公开(公告)号：US10573487B2

公开(公告)日：2020-02-25

申请号：US16174146

申请日：2018-10-29

Applicant: ASML Netherlands B.V.

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

IPC: H01J37/147 ,  H01J37/28 ,  H01J37/04 ,  H01J37/153

Abstract: One modified source-conversion unit and one method to reduce the Coulomb Effect in a multi-beam apparatus are proposed. In the modified source-conversion unit, the aberration-compensation function is carried out after the image-forming function has changed each beamlet to be on-axis locally, and therefore avoids undesired aberrations due to the beamlet tilting/shifting. A Coulomb-effect-reduction means with plural Coulomb-effect-reduction openings is placed close to the single electron source of the apparatus and therefore the electrons not in use can be cut off as early as possible.

公开(公告)号：US10541110B2

公开(公告)日：2020-01-21

申请号：US15925606

申请日：2018-03-19

Applicant: ASML Netherlands B.V.

Inventor： Shuai Li ,  Weiming Ren ,  Xuedong Liu ,  Juying Dou ,  Xuerang Hu ,  Zhongwei Chen

IPC: H01J37/28 ,  H01J37/10 ,  H01J37/20 ,  H01J37/244

Abstract: A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

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.