Browsing by Author "CHIU, RL"

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AL2O3 FILMS FORMED BY ANODIC-OXIDATION OF AL-1 WEIGHT PERCENT SI-0.5 WEIGHT PERCENT CU FILMS
(1995-02-01)
CHIU, RL
;
CHANG, PH
;
TUNG, CH
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The structure of the barrier-type anodic oxide formed on preannealed Al-1 weight percent (w/o) Si-0.5 w/o Cu thin film in a tartaric acid electrolyte was investigated. The oxide film is basically an amorphous layer with a thin dispersed gamma'-Al2O3 crystalline layer interposed in the center. Pores are observed to be associated with the gamma'-Al2O3 layer. Silicon nodules and Al2Cu particles originally present in the Al-1 w/o Si-0.5 w/o Cu film behave differently during anodization. Silicon nodules are oxidized to various degree during anodizing. The silica formed in the Si nodules is amorphous and somewhat porous possibly due to oxygen evolution associated with the Si anodization. A dark rim was found to surround each nodule in the anodic oxide film. This rim is shown to be thicker amorphous Al2O3 material, and its origin is attributed to the faster oxidation rate in the vicinity of Si nodules. Al2Cu precipitates are oxidized to form Al2O3 at about the same rate as the surrounding Al matrix. Copper is rejected by Al2O3 and accumulates at the Al2O3/Al interface.
THE EFFECT OF ANODIZING TEMPERATURE ON ANODIC OXIDE FORMED ON PURE AL THIN-FILMS
(1995-05-01)
CHIU, RL
;
CHANG, PH
;
TUNG, CH
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The structure and properties of anodic Al2O3 films formed at different anodizing temperatures from thin Al films deposited by magnetron sputtering on oxidized Si wafers have been studied by transmission electron microscopy, secondary ion mass spectrometry, and electrical measurements. The anodic oxide films formed at 8 degrees C and 25 degrees C are amorphous with excellent dielectic properties, leakage current lower than 500 nA at 7.5 MV cm(-1) and no breakdown up to 7.5 MV cm(-1). Partially crystalline gamma'-Al2O3 is grown at the upper half of the 58 degrees C oxide film. This film exhibits much inferior dielectric properties than the lower temperature films. Carbon is incorporated into the top portion of the oxide films from the electrolyte during anodizing and it has little effect on the crystalline oxide formation. Oxygen penetrates into the underlying Al layer during anodizing. The penetration increases with increasing anodizing temperature.