Abstract
We present the investigation on P- and As-desorption process from the (001) InP surface in metal organic chemical vapor deposition using surface photoabsorption (SPA). The monochromatic SPA signal showed rapid initial increase to reach In-stabilized surface value after $PH_3$ was turned off, but in case of As-desorption, the signal showed clear existence of a metastable state after the $AsH_3$ was turned off. The SPA spectra at each stable surfaces were taken to confirm the interpretation. This result indicates that the As-desorption process should be understood as a two-step process, in contrast to P-desorption of one-step process.