AVS 49th International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeP

Paper TF-WeP17
Effects of Deposition Conditions on Step Coverage Quality in Metal-organic Chemical Vapor Deposition of TiO@sub 2@

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: S.Y. No, Seoul National University, Korea
Authors: S.Y. No, Seoul National University, Korea
J.H. Oh, Seoul National University, Korea
C.S. Hwang, Seoul National University, Korea
H.J. Kim, Seoul National University, Korea
Correspondent: Click to Email
Dielectric thin films including Ti element such as (Ba,Sr)TiO@sub 3@(BST), SrTiO@sub 3@(STO) have been investigated intensively by many researchers for next generation DRAM capacitor. Recently, the problem of cationic composition non-uniformity was reported when these multi-component films were deposited on patterned structure by metal-organic chemical vapor deposition(MOCVD) method. To understand the problem of composition non-uniformity in multi-component films, it needs to know the step-coverage variation of each component film. In this study, the step coverage of TiO@sub 2@ thin films were investigated, which were grown on patterned Si substrates by liquid-injection MOCVD using Ti(O-i-Pr)@sub 2@(thd)@sub 2@ at substrate temperature ranging from 410°C to 500°C. The effects of various deposition parameters such as the chamber-wall and gas-line temperature, the source injection rate, the substrate temperature, solvents and deposition atmosphere on the step coverage quality were investigated and activation energy of deposition was also evaluated in each case. As the chamber-wall temperature increased from 230°C to 400°C, the step-coverage improved while degraded when gas line temperature was changed from 230°C to 400°C. With increasing the partial pressure of Ti source, the step-coverage improved slightly. When the substrate temperature was changed from 470°C to 410°C, the step-coverage quality enhanced, and the degree of variation in step-coverage was larger in oxygen-rich atmosphere than in Ar-rich atmosphere. Tetrahydrofuran(THF) and ethyl alcohol were used as solvents for Ti precursor dissolution and step-coverage is better when THF is used.