DIFFUSING METHOD OF IMPURITY

• Main Authors: KIWAKI YOSHINARI, ITO HARUYUKI, FUJITA SEIJI, ROKUHARA MASAHITO
• Format: Patent
• Language: English
• Published: 05.08.1994
• Edition: 5
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To enhance the manufacturing yield in a silicon substrate by a method wherein impurities (e.g. boron) are restrained from separating out of the surface of an impurity diffused layer to keep a silicon substrate high in cleanness, and impurities are prevented from being outdiffused. CONSTITUTION:For instance, a diffusion preventing mask 14 is formed on the surface of a silicon substrate 11 except an impurity diffused region 13 of the substrate 11, and then an impuriy-containing film 15 is formed on the impurity diffused region 13 in a first process, and the silicon substrate 11 is thermally oxidized in an oxygen-loaded inert gas to form thin oxide films 16 and 17 of thickness 1 to 10nm on the surface of the impurity diffused region 13 and the rear side of the substrate 11 respectively in a second process. Thereafter, the silicon substrate 11 is subjected to, for example, a thermal diffusing treatment in an inert gas atmosphere, whereby impurities contained in the film 15 are diffused into the impurity diffused region 13 through the thin oxide film 16 to form an impurity diffusion layer 18.