公开(公告)号：US11158479B2

公开(公告)日：2021-10-26

申请号：US16613460

申请日：2018-05-23

Applicant: National University of Singapore

Inventor： Anjam Khursheed ,  Xiuyuan Shao

IPC: H01J9/02 ,  H01J1/304

Abstract: A cathode structure for cold field electron emission and method of fabricating a single-tip cathode structure for cold field electron emission. The cathode structure comprises a pointed cathode wire; and a graphene-based coating on at least a tip of the pointed cathode wire. In a preferred embodiment, graphene is coated on nickel tips by chemical vapour deposition wherein nickel functions as a catalyst for growth of graphene. The cathode structure provides stable cold field emission for electron microscopy and lithography applications and exhibits an ultralow work function value of about 1.1 eV.

公开(公告)号：US09601304B2

公开(公告)日：2017-03-21

申请号：US14834821

申请日：2015-08-25

Applicant: National University of Singapore

Inventor： Anjam Khursheed

IPC: H01J37/145 ,  H01J37/153 ,  H01J37/12 ,  H01J37/28

CPC classification number: H01J37/153 ,  H01J37/12 ,  H01J37/28 ,  H01J2237/1516 ,  H01J2237/1534

Abstract: According to embodiments of the present invention, an aberration correction apparatus is provided. The aberration correction apparatus includes an aberration correction unit including a first conductive element, and a second conductive element arranged rotationally symmetrical about the first conductive element, wherein the aberration correction unit is arranged to propagate an annular beam having charged particles in between the first conductive element and the second conductive element such that propagation of the annular beam through the aberration correction unit is rotationally symmetrical about the first conductive element, and wherein the aberration correction unit is configured to generate, between the first conductive element and the second conductive element, a magnetic field force and an electric field force directed in opposite directions and superimposed on each other to act on the charged particles to change a trajectory of the charged particles, and an annular aperture optically coupled to the aberration correction unit.

公开(公告)号：US09093243B2

公开(公告)日：2015-07-28

申请号：US14284128

申请日：2014-05-21

Applicant: NATIONAL UNIVERSITY OF SINGAPORE

Inventor： Anjam Khursheed

IPC: H01J37/26 ,  H01J3/18 ,  H01J3/20 ,  H01J3/02

CPC classification number: H01J3/18 ,  H01J3/021 ,  H01J3/027 ,  H01J3/20 ,  H01J37/063 ,  H01J37/065 ,  H01J37/26 ,  H01J2237/06333 ,  H01J2237/0635 ,  H01J2237/1534

Abstract: A gun configured to generate charged particles, comprising a ring-cathode (200) electrically configured to generate a charged particle beam; a lens arranged to focus the charged particle beam on a specimen; and at least one correction focusing electrode (1406) arranged to generate at least one electrostatic/magnetic field to further divergently/convergently focus the charged particle beam for correcting in-plane geometric aberrations associated with the lens, the focusing being based on the in-plane geometric aberrations associated with the lens. A related method is also disclosed.

Abstract translation: 一种配置成产生带电粒子的枪，包括电气配置以产生带电粒子束的环形阴极（200）; 透镜，布置成将带电粒子束聚焦在样本上; 以及至少一个校正聚焦电极（1406），其布置成产生至少一个静电/磁场，以进一步发散/收敛地聚焦带电粒子束，用于校正与透镜相关联的面内几何像差， 与透镜相关的平面几何像差。 还公开了相关方法。

公开(公告)号：US08723114B2

公开(公告)日：2014-05-13

申请号：US13679181

申请日：2012-11-16

Applicant: National University of Singapore

Inventor： Anjam Khursheed ,  Hung Quang Hoang

IPC: H01J37/26 ,  H01J3/26 ,  H01J49/48 ,  H01J49/44

CPC classification number: H01J49/48 ,  H01J3/26 ,  H01J37/244 ,  H01J37/26 ,  H01J37/28 ,  H01J49/44 ,  H01J2237/05 ,  H01J2237/0535 ,  H01J2237/24485

Abstract: A sequential radial mirror analyzer (RMA) (100) for facilitating rotationally symmetric detection of charged particles caused by a charged beam incident on a specimen (112) is disclosed. The RMA comprises a 0V equipotential exit grid (116), and a plurality of electrodes (119, 120a, 120b, 120c) electrically configured to generate corresponding electrostatic fields for deflecting at least some of the charged particles of a single energy level to exit through the exit grid (116) to form a second-order focal point on a detector (106). The second-order focal point is associated with the single energy level, and the detector (106) is disposed external to the corresponding electrostatic fields. A related method is also disclosed.

Abstract translation: 公开了一种用于促进由入射在样本（112）上的带电束引起的带电粒子的旋转对称检测的顺序径向镜分析器（RMA）（100）。 RMA包括0V等电位出口格栅（116），以及多个电极（119,120a，120b，120c），其被电配置为产生相应的静电场，用于偏转单个能级的至少一些带电粒子以便通过 出口格栅（116）以在检测器（106）上形成二阶焦点。 二阶焦点与单个能级相关联，并且检测器（106）设置在相应静电场的外部。 还公开了相关方法。