JPS5656643A - Treating device for semiconductor substrate - Google Patents

Abstract

PURPOSE:To suppress discharge of V-group element from a substrate surface while III-V group compound semiconductor is annealed and thus to improve uniformity and reproducibility by enclosing vapor of V-group element efficiently and at high density in a chamber having an external inert gas and a limit passage. CONSTITUTION:An ion-implanted GaAs substrate is placed on a sample bed 4, As is given in a reservoir 5 and an inner tube 2 is inserted in an outer tube 1. It is then heated to a given temperature in H2 gas flow in a heating furnace 9. A part of As is discharged through a limited passage 3 between inner and outer tubes until a sample chamber 6 comes to balance with an external pressure, and H2 comes in from outside. Since surplus As vapor can be discharged from the chamber 6 at first until the pressure comes to balancing, As is not sticking in the chamber 6. After balancing, the vapor can be enclosed efficiently enough in the chamber 6 during annealing for diffusion according to a difference in density. Therefore annealing can be effected in good uniformity and reproducibility by controlling discharge of As according to a thermal decomposition of the substrate, and a virulent AsH3 is not necessary.