Seh America, Inc.

Timothy L Brown

Romony K San

Sergei V Koveshnikov

Dorothy E Goff

David A Beauchaine

Methods and apparatus for predicting the density of oxygen-induced stacking faults (OSF) on a surface of a wafer by measuring the surface roughness before and after a surface damaging process is presented. Such damage can be produced by, but not limited to, a wet sand blast (WSB) process, a dry sand blast (DSB) process, lapping with an abrasive material, surface grinding, and by laser irradiation. The surface roughness resulting from the surface damage is quantified and compared with the pre-damaged surface roughness. The difference between the pre- and post-damaged surface roughness is determined and correlated with oxygen-induced stacking fault density to surface roughness correlation data to obtain the predicted oxygen-induced stacking fault density. An automated computer-assisted wafer OSF density evaluation apparatus is provided comprising a computer-based comparator comprising an electronic OSF correlation database and means for inputting pre- and post-damaged surface roughness data into the computer-based comparator, the comparator adapted to compute a delta surface roughness value, the delta being the difference between the post- and pre-damaged surface roughness data, the comparator adapted to correlate the delta surface roughness value with oxygen-induced stacking fault density to surface roughness correlation data to obtain the predicted oxygen-induced stacking fault density for the wafer.

Methods and apparatus for predicting oxygen-induced stacking fault density in wafers

A semiconductor wafer manufacturing process is disclosed wherein a double side polished wafer having oxygen induced stacking faults to provide extrinsic gettering on the back surface of the wafer. The process includes polishing the back surface of the wafer, and depositing a thin polysilicon film on the polished back surface. The wafer is then subjected to a thermal oxidation step, wherein the polysilicon film is consumed by the thermal oxidation step. The oxide layer is then stripped from the back surface, leaving oxygen induced stacking faults on the back surface of the wafer. The front surface of the wafer is then polished, thereby producing a double side polished wafer containing extrinsic gettering sites on the polished back surface.

Double side polished wafers having external gettering sites, and method of producing same

A novel automated method for measuring oxygen stacking fault density on silicon wafers using methods for measuring surface roughness of a silicon wafer. A silicon wafer manufactured according to processes that include the novel automated method for measuring oxygen stacking fault density on silicon wafers using methods for measuring surface roughness of a silicon wafer.

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Vancouver, WA, United States of America

Timothy L Brown