The Best Balance of Oxygen Flow and Deposition Rate to Give Little Absorption of Aluminum Oxide Film Deposited by Electron Beam Evaporation Technique

R Shakouri

doi:10.5539/apr.v7n3p41

Abstract

The effects of deposition rate and oxygen flow rate on refractive index of aluminum oxide film are investigated. The Al 2 O 3 films are deposited by electron beam technique on glass substrate at different deposition rates and oxygen flow rates. Substrate is heated to reach 300 ° C and the temperature is kept constant during the thin film growth. Then, using the maxima and minima of transmittance, the index of refractive and the extinction coefficient of samples has been determined. It has been found that the index of refractive increase if we reduce the oxygen flow while keeping the deposition rate the same. Hardness is also increased with the decrease in the O 2 flow rate. At some low oxygen flow, the extinction coefficient is small and therefore the Al 2 O 3 films have some absorption.

Highlights

Aluminum oxide (Al2O3) is an ordinarily used intermediate index material
Aluminum oxide thin films have been deposited by various techniques, including magnetron sputtering (Ha, Choo, & Im, 2002; Segda, Jacquet, & Besse, 2001; Khanna, Bhat, Harris, & Beake, 2006; Fietzke, Goedicke, & Hempel, 1996), electron beam evaporation (Zywitzki, Goedicke, & Morgner, 2002; Patil, Bendale, Puri, & Puri, 1996), plasma enhanced chemical vapor deposition (Lin, Wang, & Hon, 1996), filtered cathodic vacuum arc (FCVA) (Zhao, Tay, Lau, & Xiao, 2003), spray pyrolysis (Aguilar-Frutis, Garcia, Falcony, Plesch, & Jimenez-Sandoval, 2001), etc
We have investigated the influence of the deposition rate and oxygen flow rate on refractive index of aluminum oxide film

Summary

Introduction

Aluminum oxide (Al2O3) is an ordinarily used intermediate index material. It is used to produce optical thin film coatings. Aluminum oxide thin films have been deposited by various techniques, including magnetron sputtering (Ha, Choo, & Im, 2002; Segda, Jacquet, & Besse, 2001; Khanna, Bhat, Harris, & Beake, 2006; Fietzke, Goedicke, & Hempel, 1996), electron beam evaporation (Zywitzki, Goedicke, & Morgner, 2002; Patil, Bendale, Puri, & Puri, 1996), plasma enhanced chemical vapor deposition (Lin, Wang, & Hon, 1996), filtered cathodic vacuum arc (FCVA) (Zhao, Tay, Lau, & Xiao, 2003), spray pyrolysis (Aguilar-Frutis, Garcia, Falcony, Plesch, & Jimenez-Sandoval, 2001), etc Films produced by these techniques in different laboratories have different refractive indexes. Motivation of this study is to find the best balance of oxygen flow and deposition rate to give little absorption and good density for higher index

Experimental Detail

Results and Discussion

Conclusion