Control of Crystallinity of Alkoxy-Derived Zirconia Thin Films by UV Irradiation Kaori Nishizawa, Takeshi Miki, Kazuyuki Suzuki, Desheng Fu, Kazumi Kato National Institute of Advanced Industrial Science and Technology, AIST 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, 463-8560 Japan Keywords : UV irradiation, wavelength dependence, ZrO 2 thin films, crystallization, metal alkoxide ABSTRACT The UV irradiation using an ultra-high pressure mercury lamp (UHPML) was effective for the improvement of the surface morphology of the crystallized zirconia (ZrO 2 ) thin films. On the other hand, the UV irradiation using a low pressure mercury lamp (LPML) was effective for the improvement of rather the crystallinity of ZrO 2 thin films than the surface roughness. The UV irradiation using a LPML was considered to be more simple and effective method for the fabrication of the more smooth and highly-crystallized ZrO 2 thin films. INTRODUCTION ZrO 2 thin films have high potentials for many application, such as a buffer layer for integration of ferroelectric thin films in nonvolatile ferroelectric memories, the gate dielectric for complementary metal oxide semiconductor and oxygen sensors[1-3]. It is important for the various applications of ZrO 2 thin films to control the crystallinity, orientation and surface morphology. In our previous study, we have found out that the surface morphology of alkoxy-derived ZrO 2 thin films has changed by UV irradiation using an UHPML, and the effects of UV irradiation were affected by the kinds of alkoxide as starting materials[4]. In this paper, we paid attention to the wavelength of UV lamps for the UV irradiation of alkoxy-derived ZrO 2 thin films prepared onto Si(100) substrate, and effects of the wavelength on the crystallinity and surface morphology of ZrO 2 thin films are investigated. EXPERIMENTAL PROCEDURE The precursor solution was prepared using a zirconium tetra n-buthoxide (Zr(O n Bu) 4 ) and 2-methoxyethanol. After partial hydrolysis (molar ratio; Zr(O n Bu) 4 :H 2 O=1:1), the solution was spin coated on p-type Si (100) substrate or SiO 2 glass substrate. Each layer was deposited by two steps of 1000 rpm for 3 s and 3000 rpm for 30 s. As-deposited films were dried at 150°C, and then irradiated by using a 250 W ultra-high pressure mercury lamp (UHPML, multilight UIV-270, Ushio Co. Ltd., Tokyo, Japan, wavelength: 270 nm - 460 nm) or a 200 W low pressure mercury lamp (LPML, VUV-165/B-1.1U, ORC manufacturing Co., Ltd., Tokyo, Japan, wavelength: 185 nm and 254 nm) at room temperature in air for 30 min. The UV processed films were calcined at 350°C in air for 10 min, and then annealed at 450°C for 10 min via a rapid raise of temperature (100°C /s) under oxygen flow. The all process from spin coating to annealing was repeated five times. The Key Engineering Materials Vol. 248 (2003) pp. 125-128 online at http://www.scientific.net © 2003 Trans Tech Publications, Switzerland Licensed to Desheng (deshengfu@yahoo.com) - Shizuoka University - Japan All rights reserved. No part of the contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net . (ID: 131.112.140.131-09/03/05,03:36:24)