FORMATION AND UV-LASER INDUCED DESORPTION OF CL-CONTAINING SPECIES ONFROM GAAS(100) SURFACE/

XPS was used to analyse the GaAs(100) substrate before and after conce ntrated HCl treatment. The untreated RTO GaAs(100) surface has a 0.17 nm thick oxide overlayer on it. HCl treatment can remove this oxide la yer and form a layer of Cl-containing species-GaClx. The 355 nm and 19 3 nm laser was tried to study the laser induced desorption of GaClx. X PS was also used to monitor the change of Cl quantity by laser irradia tion. The results show that the 355 nm laser induces a thermal desorpt ion of GaClx. By the behavior of the thermal desorption, we conclude t hat the GaClx on the HCl treated GaAs(100) surface may be GaCl. The 19 3 nm laser can dissociate GaCland induce a photo dissociation desorpti on of Cl.