High resistance silicon wafer and its manufacturing method

• Main Authors: TAKASE NOBUMITSU, ITO MAKOTO, NISHIKAWA HIDESHI, SADAMITSU SHINSUKE, SUEOKA KOJI
• Format: Patent
• Language: English
• Published: 08.07.2008
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A high-resistance silicon wafer is manufactured in which a gettering ability, mechanical strength, and economical efficiency are excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is implemented on the side of a device maker. A heat treatment for forming an oxygen precipitate nucleus is performed at 500 to 900° C. for 5 hours or more in a non-oxidizing atmosphere and a heat treatment for growing an oxygen precipitate is performed at 950 to 1050° C. for 10 hours or more on a high-oxygen and carbon-doped high-resistance silicon wafer in which resistivity is 100 Omegacm or more, an oxygen concentration is 14x1017 atoms/cm3 (ASTM F-121, 1979) or more and a carbon concentration is 0.5x1016 atoms/cm3 or more. By these heat treatments, a remaining oxygen concentration in the wafer is controlled to be 12x1017 atoms/cm3 (ASTM F-121, 1979) or less. Thus, there is provided a high-resistance, low-oxygen and high-strength silicon wafer in which resistivity is 100 Omegacm or more and an oxygen precipitate (BMD) having a size of 0.2 mum is formed so as to have high density of 1x104/cm2 or more.