Tantalum nitride and tantalum carbide films were fabricated using magnetron sputtering of tantalum followed by nitrogen and carbon plasma-based ion implantation （N-PBII and C-PBII）. The phase evolution and morpholog...Tantalum nitride and tantalum carbide films were fabricated using magnetron sputtering of tantalum followed by nitrogen and carbon plasma-based ion implantation （N-PBII and C-PBII）. The phase evolution and morphology of the films were studied using glancing angle X-ray diffraction （GXRD） and transmission electron microscopy （TEM）. It was found that the main phase in the tantalum nitride films was crystalline TaNo.1 whose grain size increases with increasing implantation voltage and phase content increases with increasing implantation dose. In the tantalum carbide film, the main phase was Ta2C. TaC phase also appeared as the implantation dose increased. XRD results from various glancing angles show that the phases with high nitrogen or carbon content, Ta4N5 and TaC, are present in the surface of the films. X-ray photoelectron spectra （XPS） from the tantalum carbide film reveal that the surface carbon content is higher than that of the inner film.展开更多
The valence electronic structures of tantalum carbide (TaC) and tantalum nitride (TaN) are studied by using the empirical electronic theory (EET). The results reveal that the bonds of these compounds have covalent,met...The valence electronic structures of tantalum carbide (TaC) and tantalum nitride (TaN) are studied by using the empirical electronic theory (EET). The results reveal that the bonds of these compounds have covalent,metallic and ionic characters. For a quantitative analysis of the relative strength of these components,their ionicities have been calculated by implanting the results of EET to the PVL model. It has been found that the ionicity of tantalum carbide is smaller than that of tantalum nitride. The EET results also reveal that the covalent electronic number of the strongest bond in the former is larger than that of the latter. All these suggest that the covalent bond of TaC is stronger than that of TaN,which coincides to that de-duced from the first-principles method.展开更多
设计并制备了用于电压衰减的Π形和T形氮化钽薄膜衰减器,对衰减器的设计值与实测值进行了对比。Π形设计时,实测衰减值与设计值之间的相对误差随着设计值的提高不断下降,衰减值为-10 d B时,相对误差为8.9%,衰减值为-30 d B时,相对误差为...设计并制备了用于电压衰减的Π形和T形氮化钽薄膜衰减器,对衰减器的设计值与实测值进行了对比。Π形设计时,实测衰减值与设计值之间的相对误差随着设计值的提高不断下降,衰减值为-10 d B时,相对误差为8.9%,衰减值为-30 d B时,相对误差为2.47%。T形设计时,实测衰减值与设计值之间的相对误差随着设计值的提高先下降,然后再上升,-20 d B时,相对误差最小,为4.75%。展开更多
基金supported by the National Basic Research Program of China (No. 2007CB607602)the Science Found for Distinguished Yong Scholars of Heilongjiang Province,China (No. JC200901)+1 种基金the National Natural Science Foundation of China (No. 50875058)the Program of Excellent Teams of Harbin Institute of Technology
文摘Tantalum nitride and tantalum carbide films were fabricated using magnetron sputtering of tantalum followed by nitrogen and carbon plasma-based ion implantation （N-PBII and C-PBII）. The phase evolution and morphology of the films were studied using glancing angle X-ray diffraction （GXRD） and transmission electron microscopy （TEM）. It was found that the main phase in the tantalum nitride films was crystalline TaNo.1 whose grain size increases with increasing implantation voltage and phase content increases with increasing implantation dose. In the tantalum carbide film, the main phase was Ta2C. TaC phase also appeared as the implantation dose increased. XRD results from various glancing angles show that the phases with high nitrogen or carbon content, Ta4N5 and TaC, are present in the surface of the films. X-ray photoelectron spectra （XPS） from the tantalum carbide film reveal that the surface carbon content is higher than that of the inner film.
基金Supported by the National Natural Science Foundation of China (Grant No. 10702060)the Ministry of Science and Technology of China (2005CB724400 and 2005CB724404)
文摘The valence electronic structures of tantalum carbide (TaC) and tantalum nitride (TaN) are studied by using the empirical electronic theory (EET). The results reveal that the bonds of these compounds have covalent,metallic and ionic characters. For a quantitative analysis of the relative strength of these components,their ionicities have been calculated by implanting the results of EET to the PVL model. It has been found that the ionicity of tantalum carbide is smaller than that of tantalum nitride. The EET results also reveal that the covalent electronic number of the strongest bond in the former is larger than that of the latter. All these suggest that the covalent bond of TaC is stronger than that of TaN,which coincides to that de-duced from the first-principles method.
文摘设计并制备了用于电压衰减的Π形和T形氮化钽薄膜衰减器,对衰减器的设计值与实测值进行了对比。Π形设计时,实测衰减值与设计值之间的相对误差随着设计值的提高不断下降,衰减值为-10 d B时,相对误差为8.9%,衰减值为-30 d B时,相对误差为2.47%。T形设计时,实测衰减值与设计值之间的相对误差随着设计值的提高先下降,然后再上升,-20 d B时,相对误差最小,为4.75%。
