Analyzing energy of charged particles

Patent metadata

Field	Value
Publication number	US-2016365221-A1
Application number	US-201615183061-A
Country	US
Kind code	A1
Filing date	Jun 15, 2016
Priority date	Jun 15, 2015
Publication date	Dec 15, 2016
Grant date	—

Abstract

An analysis device, possibly having an electrostatic and/or magnetic lens, analyzes the energy of charged particles and has an opposing field grid device to which a voltage is applied in such a way that a portion of the charged particles is reflected by the opposing field grid device. Another portion of the charged particles passes through the opposing field grid device and is detected by a detector. The opposing field grid device has a curvature. A center of curvature is an intersection point of an optical axis with the opposing field grid device. The curvature has a radius of curvature which is given by the section between the center of curvature and a starting point on the optical axis. The opposing field grid device is curved in the direction of the starting point as viewed from the center of curvature and/or is arranged to be displaceable along the optical axis.

First claim

What is claimed is:

1 . An analysis device for analyzing the energy of charged particles, comprising:
at least one detector for detecting the charged particles, wherein the detector has a detection area on which impinge the charged particles which move in a direction of incidence toward the detector; at least one opposing field grid device to which a voltage is applied in such a way that a portion of the charged particles is reflected by the opposing field grid device and not detected by the detector; at least one electrostatic and/or magnetic lens, wherein proceeding from the detector, as viewed in a direction opposite to the direction of incidence of the charged particles, firstly the detector, then the opposing field grid device and then the electrostatic and/or magnetic lens are arranged, wherein the opposing field grid device has a curvature; at least one optical axis which extends through the opposing field grid device; a center of curvature of the opposing field grid device, wherein the center of curvature is an intersection point of the optical axis with the opposing field grid device, and wherein the curvature has a radius of curvature which is given by the section between the center of curvature and a starting point on the optical axis, wherein the opposing field grid device is curved in the direction of the starting point as viewed from the center of curvature and wherein the analysis device has one of the following features: the electrostatic and/or magnetic lens is arranged along the optical axis downstream of the starting point as viewed in the direction of incidence of the charged particles; the starting point is arranged along the optical axis between the electrostatic and/or magnetic lens and the center of curvature; or the starting point is arranged along the optical axis downstream of the electrostatic and/or magnetic lens and downstream of the center of curvature as viewed in the direction of incidence of the charged particles.

2 . The analysis device as claimed in claim 1 , wherein the analysis device has one of the following features:
a crossover of the charged particles is arranged on the optical axis downstream of the starting point and upstream of the electrostatic and/or magnetic lens as viewed in the direction of incidence of the charged particles; a crossover of the charged particles is arranged downstream of the starting point as viewed in the direction of incidence of the charged particles, wherein the starting point is arranged downstream of the electrostatic and/or magnetic lens as viewed in the direction of incidence of the charged particles; or a crossover of the charged particles is arranged upstream of the electrostatic and/or magnetic lens as viewed in the direction of incidence of the charged particles, wherein the electrostatic and/or magnetic lens is arranged upstream of the starting point as viewed in the direction of incidence.

3 . The analysis device as claimed in claim 1 , wherein the direction of incidence is aligned parallel to the optical axis.

4 . The analysis device as claimed in claim 1 , wherein the analysis device has at least one of the following features:
the opposing field grid device is designed in a spherical fashion; or the opposing field grid device is designed as a sphere segment.

5 . The analysis device as claimed in claim 1 , wherein the analysis device has one of the following features:
the curvature is curved in the direction of the direction of incidence of the charged particles; or the curvature is curved in a direction opposite to the direction of incidence of the charged particles.

6 . The analysis device as claimed in claim 1 , wherein the analysis device has one of the following features:
the opposing field grid device has at least one first grid and at least one second grid; or the opposing field grid device has at least one first grid and at least one second grid, wherein the first grid is arranged concentrically with respect to the second grid, wherein the starting point is associated both with the first grid and with the second grid.

7 . The analysis device as claimed in claim 1 , wherein the analysis device has one of the following features:
at least one stigmator, wherein proceeding from the detector, as viewed in a direction opposite to the direction of incidence of the charged particles, firstly the electrostatic and/or magnetic lens and then the stigmator are arranged; at least one stigmator, wherein proceeding from the detector, as viewed in a direction opposite to the direction of incidence of the charged particles, firstly the electrostatic and/or magnetic lens and then the stigmator are arranged, wherein the electrostatic and/or magnetic lens has a minimum focal length, and wherein a distance between the stigmator and the electrostatic and/or magnetic lens maximally corresponds to the minimum focal length; at least one stigmator, wherein proceeding from the detector, as viewed in a direction opposite to the direction of incidence of the charged particles, firstly the stigmator and then the electrostatic and/or magnetic lens are arranged; at least one stigmator, wherein proceeding from the detector, as viewed in a direction opposite to the direction of incidence of the charged particles, firstly the stigmator and then the electrostatic and/or magnetic lens are arranged, wherein the electrostatic and/or magnetic lens has a minimum focal length, and wherein a distance between the stigmator and the electrostatic and/or magnetic lens maximally corresponds to the minimum focal length; or at least one stigmator designed with the electrostatic and/or magnetic lens as an individual optical unit.

8 . The analysis device as claimed in claim 7 , wherein the stigmator is of magnetic or electrostatic design.

9 . The analysis device as claimed in claim 1 , wherein the analysis device has a control device for controlling the excitation of the electrostatic and/or magnetic lens and wherein the control device is configured in such a way that the excitation of the electrostatic and/or magnetic lens is controlled depending on the voltage applied to the opposing field grid device.

10 . An analysis device for analyzing the energy of charged particles, comprising:
at least one optical axis; at least one detector for detecting charged particles, wherein the detector has a detection area on which impinge the charged particles which move in a direction of incidence toward the detector; and at least one opposing field grid device to which a voltage is applied in such a way that a portion of the charged particles is reflected by the opposing field grid device and not detected by the detector, wherein the opposing field grid device has a curvature, and wherein the opposing field grid device is designed to be displaceable along the optical axis.

11 . The analysis device as claimed in claim 10 , wherein the analysis device has at least one drive unit for moving the opposing field grid device along the optical axis.

12 . The analysis device as claimed in claim 11 , wherein the drive unit is configured in such a way that the movement of the opposing field grid device is controlled depending on the voltage applied to the opposing field grid device.

13 . The analysis device as claimed in claim 10 , wherein the direction of incidence is aligned parallel to the optical axis.

14 . The analysis device as claimed in claim 10 , wherein the optical axis extends through the opposing field grid device and wherein the opposing field grid device has at least one center of curvature, wherein the center of curvature is an intersection point of the op

Assignees

• Zeiss Carl Microscopy Gmbh

Inventors

• Preikszas Dirk

Classifications

• H01J37/10

  Lenses · CPC title

• H01J37/28 Primary

  with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} · CPC title

• H01J2237/24475

  Scattered electron detectors · CPC title

• H01J37/244

  Detectors; Associated components or circuits therefor · CPC title

• H01J2237/2449

  Detector devices with moving charges in electric or magnetic fields · CPC title