# US 2017/0287686 A1 · Multi-Channel Photomultiplier Tube Assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0287686 A1 - Document ID: US20170287686A1 - Status: Published application - Kind: A1 - Application number: 15/268,326 - Filed: 2016-09-16 - Published: 2017-10-05 - Earliest claimed: 2016-03-29 - Assignees: KLA-Tencor Corporation - Applicants: KLA-Tencor Corporation - Inventors: Derek Mackay - Web page: https://patentgrep.com/patent/US20170287686A1 ## CPC - H01J 43/20: Dynodes consisting of sheet material, e.g. plane, bent - G01J 1/16: using electric radiation detectors (G01J1/20 takes precedence) - G01J 1/4228: {arrangements with two or more detectors, e.g. for sensitivity compensation} - G01J 1/44: Electric circuits {(for command of an exposure part G03B7/02)} - G01N 21/8806: {Specially adapted optical and illumination features} - G01N 21/9501: {Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} - G01J 2001/4233: {with selection of detector} - G01J 2001/4453: {PMT} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A multi-channel photomultiplier tube (PMT) detector assembly includes a photocathode. The detector assembly includes a first dynode channel including a first set of dynode pathways. The first set of dynode pathways include a plurality of dynode stages configured to receive a first portion of the photoelectrons and direct a first amplified photoelectron current onto a first anode. The detector assembly includes an additional dynode channel including an additional set of dynode pathways. The additional set of dynode pathways includes a plurality of dynode stages configured to receive an additional portion of the photoelectrons and direct an additional amplified photoelectron current onto an additional anode. The detector assembly includes a grid configured to direct the first portion of the photoelectrons to one or more of the first set of pathways and an additional portion of the photoelectrons to one or more of the additional set of pathways. ## Claims ### Claim 1 A photomultiplier tube detector assembly, comprising: a photocathode configured to absorb photons, the photocathode further configured to emit photoelectrons; a first dynode channel, the first dynode channel including a first set of dynode pathways, at least some of the first set of dynode pathways including a plurality of dynode stages configured to receive a first portion of the photoelectrons and direct a first amplified photoelectron current onto a first anode of a first set of anodes; an additional dynode channel, the additional dynode channel including an additional set of dynode pathways, at least some of the additional set of dynode pathways including a plurality of dynode stages configured to receive an additional portion of the photoelectrons and direct an additional amplified photoelectron current onto an additional anode of an additional set of anodes; and a grid configured to direct the first portion of the photoelectrons emanating from the photocathode to one or more of the first set of pathways of the first dynode channel, wherein the grid is further configured to direct the additional portion of the photoelectrons emanating from the photocathode to one or more of the additional set of pathways of the additional dynode channel. ### Claim 2 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first dynode pathways and the additional dynode pathways are arranged in an interleaving parallel pattern. ### Claim 3 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first anode and the additional anode are arranged in an interleaved pattern. ### Claim 4 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first anode is positioned within the first dynode pathway of the first dynode channel. ### Claim 5 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the additional anode is positioned within the additional dynode pathway in the additional dynode channel. ### Claim 6 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first portion of the photoelectrons and the additional portion of the photoelectrons enter the first dynode channel and the additional dynode channel sequentially. ### Claim 7 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first portion of the photoelectrons and the additional portion of the photoelectrons enter the first dynode channel and the additional dynode channel simultaneously. ### Claim 8 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the first dynode channel and the additional dynode channel are further configured to steer the photoelectrons from the photocathode with the grid via a voltage switching process. ### Claim 9 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the illumination source is a broad band light source. ### Claim 10 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein the illumination source is a narrow band light source. ### Claim 11 (depends on 1) The photomultiplier tube detector assembly of claim 1, wherein at least one of the first anode or the additional anode comprises: a first phosphor anode configured to convert the first amplified photoelectron current to a first light signal or an additional phosphor anode configured to convert the additional amplified photoelectron current to an additional light signal. ### Claim 12 (depends on 11) The photomultiplier tube detector assembly of claim 11, further comprising: at least one of a first detector configured to detect the first light signal generated by the first phosphor anode or an additional detector configured to detect the additional light signal generated by the additional phosphor anode. ### Claim 13 (depends on 12) The photomultiplier tube detector assembly of claim 12, wherein at least one of the first detector or the additional detector comprises: at least one of a charge-coupled device (CCD) detector or a complementary metal oxide-semiconductor (CMOS) detector. ### Claim 14 An inspection system, comprising: an illumination source configured to illuminate a portion of a sample surface; a set of illumination optics configured to direct and focus the illumination onto the sample surface; and a photomultiplier tube detector assembly, comprising: a first dynode channel, the first dynode channel including a first set of dynode pathways, at least some of the first set of dynode pathways including a plurality of dynode stages configured to receive a first portion of the photoelectrons and direct a first amplified photoelectron current onto a first anode of a first set of anodes; an additional dynode channel, the additional dynode channel including an additional set of dynode pathways, at least some of the additional set of dynode pathways including a plurality of dynode stages configured to receive an additional portion of the photoelectrons and direct an additional amplified photoelectron current onto an additional anode of an additional set of anodes; and a grid configured to direct the first portion of the photoelectrons emanating from the photocathode to one or more of the first set of pathways of the first dynode channel, wherein the grid is further configured to direct the additional portion of the photoelectrons emanating from the photocathode to one or more of the additional set of pathways of the additional dynode channel. ### Claim 15 (depends on 14) The inspection system of claim 14, wherein the first dynode pathways and the additional dynode pathways are arranged in an interleaving parallel pattern. ### Claim 16 (depends on 14) The inspection system of claim 14, wherein the first anode and the additional anode are arranged in an interleaved pattern. ### Claim 17 (depends on 14) The inspection system of claim 14, wherein the first anode is positioned within the first dynode pathway of the first dynode channel. ### Claim 18 (depends on 14) The inspection system of claim 14, wherein the additional anode is positioned within the additional dynode pathway in the additional dynode channel. ### Claim 19 (depends on 14) The inspection system of claim 14, wherein the first portion of the photoelectrons and the additional portion of the photoelectrons enter the first dynode channel and the additional dynode channel sequentially. ### Claim 20 (depends on 14) The inspection system of claim 14, wherein the first portion of the photoelectrons and the additional portion of the photoelectrons enter the first dynode channel and the additional dynode channel simultaneously. ### Claim 21 (depends on 14) The inspection system of claim 14, wherein the first dynode channel and the additional dynode channel are further configured to steer the photoelectrons from the photocathode with the grid via a voltage switching process. ### Claim 22 (depends on 14) The inspection system of claim 14, wherein the illumination source is a broad band light source. ### Claim 23 (depends on 14) The inspection system of claim 14, wherein the illumination source is a narrow band light source. ### Claim 24 (depends on 14) The inspection system of claim 14, wherein at least one of the first anode or the additional anode comprises: a first phosphor anode configured to convert the first amplified photoelectron current to a first light signal or an additional phosphor anode configured to convert the additional amplified photoelectron current to an additional light signal. ### Claim 25 (depends on 24) The inspection system of claim 24, further comprising: at least one of a first detector configured to detect the first light signal generated by the first phosphor anode or an additional detector configured to detect the additional light signal generated by the additional phosphor anode. ### Claim 26 (depends on 25) The inspection system of claim 25, wherein at least one of the first detector or the additional detector comprises: at least one of a charge-coupled device (CCD) detector or a complementary metal oxide-semiconductor (CMOS) detector.