| 摘要 |
PURPOSE:To improve the reliability of a semiconductor substrate by a method wherein the semicnductor substrate is encased into a device, and treated continuously through one process in O2 at the initial stage and a mixed atmosphere of O2 and H2 at the last stage, pollution by intermediate extraction is avoided and the surface is coated with a pure oxide film. CONSTITUTION:The Si substrates 1 are encased into a vessel consisting of a quartz pipe 11 and a quartz cap 12, a gas containing a substance such as B2H6 is introduced 13 while heating the vessel by an oven and B is permeated to the surface, and N2+O2 are introduced and B is diffused to the inside at 1,200 deg.C. N2+H2 are further introduced after the time of the last stage of diffusion, SiO2 is formed onto the surfaces of the substrates 1 by utilizing nascent O generated by the reaction of H2+O2, heating is stopped at predetermined time, only N2+ H2 are flowed to cool the substrates, and the substrates are extracted. Each time is determined adequately by the depth of B diffusion and the thickness of a SiO2 film. The substrates obtained are coated with the pure SiO2 films, and dielectric resistance and other reliability are improved. |
