METHOD FOR PRODUCING MONOCRYSTAL WAFERS Russian patent published in 2006 - IPC H01L21/302 B28D5/00 B24B1/00 

FIELD: optoelectronics; producing wafers from ingots or bullions of monocrystals, such as sapphires.

SUBSTANCE: ingots or bullions are subjected to X-ray analysis to determine direction of cutting and at least one oriented flat is made thereon by grinding at its faces (0001). Then deviation from desired position is measured by means of diffraction meter and grinding process is repeated until deviation shorter than 3 minutes is attained. Cylinder blank is cut from monocrystal ingot or bullion perpendicular to at least one flat with distinct face on its surface. Then ends of cylinders are ground at 3-minute precision of their deviation from desired value. After that cylinder diameters are calibrated and base cut is made on each cylinder. Cylinders are annealed at 1300-1500 °C for minimum 8 hours. Upon cutting cylinder blanks into wafers annealing is repeated. Wafers are thinned by grinding and annealed under same conditions as cylinders.

EFFECT: ability of producing thin sapphire wafers at high precision with respect to diameter and thickness.

10 cl, 6 dwg