Lithography system, sensor and measuring method

Abstract

Lithography system, sensor and method for measuring properties of a massive amount of charged particle beams of a charged particle beam system, in particular a direct write lithography system, in whichthe charged particle beams are converted into light beams by using a converter element,using an array of light sensitive detectors such as diodes, CCD or CMOS devices, located in line with said converter element, for detecting said light beams,electronically reading out resulting signals from said detectors after exposure thereof by said light beams,utilizing said signals for determining values for one or more beam properties, thereby using an automated electronic calculator, andelectronically adapting the charged particle system so as to correct for out of specification range values for all or a number of said charged particle beams, each for one or more properties, based on said calculated property values.

The invention claimed is: 
     
       1. A method of measuring properties of a massive amount of charged particle beams of a charged particle beam system in which
 the charged particle beams are simultaneously converted into light beams by using a converter element,   using an array of light sensitive detectors such as diodes, CCD or CMOS devices, located in line with said converter element, for detecting said light beams,   electronically reading out resulting signals for each beam individually from said detectors after exposure thereof by said light beams,   utilizing said individual signals for determining values for one or more beam properties, thereby using an automated electronic calculator, and   electronically adapting the charged particle system so as to correct for out of specification range values for all or a number of said charged particle beams individually, for one or more properties, based on said calculated property values,   wherein determination of beam position and/or beam spot size is performed on the basis of signals resulting from a converted charged particle beam ( 4 ), thereby using a blocking element, configured to selectively partially and entirely block a beam, included at a known position relative to the converter   while shilling the blocking element and the charged particle beam relative to each another by one or more known shifts,   wherein the charged particle blocking element ( 6 ) is applied integrated with said converter element, located on top thereof, and wherein said detector element is applied integrated with said converter element, located on bottom thereof.   
     
     
       2. Method according to  claim 1 , wherein adaptation of the system is performed by at least one of
 electronically modifying electronic data for a pattern to be imaged by said charged particle beam system,   modifying line width, and   electronically influencing a position modifying means of said beam system, for modifying the position of one or more charged particle beams.   
     
     
       3. Method according to  claim 2 , in which the system is adapted solely by modifying said electronic data. 
     
     
       4. Method according to  claim 1 , in which the spot size of said charged particle beams is smaller than the resolution of the converter element. 
     
     
       5. Method according to  claim 4 , in which the intensity of a light beam is utilised for determining a beam property value. 
     
     
       6. Method according to  claim 5 , in which a knife-edge is used in combination with said light intensity for deriving a value for a spot size in one direction. 
     
     
       7. Method according to  claim 6 , in which values for spot size in at least two directions is used for deriving a spot shape. 
     
     
       8. Method according to  claim 1 , wherein determination of beam properties is performed on the basis of a plurality of signals resulting from a stepping proceed of a charged particle beam being scanned in one direction at a time over said blocking element. 
     
     
       9. Method according to the  claim 1 , in which a beam is switched off and on during such scan. 
     
     
       10. Method according to  claim 1 , wherein a switching “off” and “on” is incrementally delayed during multiple scans in one direction, relative to the starting point of the scan. 
     
     
       11. Method according to  claim 1 , wherein pulse duration variation is determined using a measurement with predetermined beans on/off timing. 
     
     
       12. Method according to  claim 1 , wherein the light beans resulting from impingement of a charged particle beam on said converter is optically modified for receipt by said light sensitive detector, in particular by means of a lens system, more in particular such that said resulting light beams are kept apart from one another, i.e. are modified such that no overlap between said resulting beams occurs. 
     
     
       13. Method according to  claim 1 , wherein a number of beam properties is derived using a beam detector comprising a beam blocking element, a converter element an electronically readable photon receptor element, an actuator for realising a relative movement of an electron beam and a beam blocker, and an electronic calculating unit (Cu), said properties at least including one or more of beam position, tinting delay of a possible blanker device acting upon said particle beam, beam spot size, beam current and blanking element functioning. 
     
     
       14. The method according to  claim 1 , wherein the charged particle beans system, at least the beam generating part thereof is provided with an optical sensor, and wherein the detector for detecting beam properties is utilised for optically detecting the position of said system relative to art independently moveable stage for holding a target surface and comprising said detector. 
     
     
       15. The method according to  claim 1  for measuring properties of a massive amount of charged particle beams of a direct write lithography system. 
     
     
       16. A sensor embodied for performing the measuring method in accordance wills  claim 1 . 
     
     
       17. A sensor for simultaneously measuring one or more of a beam position and a beam spot size Or one or more individual particle beams in a lithography system characterized in that the sensor comprises a converter for converting a particle beam into a light beam, as well as a photon receptor arranged for receiving a light beam emitted by said converter upon incidence of a particle beam, and transforming light from said received light beam into an electronic signal, enabling read out of said signal from the sensor by an electronic control system, its which a beam blocking element, configured to selectively partially and entirely block a beam is provided to the surface of said converter, and in which the blocking element is integrated with said converter and located on top thereof and wherein said detector element is applied integrated with said converter element, located on bottom thereof. 
     
     
       18. The sensor according to  claim 17 , characterised in that for each beamlet a separate blocking element is provided. 
     
     
       19. The sensor according to  claim 17 , in which the blocking element is provided with a sharp edge as taken perpendicularly to the surface of the converter means. 
     
     
       20. The sensor according to  claim 17 , wherein the blocking element is provided with a number of sharp edges. 
     
     
       21. The sensor according  claim 17 , in which the blocking element is composed of a heavy material, of a thickness within a range from 50 to 500 nm. 
     
     
       22. The sensor according to  claim 17 , wherein the sensor includes a thin layer of light metal, between said blocking element and said converter of a thickness within the range from 30 to 80 nm. 
     
     
       23. The sensor according to  claim 17 , wherein the sensor includes at least one blocking element having three sharp edges mutually included in a hexagon shape. 
     
     
       24. The sensor according to  claim 17 , in which an optical system is included between the converter element and the light sensitive detector. 
     
     
       25. The sensor according to  claim 17  for measuring properties of a massive amount of charged particle beams of a direct write lithography system. 
     
     
       26. A lithography system for transferring a pattern onto the surface of a target, using a charged particle beam tool, said tool being capable of generating a plurality of charged particle beams for writing said pattern on said surface, in Which either one of the measuring method according to  claim 1  and the sensor in accordance with  claim 17  is applied. 
     
     
       27. A lithography system for transferring a pattern onto the surface of a target, using a charged particle beam tool, said tool being capable of generating a plurality of charged particle beams for writing said pattern on said surface, thereby turning off and on each beam separately at writing said pattern onto the surface by means of a blanker part of said system, and of at least in advance of a writing action, sensing characteristics of a writing beam using a sensor included in a position apart from said target surface, characterised in that the sensor is arranged in the system for determination of beam position and/or beam spot size, and for directly detecting, all of said writing beams simultaneously, the sensor thereto comprising a converter converting each of said particle beans into a light beam, the sensor further comprising an array of light sensitive elements such as photodiode elements, for detecting such light beams, and for generating an electron charge upon exposure to light, which array is read out at least virtually simultaneously by a calculating unit providing correcting value signals upon such read out to a controller of the particle beam tool, and/or to a controller for said pattern, for modifying electronic data representing said pattern, in which both physical displacement of a beam spot and time delay of a blanking part for blanking a beam are measured, in which the sensor further comprises a blocking element, configured to selectively partially and entirely block a beam, included on top of said converter, and wherein said detector element is applied integrated with said converter element, located on bottom thereof. 
     
     
       28. The system according to  claim 27 , wherein adaptation of the system is performed by at least one of
 electronically modifying electronic data for a pattern to be imaged by said charged particle beam system,   modifying line width, and   electronically influencing a position modifying means of said beam system, for modifying the position of one or more charged particle beams.   
     
     
       29. The System according to  claim 27 , in which the calculating unit based on information from the sensor, provides corrective values for correcting one or more of the position of a particle beam in two directions of a plane substantially parallel to that of the target area, the intensity or current of the particle beam, the spot position and the spot size, and the sigma, of a Gaussian distribution feature of the particle beam. 
     
     
       30. The System according to  claim 27 , in which a particle beam is scanned over said sensor and switched on at an instance where it is expectedly located at a predetermined position. 
     
     
       31. The System according to  claim 30 , in which the beam is switched on for a pre-determined period of time. 
     
     
       32. System according to system  claim 27 , in which multiple scans are performed over the sensor. 
     
     
       33. The System according to  claim 27 , in which a charged particle beam is scanned over the sensor in three different directions. 
     
     
       34. System according to  claim 27 , in which a charged particle beam is scanned for a multiplicity of steps in a single direction over a sensor at different locations, shifted over at least three times an expected or determined spot diameter of the beam. 
     
     
       35. The Lithography system according to  claim 27 , comprising a stage for an object to be processed by a multi beam charged particle tool, said stage being provided with a multiplicity of sensors according to  claim 20 , for measuring charged particle beam features, wherein each sensor of said multiplicity is implemented for measuring all charged particle beams of said tool at a time, and wherein sensors of said multiplicity are distributed at various locations near said object to be processed, at mutual distances that are distributed such that calibration of the beam tool is enabled more than once at entirely treating a wafer. 
     
     
       36. The Lithography system according to  claim 35 , wherein said enabling is realised by distributing at least two sensors at even, at least corresponding distances with respect to the track which the beam tool is to follow relative to said object to be processed. 
     
     
       37. Lithography system according to  claim 35 , wherein the method according to  claim 1 , or the sensor according to  claim 20  is applied. 
     
     
       38. A multi-beam charged particle system comprising a multi beam charged particle tool configured to generate multiple charged particle beams, the system comprising:
 a sensor configured to detect the charged particle beams, the sensor comprising:   a structure comprising a plurality of patterns that are equally oriented and periodically arranged, wherein one or more patterns of the plurality of patterns are assigned per beam among the multiple charged particle beams,   wherein the structure is configured to selectively block the charged particle beams partially or entirely.   
     
     
       39. The multi-beam charged particle system of claim 38, wherein the plurality of patterns are defined by at least one knife edge. 
     
     
       40. The multi-beam charged particle system of claim 39, further comprising:
 a deflector for scanning each one of the charged particle beams over the plurality of patterns in a scanning direction relative to a first knife edge of the at least one knife edge.   
     
     
       41. The multi-beam charged particle system of claim 40, wherein the scanning direction has a sharp angle with respect to a second knife edge of the at least one knife edge. 
     
     
       42. The multi-beam charged particle system of claim 39, wherein the plurality of patterns have three sharp edges oriented at a different angle with each other. 
     
     
       43. The multi-beam charged particle system of claim 42, wherein the plurality of patterns have a hexagon shape. 
     
     
       44. The multi-beam charged particle system of claim 42, wherein the charged particle beams are scanned in at least three directions perpendicular to the three sharp edges. 
     
     
       45. The multi-beam charged particle system of claim 42, wherein adjacent sharp edges among the three sharp edges have an internal angle greater than 90 degrees and less than or equal to 120 degrees. 
     
     
       46. The multi-beam charged particle system of claim 38, wherein the sensor is configured to simultaneously measure one or more of a beam position and a beam spot size of one or more of the multiple charged particle beams. 
     
     
       47. The multi-beam charged particle system of claim 38, wherein the sensor is configured to simultaneously measure beam positions of the multiple charged particle beams. 
     
     
       48. The multi-beam charged particle system of claim 38, wherein the sensor further comprises a detector configured to detect the charged particle beams incident on the detector and the detector is positioned downstream of the beams from the plurality of patterns. 
     
     
       49. The multi-beam charged particle system of claim 38, wherein the sensor comprises a converter element for converting the charged particle beams into light beams and the detector is configured to detect the converted light beams. 
     
     
       50. The multi-beam charged particle system of claim 38, further comprising an automated electronic calculator (CU) adapted for calculating one or more charged particle beam property values for each beam of the charged particle beams based on signals electronically read out and resulting from the sensor, wherein the signals provide a set of measurement data for each charged particle beam individually as it is scanned over the plurality of patterns and the electronic calculator is configured to read out the signals substantially simultaneously. 
     
     
       51. A sensor for detecting charged particle beams of a multi-beam charged particle tool, the sensor comprising:
 a structure comprising a plurality of patterns that are equally oriented and periodically arranged, wherein one or more patterns of the plurality of patterns are assigned per beam among the charged particle beams,   wherein the structure is configured to selectively block the charged particle beams partially or entirely.   
     
     
       52. The sensor of claim 51, wherein the plurality of patterns are defined by at least one knife edge and the plurality of patterns are included at known positions relative to the tool. 
     
     
       53. The sensor of claim 52, wherein the plurality of patterns have three sharp edges oriented at a different angle with each other. 
     
     
       54. The sensor of claim 53, wherein adjacent sharp edges among the three sharp edges have an internal angle greater than 90 degrees and less than or equal to 120 degree. 
     
     
       55. The sensor of claim 51, further comprising a detector configured to detect the charged particle beams incident on the detector and the detector is positioned downstream of the beams from the plurality of patterns. 
     
     
       56. The sensor of claim 51, wherein the sensor is configured to simultaneously measure beam positions of the multiple charged particle beams. 
     
     
       57. The multi-beam charged particle system of claim 38, wherein the plurality of patterns are defined by at least one knife edge configured to determine at least one position of the charged particle beams.