WAFER AND METHOD OF PRODUCING THE SAME

• Main Authors: HUJIE KAZUO, ONO ISOROKU, MORITA ETSUROU
• Format: Patent
• Language: English
• Published: 22.08.2007
• Subjects: BASIC ELECTRIC ELEMENTS; DRESSING OR CONDITIONING OF ABRADING SURFACES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS; GRINDING; MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; PERFORMING OPERATIONS; POLISHING; SEMICONDUCTOR DEVICES; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING

A method for fabricating a wafer is provided to effectively remove micro-projections with a height not less than 1 mum such that micro-projections tend to be generated from the backside of a wafer while the micro-projections maintain an excellent GBIR(global backside ideal range), by supporting the wafer by a susceptor in a heat treatment for the wafer. While a polishing liquid is supplied to the surface of a combined abrasive cloth(2), a predetermined surface of a wafer(6) is polished to be planarized. A sheet-feed polished can be used in the polishing process. The combined cloth includes a urethane compound that includes a soft segment having polyfunctional isocyanate, a hard segment having polyfunctional polyol and an expansion ratio of 1.1~4, and a silica made of silica having a hydroxy group and an average grain size of 0.2~10 mum. The occupancy ratio of the hard segment in the urethane compound is 40~55 percent by a molecular weight ratio. The volume ratio of silica in the entire compound abrasive cloth is 20~60 percent. The Shore D hardness of the combined abrasive cloth is 40~80.