標題: STRUCTURES OF TANTALUM PENTOXIDE THIN-FILMS FORMED BY REACTIVE SPUTTERING OF TA METAL
作者: CHANG, PH
LIU, HY
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: DIELECTRICS;OXIDES;STRUCTURAL PROPERTIES;TANTALUM
公開日期: 15-三月-1995
摘要: Reactively sputtered Ta2O5 films adhere poorly on bare Si substrate, but the adhesion improves dramatically on a thermally oxidized Si surface. The films are non-stoichiometric and the atomic ratio of O to Ta is typically higher than 2.5 but decreases with increasing annealing temperature. The variation in non-stoichiometry is also reflected by a small decrease in lattice constants with increasing annealing temperature as revealed by X-ray diffraction. About 2at% of residual Ar is detected in Ta2O5 film formed by 70%Ar-30%O-2 sputtering. The as-deposited Ta2O5 film is amorphous and it transforms to crystalline Ta2O5 at temperatures higher than 600 degrees C. Crystalline Ta2O5 films contain numerous amorphous particles which have been previously incorrectly identified as voids. They are probably the remnants of the uncrystallized amorphous Ta2O5 materials. The amorphous particles have a bimodal size distribution and the average size increases with increasing annealing temperature. The deterioration of dielectric properties in crystallized Ta2O5 films is unlikely to arise from these amorphous particles because amorphous Ta2O5 is known to have very low leakage current. An interfacial SiO2 layer forms at the Ta2O5-Si interface during reactive sputtering and its thickness increases with increasing oxygen content in the sputtering gas. Annealing at high temperature in Ar ambient has little effect on the thickness of this interfacial SiO2 layer.
URI: http://hdl.handle.net/11536/2011
ISSN: 0040-6090
期刊: THIN SOLID FILMS
Volume: 258
Issue: 1-2
起始頁: 56
結束頁: 63
顯示於類別:期刊論文


文件中的檔案:

  1. A1995QN15800011.pdf