localize to the endfoot. Our findings highlight the importance of the endfoot and suggest new routes of investigation into endfoot function.

Effects of diffusion temperature and diffusion time on fabrication of Na-diffused p-type ZnO thin films

2012 ◽  
Vol 80 ◽  
pp. 175-177 ◽  
Author(s):  
Huibin Liu ◽  
Xinhua Pan ◽  
Ping Ding ◽  
Zhizhen Ye ◽  
Haiping He ◽  
...  
Keyword(s):  
Thin Films ◽  
Diffusion Time ◽  
Zno Thin Films ◽  
Diffusion Temperature ◽  
P Type ◽  
And Diffusion

Effect of Interface Conditions on Yield Behavior of Passivated Copper Thin Films

2002 ◽  
Vol 17 (7) ◽  
pp. 1863-1870 ◽  
Author(s):  
Richard P. Vinci ◽  
Stefanie A. Forrest ◽  
John C. Bravman
Keyword(s):  
Thin Films ◽  
Driving Force ◽  
Copper Film ◽  
Dislocation Motion ◽  
Yield Behavior ◽  
Dislocation Glide ◽  
Preferential Diffusion ◽  
Continuous Vacuum ◽  
And Diffusion ◽  
Induced Dislocation

Wafer curvature was used to study the thermal–mechanical behavior of 1-μm Cu thin films capped with a 100-nm-thick Si3N4 layer. These films were grown with either a Ta or a Si3N4 underlayer. Films on Si3N4 that were exposed to oxygen at the film/capping layer interface or at the center of the copper layer exhibited Bauschinger-like yielding at low stress. Stacks deposited under continuous vacuum, with a Ta underlayer, with carbon exposure at the upper surface of the copper film, or with oxygen exposure of only the underlayer did not demonstrate the anomalous yielding. Preferential diffusion of oxygen into copper grain boundaries or interfaces is the likely cause of the early yield behavior. Possible mechanisms include an increase in interface adhesion due to the presence of oxygen in solution and diffusion-induced dislocation glide as an additional driving force for dislocation motion at low applied stress.

Eco-friendly Leather Dyeing using Ultrasound Technique

2020 ◽  
Vol 115 (6) ◽  
pp. 199-205
Author(s):  
Md. Abu Sayid Mia ◽  
Refat E Ashraf ◽  
Mohammad Nurnabi ◽  
Md. Zahnagir Alam
Keyword(s):  
Cross Section ◽  
Fiber Structure ◽  
Dye Uptake ◽  
Scanning Calorimetry ◽  
Mechanical Agitation ◽  
Ultrasound Technique ◽  
Dye Penetration ◽  
Spent Liquor ◽  
And Diffusion ◽  
Sem Analyses

In this study, leather was dyed using ultrasound and conventional methods to investigate the influence of ultrasound on leather dyeing. Ultrasound is more effective than mechanical agitation in enhancing leather dyeing. Effects of various process parameters, such as, dyeing temperature, dyeing time and doses of dye on dyeing of leather in presence of ultrasound were investigated. Dyed leathers were characterized with scanning electron microscopy (SEM), photomicrographic analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), etc. It was observed that percentage exhaustion of dye, dye uptake, dye penetration and diffusion coefficient were increased significantly in presence of ultrasound compared to those of dyeing in absence of ultrasound. Moreover, physical properties of the dyed leathers were also investigated. Color rub fastness, perspiration, tensile strength, etc. of dyed leather in presence of ultrasound were higher than that of without ultrasound. SEM analyses of the surface and cross section of the dyed leather showed that fiber structure was not affected by ultrasound. Photomicrographic analysis of cross-section of the dyed leather also showed a deeper penetration of dye in presence of ultrasound. Consequently, dye content in the spent liquor was decreased resulting in a lower environmental pollution.

Growth Mechanisms and Diffusion in Multinary and Multilayer Chalcopyrite Thin Films

1993 ◽  
Vol 32 (S3) ◽  
pp. 57 ◽  
Author(s):  
R. Klenk ◽  
T. Walter ◽  
D. Schmid ◽  
H. W. Schock
Keyword(s):  
Thin Films ◽  
Growth Mechanisms ◽  
And Diffusion
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