tailieunhanh - Enhancement-Mode Metal Organic Chemical Vapor Deposition-Grown ZnO Thin-Film Transistors on Glass Substrates Using N2O Plasma Treatment

The premium price accruing to organic food prod- ucts directly impacts the consumption levels (Aryal et al. 2009). Instead the demand for organic products must be seen in relative proportion of income that is usually spent on food consumption (Tsakiridou et al. 2008). Furthermore, consumer behavior is a dynamic process because of con- tinuous changes in ideas, perceptions and activities of the consumers. Attitude is shaped selec- tively to compromise consumers needs. Learning is gained by experience and it affects consum- ers’ behavior. Scientific evidence suggests that almost all behaviors are learnt. Learning differen- tiates between stimuli and a response, and consumer behaviors translated. | Japanese Journal of Applied Physics 49 2010 04DF20 REGULAR PAPER Enhancement-Mode Metal Organic Chemical Vapor Deposition-Grown ZnO Thin-Film Transistors on Glass Substrates Using N2O Plasma Treatment Kariyadan Remashan Yong-Seok Choi1 Se-Koo Kang2 Jeong-Woon Bae2 Geun-Young Yeom2 Seong-Ju Park1 and Jae-Hyung Jang Department of Information and Communications and Department of Nanobio Materials and Electronics Gwangju Institute of Science and Technology Gwangju 500-712 Korea 1 Department of Materials Science and Engineering Gwangju Institute of Science and Technology Gwangju 500-712 Korea 2 Department of Advanced Materials Science and Engineering Sungkyunkwan University Suwon Gyeonggi-do 440-746 Korea Received October 5 2009 revised November 3 2009 accepted November 9 2009 published online April 20 2010 Thin-film transistors TFTs were fabricated on a glass substrate with a metal organic chemical vapor deposition MOCVD -grown undoped zinc oxide ZnO film as a channel layer and plasma-enhanced chemical vapor deposition PECVD -grown silicon nitride as a gate dielectric. The as-fabricated ZnO TFTs exhibited depletion-type device characteristics with a drain current of about 24 mA at zero gate voltage a turn-on voltage Von of -24V and a threshold voltage VT of -4V. The field-effect mobility subthreshold slope off-current and on off current ratio of the as-fabricated TFTs were 5 cm2 V-1 s_1 V decade nA and 106 respectively. The postfabrication N2O plasma treatment on the as-fabricated ZnO TFTs changed their device operation to enhancement-mode and these N2O-treated ZnO TFTs exhibited a drain current of only 15 pA at zero gate voltage a Von of V and a VT of 11 V. Compared with the as-fabricated ZnO TFTs the off-current was about 3 orders of magnitude lower the subthreshold slope was nearly 7 times lower and the on off current ratio was 2 orders of magnitude higher for the N2O-plasma-treated ZnO TFTs. X-ray phtotoelectron spectroscopy analysis showed that the .