Formation of polycrystalline-silicon-germanium films by pulsed laser-induced rapid annealing

Pulsed laser rapid annealing of silicon-germanium (SiGe) films on quartz glass substrate was investigated. Laser-induced melt-regrowth properties were analyzed by the transient conductance measurements. The maximum electrical conductivity of the germanium films associated with the maximum melt depth was increased from 370 to 4420 S/cm as laser energy density increased from 130 to 200 mJ/cm2. The complete melting of the films was observed at laser energy density above 200 mJ/cm2. The electrical conductivity of the silicon films was increased from 340 to 4480 S/cm as laser energy density increased from 280 to 530 mJ/cm2. The melt duration of germanium films slightly increased from 73 to 81 ns as the laser energy density increased from 130 to 180 mJ/cm2. On the other hand, the melt duration of the silicon films was increased from 56 to 120 ns as laser energy density increased from 330 to 500 mJ/cm2. In the complete melting condition, they were furthermore increased to 117 and 145 ns for germanium and silicon, receptivity. The average size of crystalline grain was increased from 66 to 120 nm as germanium concentration increased from 20 to 60%. The crystallization to the lateral direction induced by the deep melting and rapid solidification increased the grain size.