Takashi Nakao

Gas cleaning technique for batch furnace at Agile-fab concept manufacturing

To satisfy both the quick turn around time and the process compatibility with the current product line at LPCVD process, the mini-batch furnace is one of the reasonable options. For the high tool utility and the capital scalability at small manufacturing line, the minibatch furnaces are required short time and high frequency tool cleaning for the low machine down time and process commonality for different kind of films LPCVD. In this paper, the short time and high frequency tool cleaning is proposed not only for productivity but also for particle controls.

Slow/Rapid Diffusion of Arsenic in SiO2

The As diffusion in SiO2 had been investigated by using AsSG film. As diffusivities and chemical states in SiO2 are different for N2 and H2+N2 annealing anbients. In N2, the chemical state is not changed from that of as deposited film, and it is the oxidized state with a large diffusivity. On the contrary, As has been changed to the reduced state with a small diffusivity by a H2+N2 annealing. This chemical state transition is a reversible reaction. The diffusion mechanism is assumed to be a substitutional change with Si atoms of the SiO2 network for the oxidized state As and an interstitial diffusion for the reduced state As.