公开(公告)号：US20190259573A1

公开(公告)日：2019-08-22

申请号：US16398178

申请日：2019-04-29

Applicant: ASML Netherlands B.V.

Inventor： Weiming REN ,  Shuai Li ,  Xuedong Liu ,  Zhongwei Chen

IPC: H01J37/28 ,  H01J37/12 ,  H01J37/147

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput is proposed. In the apparatus, a source-conversion unit changes a single electron source into a virtual multi-source array, a primary projection imaging system projects the array to form plural probe spots on the sample, and a condenser lens adjusts the currents of the plural probe spots. In the source-conversion unit, the image-forming means is on the upstream of the beamlet-limit means, and thereby generating less scattered electrons. The image-forming means not only forms the virtual multi-source array, but also compensates the off-axis aberrations of the plurality of probe spots.