Laser bilayer etching of GaAs surfaces

An excimer-laser-stimulated etching technique is described for controlled pulse-by-pulse stripping of molecular bilayers from GaAs surfaces. The process is carried out in a molecular beam epitaxy (MBE) system equipped with an auxiliary low-pressure Cl2 chamber. 193 nm ArF laser light is used to pattern surfaces via projection optical imaging with high processing speed and without exposure to air between etching and MBE steps. A laser stroboscopic method has permitted temporal reaction mapping of the etching mechanisms involved.