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Superconductor to Normal-Metal Contacts
Published in David A. Cardwell, David C. Larbalestier, Aleksander I. Braginski, Handbook of Superconductivity, 2023
To achieve high quality contacts to oxide-film superconductors, the same interfacial chemistry problems have to be faced as discussed above (Section E5.1.3—Interfacial chemistry) for high current HTS materials. The contact pads must be made from a material with a low oxygen affinity, like gold or silver. As described below, the main difference in technique between the bulk and film cases is that the optimum oxygen annealing temperatures are slightly lower and times are shorter for films. Another important distinction for film samples (versus bulk samples) is that it is possible in some cases to use an in situ technique to deposit contact pads.
AlGaN/GaN HEMT Fabrication and Challenges
Published in D. Nirmal, J. Ajayan, Handbook for III-V High Electron Mobility Transistor Technologies, 2019
Gourab Dutta, Srikanth Kanaga, Nandita DasGupta, Amitava DasGupta
After gate lithography, contact pad metallization is done using a bilayer metal scheme. In this process contact pads are created which are required for electrical characterization and wire bonding. Finally, the fabricated devices are passivated by depositing a suitable dielectric material. Si3N4 is the common choice as a passivation layer. Contacts pads are then opened by dry/wet etching of Si3N4 passivation layer.
Investigation of Cu-Sn-Cu transient liquid phase bonding for microsystems packaging
Published in Materials and Manufacturing Processes, 2023
Karan Pawar, Harsha S, Pradeep Dixit
Mechanical shear test specimens were bonded at two levels of bonding temperature (275℃ and 300℃), bonding durations (800 s and 1600 s), and three levels of bonding force (5 kg, 10 kg, and 20 kg). These parameters not only influence the formation of intermetallics layers (Cu6Sn5, Cu3Sn) but also affect the void formation at the interfaces.[36] The final shear strengths of the Cu-Sn-Cu joints were decided by these bonding parameters, as discussed in the next section. After fabricating the device and substrate wafers, dicing was used to separate individual dies. Optical images of the device die (having copper pillar with Sn cap) and substrate die (bottom RDL and electrical contact pad) are shown in Figs. 4a and 4c, respectively.
Temperature-dependent Electrical Characterization of Single and Dual-gate Flexible Carbon Nanotube Thin Film Transistors
Published in IETE Journal of Research, 2022
M. C. Chandrashekhar, K. C. Narasimhamurthy
The palladium (Pd) of 8 nm thickness was deposited by 4TEBE to realize source and drain contacts of CNTTFTs. The Pd source and drain contacts were patterned by photolithography and the subsequent cross-sectional view is appeared in Figure 1(g). Ti/Au source, drain and gate electrode contact pad regions of thickness 5/50 nm were deposited by RF sputtering and patterned utilizing photolithography. The cross-sectional view of the Ti/Au source, drain, and gate electrode contact pad regions are appeared in Figure 1(h).