tailieunhanh - Engineering Materials and Processes phần 4

Sự sụt giảm nhanh chóng ban đầu là nhiệt độ phụ thuộc và sự thay đổi điện trở suất là chậm hơn nhiều cho thời gian ủ lâu hơn. Hành vi này được quan sát thấy nồng độ hợp kim của 6-26.%. Các điện trở suất là một hàm số của thời gian ủ được hiển thị cho một Ag (19% Ti.) Hợp kim, nitrided ở nhiệt độ khác nhau trong NH3 | Diffusion Barriers and Self-encapsulation 33 The XRD spectra obtained from the TaN films deposited on Si using different nitrogen flow ratios are shown in Figure . The variations in position intensity and shape of the peaks indicate changes in the phase of the TaN films. From Figure the phases present in the films were identified by comparing the observed peak positions 20 in the XRD spectra with data from JCPDS cards. The diffraction peaks of the films deposited with 15 nitrogen flow Figure can be indexed as belonging to a mixture of P-Ta and Ta-rich nitride Ta2N . When the nitrogen partial flow rate is increased to 25 Figure a small fraction of the phases observed at 15 are still present but the dominant phase is stoichiometric TaN. Upon increasing the flow rate from 30-40 only peaks at 20 35 41 60 and 72 which correspond to TaN are observed Figure . As the nitrogen flow ratio is increased to 30 the diffraction peak at 20 a 35 shifts to a lower angle and the shift becomes even more evident for the 40 spectrum. The shift of the peaks to lower angles confirmed that a new phase is formed with increasing nitrogen. In the range of 30-40 N2 flow rate the diffraction peaks become increasingly broader and peak intensities drop. 20 degree Figure . XRD spectra obtained from TaN films as-deposited using various N2 Ar flow ratios a 15 N2 b 25 N2 c 30 N2 and d 40 N2 5 34 Silver Metallization Figure shows the resistivity of the reactively sputtered TaN films as a function of nitrogen flow ratio. For reference purposes the resistivity of P-Ta 18 is indicated on Figure . A noticeable increase in resistivity is observed when the nitrogen flow rate is changed from 15 to 20 . As flow rate is increased from 20 to 30 the resistivity of the TaN film increases slightly from 155 to 169 pQ-cm. When flow rate is further increased the resistivity of the film increases drastically to a value of 532 pQ-cm at 40 . The change in film resistivity will .