Browsing by Author "Chang, PH"

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Observations of Guinier-Preston zones in an As-deposited Al-1wt.%Si-0.5wt.%Cu thin film
(1996-05-01)
Tung, CH
;
Chiu, RL
;
Chang, PH
;
材料科學與工程學系
;
電子工程學系及電子研究所
Observations of Guinier-Preston zones in an As-deposited Al-1wt.%Si-0.5wt.%Cu thin film
(1996-05-01)
Tung, CH
;
Chiu, RL
;
Chang, PH
;
材料科學與工程學系
;
Department of Materials Science and Engineering
On liquid-phase deposition of silicon dioxide by boric acid addition
(1997-03-01)
Chang, PH
;
Huang, CT
;
Shie, JS
;
材料科學與工程學系
;
光電工程學系
The current status of liquid-phase deposition (LPD) of SiO2 by adding boric acid (H3BO3) to a hydrofluosilicic acid (H2SiF6) is reviewed and compared with some new results from the authors' laboratory. Large discrepancies exist in the literature concerning the effects of Various processing parameters on deposition rate. We have shown that much confusion arises from the misconception of using an SiO2 additive to ''saturate'' and usng water to ''dilute'' the growth solution. In this paper the role of H2O as a reagent and the detrimental effect of an SiO2 additive as seeds for depleting the nutrient in the growth solution if added after the H2O addition are emphasized. Despite the variations between different investigators, the following characteristics of the LPD process are in general agreement: (i) the deposition process is surface controlled, (ii) the deposition rate depends approximately linearly on temperature, (iii) the deposition rate is constant (independent of time) over a wide range of experimental conditions, and (iv) the deposition rate increases with increasing boric acid concentration.
On liquid-phase deposition of silicon dioxide by boric acid addition
(1997-03-01)
Chang, PH
;
Huang, CT
;
Shie, JS
;
材料科學與工程學系
;
光電工程研究所
The current status of liquid-phase deposition (LPD) of SiO2 by adding boric acid (H3BO3) to a hydrofluosilicic acid (H2SiF6) is reviewed and compared with some new results from the authors' laboratory. Large discrepancies exist in the literature concerning the effects of Various processing parameters on deposition rate. We have shown that much confusion arises from the misconception of using an SiO2 additive to ''saturate'' and usng water to ''dilute'' the growth solution. In this paper the role of H2O as a reagent and the detrimental effect of an SiO2 additive as seeds for depleting the nutrient in the growth solution if added after the H2O addition are emphasized. Despite the variations between different investigators, the following characteristics of the LPD process are in general agreement: (i) the deposition process is surface controlled, (ii) the deposition rate depends approximately linearly on temperature, (iii) the deposition rate is constant (independent of time) over a wide range of experimental conditions, and (iv) the deposition rate increases with increasing boric acid concentration.
Photoassisted liquid-phase deposition of silicon dioxide
(1996-06-01)
Huang, CT
;
Chang, PH
;
Shie, JS
;
材料科學與工程學系
;
光電工程研究所
The deposition rate of SiO2 by liquid-phase deposition (LPD) in a H2SiF6 solution is significantly increased by 254 nm ultraviolet (UV) illumination. The photoenhancement effect is much stronger at 3.09 M H2SiF6 than at 1.34 M H2SiF6 concentration. At a constant boric acid concentration the deposition rate of SiO2 is found to increase linearly with UV light intensity. The photoassisted effect is much stronger at higher boric acid concentration. However, within the UV intensity range studied, the photoeffect on the oxide growth rate is not as strong as other parameters such as H2SiF6 concentration and boric acid addition. The UV spectrophotometric results show that the strong UV absorption of the growth solution is associated with SiF62- but not with H2O, H3BO3, or BF4- species in the solution. The observed photoenhancement effect is discussed in the light of the existing LPD models.
Photoassisted liquid-phase deposition of silicon dioxide
(1996-06-01)
Huang, CT
;
Chang, PH
;
Shie, JS
;
材料科學與工程學系
;
光電工程學系
The deposition rate of SiO2 by liquid-phase deposition (LPD) in a H2SiF6 solution is significantly increased by 254 nm ultraviolet (UV) illumination. The photoenhancement effect is much stronger at 3.09 M H2SiF6 than at 1.34 M H2SiF6 concentration. At a constant boric acid concentration the deposition rate of SiO2 is found to increase linearly with UV light intensity. The photoassisted effect is much stronger at higher boric acid concentration. However, within the UV intensity range studied, the photoeffect on the oxide growth rate is not as strong as other parameters such as H2SiF6 concentration and boric acid addition. The UV spectrophotometric results show that the strong UV absorption of the growth solution is associated with SiF62- but not with H2O, H3BO3, or BF4- species in the solution. The observed photoenhancement effect is discussed in the light of the existing LPD models.
The effect of preheating treatment on anodic Al2O3 formed on sputtered Al thin films
(1996-03-01)
Chiu, RL
;
Chang, PH
;
Tung, CH
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Al2O3 layers were grown by anodizing Al films sputtered on borophosphosilicate glass/SiO2/Si substrates and subsequently characterized by transmission electron microscopy, and by current-voltage and capacitance-voltage measurements using a metal/insulator/metal structure. Amorphous anodic oxide is formed on nonpreannealed Al film but a complex oxide film generally consisting of five sublayers (designated as amorphous I, porous I, crystalline, porous II, and amorphous II) is formed on preannealed Al film. Freshly formed anodic oxide is always amorphous in both preannealed and nonpreannealed Al thin films. The growth of the crystalline layer in preannealed samples is due to the amorphous-to-crystalline transition of the amorphous II layer. The porous I layer is formed well before the crystalline layer. The voids in this layer are probably due to the trapping of oxygen at the sites of crystalline oxide. The voids in the porous II layer are small and their formation can be attributed to the volume shrinkage associated with the amorphous-to-crystalline transition of the amorphous II layer. The amorphous oxide films exhibit excellent dielectric properties. The dielectric properties of the complex oxide are much inferior and vary significantly due to structural variation.
Thickness dependence of refractive index for anodic aluminium oxide films
(1997-01-15)
Chiu, RL
;
Chang, PH
;
材料科學與工程學系
;
Department of Materials Science and Engineering