Key Engineering Materials Vol. 503

Abstract: The Self-Organizing Anodic Aluminium Oxide(AAO) Template Is Widely Used to Construct the Nanomaterials. but the AAO Film Is Very Thin and Brittle, the AAO Templates Are Easily Been Destroied when Widening and Opening the Nanopores. the Nanorods/wires Constructed by this Template Likely Aggregate because of the High Activity of Nano-Surface at Short Range. this Paper Proposed a Novel Image of AAO Template in which Several Nanopores Combined Together to Form a Large Open Holes without Widening the Cells and Opening Barrier Layers. the Electronic Aluminium Foils with 99.99% Purity Is Anodized in Phosphoric Acid by Two-Steps, then Polarized under a Negative Voltage in the Kcl Solution. the Result of Experiment Demostrated the Possibility of the Formation Mechanism of this New Templates.

Abstract: In this Paper, we Propose an Alignment Method for Lift-Off on Shallow Grooves in Transparent Substrates without an Extra Mask. An Assistant Metal Layer Was Deposited on the Glass Substrate with Grooves to Increase the Reflectance, and then a Layer of Photoresist for Lift-Off Process Was Coated and Patterned Aligning with the Shallow Grooves. We Compared the Effect of Aluminum and Chromium Films with Different Thickness as Reflecting Layers. an Aluminum or Chromium Film with the Thickness Larger than 10nm Provides High Enough Image Contrast of Profile of the Alignment Marks Beneath the Photoresist. the Image Contrast of Contour Profile of the Marks Was Enhanced as the Thickness Increased. Lift-Off Process Was then Implemented on the Assistant Reflecting Layer. With a 20nm Cr Layer, we Successfully Did Lithography and Finished the Lift-Off Process to Pattern a Cr/Au Layer on Shallow Grooves in a Glass Wafer. Finally, the Assistant Cr Layer Was Removed Using Dry Etching. the Assistant Metal Layer Has No Undesirable Influence on the Following Process and the Device Property.

Abstract: MWNT –SiO2 composite film humidity sensors with different MWNTs proportions were fabricated and their performances under alternating current testing signals are investigated. Influence of MWNT content on humidity sensing characteristics of the sensors is explored and explained by vapor adsorption and capillary condensation effect. It is proved that 60% MWNT content sensors have humidity sensitivity of 1500% at 400 kHz testing frequency, much higher than those with other MWNT contents. In sensors’ sensitivity-frequency relation, maximum sensitivity comes from frequency section of 400kHz to 500kHz for sensors with higher MWNTs proportions.