Ultra-shallow Junction Formed by Plasma Doping and Laser Annealing
We investigated ultra-shallow junction prepared by plasma doping (PLAD) and laser annealing (LA). Although PLAD is promising doping technology for the sub-45nm technology node due to the high dose rate at low energy, it has problems which is related with hydrogen or fluorine. The implanted hydrogen generally increases damage in the Si substrate. The fluorine also retards dopant activation and increases dopant deactivation during post-annealing step. Conventional one step annealing processes such as rapid thermal annealing (RTA) or excimer laser annealing (LA) are not effective method for high dopant activation. To minimize the effect of hydrogen or fluorine, we propose additional pre-annealing followed by conventional laser annealing. By employing low temperature pre-annealing, we can improve electrical characteristics such as low sheet resistance, high activation rates, shallow junction depth and reduced dopant deactivation. The improvement can be explained by reduced defect density and out-diffusion of fluorine or hydrogen which in turn enhances dopant activation during ELA
High performance Ge ultra-shallow junctions fabricated by a novel formation technique featuring spin-on dopant and laser annealing for sub-10 nm technology applications
Abstract In this work, we explored a novel technique for the formation of ultra-shallow p+/n and n+/p junctions on Ge substrate using the spin-on dopant (SOD) followed by laser annealing (LA). The junction depth and doping profiles were extracted and compared between Ge junctions activated by LA and by the conventional rapid thermal annealing (RTA). It is experimentally confirmed that the process of SOD followed by LA method outperformed that by RTA technique in terms of the ultra-shallow junction depth, higher surface doping concentration and steeper doping profiles. Therefore, the high performance Ge p+/n and n+/p junctions fabricated by SOD followed by LA method exhibit suppressed junction leakage current and raised on/off ratios, making this novel technique a promising way for source/drain formation in future technology nodes.
Adsorption of immunoglobulin Y in supermacroporous continuous cryogel with immobilized Cu(2+) ions.
The influence of temperature, pH and ionic strength on the adsorption of Immunoglobulin Y (IgY) in IDA-Cu(2+) cryogel system was studied by batch equilibrium measurements. The adsorptive equilibrium data were obtained at 17 and 27°C, pH 5.0 and 6.5, and at ionic strength of 50 and 200mmolL(-1) NaCl. Langmuir, Freundlich and Langmuir-Freundlich models were fitted to equilibrium data, while the enthalpy of adsorption of IgY in IDA-Cu(2+) cryogel system was calculated through Van't Hoff analysis. The binding of IgY on cryogel was stronger at 27°C and lowest pH and ionic strength values, with apparent maximum adsorption capacity of 27mgg(-1). The adsorption of protein in the resin was spontaneous in all analyzed cases. The results provide valuable information to enable the improvement of IgY purification processes.