Study of Extended Defect Structure Induced by Pulsed Laser Annealing in Implanted Silicon Crystals
(a) Institute of Physics, Polish Academy of Sciences, Al. Lotniko´w 32/46,PL-02-668 Warsaw, Poland(b) Institute of Experimental Physics, Warsaw University, Ul. Hoz˙a 69,PL-00-681 Warsaw, Poland(c) Institute of Electron Technology, Al. Lotniko´w 32/46, PL-02-668 Warsaw, Poland(Received October 1, 1998)An analysis of extended defects generated during annealing by pulsed excimer laser radiation in sili-con crystals implanted with Ge ions is presented. The investigation was performed by means of twocomplementary methods: the interference-polarizing microscopy and the Lang X-ray transmissiontopography. The existence of extended defects was revealed. It has been stated that the distributionof these defects depends on the distribution of the power density in the laser beam cross-section.
Evolution of defect structure of Ge-implanted Si crystal during nanosecond laser annealing
The influence of the laser annealing on the defect structure of the near-surface layer of silicon crystal implanted with 40 keV Ge ions is reported. Evolution of defect structure during nanosecond pulse laser annealing is characterised by means of several complementary methods: reflection high-energy electron diffraction, interference-polarizing microscopy, Rutherford back-scattering and secondary ion mass spectrometry. Regions irradiated with different energy densities of the laser beam are compared. The role of the dopant in the layer recrystallised from the melt is discussed.
Computer simulation of high speed melting of amorphous silicon
The laser melting of amorphous Si is accurately modelled by computer calculations. It is found that the thermal conductivity of the amorphous phase must be set at approximately 10−2 W/cm K, a value much lower than that of crystalline material to obtain close agreement with experimental measurements. This low value is, however, consistent with the thermal conductivities of other amorphous materials. The results of the computations, when compared with experimental observations, confirm that the melting point of ion implanted amorphous Si is below that of crystalline Si, with a best estimate in the range 1185–1385 K.