tailieunhanh - Engineering Materials and Processes phần 3

Điện trở suất so với thời gian ủ cho một Ag (19 tại Ti%) hợp kim, được ủ ở ba nhiệt độ khác nhau được thể hiện trong hình . Điện trở suất giảm nhanh chóng trong vòng 10 phút đầu tiên từ giá trị cao (~ 109,0 μΩ-cm) của mẫu khi gửi tới ~ 8 μΩ-cm ở 500 ° C. Tỷ lệ thay đổi khối lượng sau đó trở thành | Diffusion Barriers and Self-encapsulation 19 Figure . Dealloying kinetics obtained with Ag 26 at. Ti alloy films. The residual Ti concentration is shown as a function of annealing time for three different temperatures. The annealing took place in a NH3 ambient and the data was obtained using MeV He 2 RBS 9 . Resistivity versus annealing time for an Ag 19 at. Ti alloy annealed at three different temperatures is shown in Figure . The resistivity drops rapidly within the first 10 minutes from the high value pQ-cm of the as-deposited sample to 8 pQ-cm at 500 C. The initial rapid drop is temperature dependent and the resistivity change is much slower for longer annealing times. This behavior is observed for alloy concentrations of 6-26 at. . 20 Silver Metallization Figure . The resistivity as a function of annealing time is shown for an Ag 19 at. Ti alloy nitrided at different temperatures in NH3 9 Discussion Nitridation annealing of Ag-Ti alloys above 300 C resulted in Ti segregating at the surface as well as at the interface. At the surface Ti reacted with NH3 and residual O2 to form a TiN O layer and at the interface with SiO2 to form an oxide-silicide bilayer structure. The Ti-nitride thickness obtained from nitridation of the Ag Ti alloys increases moderately with temperature in the range 300-600 C but reaches a finite thickness 20 nm at higher temperatures. The amount of Ti available for reaction is controlled by the dealloying mechanism as reflected by the relationship between the residual Ti concentration and annealing temperature 8 . In the case of Ag-Ti the Ti SiO2 reaction occurs at temperatures as low as 350 C. Earlier studies have indicated that significant reaction between pure Ti on SiO2 only occurs at temperatures 600 C. AES depth profiling analysis has supported the RBS analysis that nitridation of the Ag-Ti alloys results in the formation of a Ti-oxide Ti-silicide structure at the alloy and SiO2 interface. RBS analysis .