Thermal properties of semiconductor wafers heated locally by Nd:YAG laser beam

Thermal properties of semiconductor wafers, such as Si, GaAs, GaP and InP have been investigated by a combined method of local heating by Nd:YAG laser beam and, 'in situ' or 'ex situ' observation by X-ray diffraction. (1) Characteristic alterations in each kind of wafer can be observed when they are heated locally at a very steep thermal gradient, between room temperature and their melting points, in an air environment. (2) If the specimen is heated in a thin refractory film coated state, on the other hand, the alterations mentioned above can be largely suppressed and the trace of the elastic thermal vibration of semiconductor crystal lattice can be clearly caught at the higher temperatures. (3) On the basis of these experimental results, the comparison of thermal properties between Si, GaAs, GaP and InP is discussed from the standpoints of semiconductor substrate use.