WO2005096060A1 - Optical microscope with high magnification, which can be used in the extreme ultraviolet radiation - Google Patents

Optical microscope with high magnification, which can be used in the extreme ultraviolet radiation Download PDF

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Publication number
WO2005096060A1
WO2005096060A1 PCT/FR2005/000459 FR2005000459W WO2005096060A1 WO 2005096060 A1 WO2005096060 A1 WO 2005096060A1 FR 2005000459 W FR2005000459 W FR 2005000459W WO 2005096060 A1 WO2005096060 A1 WO 2005096060A1
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optical
magnification
catoptric
mirrors
mirror
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PCT/FR2005/000459
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French (fr)
Inventor
Miguel Boutonne
Xavier Bozec
Roland Geyl
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SAGEM Défense Sécurité
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Publication of WO2005096060A1 publication Critical patent/WO2005096060A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/02—Objectives
    • G02B21/04—Objectives involving mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B21/00—Microscopes
    • G02B21/16—Microscopes adapted for ultraviolet illumination ; Fluorescence microscopes

Definitions

  • the present invention is in the field of optical microscopes, and more particularly it is in the field of optical microscopes suitable for the observation of objects of very small dimensions of the order of ten nanometers.
  • the observation of an object having a dimension of the order of a few tens of nanometers requires the use of a illumination light of the object which has a wavelength not exceeding the order of magnitude of half the dimension of the object to be observed.
  • the light chosen for practical implementation has a wavelength of the order of 13.5 nm (that is to say that it is in the range extreme ultraviolet) and allows observation of objects of about 25 nm.
  • magnification is meant a magnification of several hundred times, preferably of the order of at least 500 times.
  • the object of the invention is therefore to propose an optical microscope with a strong catoptric structure. magnification which can be used in the extreme ultraviolet range, typically with light having a wavelength of the order of 13.5 nm.
  • the invention provides a high magnification microscope usable in the extreme ultraviolet, characterized in that it comprises:
  • an illumination part for lighting an object to be observed from a light source emitting in the extreme ultraviolet which illumination part successively comprises:. a first catoptric system having an optical axis (first optical axis) directed in a first direction, and. a field mirror located on said first optical axis and inclined on this axis by an angle less than about 15 °, and - an imaging part for collecting on a detector an enlarged image of the illuminated object, which part of imagery successively includes:. a second catoptric system having a second optical axis, receiving the light reflected by the illuminated object and having a given magnification Gi, and.
  • the structure of the optical microscope according to the invention uses only reflective surfaces (catoptric structure), having received a MoSi processing with regard to the range of wavelengths to be used, which furthermore is capable of providing the desired high magnification.
  • the surfaces implemented under the conditions of use provided for in the framework mentioned above are not reflective only at certain angles of incidence of the light beam: light with grazing incidence or light with normal incidence.
  • the mirrors used must therefore be arranged so as to meet these requirements.
  • the distance between the support mechanism of the second catoptric system and the object to be observed is too small to position an optical element (folding mirror, optical square) capable of directing the light beam on the object under the conditions suitable incidence (due to surface treatment) to obtain bright field lighting.
  • the lighting beam is injected directly into the second catoptric system to combine the light source with the object to be observed (lighting called "critical lighting”").
  • the catoptric systems are Schwarzschild objectives or telescopes, which allow, under a relatively small volume, to confer a large magnification.
  • the manufacture of the concave and convex surfaces of their two constituent elements does not pose any particular difficulties.
  • half of the Schwarzschild objective of the second catoptric system transmits the incident light beam of the object to be observed and its the other half transmits the beam reflected by the illuminated object.
  • the optical system with several concave spherical mirrors comprises two concave spherical mirrors facing each other, such an optical system being capable of providing significant magnifications. It is possible to ensure that, in the imaging part, the second catoptric system, in particular arranged in the form of a Schwarzschild objective, has a magnification Gi of approximately 15 and that the optical system with several concave spherical mirrors has a magnification G 2 of about 33, whereby the magnification of the microscope is about 500, in accordance with the desired objective.
  • the mirrors planes of the folding system are in number and arrangement such that the above first and second optical axes respectively of the first and second catoptric systems are substantially perpendicular to each other. Thanks to the arrangements in accordance with the invention which have just been exposed, there is an optical microscope of the fully catoptric type which is capable of operating in the extreme ultraviolet, typically with light having a wavelength of order of 13.5 nm, and which therefore allows the observation of an object having dimensions of an order of magnitude twice the wavelength (about 25 nm).
  • the invention will be better understood on reading the detailed description which follows of certain embodiments given solely by way of non-limiting examples.
  • Figure 1 is an optical diagram of an illumination part for an optical microscope arranged in accordance with the invention
  • - Figure 2 is an optical diagram of a preferred embodiment of the illumination part of Figure 1
  • - Figure 3 is an optical diagram of an imaging part for an optical microscope arranged in accordance with the invention
  • - Figure 4 is an overall optical diagram of a preferred embodiment of an optical microscope according to the invention.
  • Figure 1 shows the optical diagram of an illumination part, generally designated by the reference 1, for lighting of an object O to be observed from a light source S emitting in the extreme ultraviolet, typically with a wavelength of the order of 13.5 nm.
  • the illumination part 1 successively comprises the following optical elements.
  • a first catoptric system 2 has an optical axis (or first optical axis) Dx directed in a first direction.
  • This first catoptric system 2 is preferably constituted in the form of a Schwarzschild objective or telescope, with a concave mirror 3 turned towards the source S and receiving on its edge the light beam coming from it and with a convex mirror 4 located opposite the concave mirror 3 and reflecting the beam from the concave mirror 3 axially in the direction of a central hole 5 made therein.
  • the light beam then reaches a concave field mirror 6, combining the image plane of the source S and the image plane of the object O, and allowing the light beam to be folded to reduce the dimensions of the device.
  • the mirror 6 is located on the first optical axis and inclined relative to the latter by an angle such that it receives the light beam at an incidence of less than about 15 °.
  • the beam reflected by the mirror 6 arrives in a focusing optical device 7 having its axis (second optical axis) D 2 directed in a second direction which, here, coincides with the direction followed by the beam reflected by the mirror 6.
  • D x and D 2 are angularly separated one on the other by at most 15 °, which leaves too little room, in practice, for the installation of the light source S and the positioning of the object O to be observed.
  • the two aforementioned optical axes Di and D are angularly more apart from one another, and that in particular, in a preferred embodiment, they are perpendicular to each other as illustrated in the FIG. 2.
  • an optical folding system 10 comprising a plurality of plane folding mirrors successively reflecting the beam returned by the field mirror 6 in a second direction which differs from the direction of reflection of the field mirror 6, said folding mirrors being arranged so as to receive the beam under respective incidences exceeding approximately 75 ° (grazing incidences).
  • the folding mirrors of the folding system 10 are in number and in arrangement such that the two optical axes D x and D 2 are substantially perpendicular to each other.
  • the folding system 10 consists here of two plane mirrors 11 and 12.
  • the imaging part 13 comprises a second catoptric system 14 comprising a concave mirror 15 turned towards the object 0 associated with a convex mirror 16, the assembly being, here again, advantageously constituted in the form of a Schwarzschild objective or telescope .
  • the concave mirror 15 is slightly aspherical.
  • the set of two mirrors 15 and 16 has a magnification of approximately 15.
  • the concave mirror 15 has a useful diameter of approximately 100 mm and has an aspherization of 100 nm over its useful area;
  • the convex mirror 16 has an aspherization of 120 nm with a maximum slope of 0.08 ⁇ m / mm over an area of 22.5 mm in diameter (the useful area being 19.5 mm);
  • the angles of incidence vary from 2.2 ° to 4.6 ° for the concave mirror 15 and from 7.2 ° to 14.5 ° for the convex mirror 16.
  • the imaging part 13 also comprises, downstream of the objective of Schwarzschild 14, an optical system 17 with several concave spherical mirrors facing each other. In the example illustrated in FIG.
  • FIG. 3 illustrates a complete apparatus, uniting the illumination part 1 illustrated in FIG. 2 and the imaging part 13 illustrated in figure 3.
  • the distance between the front convex lens 16 of the Schwarzschild objective 14 and the object 0 is too small for the light beam to be applied to the object under an approximately normal incidence from of the focusing device 7.
  • the clever solution according to the invention then consists in injecting the light beam into the catoptric system 14, here in the Schwarzschild objective, in other words to constitute the focusing device 7 in the form of a Schwarzschild objective structure.
  • the Schwarzschild objective is then used to transmit the light beam to the object O, while the other half is used to transmit the light beam reflected by the object illuminated.
  • the beam from the concave mirror system 17 is reflected by a plane mirror 20, which is arranged to receive this beam under an approximately normal incidence of at most 15 °.
  • a catoptric microscope is formed which solves the problem posed by the correct lighting of the object 0 by using a common objective between the lighting path and the imaging path.
  • the system works in the field, which avoids stray light because the detector D does not directly see the object O.
  • the microscope thus arranged has a high magnification which allows the observation of small objects.
  • the distance between the object and the front element is large, which facilitates handling and the installation of any auxiliary devices.
  • this microscope arrangement has a small central field of very good optical quality surrounded by a large peripheral field with degraded optical quality: this makes it possible, during observation, to probe the areas around that observed with precision in the little field.
  • the mirrors are spherical or slightly aspherical, which induces relative ease of manufacture.
  • the two catoptric systems 2 and 7 are preferably Schwarzschild objectives or telescopes because of the inherent advantage of this type of objective, and it is in this form that they are illustrated in FIG. 4.
  • any other type of catoptric objective capable of providing a similar magnification - one could use a objective consisting of a concave mirror and a convex mirror, the mirrors 18 and 19 remaining concave in order to maintain the zero Petzval; - One could use an objective consisting of two concave mirrors, at least one of the mirrors 18, 19 being convex to maintain the zero Petzval. In both cases, the asphericity of the mirrors increases.

Abstract

The invention relates to an optical microscope with high magnification, which can be used in the extreme ultraviolet radiation. The inventive microscope consists of: an illuminating part (1) which is used to illuminate an object (O) from a light source (S) and which comprises (i) a catoptric system (2) with an optical axis (D1) and (ii) a field mirror (6) which is inclined along said axis at an angle of less than approximately 15°; and an imaging part (13) which is used to form a magnified image of the illuminated object on a detector (D), said imaging part comprising successively (a) a catoptric system (14) having an optical axis (D2), which receives the light reflected by the illuminated object and which has a given magnification G1, and (b) an optical system (17) with several concave spherical mirrors having a given magnification G2. According to the invention, the field mirror (6) reflects the illuminating light along the optical axis (D2) such that the catoptric system (14) focuses the illuminating light beam on the object to be observed.

Description

MICROSCOPE OPTIQUE A FORT GRANDISSEMENT UTILISABLE DANS L'EXTREME ULTRAVIOLET HIGH-MAGNIFICATION OPTICAL MICROSCOPE FOR USE IN EXTREME ULTRAVIOLET
La présente invention se situe dans le domaine des microscopes optiques, et plus particulièrement elle se situe dans le domaine des microscopes optiques propres à l'observation d'objets de très faibles dimensions de l'ordre de la dizaine de nanometres. L'observation d'un objet ayant une dimension de l'ordre de quelques dizaines de nanometres (il peut par exemple s'agir du contrôle de masques utilisés dans la fabrication des circuits intégrés à très forte intégration) nécessite l'utilisation d'une lumière d'éclairage de l'objet qui possède une longueur d'onde n'excédant pas l'ordre de grandeur de la moitié de la dimension de l'objet à observer. Pour des raisons de conception de la source lumineuse, la lumière choisie pour une mise en œuvre pratique a une longueur d'onde de l'ordre de 13,5 nm (c'est-à-dire qu'elle se situe dans le domaine de l'extrême ultraviolet) et autorise l'observation d'objet d'environ 25 nm. Toutefois, on ne connaît pas, actuellement, de matériau qui soit transparent pour ce domaine de longueurs d'onde. Il n'est donc pas possible de réaliser des éléments dioptriques et notamment des lentilles, et par conséquent il n'est pas possible de concevoir actuellement un microscope optique qui soit au moins en partie de type dioptrique . Par ailleurs, par "fort grandissement", on entend un grandissement de plusieurs centaines de fois, préférentiellement de l'ordre d'au moins 500 fois. L'invention a donc pour objet de proposer un microscope optique à structure catoptrique à fort grandissement qui soit utilisable dans le domaine de l'extrême ultraviolet, typiquement avec une lumière ayant une longueur d'onde de l'ordre de 13,5 nm. A ces fins, l'invention propose un microscope à fort grandissement utilisable dans l'extrême ultraviolet, caractérisé en ce qu'il comprend :The present invention is in the field of optical microscopes, and more particularly it is in the field of optical microscopes suitable for the observation of objects of very small dimensions of the order of ten nanometers. The observation of an object having a dimension of the order of a few tens of nanometers (it can for example be the control of masks used in the manufacture of integrated circuits with very high integration) requires the use of a illumination light of the object which has a wavelength not exceeding the order of magnitude of half the dimension of the object to be observed. For reasons of design of the light source, the light chosen for practical implementation has a wavelength of the order of 13.5 nm (that is to say that it is in the range extreme ultraviolet) and allows observation of objects of about 25 nm. However, no material is currently known which is transparent for this wavelength range. It is therefore not possible to produce dioptric elements and in particular lenses, and therefore it is not possible to currently design an optical microscope which is at least partly of dioptric type. Furthermore, by "large magnification" is meant a magnification of several hundred times, preferably of the order of at least 500 times. The object of the invention is therefore to propose an optical microscope with a strong catoptric structure. magnification which can be used in the extreme ultraviolet range, typically with light having a wavelength of the order of 13.5 nm. For these purposes, the invention provides a high magnification microscope usable in the extreme ultraviolet, characterized in that it comprises:
- une partie d'illumination pour l'éclairage d'un objet à observer à partir d'une source de lumière émettant dans l'extrême ultraviolet, laquelle partie d'illumination comprend successivement : . un premier système catoptrique ayant un axe optique (premier axe optique) dirigé selon une première direction, et . un miroir de champ situé sur ledit premier axe optique et incliné sur cet axe d'un angle inférieur à environ 15°, et - une partie d'imagerie pour recueillir sur un détecteur une image agrandie de l'objet éclairé, laquelle partie d'imagerie comprend successivement : . un second système catoptrique ayant un second axe optique, recevant la lumière réfléchie par l'objet éclairé et ayant un grandissement Gi donné, et . un système optique à plusieurs miroirs sphériques concaves ayant un grandissement G2 donné, - ledit miroir de champ de la partie d'illumination réfléchissant la lumière d'éclairage selon ledit second axe optique de façon que ledit second système catoptrique focalise le faisceau lumineux d'éclairage sur l'objet à observer. Ainsi, la structure du microscope optique conforme à l'invention fait appel uniquement à des surfaces réfléchissantes (structure catoptrique) , ayant reçues un traitement MoSi eu égard au domaine de longueurs d'onde devant être utilisées, qui en outre est apte à procurer le grandissement élevé recherché. Il faut également noter que les surfaces mises en œuvre dans les conditions d'utilisation prévues dans le cadre mentionné plus haut (surfaces traitées MoSi utilisées avec une lumière ayant une longueur d'onde de l'ordre de la dizaine de nanometres) ne sont réfléchissantes que sous certains angles d'incidence du faisceau lumineux : lumière à incidence rasante ou lumière à incidence normale. Les miroirs mis en œuvre doivent donc être disposés de manière à satisfaire ces exigences. Enfin, la distance entre la mécanique de support du second système catoptrique et l'objet à observer est trop faible pour positionner un élément optique (miroir de repli, équerre optique) propre à diriger le faisceau d'éclairage sur l'objet dans les conditions convenables d'incidence (en raison du traitement des surfaces) pour obtenir un éclairage en fond clair. C'est donc de façon très astucieuse, pour contourner cette difficulté, que conformément à l'invention le faisceau d'éclairage est injecté directement dans le second système catoptrique pour conjuguer la source lumineuse à l'objet à observer (éclairage dit "éclairage critique"). Dans un mode de réalisation préféré, les systèmes catoptriques sont des objectifs ou télescopes de Schwarzschild, qui permettent, sous un relativement faible volume, de conférer un grandissement important. En outre, la fabrication des surfaces concave et convexe de leurs deux éléments constitutifs ne pose pas de difficultés particulières. Dans ce cas, une moitié de l'objectif de Schwarzschild du second système catoptrique transmet le faisceau incident d'éclairage de l'objet à observer et son autre moitié transmet le faisceau réfléchi par l'objet éclairé. Par ailleurs, on prévoit avantageusement que, dans la partie d'imagerie, le système optique à plusieurs miroirs sphériques concaves comporte deux miroirs sphériques concaves en vis-à-vis, un tel système optique étant apte à procurer des grandissements importants. Il est possible de faire en sorte que, dans la partie d'imagerie, le second système catoptrique, notamment agencé sous forme d'un objectif de Schwarzschild, ait un grandissement Gi d'environ 15 et que le système optique à plusieurs miroirs sphériques concaves ait un grandissement G2 d'environ 33, ce grâce à quoi le grandissement du microscope est d'environ 500, conformément au but recherché. Avantageusement, dans la partie d'imagerie, on prévoit en outre, après le dernier miroir sphérique concave du système à miroirs sphériques concaves, un miroir plan de repliement incliné pour recevoir le faisceau sous une incidence n'excédant pas 15° : ce repliement du faisceau lumineux permet de réaliser le microscope sous une forme plus compacte. On peut également accroître la compacité du microscope en prévoyant, dans la partie d'illumination et entre le miroir de champ et le second système catoptrique, un système optique de repliement du faisceau lumineux comprenant une pluralité de miroirs plans de repliement réfléchissant successivement le faisceau renvoyé par le miroir de champ selon une seconde direction différente de la susdite première direction, lesdits miroirs de repliement étant disposés de manière à recevoir le faisceau sous des incidences respectives excédant environ 75° (incidence rasante) . De préférence alors, les miroirs plans du système de repliement sont en nombre et en arrangement tels que les susdits premier et second axes optiques respectivement des premier et second systèmes catoptriques soient sensiblement perpendiculaires l'un à l'autre. Grâce aux dispositions conformes à l'invention qui viennent d'être exposées, on dispose d'un microscope optique de type intégralement catoptrique qui est apte à fonctionner dans l'extrême ultraviolet, typiquement avec une lumière ayant une longueur d'onde de l'ordre de 13,5 nm, et qui autorise donc l'observation d'un objet ayant des dimensions d'un ordre de grandeur du double de la longueur d'onde (environ 25 nm) . L'invention sera mieux comprise à la lecture de la description détaillée qui suit de certains modes de réalisation donnés uniquement à titre d'exemples nullement limitatifs. Dans cette description, on se réfère aux dessins annexés sur lesquels : - la figure 1 est un schéma optique d'une partie d'illumination pour un microscope optique agencé conformément à l'invention ; - la figure 2 est un schéma optique d'une variante de réalisation préférée de la partie d'illumination de la figure 1 ; - la figure 3 est un schéma optique d'une partie d'imagerie pour un microscope optique agencé conformément à l'invention ; et - la figure 4 est un schéma optique d'ensemble d'un mode de réalisation préféré d'un microscope optique conforme à l'invention. On se réfère tout d'abord à la figure 1 qui montre le schéma optique d'une partie d'illumination, désignée dans son ensemble par la référence 1, pour l'éclairage d'un objet O à observer à partir d'une source de lumière S émettant dans l'extrême ultraviolet, typiquement avec une longueur d'onde de l'ordre de 13,5 nm. La partie d'illumination 1 comprend successivement les éléments optiques suivants. Un premier système catoptrique 2 possède un axe optique (ou premier axe optique) Dx dirigé selon une première direction. Ce premier système catoptrique 2 est de préférence constitué sous forme d'un objectif ou télescope de Schwarzschild, avec un miroir concave 3 tourné vers la source S et recevant sur son bord le faisceau lumineux issu de celle-ci et avec un miroir convexe 4 situé en regard du miroir concave 3 et réfléchissant le faisceau issu du miroir concave 3 axialement en direction d'un trou central 5 pratiqué dans celui-ci . Le faisceau lumineux parvient ensuite sur un miroir de champ 6, concave, conjuguant le plan image de la source S et le plan image de l'objet O, et permettant un repliement du faisceau lumineux pour réduire les dimensions de l'appareil. Le miroir 6 est situé sur le premier axe optique et incliné par rapport à celui-ci d'un angle tel qu'il reçoive le faisceau lumineux sous une incidence inférieure à environ 15°. Enfin, le faisceau réfléchi par le miroir 6 parvient dans un dispositif optique focaliseur 7 ayant son axe (second axe optique) D2 dirigé selon une seconde direction qui, ici, coïncide avec la direction suivie par le faisceau réfléchi par le miroir 6. Un exemple de mise en œuvre pratique du dispositif focaliseur 7 sera indiqué plus loin. Dans l'agencement qui vient d'être décrit, les deux axes optiques Dx et D2 sont écartés angulairement l'un de l'autre d'au plus 15°, ce qui laisse trop peu de place, en pratique, pour l'installation de la source lumineuse S et le positionnement de l'objet O à observer. Il est donc souhaitable que les deux susdits axes optiques Di et D soient angulairement plus écartés l'un à l'autre, et que notamment, dans un mode de réalisation préféré, ils soient perpendiculaires l'un à l'autre comme illustré à la figure 2. Pour ce faire, on prévoit d'interposer, entre le miroir de champ 6 et le dispositif focaliseur 7, un système optique de repliement 10 comprenant une pluralité de miroirs plans de repliement réfléchissant successivement le faisceau renvoyé par le miroir de champ 6 selon une seconde direction qui diffère de la direction de réflexion du miroir de champ 6, lesdits miroirs de repliement étant disposés de manière à recevoir le faisceau sous des incidences respectives excédant environ 75° (incidences rasantes). Dans l'exemple illustré à la figure 2, les miroirs de repliement du système de repliement 10 sont en nombre et en arrangement tels que les deux axes optiques Dx et D2 sont sensiblement perpendiculaires l'un à l'autre. Pour ce faire, le système de repliement 10 est constitué ici de deux miroirs plans 11 et 12. A la figure 3 est illustrée la partie d'imagerie, désignée dans son ensemble par la référence 13, qui est propre à former sur un détecteur D une image agrandie de l'objet O éclairé. La partie d'imagerie 13 comprend un second système catoptrique 14 comportant un miroir concave 15 tourné vers l'objet 0 associé à un miroir convexe 16, l'ensemble étant, ici encore, avantageusement constitué sous forme d'un objectif ou télescope de Schwarzschild. Le miroir concave 15 est légèrement asphérique. L'ensemble des deux miroirs 15 et 16 a un grandissement d'environ 15. Dans un exemple concret de réalisation, le miroir concave 15 a un diamètre utile d'environ 100 mm et présente une asphérisation de 100 nm sur sa zone utile ; le miroir convexe 16 présente une asphérisation de 120 nm avec une pente maximale de 0,08 μm/mm sur une zone de 22,5 mm de diamètre (la zone utile étant de 19,5 mm) ; les angles d'incidence varient de 2,2° à 4,6° pour le miroir concave 15 et de 7,2° à 14,5° pour le miroir convexe 16. La partie d'imagerie 13 comprend également, en aval de l'objectif de Schwarzschild 14, un système optique 17 à plusieurs miroirs sphériques concaves en vis-à-vis. Dans l'exemple illustré à la figure 3, il comporte deux miroirs sphériques concaves respectivement 18 et 19. Le miroir 19 est percé centralement pour laisser passage au faisceau en provenance de l'objectif de Schwarzschild. Le grandissement du couple de miroirs 18 et 19 est d'environ 33. Avantageusement, la courbure du miroir concave 18 est sensiblement la même que celle du miroir convexe 16 pour annuler le Petzval, et donc la courbure du champ. Le grandissement global de la partie d'imagerie agencée conformément à l'invention est de l'ordre de 500. La figure 4 illustre un appareil complet, réunissant la partie d'illumination 1 illustrée à la figure 2 et la partie d'imagerie 13 illustrée à la figure 3. La distance entre la lentille convexe frontale 16 de l'objectif de Schwarzschild 14 et l'objet 0 est trop faible pour que le faisceau d'éclairage puisse être appliqué à l'objet sous une incidence approximativement normale à partir du dispositif focaliseur 7. La solution astucieuse conforme à l'invention consiste alors à injecter le faisceau d'éclairage dans le système catoptrique 14, ici dans l'objectif de Schwarzschild, autrement dit à constituer le dispositif focaliseur 7 sous forme d'une structure d'objectif de Schwarzschild. Ainsi une moitié de l'objectif de Schwarzschild sert alors à la transmission du faisceau d'éclairage vers l'objet O, tandis que l'autre moitié sert à transmettre le faisceau de lumière réfléchie par l'objet éclairé. Toujours dans le but de réaliser un appareil compact, le faisceau issu du système de miroirs concaves 17 est réfléchi par un miroir plan 20, lequel est disposé pour recevoir ce faisceau sous une incidence approximativement normale d'au plus 15°. Grâce aux dispositions conformes à l'invention, on constitue un microscope catoptrique qui résout le problème posé par l'éclairage correct de l'objet 0 en utilisant un objectif commun entre la voie d'éclairage et la voie de l'imagerie. Le système travaille dans le champ, ce qui permet d'éviter la lumière parasite car le détecteur D ne voit pas directement l'objet O. Le microscope ainsi agencé possède un grandissement élevé qui permet l'observation de petits objets. La distance entre l'objet et l'élément frontal est importante, ce qui facilite les manipulations et l'implantation de dispositifs auxiliaires éventuels. De plus, cet agencement de microscope présente un petit champ central de très bonne qualité optique entouré d'un grand champ périphérique ayant une qualité optique dégradée : cela permet, au cours de l'observation, de sonder les zones avoisinant celle observée avec précision dans le petit champ. Enfin, les miroirs sont sphériques ou faiblement asphériques, ce qui induit une relative facilité de fabrication. Dans ce qui précède, les deux systèmes catoptriques 2 et 7 sont de préférence des objectifs ou télescopes de Schwarzschild en raison de l'avantage propre de ce type d'objectif, et c'est sous cette forme qu'ils sont illustrés à la figure 4. Toutefois, on pourrait mettre en œuvre tout autre type d'objectif catoptrique apte à procurer un grandissement analogue : - on pourrait utiliser un objectif constitué d'un miroir concave et d'un miroir convexe, les miroirs 18 et 19 restant concaves afin de maintenir le Petzval nul ; - on pourrait utiliser un objectif constitué de deux miroirs concaves, l'un au moins des miroirs 18, 19 étant convexe pour maintenir le Petzval nul . Dans les deux cas, 1 ' asphérisation des miroirs augmente. - an illumination part for lighting an object to be observed from a light source emitting in the extreme ultraviolet, which illumination part successively comprises:. a first catoptric system having an optical axis (first optical axis) directed in a first direction, and. a field mirror located on said first optical axis and inclined on this axis by an angle less than about 15 °, and - an imaging part for collecting on a detector an enlarged image of the illuminated object, which part of imagery successively includes:. a second catoptric system having a second optical axis, receiving the light reflected by the illuminated object and having a given magnification Gi, and. an optical system with several concave spherical mirrors having a given magnification G 2 , - said field mirror of the illumination part reflecting the light light along said second optical axis so that said second catoptric system focuses the light beam of lighting on the object to be observed. Thus, the structure of the optical microscope according to the invention uses only reflective surfaces (catoptric structure), having received a MoSi processing with regard to the range of wavelengths to be used, which furthermore is capable of providing the desired high magnification. It should also be noted that the surfaces implemented under the conditions of use provided for in the framework mentioned above (MoSi treated surfaces used with light having a wavelength of the order of ten nanometers) are not reflective only at certain angles of incidence of the light beam: light with grazing incidence or light with normal incidence. The mirrors used must therefore be arranged so as to meet these requirements. Finally, the distance between the support mechanism of the second catoptric system and the object to be observed is too small to position an optical element (folding mirror, optical square) capable of directing the light beam on the object under the conditions suitable incidence (due to surface treatment) to obtain bright field lighting. It is therefore very cleverly, to circumvent this difficulty, that in accordance with the invention the lighting beam is injected directly into the second catoptric system to combine the light source with the object to be observed (lighting called "critical lighting""). In a preferred embodiment, the catoptric systems are Schwarzschild objectives or telescopes, which allow, under a relatively small volume, to confer a large magnification. In addition, the manufacture of the concave and convex surfaces of their two constituent elements does not pose any particular difficulties. In this case, half of the Schwarzschild objective of the second catoptric system transmits the incident light beam of the object to be observed and its the other half transmits the beam reflected by the illuminated object. Furthermore, it is advantageously provided that, in the imaging part, the optical system with several concave spherical mirrors comprises two concave spherical mirrors facing each other, such an optical system being capable of providing significant magnifications. It is possible to ensure that, in the imaging part, the second catoptric system, in particular arranged in the form of a Schwarzschild objective, has a magnification Gi of approximately 15 and that the optical system with several concave spherical mirrors has a magnification G 2 of about 33, whereby the magnification of the microscope is about 500, in accordance with the desired objective. Advantageously, in the imaging part, there is also provided, after the last concave spherical mirror of the system of concave spherical mirrors, a plane folding mirror inclined to receive the beam at an incidence not exceeding 15 °: this folding of the light beam allows the microscope to be produced in a more compact form. It is also possible to increase the compactness of the microscope by providing, in the illumination part and between the field mirror and the second catoptric system, an optical system for folding the light beam comprising a plurality of plane folding mirrors successively reflecting the returned beam. by the field mirror in a second direction different from the aforesaid first direction, said folding mirrors being arranged so as to receive the beam under respective incidences exceeding approximately 75 ° (grazing incidence). Preferably then, the mirrors planes of the folding system are in number and arrangement such that the above first and second optical axes respectively of the first and second catoptric systems are substantially perpendicular to each other. Thanks to the arrangements in accordance with the invention which have just been exposed, there is an optical microscope of the fully catoptric type which is capable of operating in the extreme ultraviolet, typically with light having a wavelength of order of 13.5 nm, and which therefore allows the observation of an object having dimensions of an order of magnitude twice the wavelength (about 25 nm). The invention will be better understood on reading the detailed description which follows of certain embodiments given solely by way of non-limiting examples. In this description, reference is made to the appended drawings in which: - Figure 1 is an optical diagram of an illumination part for an optical microscope arranged in accordance with the invention; - Figure 2 is an optical diagram of a preferred embodiment of the illumination part of Figure 1; - Figure 3 is an optical diagram of an imaging part for an optical microscope arranged in accordance with the invention; and - Figure 4 is an overall optical diagram of a preferred embodiment of an optical microscope according to the invention. We first refer to Figure 1 which shows the optical diagram of an illumination part, generally designated by the reference 1, for lighting of an object O to be observed from a light source S emitting in the extreme ultraviolet, typically with a wavelength of the order of 13.5 nm. The illumination part 1 successively comprises the following optical elements. A first catoptric system 2 has an optical axis (or first optical axis) Dx directed in a first direction. This first catoptric system 2 is preferably constituted in the form of a Schwarzschild objective or telescope, with a concave mirror 3 turned towards the source S and receiving on its edge the light beam coming from it and with a convex mirror 4 located opposite the concave mirror 3 and reflecting the beam from the concave mirror 3 axially in the direction of a central hole 5 made therein. The light beam then reaches a concave field mirror 6, combining the image plane of the source S and the image plane of the object O, and allowing the light beam to be folded to reduce the dimensions of the device. The mirror 6 is located on the first optical axis and inclined relative to the latter by an angle such that it receives the light beam at an incidence of less than about 15 °. Finally, the beam reflected by the mirror 6 arrives in a focusing optical device 7 having its axis (second optical axis) D 2 directed in a second direction which, here, coincides with the direction followed by the beam reflected by the mirror 6. A example of practical implementation of the focusing device 7 will be indicated below. In the arrangement which has just been described, the two optical axes D x and D 2 are angularly separated one on the other by at most 15 °, which leaves too little room, in practice, for the installation of the light source S and the positioning of the object O to be observed. It is therefore desirable that the two aforementioned optical axes Di and D are angularly more apart from one another, and that in particular, in a preferred embodiment, they are perpendicular to each other as illustrated in the FIG. 2. To do this, provision is made to interpose, between the field mirror 6 and the focusing device 7, an optical folding system 10 comprising a plurality of plane folding mirrors successively reflecting the beam returned by the field mirror 6 in a second direction which differs from the direction of reflection of the field mirror 6, said folding mirrors being arranged so as to receive the beam under respective incidences exceeding approximately 75 ° (grazing incidences). In the example illustrated in FIG. 2, the folding mirrors of the folding system 10 are in number and in arrangement such that the two optical axes D x and D 2 are substantially perpendicular to each other. To do this, the folding system 10 consists here of two plane mirrors 11 and 12. In FIG. 3 is illustrated the imaging part, generally designated by the reference 13, which is suitable for forming on a detector D an enlarged image of the illuminated object O. The imaging part 13 comprises a second catoptric system 14 comprising a concave mirror 15 turned towards the object 0 associated with a convex mirror 16, the assembly being, here again, advantageously constituted in the form of a Schwarzschild objective or telescope . The concave mirror 15 is slightly aspherical. The set of two mirrors 15 and 16 has a magnification of approximately 15. In a concrete embodiment, the concave mirror 15 has a useful diameter of approximately 100 mm and has an aspherization of 100 nm over its useful area; the convex mirror 16 has an aspherization of 120 nm with a maximum slope of 0.08 μm / mm over an area of 22.5 mm in diameter (the useful area being 19.5 mm); the angles of incidence vary from 2.2 ° to 4.6 ° for the concave mirror 15 and from 7.2 ° to 14.5 ° for the convex mirror 16. The imaging part 13 also comprises, downstream of the objective of Schwarzschild 14, an optical system 17 with several concave spherical mirrors facing each other. In the example illustrated in FIG. 3, it comprises two concave spherical mirrors 18 and 19 respectively. The mirror 19 is drilled centrally to allow passage of the beam coming from the Schwarzschild objective. The magnification of the pair of mirrors 18 and 19 is approximately 33. Advantageously, the curvature of the concave mirror 18 is substantially the same as that of the convex mirror 16 to cancel the Petzval, and therefore the curvature of the field. The overall magnification of the imaging part arranged in accordance with the invention is of the order of 500. FIG. 4 illustrates a complete apparatus, uniting the illumination part 1 illustrated in FIG. 2 and the imaging part 13 illustrated in figure 3. The distance between the front convex lens 16 of the Schwarzschild objective 14 and the object 0 is too small for the light beam to be applied to the object under an approximately normal incidence from of the focusing device 7. The clever solution according to the invention then consists in injecting the light beam into the catoptric system 14, here in the Schwarzschild objective, in other words to constitute the focusing device 7 in the form of a Schwarzschild objective structure. Thus one half of the Schwarzschild objective is then used to transmit the light beam to the object O, while the other half is used to transmit the light beam reflected by the object illuminated. Still with the aim of making a compact device, the beam from the concave mirror system 17 is reflected by a plane mirror 20, which is arranged to receive this beam under an approximately normal incidence of at most 15 °. Thanks to the arrangements according to the invention, a catoptric microscope is formed which solves the problem posed by the correct lighting of the object 0 by using a common objective between the lighting path and the imaging path. The system works in the field, which avoids stray light because the detector D does not directly see the object O. The microscope thus arranged has a high magnification which allows the observation of small objects. The distance between the object and the front element is large, which facilitates handling and the installation of any auxiliary devices. In addition, this microscope arrangement has a small central field of very good optical quality surrounded by a large peripheral field with degraded optical quality: this makes it possible, during observation, to probe the areas around that observed with precision in the little field. Finally, the mirrors are spherical or slightly aspherical, which induces relative ease of manufacture. In the above, the two catoptric systems 2 and 7 are preferably Schwarzschild objectives or telescopes because of the inherent advantage of this type of objective, and it is in this form that they are illustrated in FIG. 4. However, one could implement any other type of catoptric objective capable of providing a similar magnification: - one could use a objective consisting of a concave mirror and a convex mirror, the mirrors 18 and 19 remaining concave in order to maintain the zero Petzval; - One could use an objective consisting of two concave mirrors, at least one of the mirrors 18, 19 being convex to maintain the zero Petzval. In both cases, the asphericity of the mirrors increases.

Claims

REVENDICATIONS
1. Microscope optique à fort grandissement utilisable dans l'extrême ultraviolet, caractérisé en ce qu'il comprend :1. High magnification optical microscope usable in the extreme ultraviolet, characterized in that it comprises:
- une partie d'illumination (1) pour l'éclairage d'un objet (O) à observer à partir d'une source de lumière (S) émettant dans l'extrême ultraviolet, laquelle partie d'illumination (1) comprend successivement : . un premier système catoptrique (2) ayant un premier axe optique (Di) dirigé selon une première direction, et . un miroir de champ (6) situé sur ledit premier axe optique et incliné sur cet axe d'un angle inférieur à environ 15°, et- an illumination part (1) for lighting an object (O) to be observed from a light source (S) emitting in the extreme ultraviolet, which illumination part (1) successively comprises :. a first catoptric system (2) having a first optical axis (Di) directed in a first direction, and. a field mirror (6) located on said first optical axis and inclined on this axis by an angle less than about 15 °, and
- une partie d'imagerie (13) pour recueillir sur un détecteur (D) une image agrandie de l'objet éclairé, laquelle partie d'imagerie (13) comprend successivement : . un second système catoptrique (14) ayant un second axe optique (D2) , recevant la lumière réfléchie par l'objet éclairé et ayant un grandissement Gi donné, et . un système optique (17) à plusieurs miroirs sphériques concaves ayant un grandissement G2 donné, - ledit miroir de champ (6) de la partie d'illumination réfléchissant la lumière d'éclairage selon ledit second axe optique (D2) de façon que ledit second système catoptrique (14) focalise le faisceau lumineux d'éclairage sur l'objet à observer. - an imaging part (13) for collecting on an detector (D) an enlarged image of the illuminated object, which imaging part (13) successively comprises: a second catoptric system (14) having a second optical axis (D 2 ), receiving the light reflected by the illuminated object and having a given magnification Gi, and. an optical system (17) with several concave spherical mirrors having a given magnification G 2 , - said field mirror (6) of the illumination part reflecting the lighting light along said second optical axis (D 2 ) so that said second catoptric system (14) focuses the lighting light beam on the object to be observed.
2. Microscope selon la revendication 1, caractérisé en ce que les systèmes catoptriques (2, 14) sont des objectifs de Schwarzschild. 2. Microscope according to claim 1, characterized in that the catoptric systems (2, 14) are Schwarzschild objectives.
3. Microscope selon la revendication 1 ou 2, caractérisé en ce que, dans la partie d'imagerie (13), le système optique (17) à plusieurs miroirs sphériques concaves comporte deux miroirs sphériques concaves (18, 19) en vis-à-vis. 3. Microscope according to claim 1 or 2, characterized in that, in the imaging part (13), the optical system (17) with several concave spherical mirrors comprises two concave spherical mirrors (18, 19) facing each other -screw.
4. Microscope selon l'une quelconque des revendications 1 à 3, caractérisé en ce que, dans la partie d'imagerie (13), le second système catoptrique (14) a un grandissement Gi d'environ 15 et le système optique (17) à plusieurs miroirs sphériques concaves a un grandissement G2 d'environ 33, ce grâce à quoi le grandissement du microscope est d'environ 500. 4. Microscope according to any one of claims 1 to 3, characterized in that, in the imaging part (13), the second catoptric system (14) has a magnification Gi of about 15 and the optical system (17 ) with several concave spherical mirrors has a magnification G 2 of approximately 33, which makes the magnification of the microscope approximately 500.
5. Microscope selon l'une quelconque des revendications 1 à 4, caractérisé en ce que, dans la partie d'imagerie (13), il est prévu en outre, après le dernier miroir spherique concave (19) du système à miroirs sphériques concaves (17) , un miroir plan de repliement (20) incliné pour recevoir le faisceau incident sous un angle d'incidence d'au plus 15°. 5. Microscope according to any one of claims 1 to 4, characterized in that, in the imaging part (13), there is further provided, after the last concave spherical mirror (19) of the system of concave spherical mirrors (17), a plane folding mirror (20) inclined to receive the incident beam at an angle of incidence of at most 15 °.
6. Microscope selon l'une quelconque des revendications 1 à 5, caractérisé en ce que, dans la partie d'illumination (1), il est prévu, entre le miroir de champ (6) et le second système catoptrique (14) , un système optique (10) de repliement du faisceau lumineux comprenant une pluralité de miroirs plans de repliement (11, 12) réfléchissant successivement le faisceau renvoyé par le miroir de champ (6) selon une direction différente de la direction de réflexion du miroir de champ, lesdits miroirs de repliement (11, 12) étant disposés de manière à recevoir le faisceau sous des incidences respectives d'au moins environ 75°. 6. Microscope according to any one of claims 1 to 5, characterized in that, in the illumination part (1), there is provided, between the field mirror (6) and the second catoptric system (14), an optical system (10) for folding the light beam comprising a plurality of flat folding mirrors (11, 12) successively reflecting the beam returned by the field mirror (6) in a direction different from the direction of reflection of the field mirror , said folding mirrors (11, 12) being arranged so as to receive the beam at respective angles of at least about 75 °.
7. Microscope selon la revendication 6, caractérisé en ce que les miroirs plans (11, 12) du système de repliement (10) sont en nombre et en arrangement tels que les susdits premier et second axes optiques (Di, D2) respectivement des premier et second systèmes catoptriques (2, 14) sont sensiblement perpendiculaires l'un à l'autre. 7. Microscope according to claim 6, characterized in that the plane mirrors (11, 12) of the folding system (10) are in number and in arrangement such that the above first and second optical axes (Di, D 2 ) respectively first and second catoptric systems (2, 14) are substantially perpendicular to each other.
8. Microscope selon l'une quelconque des revendications 1 à 7, caractérisé en ce que la lumière d'éclairage en extrême ultraviolet a une longueur d'onde d'environ 13,5 nm. 8. Microscope according to any one of claims 1 to 7, characterized in that the lighting light in extreme ultraviolet has a wavelength of about 13.5 nm.
PCT/FR2005/000459 2004-03-03 2005-02-25 Optical microscope with high magnification, which can be used in the extreme ultraviolet radiation WO2005096060A1 (en)

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FR0402206A FR2867282B1 (en) 2004-03-03 2004-03-03 HIGH-THROUGH OPTICAL MICROSCOPE FOR USE IN EXTREME ULTRAVIOLET
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009035583A1 (en) * 2009-07-29 2011-02-03 Carl Zeiss Sms Gmbh Magnifying imaging optics and metrology system with such an imaging optics
US8553217B2 (en) 2009-06-19 2013-10-08 Kla-Tencor Corporation EUV high throughput inspection system for defect detection on patterned EUV masks, mask blanks, and wafers

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0433613A1 (en) * 1989-11-03 1991-06-26 Horiba, Ltd. Microscopic spectrometer with Cassegrain objective
US5331456A (en) * 1991-12-09 1994-07-19 Olympus Optical Co., Ltd. Radiation microscope

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0433613A1 (en) * 1989-11-03 1991-06-26 Horiba, Ltd. Microscopic spectrometer with Cassegrain objective
US5331456A (en) * 1991-12-09 1994-07-19 Olympus Optical Co., Ltd. Radiation microscope

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TICHENOR D A ET AL: "SOFT-X-RAY PROJECTION LITHOGRAPHY EXPERIMENTS USING SCHWARZSCHILD IMAGING OPTICS", APPLIED OPTICS, OPTICAL SOCIETY OF AMERICA,WASHINGTON, US, vol. 32, no. 34, 1 December 1993 (1993-12-01), pages 7068 - 7071, XP000414611, ISSN: 0003-6935 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8553217B2 (en) 2009-06-19 2013-10-08 Kla-Tencor Corporation EUV high throughput inspection system for defect detection on patterned EUV masks, mask blanks, and wafers
US8692986B2 (en) 2009-06-19 2014-04-08 Kla-Tencor Corporation EUV high throughput inspection system for defect detection on patterned EUV masks, mask blanks, and wafers
US9377414B2 (en) 2009-06-19 2016-06-28 Kla-Tencor Corporation EUV high throughput inspection system for defect detection on patterned EUV masks, mask blanks, and wafers
EP2443440A4 (en) * 2009-06-19 2018-02-28 KLA-Tencor Corporation Euv high throughput inspection system for defect detection on patterned euv masks, mask blanks, and wafers
DE102009035583A1 (en) * 2009-07-29 2011-02-03 Carl Zeiss Sms Gmbh Magnifying imaging optics and metrology system with such an imaging optics
US8842284B2 (en) 2009-07-29 2014-09-23 Carl Zeiss Smt Gmbh Magnifying imaging optical unit and metrology system including same
US9482794B2 (en) 2009-07-29 2016-11-01 Carl Zeiss Smt Gmbh Magnifying imaging optical unit and metrology system including same

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