| 摘要 |
PURPOSE:To improve the characteristics of ion implanting layer by a method wherein a protective film for annealing 1 is preliminarily implanted with As ion to minimize the external diffusion (thermal dissociation) of As in GaAs substrate during annealing process. CONSTITUTION:A semiinsulating GaAs substrate 3 is implanted with Zn<+> or Si<+> ion to form a P or N layer 2. Firstly the layer 2 is coated with Si3N41 with proper thickness by means of plasma CVD process and then ion-implanted with As<+> to maximize the As concentration at the central part of thickness in the film 1. Secondly the impurity implanted layer 2 is annealed in N2 gas for activating the layer 2 to form another P or N layer again. At this time, any depletion layer region near surface or carrier concentration declining region may be reduced remarkably to form excellent conductive layer 2 since As in the layer 2 may prevent As in the substrate 3 from reducing. |
