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
  • H01J37/10—Lenses
  • H01J37/12—Lenses electrostatic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y40/00—Manufacture or treatment of nanostructures
• • 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
  • H01J37/317—Electron-beam or ion-beam tubes for localised treatment of objects for changing properties of the objects or for applying thin layers thereon, e.g. for ion implantation
  • H01J37/3174—Particle-beam lithography, e.g. electron beam lithography
  • H01J37/3177—Multi-beam, e.g. fly's eye, comb probe

Definitions

• the present invention relates to a technology of a
• charged particle beam optical system used for a charged particle beam exposure equipment such as an electron beam exposure equipment or an ion beam exposure
• the present invention relates to an
• electrode for an electrostatic lens typically, an electrode for an electrostatic objective lens
• the electron beam exposure equipment As a exposure equipment for exposing patterns in which fine patterns having a width of 0.1 micrometers or less are packed at high density, the electron beam exposure equipment is quite prospective.
• an electron beam exposure equipment that is capable of patterning with multiple electron beams simultaneously without using a photomask is quite prospective because it can support flexible production with high throughput.
• chemical substances of a resist or the like at the spot irradiated by the electron beam may be scattered, and hence it is inevitable that the resist or the like adheres to lenses, particularly to an objective lens closest to a sample (object). This adhesion of the resist or the like causes deterioration of optical characteristics of the lens, and is apt to be an
• Patent Literature 1 In order to solve this problem, Patent Literature 1
• this apparatus includes a conductive plate having an electron beam passage
• conductive plate is disposed for preventing the
• an electrode of the present invention to be used for an electrostatic charged particle beam lens includes at least one through hole.
• the at least one through hole includes a first region having a first opening contour and a second region having a second opening contour to be positioned on an upstream side of a charged particle beam with respect to the first region.
• the first opening contour is included in the second opening contour when viewed in an optical axis direction.
• the opening contour of the first region is included in the opening contour of the second region when viewed in the optical axis direction, and hence a scattered substance or the like of an object is blocked by the first region so as to hardly reach the second region and a region closer to a charged particle source with respect to the second region. Therefore, it is
• FIGS. 1A and IB are diagrams illustrating an electrode of a charged particle beam objective lens according to a first embodiment of the present invention.
• FIGS. 2A and 2B are cross-sectional views illustrating an electrostatic charged particle beam objective lens according to a second embodiment of the present
• FIGS. 3A and 3B are diagrams illustrating patterns in the case where internal diameter contours as the
• FIG. 4 is a diagram illustrating a multi-charged particle beam exposure equipment according to a fourth embodiment of the. present invention.
• FIGS. 5A, 5B, and 5C are diagrams illustrating various variation forms of the electrode according to the first embodiment of the present invention.
• An electrode of the present invention has a feature
• a through hole for transmitting a charged particle beam is formed so that a first opening contour of the through hole on the downstream side is included in a second opening contour of the through hole on the upstream side when viewed in the optical axis direction.
• the charged particle beam propagates along the optical axis at substantially the center of the through hole from the upstream side to the downstream side and irradiates the object. In this action, a scattered substance or the like is likely to enter the electrode.
• By setting the first opening contour on the downstream side smaller than the second opening contour on the upstream side it is possible to prevent the scattered substance or the like from entering. What degree to set the first opening contour on the downstream side smaller is appropriately designed in accordance with how to use the electrode or a specification of the electrode.
• the phrase "along the optical axis" includes the phrase “substantially along the optical axis". In other words, not only the case of being strictly aligned with the optical axis but also the case of being regarded substantially to be along the optical axis even if deviated within an error range .
• FIG. IB is a schematic top view of an electrode closest to an object to be irradiated by a charged particle beam, which is used for a charged particle beam
• FIG. 1A is a schematic cross-sectional view taken along the line 1A-1A of FIG. IB.
• Electrode 1 closest to the object to be irradiated by the charged particle beam is a flat plate having an optical axis 3 as the normal, and has a through hole 4.
• This through hole 4 has a circular cross section, which includes a first region a having a first internal diameter pl and a second region ⁇ having a second internal diameter cp2. The relationship between those internal diameters is ⁇ 2> ⁇ 1.
• the second region ⁇ having the relatively larger internal diameter is positioned on the side closer to a charged particle source as a light source (not shown) , namely an
• the first region having the relatively smaller internal diameter has a shield plate structure, which has a function of preventing scattered substance, evaporated substance, or the like of a sample as the object to be irradiated by the charged particle beam from entering the second region ⁇ or the charged particle source side with respect to the electrode 1.
• the region corresponding to a difference between the internal diameter ⁇ and the internal diameter cp2 of the first region is the shield plate structure region having the shield plate function.
• the through hole 4 is illustrated as a through hole having two internal diameters, in which the shield plate structure region for blocking the scattered substance, the evaporated substance, or the like of the sample is the first region a, and the region to which the scattered substance, the evaporated substance, or the like of the sample should not adhere is the second region ⁇ .
• the through hole 4 may have other regions having an internal diameter or an opening contour different from the first region a or the second region ⁇ . The reason why the above- mentioned shield plate structure region as the first region a has an effect of blocking the scattered
• the step of irradiating the object with the charged particle beam is performed in a vacuum or a low
• the shielding effect can be obtained by disposing the first region a on the straight line connecting the position irradiated with the charged particle beam and the second region ⁇ as the region to which the
• the electrode 1 is made Of single crystal silicon or the like. A surface of the electrode 1 and a side wall of the through hole 4 may be covered with a conductive material film as necessary. As the conductive material, there is selected a
• the conductive material is selected from titanium, platinum, gold, molybdenum, and the like.
• the electrode 1 has a total thickness of 100
• micrometers and is formed of a first region a having a thickness of 10 micrometers and a second region ⁇ having a thickness of 90 micrometers.
• the internal diameter cpl. of the first region a is 20 micrometers
• the internal diameter cp2 of the second region ⁇ is 30 micrometers.
• a groove having an internal diameter of 30 micrometers and a depth of 90 micrometers is formed in a silicon substrate having a thickness of 100 micrometers by photolithography technology and deep dry etching technology, to thereby form a region
• the electrode 1 can be formed.
• SOI silicon on insulator
• the through hole by patterning both sides of the silicon substrate using photolithography technology, and by etching both the sides using dry or wet etching technology .
• the electrode 1 is manufactured by the steps of
• an actual shape of the electrode 1 may be as illustrated in FIG. 5A.
• a chip 6 may occur in an edge portion, or a recess 7 may occur as a notch when the second region ⁇ is formed.
• a rounding 8 may be formed in the edge portion.
• the first region a and the second region ⁇ are regarded to be in the range illustrated in FIG. 5A.
• the through hole is formed by patterning both sides of a silicon substrate having a thickness of 100 micrometers using photolithography technology, and by etching both the sides using dry or wet etching technology.
• the opening contour of the through hole may have a tapered shape as illustrated in FIG. 5B. Then, as illustrated in FIG. 5B, it is considered that a point having the smallest internal diameter is the first region a, and that a part or a whole region closer to the charged particle source with respect to the first region a is the second region ⁇ .
• the first region a is formed using an SOI substrate including a device layer having a
• the second region ⁇ that determines optical performance of the lens is formed using another SOI substrate including a device layer having a thickness of 10 micrometers. Then, the region between the first region a and the second region ⁇ is formed using a silicon substrate having a
• the electrode 1 is manufactured by joining the regions.
• the first region a and the second region ⁇ are regarded to be in the range illustrated in FIG. 5C.
• the electrode for the objective lens to be used closest to the object to be irradiated by the charged particle ⁇ beam it is possible to realize an electrode including the first region having the shield plate function of preventing the scattered substance, the evaporated substance, or the like of the sample from entering the second region or the charged particle source side with respect to the electrode.
• FIG. 2A a second embodiment of the present invention is described.
• This embodiment is a charged particle beam objective lens using an electrode described in the first embodiment.
• a portion having the same function as the first embodiment is denoted by the same reference numeral or symbol, and overlapping description thereof is omitted.
• the charged particle beam objective lens of this embodiment includes three electrodes 1A, IB, and 1C.
• the three electrodes are flat plates having the optical axis 3 as the normal and are electrically insulated from each other.
• the three electrodes have through holes 4A, 4B, and 4C,
• the centers of the through holes 4A, 4B, and 4C are aligned along the optical axis direction. If each electrode has multiple through holes, corresponding through holes of the multiple electrodes are aligned along the optical axis direction.
• the electrode 1C is an electrode closest to the sample, for which the electrode of the first embodiment described above is used.
• Each of the three electrodes has at least one charge pad (not shown) so as to apply a electrical potential, and the electrical potential of each electrode is determined so that desired optical characteristics are expressed.
• the electrode 1A and the electrode 1C are set to the ground potential, and a negative voltage is applied to the electrode IB.
• an Einzel-type electrostatic objective lens can be constituted.
• the charged particle beam lens is determined by a shape of an electrostatic field formed in a region through which the charged particle beam passes. This corresponds to the electrostatic field formed in the regions of the through holes 4A to 4C through which the charged particle beam passes as illustrated in FIG. 2A. As the electrostatic field formed in this region becomes more rotationally symmetric about the optical axis 3, aberration of the charged particle beam lens becomes smaller. In the case of the electrostatic charged particle beam objective lens, the region of the
• aberration is the region from the lower half of the through hole 4A to the upper half of the through hole 4C.
• a material forming the sample surface for example, an organic substance forming the resist is scattered and evaporated from the sample surface.
• the scattered substance and the evaporated substance from the sample surface adhere to a part of the objective lens close to the sample.
• the electrostatic field formed in the objective lens is changed from an initial state due to electrification or the like. Then, aberration characteristics of the objective lens gets worse .
• the plate structure on the sample side is used as the electrode 1C closest to the sample in the objective lens.
• the first embodiment is applied to the electrode 1C.
• the electrodes 1A and IB are made of single crystal silicon.
• a surface of each electrode and side walls of the through holes 4A and 4B may be covered with a conductive material film.
• the conductive material there is selected a material having good adhesiveness to silicon, high conductivity, and resistance to oxidization.
• the conductive material is selected from titanium, platinum, gold, molybdenum, and the like.
• Each of the electrodes 1A and IB has a thickness of 100 micrometers.
• Each of the through holes 4A and 4B has an internal diameter of 30 micrometers.
• the electrodes 1A, IB, and 1C are electrically insulated in the direction of the optical axis 3 and are disposed with spaces of 400 micrometers each.
• the electrodes 1A, IB, and 1C may be disposed via insulating glass or an insulating material. Electrical potentials can be applied to the electrodes 1A, IB, and 1C, individually. For instance, -3.7 kV is applied to the electrode IB, and the electrodes 1A and 1C are set to the ground potential.
• an Einzel- type electrostatic lens can be constituted.
• the first embodiment is applied to the electrode 1C.
• the through holes 4A and 4B are formed in a silicon .
• substrate having a thickness of 100 micrometers by photolithography technology and silicon deep dry etching .
• the electrode having the shield structure is used as the electrode closest to the sample.
• the electrode having the shield structure is used as the electrode closest to the sample.
• FIG. 2B is a schematic cross-sectional view of the charged particle beam objective lens and its vicinity of the charged particle beam exposure equipment
• a sample 2 is irradiated with the charged particle beam passing through the through holes 4A, 4B, and 4C of the electrodes 1A, IB and 1C to reach the sample 2.
• a material forming the sample surface for example, an organic substance forming the resist is scattered linearly from the surface of the sample 2 at the part irradiated with the charged
• the second region ⁇ is a part having a large influence to the aberration characteristics of the objective lens. Therefore, if the second region ⁇ cannot be viewed directly from the sample 2, the scattered substance from the surface of the sample 2 can hardly adhere to the second region ⁇ .
• the electrode 1C has a structure including the first
• the shape of the electrode 1C and a relative positional relationship between the electrode 1C and the sample 2 considering a position shift in manufacturing process.
• the resolution of the patterning apparatus as the exposure equipment is increased more, the distance between the objective lens and the sample 2 becomes smaller. Therefore, the scattered substance from the sample surface, which is scattered when the sample is irradiated with the charged particle beam, is more likely to adhere to the objective lens. Therefore, it is very important to design the shape of the electrode 1C and the relative positional relationship between the electrode 1C and the sample 2 to be a preferred condition.
• FIG. 3A is a schematic plan view in which an internal diameter contour of the first region a and an internal diameter contour of the second region ⁇ of the
• FIG. 3A x represents a minimum space between the internal diameter contour of the first region a and the internal diameter contour of the second region ⁇ .
• FIG. 3B is an enlarged view of. the through hole 4C and its vicinity of FIG. 2B.
• h represents the thickness of the electrode 1C in the optical axis direction
• WD represents a space between the electrode 1C and the sample 2 in the optical axis direction
• ⁇ represents the internal diameter of the first region a
• y represents a distance between the surface of the
• the second region ⁇ is not directly viewed from the sample 2 at all. Therefore, the scattered substance, the evaporated substance, or the like of the sample, which may adhere to the second region ⁇ , can be blocked more appropriately by the first region a.
• This embodiment shows a charged particle beam exposure equipment using
• FIG. 4 is a diagram illustrating a structure of a
• This embodiment is a so-called multi-column type exposure equipment having individual projection systems.
• the radiated electron beam emitted from an electron source 108 as the charged particle source and attracted by anode electrodes 109 and 110 forms an irradiation optical system crossover 112 by a crossover adjustment optical system 111.
• a so-called thermoelectron type electron source such as LaB6 or BaO/ (dispenser cathode) is used as the
• the crossover adjustment optical system 111 includes a two-stage electrostatic lens. In both the first and second stages, the electrostatic lens is an Einzel-type electrostatic lens formed of . three electrodes, in which a negative voltage is
• the focus lens array 119 is an electrostatic lens including three multihole electrodes and is an Einzel-type electrostatic lens array controlled by a lens control circuit 105, in which a negative voltage is applied only to the intermediate electrode out of the three electrodes, and the upper and lower electrodes are connected to the ground.
• the aperture array 117 is disposed at a pupil plane position of the focus lens array 119 (front focal plane position of the focus lens array) so as to have a role to define an NA (convergence half angle) .
• the blanker array 122 is a device having individual deflection electrodes and turns on and off the beams individually according to a lithography pattern based on a blanking signal
• a voltage is not applied to the deflection electrode of the blanker array 122 when the beam is in an on state, while the voltage is applied to the deflection electrode of the blanker array 122 when the beam is in an off state, so as to deflect the multiple electron beams.
• Multiple electron beams 125 deflected by the blanker array 122 are blocked by a stop aperture array 123 disposed in a post stage (on the downstream side) so that the beams become the off state.
• Multiple aligners 120 are controlled by an aligner control circuit 107 so as to adjust an incident angle and an incident position of the electron beam.
• a controller 101 controls the entire circuit.
• the blanker array has two stages, in which a second blanker array 127 and a second stop aperture array 128 having the same structures as the blanker array 122 and the stop aperture array 123 are disposed in the post stage.
• the multiple electron beams after passing through the blanker array 122 form images on the second blanker array 127 by a second focus lens array 126.
• the multiple electron beams are focused by third and fourth focus lenses so as to form images on a wafer 133.
• the second focus lens array 126, a third focus lens array 130, and a fourth focus lens array 132 are Einzel-type
• electrostatic lens arrays similarly to the focus lens array 119.
• the fourth focus lens array 132 is the objective lens, and a reduction ratio thereof is set to approximately 100.
• an electron beam 121 (having a spot diameter of 2 micrometers in FWHM) on an
• Each through hole of the fourth focus lens array 132 has the above-mentioned shield plate structure (not shown) according to the present
• the scattered substance and the evaporated substance from the surface of the wafer 133 is prevented from adhering to a part of the fourth focus lens array 132 that strongly affects the
• FIG. 4 illustrates two-stage deflectors as one unit for simple
• the deflector 131 is driven by a signal of a deflection signal generation circuit 104.
• the wafer 133 is moved continuously in the X direction by a stage 134 during the patterning. Then, based on a result of measurement in actual time by a laser
• the multi-charged particle beam exposure equipment includes the electrostatic charged particle beam objective lens of the present invention, and multiple charged particle beams from the charged particle source pass through multiple through holes of the electrode of the objective lens and irradiate the object. In this way, by using multiple charged

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• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)

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• 2011
  • 2011-06-23 JP JP2011139965A patent/JP2013008534A/ja not_active Withdrawn
• 2012
  • 2012-05-17 WO PCT/JP2012/063235 patent/WO2012176574A1/en not_active Ceased
  • 2012-05-17 US US14/119,217 patent/US20140091229A1/en not_active Abandoned

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