| 摘要 |
PURPOSE:To realize safe open tube diffusion in which toxic gas such as PH3 is not employed and which does not give thermal damage to a semiconductor substrate by a method wherein impurity is diffused into the group III-V compound semiconductor substrate containing group V elements with a solution in which group V elements are dissolved as a source of diffusion. CONSTITUTION:In the core tube 11 of an electric furnace 16, Zn is diffused by vaporizing P for applying the vapor pressure of P to Zn and an InP substrate 14 from an Sn solution 13. For instance, the Sn solution 13 is composed of 4g of an Sn solution and 0.23g of InP and 0.2g of Zn dissolved in the Sn solu tion. Then a graphite boat 12 is loaded with the Sn solution 13 and the InP substrate 14 and covered with a graphite cover 15 and put into the core tube 11. Then H2 gas is introduced into the core tube 11 and heated by the electric furnace 16. The heating is carried out, for instance, at 600 deg.C for 10 minutes. With this constitution, the Zn diffusion with surface impurity concentration of 2X10<18>cm<-3> and depth of diffusion of 9mum can be performed.
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