The authors give a broad overview of some of the possible (and actual) applications of rapid thermal processing (RTP) techniques. Pioneering work done in the field of RTP is described, and a large number of references (about 90) are given. Because of the very wide range of possible applications the detail in which each is discussed may not be in direct relation to their importance for commercial or research purposes. The three main modes of RTP, the adiabatic, thermal flux and isothermal modes are described and contrasted in terms of heat flow, physical processes and suitability for various applications in the field of silicon semiconductor processing. The main types of equipment utilised for RTP research studies are briefly described, ranging from pulsed and CW laser and electron beam sources to radiant heat sources such as graphite plate and lamp systems. Three examples of the application of RTP to silicon semiconductor processing are described in some detail, with comparisons to conventional processing techniques made where relevant. The use of isothermal annealing systems for the activation of ion-implanted dopants is described and reviewed. The possible advantages of RTP are given, and the place of such technology in modern CMOS processing are briefly summarised. The formation of silicon-on-insulator structures using RTP techniques is described and compared with the competing technologies of oxygen implantation and porous silicon. Finally, the wide-ranging, new field of in situ multi-stage processing (or limited reaction processing) is briefly described, and possible applications discussed. This final section covers a subject in which much interest at the research level is presently focused.