A combination of rapid thermal processing and photochemical deposition for the growth of SiO₂ suitable for InP device applications

A combination of ultraviolet and infrared lamps is used to obtain the growth of SiO₂ on InP substrates at low temperature under rapid thermal processing conditions. Thorough infrared spectroscopy characterization of the dielectric layers shows that the ultraviolet-assisted growth process without mercury sensitization leads to good quality silica interspersed with oxygen-deficient inclusions. Rapid annealing improves them so as to be suitable for InP-based field-effect devices, with interface trap density around 5×10¹¹ cm^-2. A study of the interface trap density made with this technique shows the relevance of fast thermal processing, even at low growth temperatures, for the improvement of these devices.