Junction fabrication

Kawai H, Yeo YK, Saeys M, Joachim C (2010) Conductance decay of a surface hydrogen tunneling junction fabricated along a Si(001)-(2xl)-H atomic wire. Phys Rev B 81 195316... 

Kelvin-probe) AFM, and STM] to analyze the local phenomena and structure after top contact constmction. Development of new techniques such as surface plasmon resonance Raman, for example, could be applied to advantage for junctions fabricated with plasmonically active metals such as silver [125] or gold [126]. 

In this section, low resistance tunnel junctions prepared by natural oxidation [42-45] or remote plasma oxidation techniques [46] will be described, since up to now they have provided the lowest junction resistances, required to supplant spin valves for read head applications above 100-200 Gbit/in2. At the heart of tunnel junction fabrication lays the barrier fabrication. For read head applications, in the 100-300 Gbit/in2 region, junction resistance must be around 1 Qpm2 [47-51]. Figure 9(a) shows a TEM micrograph for a 1 nm thick AlHfOx low RA barrier [52],... 

The metallization of local regions of HTSC surfaces is being studied in connection with the problem of junction fabrication. In this case, the adhesion that determines the ohmic resistance on the HTSC/metal interface is of greatest importance. 

Another important problem is the elimination of the chemical interactions between contacting phases and also of the diffusion of metal atoms into the oxide bulk [487 89], One example is the operation of commonly used indium junctions, which are convenient because films of this soft metal and its alloys can be applied mechanically [490], This fact stimulates the quest for low-temperature techniques for junction fabrication. It is known that silver, gold, and copper, and also probably platinum [202] and palladium [487], are most suitable because of their weak interaction with HTSCs. 

It was shown that thin films of Cu, Co and Ni could be successfully deposited onto Si substrates, without the need of a seed layer. For all three metals, uniform layers with a compact and granular morphology could be obtained. From RBS data the deposition rates as well as the current efficiencies could be determined. For Co films it was shown that addition of boric acid caused the evolution of hydrogen. On the other hand, it was possible to improve the current efficiency of electrolytes containing boric acid by increasing the concentration of cobalt sulfate in the bath. For Ni films electrodeposited from a highly concentrated sulfate electrolyte, it was observed the formation of texture in the (220)-direction. Electric measurements performed on Ni/n-Si structures yielded values for Schottky barriers which are comparable to the ones obtained for junctions fabricated by vapor deposition. 

Fig. 3.8. Josephson junction fabricated by a focused electron probe in a STEM.

To satisfy the conditions described above, arrays with characteristic capacitances of 10 10 F, typical values for junctions fabricated lithographically with present-... 

NbN film fabrication has been reported (21). Low deposition rate is a serious problem. Junction fabrication has never been reported. 

This method has been developed recently. We can make a film of a material with a high melting point by this method. NbN film fabrication has been reported. A high deposition rate is easily realized in this method (22,23). Junction fabrication has never been reported. 

A Shoji, F Shinoki, S Kosaka, M Aoyagi, H Hayakawa. AU refractory Josephson tunnel Junctions fabricated by reactive ion etching. IEEE Trans Magn 19 827, 1983. 

J Talvacchio AI Braginski. Tunnel junctions fabricated from coherent NbN/MgO/NbN and NbN/ Al203/NbN structures. IEEE Trans Magn 23 859, 1987. 

Z Wang, A Kawakami, Y Uzawa, B Komiyama. High critical current density NbN/AlN/NbN tunnel junctions fabricated on ambient temperature MgO substrates. Appl Phys Lett 64 2034, 1994. 

Another recent probe design utilizes a thermocouple junction fabricated on the end of a standard microfabricated AFM tip. This probe is also scanned over a surface using normal force feedback. The temperature of the surface is mapped simultaneously by recording the calibrated voltage between the two leads of the thermocouple. 

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