1987/03/01 by T. Hara, N. Ohtsuka, Noboru Ohtsuka +3
Physics and Astronomy · Engineering · #Semiconductor materials and interfaces #Intermetallics and Advanced Alloy Properties #Metal and Thin Film Mechanics
paper · doi:10.1109/t-ed.1987.22968
The barrier effect of W-Ti interlayers in Al ohmic contact systems is studied. An Al-Si/W-Ti/Si structure was continuously deposited by dc magnetron sputtering. Interfacial reaction was observed by a 1.5-MeV He <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> Rutherford backscattering spectrometry technique after tungsten-halogen lamp rapid thermal annealing was performed at 450-550°C. Reaction did not occur at temperatures below 480°C and at 500 °C for 20 s because the Al-Si interlayer provided a sufficient barrier. When annealing was performed at 550°C, however, interdiffusion took place at both interfaces. As a result, aluminum increasingly penetrated into the Si substrate. The contact resistance of W-Ti to n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> Si in Al-Si/W-Ti/Si is held nearly constant at temperatures up to 480°C in furnace annealing. These results indicate that a sufficient barrier effect can be achieved in a W-Ti interlayer at temperatures below 480°C.