Direct Formation of Three-Dimensional Structures in GaAs by Excimer Laser Doping

Direct formation of three-dimensional structures of Si in GaAs by excimer laser doping has been demonstrated. The doped Si is limited in a very shallow region (30∼110 nm) of GaAs with very high concentration (>1×10 20 cm -3 ) that might be controlled easily by laser irradiation conditions. By using a thin solid Si dopant source, linewidths as narrow as 0.3 µm are achieved. On the other hand, the linewidths of 0.76 µm are obtained by projection patterned doping in SiH 4 gas ambient. The linewidths of the doped regions are discussed relating to the lateral profiles of the calculated transient temperature rise of the substrates.