Effects of Deposition Pressure and Target-Substrate Distance on Growth of ZnO by Femtosecond Pulsed Laser Deposition

Abstract

This paper applies a combined precision stage to fabricate micro-structures by two-photon polymerization (TPP). The combined stage consists of PZT and stepper-motor stages to achieve precision positioning in long displacements. First, we derive the models of the stages by identification experiments. Second, we apply robust loop-shaping techniques to improve the positioning performance of the stages. Third, we integrate the stages and develop a multi-loop control structure to provide long-stroke and high precision. In addition, we propose coordinate transformation and anti-locking functions for further improvement of the system performance. Last, we apply the combined stage to a TPP system for fabricating micro-structures, and define performance indexes based on image processing and optical qualities. The obtained performance criteria can be used to adjust controller design to improve precision manufacturing.

Two-Step Dry Synthesis of Binderless 3D Low Pt-Loading Electrocatalysts for Direct Alkaline Methanol Fuel Cell Anodes

“…During this expansion, supersaturation, condensation, and solidification occur, and nanoparticles are formed and deposited (collected) on a substrate facing the target. The characteristics of the formed nanoparticles vary widely by changing the operating conditions, target materials, background gas compositions, and pressures. − The structure of the Pt nanoparticle thin coating on the MWCNTs evolves from a dense to a porous granular coating by increasing the chamber pressure from 10 –5 to 1 Torr, as evidenced by the SEM images (Figure e–j). This trend can be schematically presented and explained by referring to the schematic view of the PLA process in Figure a.…”

Ultra-Short Pulsed Laser Deposition of Oxides, Borides and Carbides of Transition Elements

“…In the period 2016-2019, four papers on ultra-short PLD of ZnO were published. In 2016, De Mesa et al studied the deposition of ZnO ablated using a laser with a pulse duration of 100 fs, a power of 600 mW, a wavelength of 800 nm and a repetition rate of 80 MHz [60]. Rather surprisingly, they were unable to obtain stoichiometric ZnO films both in vacuum and at a pressure of 10 −2 mbar of oxygen.…”

Morphology and I-V Characteristics of Electrochemically Deposited Zinc Oxide on Silicon

“…Various deposition processes had been reported to deposit ZnO on Si substrates, such as arc discharge [5,6], pulse laser deposition (PLD) [7,8], pyrolysis [9,10] and also electrochemical deposition [11][12][13]. The electrochemical deposition is a process where a film of conducting material is deposited from a solution containing ions onto an electrically conducting surface.…”