Abstract: Disclosed herein is a novel process for the manufacture of optical bistable switching device including multiple quantum wells. The process is carried out by: supplying a first organo-metallic compound as the source of a first metallic element and a reaction gas continuously while supplying a second organo-metallic compound as the source of a second metallic element in a discrete mode into a reactor and cultivating a semiconductor multiple quantum wells region having multiple pairs of intrinsic semiconductor-layer/semiconductor-layer(GaAs/AlGaAs), one of the layer containing said second metallic element(Al), while controlling the mole fraction of said second metallic element(Al) to be in the range of 0.01 to 0.25 of the total first and second metal contents existing in the layer containing the second metallic element, thereby lowering the impurity concentration and optimizing the negative resistance.