Rapid chemography of porous silicon undergoing hydrolysis


  • It is a pleasure to acknowledge discussions on arsine and phosphine evolution from III—V semiconductor surfaces with P. E. Oliver, P. A. Lane, T. Martin, G. W. Smith, M. Emeny; W. Y. Leong, P. C. Stevens for the provision of silane detection equipment; and A. J. Pidduck, A. G. Cullis, M. J. Saker, J. M. Keen for discussions on other aspects of the work. This work received partial support from Esprit Basic Research Programme number 7228 “EOLIS” (Emission of Light in Silicon).


Highly porous silicon reacts with water vapor in the air to create images on photographic plates within seconds. It is demonstrated that this process, known as chemography, can be used diagnostically to reveal inhomogeneity in porous silicon layers that is not always detectable by optical or electron microscopy. It is suggested that many dried highly porous semiconductors may constitute a significant health hazard owing to the liberation of high concentrations of toxic hydrides through hydrolysis.