US3864597A - Device for increasing the accuracy of addressing an electron beam striking a target - Google Patents

Device for increasing the accuracy of addressing an electron beam striking a target Download PDF

Info

Publication number
US3864597A
US3864597A US350719A US35071973A US3864597A US 3864597 A US3864597 A US 3864597A US 350719 A US350719 A US 350719A US 35071973 A US35071973 A US 35071973A US 3864597 A US3864597 A US 3864597A
Authority
US
United States
Prior art keywords
rods
deflection
point
levelling
target
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US350719A
Other languages
English (en)
Inventor
Jacques Trotel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thales SA
Original Assignee
Thomson CSF SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thomson CSF SA filed Critical Thomson CSF SA
Application granted granted Critical
Publication of US3864597A publication Critical patent/US3864597A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/02—Details
    • H01J37/04—Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement
    • H01J37/147—Arrangements for directing or deflecting the discharge along a desired path
    • H01J37/1471—Arrangements for directing or deflecting the discharge along a desired path for centering, aligning or positioning of ray or beam
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H01J29/70—Arrangements for deflecting ray or beam
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/30—Electron-beam or ion-beam tubes for localised treatment of objects
    • H01J37/304—Controlling tubes by information coming from the objects or from the beam, e.g. correction signals
    • H01J37/3045—Object or beam position registration
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S505/00—Superconductor technology: apparatus, material, process
    • Y10S505/825—Apparatus per se, device per se, or process of making or operating same
    • Y10S505/872—Magnetic field shield

Definitions

  • ABSTRACT The present invention relates to systems which utilise a very thin electron beam (diameter one-tenth of a micron or less) to reach a point upon a given surface or to write-in an information there or to read one information therefrom.
  • the object of the invention is to achieve a relative accuracy in the order of 10 to 10*.
  • Two scales are marked at two adjacent sides of a square or rectangular target. They comprise studs or spots of metal having a high secondary electron emission coefficient, these electrons being detected by an auxiliary electrode. These studs define a cross-ruled arrangement on the target, which serves for coarse guidance or location. Fine adjustment is obtained by interpolation within a small square of the cross-ruled arrangement.
  • the present invention relates to systems comprising an electron-gun and a target, located inside an evacuated enclosure.
  • the object of the invention is to provide a suitable device in order to improve the accuracy of guidance and location of the electron beam striking said target.
  • the term addressing will be used here to describe the operation which makes it possible to attain a given point on the target (guidance) and, to determine the coordinates of the point of impact of the electron beam. (location).
  • the object of the present invention is an addressing device which satisfies this requirement.
  • the device in accordance with the invention comprises:
  • two levelling-rods which define two rectangular coordinate axes, perpendicular to one another and located in the plane of the target;
  • FIG. 1 is a schematic section of an electronic masking apparatus comprising an addressing mask-maker type, equipped with the device in accordance with the invention.
  • FIG. 2 is a perspective view of the essential elements of the apparatus shown in FIG. 1.
  • FIGS. 3, 4 and 5 are explanatory diagrams pertaining to the operation of said apparatus.
  • FIG. 6 is a block diagram of part of the device in accordance with the invention.
  • FIG. 1 a schematic section of an electronic masking apparatus incorporating an embodiment of the device in accordance with the invention, has been shown.
  • the masks concerned here are employed in planar semiconductor technology and monolithic integrated circuits on silicon substrates.
  • An evacuated enclosure comprises an inlet port 11, connected to a pumping system which has not been shown, a bottom 12 with a bell-jar l3 and inside the latter a hollow base 121 designed to support a target I.
  • the method of attachment of the target involves a flange 3 and springs 122 which load the target against the flange.
  • the target is generally constituted by a small plate which we will assume in this case to be rectangularly shaped.
  • Two levelling-rods 41 and 42 (the latter being visible in FIG. 2 only) border two adjacent sides of the target.
  • the bell-jar 13 contains a tank 14 communicating with the outside through an opening 141 and a tank 17 communicating with the outside through an opening 171.
  • the tanks are designed to act as cryostats and to this end are supplied respectively with liquid nitrogen 140 and liquid helium 170.
  • the tank 14 surrounds the tank 17 which latter in turn surrounds a cylindrical space in which the electron gun 5 containing cathode 7, is located.
  • This space is protected from external magnetic fields (in the case of the invention) by a screen 19 which is rendered superconductive when the wall 18 against which it is located is at the temperature of the liquid helium.
  • the screen 19 is extended at the end adjacent the target 1, in the form of a frustoconical portion 181 surrounding a further frustoconical portion 16 which is itself the extension of the gun 5 and the cylinder 51 containing the focussing and deflection elements of the cathode ray tube.
  • the space 'between the screen 19 and the frusto-conical portion 16, is narrow. This arrangement facilitates magnetic protection and the production of a high vacuum in the neighbourhood of the gun 5, because a cryogenic pumping effect is produced along the wall 18 at the temperature of the liquid helium.
  • the gun 5 will preferably comprise an electron source 7 of the thin point field-excited cold-emission type, or again an electron source of some other type (the field effect benefits from the cryogenic pumping action).
  • the electrons pass through an electrostatic or electromagnetic lense 8 and then through two successive deflection systems 9 and 10. Also, above the levelling-rod system 41 and 42, and angle piece 20, having respective sides parallel to the rods and constituting an electrode for picking up secondary electrons, is located.
  • the electron beam 50 emitted by the source 7 and passing successively through the lense 8, the devices 9 and 10 which deflect the beam so that for example it strikes the levelling-rod 41 (direction OX of deflection), can be seen.
  • These devices are deflection units which have been illustrated, by way of example,.in the form of double pairs of deflection plates.
  • the plates 91 and 101 are OY deflection plates perpendicular to OX. They have been respectively connected to the terminals and 105.
  • the plates 92 and 102 are OX deflection plates, respectively connected to the terminals 94 and 104.
  • the deflection device 9 which has a low deflection amplitude is designed to improve the accuracy of addressing carried out by the deflection device 10, the latter being the main, high-amplitude deflector device.
  • the device 9 is designed so that the positional error in the point of impact of the beam upon either of the levelling-rods, is less than the width of a scale line and therefore much smaller than the gap between two scale lines. In the following, other conditions which have to be satisfied by the devices 9 and 10, will be described.
  • the levelling-rods 41 and 42 are connected in parallel to the terminal 401 whilst the electrode 20 is connected to a terminal 402.
  • I is the current flowing from the terminal 401 to the levelling-rods
  • I is the current through the electrode 20, flowing between it and the terminal 402
  • I is the electron beam current.
  • FIG. 3 a part of the levelling-rod 41 has been shown, on which a rectangular graduation has been indicated in the form for example of a gold stud or spot deposited upon a chromium substrate which constitutes the remainder of the levelling-rod.
  • the zone of impact of the electron beam has been marked F.
  • the aim is to locate the position of the beam, in which the two aereas H and H of this zone of impact having the side of a graduation N, as their common limit, have respective surfaces equal to one another.
  • FIG. 6 a single-wire diagram of a servo-device comprising the following elements, has been shown:
  • a comparator-detector 601 A comparator-detector 601;
  • the device 10 is then supplied in such a fashion (voltage V, at the terminal 104, voltage V, at terminal that the beam 50 impinges upon the levelling-rod 41 in the neighbourhood of the graduation N
  • the comparator-detector 601 supplies the terminals 401 and 402 with a positive direct voltage and, as we have seen, currents I and I, are generated as a consequence.
  • the detected error signal is applied to the input E of the adder 604 across the integrator 602. There are two other inputs to the adder. the purpose of which will be explained hereinafter.
  • the sole output of the adder 604 is connected to the terminal 94 (OX deflection).
  • first problem guiding the beam and stopping it at the predetermined point P on the target 1; second problem, locating the position of the beam by measuring the coordinates of the point of impact.
  • FIG. 5 a cross-ruled arrangement constructed on two rectangular axes OX and CY, has been shown which we will assume to be traced upon the plane of the target 1, this arrangement having been extended to contain the graduations on the levelling-rods 41 and 42, which are located along the axes OX and CY.
  • Q be a point having the coordinates N N such that for the point P (x, y), we have:
  • the method of utilising the overall device consists in adjusting the beam to the point Q (FIG. with a strict accuracy and then displacing the beam with a lesser accuracy to obtain an impact upon the point P.
  • Deflector has a scanning range which includes the target 1 and the levelling rods 41 and 42;
  • Stability of the voltage supplies to the deflectors to be maintained during a time longer than a predetermined value, for example longer than that which is broadly required to execute a complete pattern in the case of a production of a mask.
  • Control of the beam to bring it to the point O is carried out in two stages. First of all, the switches 606 and 607 (FIG. 6) are switched in position I and the beam deflected in the OX direction. Then, the switches 606 and 607 are switched in position II and the beam deflected in the direction OY. Finally the servo-device is disconnected and the beam displaced simply under the control of the device 9, by means of the voltage u, and a applied respectively to the corresponding inputs of the adders 604 and 605. This presumes that the device 9 has been previously calibrated.
  • Distortions which may be exhibited by the device 10 must be taken into account so that the addressing of the electron beam takes place in an identical way from one apparatus to another.
  • a start is made by storing the corrections Au, and Au which have to be made to the voltages u, and u in order to bring the point 0 (N N,,) to the point 0,, which is the intersection of standard cross-ruling arrangement applied to the target 1.
  • Calibration can be carried out, for example, by utilising the apparatus as a scanner-type electron microscope, in order to show the standard crossruling arrangement.
  • the voltages 14,, u, and the corrections Au, and Au are introduced into the servodevice of FIG. 6, at the auxiliary inputs of the adders 604 and 605.
  • the drift in the supply voltages over a period of time must not be neglected.
  • the time T at the end of which this drift reaches the same order of magnitude as the resolving power of the apparatus, must be determined.
  • the duration of the calibrating and addressing operations should be substantially less than the time T, if valid results are to be obtained.
  • a time of I second for the time T is indicated, and the operations can be carried out in less than 1 ms in the case of the servodevice described hereinbefore.
  • the invention incorporates variant embodiments in which the graduations of the levelling rods, under the effect of bombardment by the electrons of the beam are the location of secondary effects which differ from the secondary emission phenomenon, for example:
  • the invention applies to numerous cases where use is made of a very thin electron beam which can be deflected in order to reach any point upon a given surface, either to deposit information there or to read out a piece of information.
  • the information furnished by the electron beam constitutes an image which is rendered visible by a luminescent deposit
  • the information read by the beam is an optical image
  • peripheral equipment of computers which displays results of calculations upon the screen of a cathode ray tube
  • mask-making machines for the manufacture of semiconductor devices where the resist of which the mask is made is exposed to a very thin electron beam; certain machines for testing semiconductor devices in which the electronic state of certain points of the circuit can be measured by the effects produced there under the impact of an electron beam;
  • a device for increasing the accuracy of addressing an electron beam striking a surface comprising in an evacuated enclosure a cathode capable of emitting an electron beam in an electric field;
  • levelling rods perpendicular to one another said levelling rods respectively having graduations, said graduations being made of a substance responding to electron impact, in another manner than that of the remainder of the rods; means for detecting the response to said electron impact; means for adressing a predetermined point of said target, by scanning successively in the directions of one rod, and of the other, for impinging upon the corresponding graduation of the rods.
  • said deflection system comprises a servodevice which causes the beam to displace to a position astride a predetermined edge of an arbitrary graduation on one or the other of said levelling-rods.
  • said enclosure further comprises around said cathode a screen which is rendered superconductive by thermic contact Y with a cryogenic source consisting of a reservoir containing a liquid gas surrounding said screen.
  • flection means comprise a first and a second unit; said 10 X 0 first unit serving to move the beam into the neighbour- Y N hood of a predetermined graduation, an said second unit serving to locate the beam astride one of the edges C t o f he eflection in Order to bring the imof said graduation. pact point the beam to the point:
  • a cathode ray tube comprising a device as claimed in claim I. Y y 9.
  • An electronic mask-making device comprising a on the reference axes of the system (XX), and the device as claimed in claim 1. quantities x and y represent fractions of such an inter-

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Electron Beam Exposure (AREA)
  • Particle Accelerators (AREA)
  • Welding Or Cutting Using Electron Beams (AREA)
US350719A 1972-04-25 1973-04-13 Device for increasing the accuracy of addressing an electron beam striking a target Expired - Lifetime US3864597A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR727214639A FR2181467B1 (enrdf_load_stackoverflow) 1972-04-25 1972-04-25

Publications (1)

Publication Number Publication Date
US3864597A true US3864597A (en) 1975-02-04

Family

ID=9097484

Family Applications (1)

Application Number Title Priority Date Filing Date
US350719A Expired - Lifetime US3864597A (en) 1972-04-25 1973-04-13 Device for increasing the accuracy of addressing an electron beam striking a target

Country Status (5)

Country Link
US (1) US3864597A (enrdf_load_stackoverflow)
JP (1) JPS5218958B2 (enrdf_load_stackoverflow)
DE (1) DE2320888C3 (enrdf_load_stackoverflow)
FR (1) FR2181467B1 (enrdf_load_stackoverflow)
GB (1) GB1396209A (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233515A (en) * 1978-07-19 1980-11-11 Leybold-Heraeus Gmbh Instrument for determining the radiation parameters of a focused charged-particle beam and method
US4243866A (en) * 1979-01-11 1981-01-06 International Business Machines Corporation Method and apparatus for forming a variable size electron beam
US4260897A (en) * 1978-05-12 1981-04-07 U.S. Philips Corporation Method of and device for implanting ions in a target
US4338508A (en) * 1978-10-02 1982-07-06 Jones Geraint A C Inscribing apparatus and methods
US4413186A (en) * 1979-08-29 1983-11-01 Fujitsu Limited Method for detecting a position of a micro-mark on a substrate by using an electron beam
US4677296A (en) * 1984-09-24 1987-06-30 Siemens Aktiengesellschaft Apparatus and method for measuring lengths in a scanning particle microscope
US4721842A (en) * 1986-08-29 1988-01-26 Ferranti Sciaky, Inc. Beam position correction device
US4785187A (en) * 1984-03-27 1988-11-15 Canon Kabushiki Kaisha Alignment device
WO1996000978A1 (en) * 1994-06-28 1996-01-11 Leica Cambridge Ltd. Electron beam lithography machine

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5186357A (en) * 1975-01-27 1976-07-28 Nippon Electron Optics Lab Denshisenichisetsuteihohooyobisoreojitsushiserusochi
JPS5621321A (en) * 1979-07-27 1981-02-27 Fujitsu Ltd Automatically setting method of focus and exposure coefficient of electron beam exposure apparatus
JPS6068692U (ja) * 1983-10-14 1985-05-15 横河電機株式会社 回路ユニツト収納機構

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3491236A (en) * 1967-09-28 1970-01-20 Gen Electric Electron beam fabrication of microelectronic circuit patterns
US3509275A (en) * 1965-09-23 1970-04-28 Ass Elect Ind Automatic focusing of electron microscopes
US3547074A (en) * 1967-04-13 1970-12-15 Block Engineering Apparatus for forming microelements
US3699304A (en) * 1969-12-15 1972-10-17 Ibm Electron beam deflection control method and apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3509275A (en) * 1965-09-23 1970-04-28 Ass Elect Ind Automatic focusing of electron microscopes
US3547074A (en) * 1967-04-13 1970-12-15 Block Engineering Apparatus for forming microelements
US3491236A (en) * 1967-09-28 1970-01-20 Gen Electric Electron beam fabrication of microelectronic circuit patterns
US3699304A (en) * 1969-12-15 1972-10-17 Ibm Electron beam deflection control method and apparatus

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4260897A (en) * 1978-05-12 1981-04-07 U.S. Philips Corporation Method of and device for implanting ions in a target
US4233515A (en) * 1978-07-19 1980-11-11 Leybold-Heraeus Gmbh Instrument for determining the radiation parameters of a focused charged-particle beam and method
US4338508A (en) * 1978-10-02 1982-07-06 Jones Geraint A C Inscribing apparatus and methods
US4243866A (en) * 1979-01-11 1981-01-06 International Business Machines Corporation Method and apparatus for forming a variable size electron beam
US4413186A (en) * 1979-08-29 1983-11-01 Fujitsu Limited Method for detecting a position of a micro-mark on a substrate by using an electron beam
US4785187A (en) * 1984-03-27 1988-11-15 Canon Kabushiki Kaisha Alignment device
US4677296A (en) * 1984-09-24 1987-06-30 Siemens Aktiengesellschaft Apparatus and method for measuring lengths in a scanning particle microscope
US4721842A (en) * 1986-08-29 1988-01-26 Ferranti Sciaky, Inc. Beam position correction device
WO1988001551A1 (en) * 1986-08-29 1988-03-10 Ferranti Sciaky, Inc. Beam position correction device
WO1996000978A1 (en) * 1994-06-28 1996-01-11 Leica Cambridge Ltd. Electron beam lithography machine

Also Published As

Publication number Publication date
FR2181467A1 (enrdf_load_stackoverflow) 1973-12-07
JPS5218958B2 (enrdf_load_stackoverflow) 1977-05-25
JPS4954999A (enrdf_load_stackoverflow) 1974-05-28
GB1396209A (en) 1975-06-04
DE2320888B2 (de) 1979-02-22
DE2320888A1 (de) 1973-11-08
DE2320888C3 (de) 1979-10-25
FR2181467B1 (enrdf_load_stackoverflow) 1974-07-26

Similar Documents

Publication Publication Date Title
US3864597A (en) Device for increasing the accuracy of addressing an electron beam striking a target
US6057907A (en) Method of and system for exposing pattern on object by charged particle beam
KR101101463B1 (ko) 측정 기능을 구비한 주사형 전자 현미경 및 시료 치수 측정 방법
US3914608A (en) Rapid exposure of micropatterns with a scanning electron microscope
US2761988A (en) Cathode ray apparatus
US4260897A (en) Method of and device for implanting ions in a target
US3922546A (en) Electron beam pattern generator
JPH1064799A (ja) 荷電ビーム描画装置及び描画方法
US3753034A (en) Electron beam apparatus
EP0024884B1 (en) Method of detecting the position of a substrate using an electron beam
US6495841B1 (en) Charged beam drawing apparatus
CA1103813A (en) Apparatus for electron beam lithography
JPH0324771B2 (enrdf_load_stackoverflow)
US6624430B2 (en) Method of measuring and calibrating inclination of electron beam in electron beam proximity exposure apparatus, and electron beam proximity exposure apparatus
US5153441A (en) Electron-beam exposure apparatus
US3857041A (en) Electron beam patterning system for use in production of semiconductor devices
US3855023A (en) Manufacture of masks
JPS6222260B2 (enrdf_load_stackoverflow)
US4392058A (en) Electron beam lithography
US2837689A (en) Post acceleration grid devices
US2925524A (en) Methods and structures correcting for beam deflections in a television picture tube
SU1191980A1 (ru) Растровый электронный микроскоп
US4803430A (en) Magnetic/electric field measuring device by means of an electron beam
US4152599A (en) Method for positioning a workpiece relative to a scanning field or a mask in a charged-particle beam apparatus
JP6869695B2 (ja) 荷電粒子ビーム描画装置及び荷電粒子ビーム描画方法