Patent ID: 9255894
Filing Date: 2016-02-09
CPC Classification: G01N

Claim Text:
1. A system for detecting cracks in a wafer comprising: a rotational wafer stage assembly configured to secure the wafer and selectively rotate the wafer, wherein the rotational wafer stage assembly includes a spindle; a light source positioned on a first side of a surface of the wafer and configured to direct at least a portion of a light beam through the wafer, wherein the light beam is at least partially transmittable through the wafer; a sensor positioned on a second side of the wafer opposite the first side and configured to monitor one or more characteristics of light transmitted through the wafer as the rotational wafer stage assembly rotates the wafer, wherein the rotational wafer stage assembly and the light source are configured to cause the light beam to trace a pattern across the wafer; and a controller communicatively coupled to the sensor and a portion of the rotational wafer stage assembly including the spindle, wherein the controller is configured to determine the presence of one or more cracks in the wafer based on the monitored one or more characteristics of light transmitted through the wafer, wherein the spindle adjusts the rotational condition of the wafer in response to the determination of the presence of one or more cracks by the controller.