A heat treatment machine for heat-treating semiconductor wafers, each wafer having two faces. A first lamp is arranged to heat a first spot of first diameter on one face of the wafer and a second lamp is arranged to heat a second spot of second diameter on the other face of the wafer, both by reflection...http://www.google.co.uk/patents/US4581520?utm_source=gb-gplus-sharePatent US4581520 - Heat treatment machine for semiconductors
