Method of region of interest processing for reticle particle detection

An inspection system includes a radiation source that generates a radiation beam and illuminates a first surface of an object, thereby defining a region of the first surface of the object. The radiation source also irradiates a second surface of the object, defining a region of the second surface, where the second surface is located within the object at a different depth level than the first surface. The inspection system may also include a detector defining a field of view (FOV) of the first surface including the region of the first surface and receiving radiation scattered from the region of the first surface and the region of the second surface. The inspection system may also include a processor that discards image data that is not received from the region of the first surface and constructs a composite image that includes the image data from the region throughout the first surface. 检查系统包括产生辐射束并且照射物体的第一表面的辐射源，从而限定所述物体的所述第一表面的区。所述辐射源还照射所述物体的第二表面，从而限定所述第二表面的区，其中所述第二表面位于所述物体内的与所述第一表面不同的深度水平处。所述检查系统也可以包括检测器，所述