Investigations on the temperature profiles and formation of crystalline Si in rapid thermal annealing induced by thermal plasma jet (TPJ) irradiation have been reviewed. Substrate surface temperature during annealing has been measured by an optical probe method which has an accuracy of 30 K and a time resolution of millisecond. By changing the annealing conditions such as scan speed (v), plasma-substrate gap (d) and Ar gas flow rate (f), maximum surface temperature (T max) is controlled in the ranges of 960 to 1860 K with a typical annealing duration (t a) of $3 ms. On the basis of temperature measurement and in-situ reflectivity measurement techniques, the phase transformation of amorphous Si (a-Si) films has been investigated. When the a-Si films are heated to a temperature higher than the melting point, solid phase crystallization (SPC) followed by melting and resolidification of the films have been observed. It was found that SPC temperature increased from 1096 to 1284 K with decreasing crystallization time from 1.4 to 0.12 ms. Thin-film transistors (TFTs) fabricated using the SPC films show good electrical characteristics with an average field effect mobility of 61 cm 2 ÁV À1 Ás À1 and a threshold voltage of 3.4 V. By annealing SiO x films at temperatures higher than 1430 K using a TPJ, the precipitation of nanocrystalline Si with a size ranging from 10 to 250 nm has been observed.

An in-situ measurement technique for the temperature profile of a Si wafer during millisecond rapid thermal annealing has been developed. By analyzing the oscillation observed in transient reflectivity of the Si wafer during annealing, we obtain a transient temperature profile with a millisecond time resolution. Since this measurement is based on optical interference, a highly sensitive temperature measurement with an accuracy of 2 K is expected. Using this measurement technique, we controlled Si wafer surface temperature during thermal plasma jet irradiation with the heating and cooling rates in the order of 10 4 {10 5 K/s.

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La 0.67 Ba 0.33 MnO 3 (LBMO) thin films of high quality were successfully fabricated at low temperature (400-450 • C) using pulsed laser deposition assisted by CO 2 laser irradiation. It is shown that, at a low deposition temperature, LBMO thin films exhibit poor crystallinity and electrical and magnetic properties. With the aid of laser irradiation, LBMO thin films are significantly improved in their structure and quality and display a resistivity maximum of 6.3 m cm at 304 K, a large magnetoresistance of 20% (at 300 K, H = 2 T) and a ferromagnetic Curie temperature of ∼320 K, which are close to those of the LBMO thin films deposited at 800 • C. The observed improvement in the properties of the LBMO thin films deposited at low temperature is inferred to be largely associated with the enhanced crystallinity of the film and a decrease in the oxygen deficiency due to laser irradiation.

Radiation damage was studied by deep-level transient spectroscopy and Hall effect measurements for the neutron-transmutation-doped silicon of initially high-and low-resistivity (phosphorus-contained) materials. In the irradiated materials a total of twelve electron traps was observed. A large reduction of carrier concentration and a small reduction of carrier mobility were found in the initially low-resistivity samples ( c 1 2 R cm), correlated closely with the divacancy responsible for two traps ( E 4 and E8). For the initially highresistivity samples ( > 1000 R cm) results showed large reductions of carrier concentration and mobility; these reductions are closely correlated with electron traps E3, E5 and E10. It appeared that the latter three traps correspond to some energy levels within the fast-neutron-induced defect clusters. However, in the initially low-resistivity samples, t h e formation of these traps appeared to be controlled by initially doped phosphorus atoms. In other words, due to the difference in the annealing temperature of divacancy and defect cluster, the annealing-out temperatures of carrier concentration and mobility were lower for the initially low-resistivity samples in comparison with t h e initially highresistivity samples.