NUMERICAL ANALYSIS ON HEAT TRANSFER CHARACTERISTICS OF A SILICON FILM IRRADIATED BY PICO-TO FEMTOSECOND PULSE LASERS

This work aims to investigate the heat transfer characteristics of a silicon microstructure irradiated by picosecond-to-femtosecond ultrashort laser pulses from a microscopic point of view. Carrier-lattice nonequilibrium interactions are simulated with a set of governing equations for the carrier and lattice temperatures to obtain the time evolutions of the lattice temperatures, the carrier number densities, and carrier temperatures. In particular, the relaxation time for approaching the thermal equilibrium between carriers and lattices is introduced to estimate duration of the nonequilibrium state. An appropriate regime map to make a distinction between one-peak and two-peak structures is also established for picosecond laser pulses. It is noted that a substantial increase in carrier temperature is observed for pulse lasers of a few picoseconds duration, whereas the lattice temperature rise is relatively small with decreasing laser pulse widths. It is also found that the laser fluence significantly affects the N 3 decaying rate of the Auger recombination, the carrier temperature distribution exhibits two peaks as a function of time due to the Auger heating as well as the direct laser heating of carriers, and finally, both laser fluence and pulse width play an important role in controlling the nonequilibrium between carriers and lattices.

[1]  W. C. Shumay.  Corrosion in electronics , 1987 .

[2]  Randy Simon,et al.  High‐Tc Thin Film and Electronic Devices , 1991 .

[3]  D. Agassi.  Phenomenological model for pisosecond‐pulse laser annealing of semiconductors , 1984 .

[4]  C. L. Tien,et al.  Heat transfer mechanisms during short-pulse laser heating of metals , 1993 .

[5]  C. Lu,et al.  Computer-simulated explosion of poly-silicide links in laser-programmable redundancy for VLSI memory repair , 1989 .

[6]  K. Seeger,et al.  Semiconductor Physics: An Introduction , 1973 .

[7]  J. Bokor,et al.  Surface adhesion reduction in silicon microstructures using femtosecond laser pulses , 1996 .

[8]  C. Tien,et al.  OPTIMIZATION OF LASER PARAMETERS FOR ULTRASHORT-PULSE LASER RECOVERY OF STICTION-FAILED MICROSTRUCTURES , 1999 .

[9]  G. Srivastava,et al.  Laser induced damage in GaAs at 1.06 μm wavelength: surface effects , 1996 .

[10]  Kazuyoshi Fushinobu,et al.  Effect of gate voltage on hot‐electron and hot phonon interaction and transport in a submicrometer transistor , 1995 .

[11]  van Driel Hm.  Kinetics of high-density plasmas generated in Si by 1.06- and 0.53- microm picosecond laser pulses. , 1987 .

[12]  N. C. Tien,et al.  Ultrashort-pulse laser heating of silicon to reduce microstructure adhesion , 1996 .

[13]  J. Narayan,et al.  Laser Method for Synthesis and Processing of Continuous Diamond Films on Nondiamond Substrates , 1991, Science.

[14]  van Driel HM.  Kinetics of high-density plasmas generated in Si by 1.06- and 0.53- microm picosecond laser pulses. , 1987, Physical review. B, Condensed matter.

[15]  C. Tien,et al.  Electronic Desorption of Surface Species Using Short-Pulse Lasers , 1998 .

[16]  Jerry R. Meyer,et al.  Optical heating in semiconductors: Laser damage in Ge, Si, InSb, and GaAs , 1980 .

[17]  A. Singh,et al.  Thermal and mechanical damage of GaAs in picosecond regime , 2001 .

[18]  G. Eesley.  Picosecond dynamics of thermal and acoustic transport in metal films , 1990 .

[19]  R. Pierret,et al.  Advanced semiconductor fundamentals , 1987 .

[20]  C. L. Tien,et al.  Femtosecond laser heating of multi-layer metals—I. Analysis , 1994 .

[21]  T Appenzeller,et al.  The man who dared to think small. , 1991, Science.