Source: http://www.google.com/patents/US20040246459?dq=6150774
Timestamp: 2017-08-21 20:14:01
Document Index: 617457795

Matched Legal Cases: ['art 14', 'art 16', 'art 16', 'art 50', 'art 50', 'art 50', 'art 50', 'art 34', 'art 34']

Patent US20040246459 - Lithographic support structure - Google Patents
The present invention relates to a lithographic projection apparatus with a supporting structure to support and move an object, like a substrate. The supporting structure may be a robot having a robotic arm with a support frame for supporting, e.g. the substrate. The support frame includes a clamping...http://www.google.com/patents/US20040246459?utm_source=gb-gplus-sharePatent US20040246459 - Lithographic support structure
Publication number US20040246459 A1
Also published as CN1534386A, CN100492174C, US7486384, US20080297758
Publication number 10813687, 813687, US 2004/0246459 A1, US 2004/246459 A1, US 20040246459 A1, US 20040246459A1, US 2004246459 A1, US 2004246459A1, US-A1-20040246459, US-A1-2004246459, US2004/0246459A1, US2004/246459A1, US20040246459 A1, US20040246459A1, US2004246459 A1, US2004246459A1
Inventors Patricius Tinnemans, Edwin Buis, Sjoerd Donders, Jan Van Elp, Jan Hoogkamp, Aschwin Lodewijk Hendricus Van Meer, Patrick Johannes Cornelus Hendrik Smulders, Franciscus Andreas Cornelis Johannes Spanjers, Johannes Petrus Martinus Bernardus Vermeulen, Raimond Visser, Henricus Tegenbosch, Johannes Van Den Berg, Henricus Johannes Adrianus Van De Sande, Thijs Vervoort
Patent Citations (23), Referenced by (10), Classifications (22), Legal Events (3)
US 20040246459 A1
a moveable support structure configured to support and move an object, said support structure comprising a clamp that clamps the substrate; and
a compliant structure configured to compensate for at least one of a tilt and displacement between said object and said clamp.
2. The lithographic support system of claim 1, wherein said support structure comprises a robot arm having a support frame for holding said object.
3. The lithographic support system of claim 2, wherein said robot arm comprises a rod coupled to said support frame, said rod comprising said compliant structure.
4. The lithographic support system of claim 2, wherein said support frame comprises said compliant structure.
5. The lithographic support system of claim 2, wherein said compliant structure is provided on said clamp.
6. The lithographic support system of claim 2, wherein said support frame is in a plane defined by a x-axis, a y-axis, and a z-axis being perpendicular to said x-axis and said y-axis, said compliant structure providing a compliance in at least one of a first rotation (Rx) about said x-axis, a second rotation (Ry) about said y-axis, and a z-direction parallel to said z-axis.
7. The lithographic support system of claim 3, wherein said compliant structure is arranged such that said support frame is allowed to rotate about a predetermined center of rotation.
8. The lithographic support system of claim 1, wherein said object comprises a substrate (W).
9. The lithographic support system of claim 1, wherein said support structure comprises a rod provided with said compliant structure.
10. The lithographic support system of claim 1, wherein said compliant structure comprises a metal flexure.
11. A lithographic clamping structure, comprising:
a Johnson-Raybeck effect type clamp having an upper surface for clamping an object; and
an oxidized layer, provided on said upper surface of said Johnson-Raybeck effect type clamp to minimize heating effects transferred to said object.
12. The lithographic clamping structure of claim 11, wherein said predetermined decaying AC-profile is an RF AC profile.
13. A lithographic support structure for holding and moving an objects, comprising:
at least one Johnson-Raybeck effect type clamp; and
a controller coupled to said Johnson-Raybeck effect type clamp and configured to provide a clamping and de-clamping voltage to said Johnson-Raybeck effect type clamp,
wherein said controller is arranged to generate said de-clamping voltage with a decaying AC-profile.
14. Method of cleaning a substrate holder in a lithographic apparatus including a clamp for clamping a substrate, the method comprising:
introducing a substrate in said lithographic projection apparatus;
clamping said substrate to said substrate holder such that said substrate contacts said substrate holder at a first location;
de-clamping said substrate from said substrate holder;
repeating said clamping and de-clamping a number of times such that said substrate contacts said substrate table repeatedly on at least one of said first location and at a location other than said first location.
15. A lithographic robot, comprising:
a robotic arm configured to hold and move an object; and
a compliant structure configured to compensate for at least one of a tilt and displacement between said object and said robotic arm.
16. The lithographic robot of claim 15, wherein said robotic arm comprises a support frame for holding said object.
17. The lithographic robot of claim 16, wherein said robot arm comprises a rod coupled to said support frame in which said rod comprises said compliant structure.
a compliant structure configured to compensate for at least one of a tilt and displacement between said substrate, said patterning device, or said object and said clamp.
a Johnson Raybeck effect type clamp configured to clamp at least one of said substrate patterning device, said clamp having an upper surface and an oxidized layer, provided on said upper surface, to minimize heating effects transferred to said at least one of said substrate and said patterning device.
a projection system configured to project said patterned beam onto a target portion of said substrate;
a robot configured to hold and move a substrate;
a clamp configured to clamp said substrate to said substrate holder such that said substrate contacts said substrate holder at a first location; and
a processor configured to instruct repeated clamping and de-clamping of said substrate by said clamp, such that said substrate contacts said substrate holder repeatedly at one of at least said first location and a location other than said first location.
providing a substrate via a support system, said supporting system configured to hold and move said substrate by clamping said substrate through a clamping structure and compensating for at least one of a tilt and displacement between said substrate and said clamping structure by employing a compliant structure;
providing a substrate via a clamping structure, said clamping structure comprising a Johnson-Raybeck effect type clamp having an upper surface and an oxidized layer on said upper surface;
[0023]FIG. 2 schematically depicts a part of a lithographic apparatus in which the present invention can be used according to an embodiment of the invention; and
[0024]FIG. 3a schematically shows a robot arm supporting a substrate;
[0025]FIG. 3b shows a side view of the arrangement according to FIG. 3a;
[0026]FIG. 4a shows a side view of a support frame of a robot arm with a clamp to hold a substrate according to an embodiment of the invention;
[0027]FIG. 4b shows a side view of a support frame of a robot arm with a clamp to hold a substrate according to an embodiment of the invention, wherein the substrate is warped;
[0028]FIG. 4c shows a cross section of a supporting structure in the form of a moveable rod with a compliant part according to an embodiment of the invention;
[0029]FIG. 4d shows a cross section of the rod of FIG. 4c;
[0030]FIGS. 4e and 4 f show a further embodiment of a flexible supporting structure;
[0031]FIG. 5 shows a side view of a support frame of a robot arm with a clamp to hold a substrate, the clamp being provided with an oxidized upper surface according to an embodiment of the invention;
[0032]FIG. 6a shows a side view of a support frame with a clamp to hold a substrate, the clamp being a Johnson-Raybeck type clamp according to an embodiment of the invention;
[0033]FIG. 6b shows an enlarged portion of the clamp of FIG. 6a;
[0034]FIG. 7 shows a de-clamping voltage provided to a Johnson-Raybeck type clamp in accordance with an embodiment of the invention;
[0035]FIG. 8 shows a substrate table with an actuator to lift and lower a substrate from and towards the substrate table according to an embodiment of the invention.
[0037]FIG. 1 schematically depicts a lithographic apparatus according to a particular embodiment of the invention. The apparatus comprises:
[0051]FIG. 2 schematically depicts several parts of the lithographic apparatus through which, in operation, substrates (and possibly other objects) may be moved. FIG. 2 shows a load lock LL, a handling chamber HC and a projection chamber PC. The load lock LL comprises two doors 2, 4. The first door 2 faces the inside of the lithographic projection apparatus 1, comprising the handling chamber HC and the projection chamber PC, in which, in an embodiment, vacuum conditions, having a pressure Pvac, are maintained. The second door 4 faces, e.g., atmospheric conditions, having a pressure that is, for instance, equal to atmospheric pressure Patm. However, the invention can also advantageously be applied for other pressure values.
These actions as listed above refer to atmospheric conditions outside the first door 2. However, as is known to persons skilled in the art there maybe other pressure conditions outside the load lock. The example given above is by no means intended to restrict the use of the load lock LL. Hazardous particles and contaminating molecules, such as oxygen, hydrocarbons and/or H2O that may interfere with processes in the lithographic projection apparatus, are limited from entering the load lock LL by filling the load lock LL with a specially chosen gas that doesn't comprise these particles or molecules. Gasses, such as N2 gas, Ar gas or synthetic air, but of course also other suitable gasses, can be used, as will be understood by a person skilled in the art.
[0072]FIG. 3a shows a robot arm 10 of robot 8 in more detail. The robot arm 10 comprises a rod 12 connected to a support frame 18 by means of a compliant part 14 and an intermediate part 16.
The support frame 18 defines a plane in which the substrate W lies when it is clamped by the clamps 20, 22, and 24. That plane is defined by an x-axis and an y-axis. The x-axis is in the longitudinal direction of the rod 12, whereas the y-axis is perpendicular to the x-axis. A z-axis is defined perpendicular to both the x-axis and the y-axis. The z-axis is not shown in FIG. 3a but is shown in FIG. 3b. The x-, y- and z-axes have an origin 19 that is defined to be the location where the center of the substrate W is to be substantially located during movement of the substrate W through the apparatus shown in FIG. 2.
[0075]FIG. 3b shows a side view of the arrangement shown in FIG. 3a. FIG. 3b, additionally, shows the substrate table WT (which is not shown in FIG. 3a). Moreover, FIG. 3b shows that support frame 18 may be provided with a compliant portion (or flexible portion) 26. The compliant portion 26 may be located behind the “fingers” of support frame 18 but may also be located within one or both of the “fingers”.
As shown in FIG. 3b, the compliant portion 14 may comprise two or more compliant rods 14, rotatable at their ends. Thus, the intermediate part 16 is able to rotate slightly about both the x-axis and the y-axis. Moreover, it can be lifted slightly in the z-direction. Of course, the compliant portion 14 can be made of any other structure or of any material, having a flexible or compliant feature.
As shown in FIG. 3b, the compliant portion 26 of the support frame 18 is produced by providing the support frame 18 with a notch, such that the front side of the support frame designed to hold the substrate W is allowed to rotate about both the x-axis and the y-axis, and to lift slightly in the z-direction, without any movement of the rod 12.
[0081]FIGS. 4a and 4 b show that the provision of compliant parts within a clamp may also help correcting for tilt and displacements when clamping a substrate W (or any other object) to a clamp on a support frame 18 of a robot arm.
[0082]FIG. 4a shows the support frame 18 provided with the clamp 20, approaching a substrate W to be clamped. There is a tilt angle α between the top of the clamp 20 and the substrate W. The substrate W has a diameter D1 that maybe 200 mm. The clamp 20 has a diameter D2 that may be 40 mm. In an example, for a proper clamp functioning, the tilt angle α requirements can be so low that the distance indicated by D3 in FIG. 4a needs to be below 8 micrometers. The clamping device may be a vacuum pad or an electrostatic clamp, like a Johnson-Raybeck effect clamp. As is known to persons skilled in the art, tilt requirements are more stringent for the electrostatic clamps.
[0083]FIG. 4b shows that the substrate W may not be perfectly flat in a plane but may, e.g., be undulated when viewed in cross-section. The undulation amplitude D4 may be as large as 500 micrometer. This undulation may be the result of all kinds of process steps during the lithography process, as is known to persons skilled in the art. Due to the undulated cross-section of the substrate W, the stringent tilt requirements may not be met at all locations of the substrate W.
To compensate then for a tilt and/or displacement between the substrate and the clamp, the clamp 20 may be provided with a compliant portion 28 as shown in FIG. 4b. This compliant portion 28 may be made of a metal flexure or any other flexible material or structure suitable for a lithographic projection apparatus. The compliant portion 28 provides the clamp with Rx, Ry, and z compliance. Either the weight of the substrate W or a small positive force in the z-direction used during hand-over of the substrate W may, then, ensure that the surface of the clamp will align with the rear surface of the substrate W. When aligned, the clamp 20 will hold the rear surface of the substrate W. The clamp force will then be sufficient to keep the substrate W clamped during movement through the apparatus. The clamp compliance can be made such that the substrate's x, y and Rz position are not changed. This maintains positional accuracy of the substrate, as is required for other processes in the lithographic projection apparatus.
[0086]FIGS. 4c and 4 d show the provision of compliant portions with supporting structures that are allowed to move in one direction only. The supporting structure shown comprises a rod like a substrate table pin 38 having a clamp 20 mounted on an end. The pin 38 comprises compliant portion 28. The compliant portion 28 is made by providing the pin with two notches 29 that provide the pin 38 with a flexibility in a first direction perpendicular to its direction of movement. There may be provided two other notches 31, as indicated with dashed lines, in the pin 38 perpendicular to the notches 29 to provide the pin 38 with a flexibility in a second direction perpendicular to the first direction.
[0087]FIG. 4d shows a cross section of the pin of FIG. 4c in the direction of IVd-IVd, as shown in FIG. 4c to better show the notches 29 and optional notches 31.
Of course, other compliant parts than the one shown in FIGS. 4c and 4 d can be used. The rod 38 may a cross section different from the circular one shown.
A further embodiment of a flexible supporting structure to be used with, e.g., an electrostatic clamp for clamping, e.g., a wafer or a reticle, is shown in FIGS. 4e and 4 f.
The supporting structure shown comprises an outer ring 46, an interface ring 48 and a central part 50. The outer ring 46 will be fixed in a gripper (not shown) or a stage (not shown). On top of the central part 50, an electrostatic clamp (not shown) will be attached, e.g., by gluing. In the outer ring 46, the interface ring 48 is fixed with two leaf springs 52 a and 52 b releasing the y, Rx and Rz d.o.f.'s (=degrees of freedom). The central part 50 on its turn is fixed to the interface ring 48 by two leaf springs 54 a, 54 b and two rods 56 a, 56 b. The leaf springs 54 a, 54 b are oriented to block the Rx d.o.f. Thus, together with the rods 56 a, 56 b the arrangement is such that the interface ring with respect to the central part 50 releases only one rotation, i.e., Ry. Two remaining translations are fixed with the flexible supporting structure of FIGS. 4e and 4 f, i.e., x and z d.o.f.'s.
[0092]FIG. 5 shows a further embodiment of the invention, in which the clamp 20 on the support frame 18 is a Johnson-Raybeck effect type clamp. As known to persons skilled in the art, a Johnson-Raybeck effect type clamp is provided with a dielectric material made from a very low conductive material. Due to the very low conductivity (of electrical resistance) of the dielectric material, electrical clamping charges migrate through the dielectric material towards the clamping surface. In use, contact with substrate W is only made at some tiny spots. Between those tiny spots there are “open” spaces defining a distance between the clamping surface and the rear side of substrate W. Charges opposite the “open” spaces in both the clamping surface and the substrate W create a clamp with a very small distance between the charges, only the remaining gap, and hence create very large clamping forces.
[0096]FIG. 6a shows the support frame 18 provided with the clamp 20, the clamp 20 being a Johnson-Raybeck effect clamp. The clamp 20 holds the substrate W. The clamping effect is generated by a controller, shown as a series connection of a DC voltage source and an AC voltage source. As will be appreciated by a person skilled in the art, the controller may be based on any suitable electronic circuit or may be implemented by a computer.
[0097]FIG. 6b shows a portion of FIG. 6a on an enlarged scale. FIG. 6b shows that the Johnson-Raybeck effect type clamp 20 is provided with a conductive part 34 and a electrically leaky insulator 32. Due to the leaky insulator 32, an electrical current will flow between the conductor part 34 and the substrate W resulting in trapped charges in the leaky insulator 32.
[0102]FIG. 8 shows the substrate table WT with a substrate W. The lithographic apparatus is provided with an actuator 42 provided with pins 38. In use, the actuator 42 is arranged to displace the substrate W from and towards the substrate table WT. The substrate table WT is provided with a substrate support 36 (such as pimples) for supporting the substrate W. By providing the substrate table WT with the substrate support 36, the actual surface of contact between the substrate table WT and the substrate W is reduced while still providing a proper support.
US5685588 * Jan 29, 1996 Nov 11, 1997 Taiwan Semiconductor Manufacturing Company Ltd. Wafer handler having a flexible pad
US6631062 * Dec 6, 1999 Oct 7, 2003 Nihon Ceratec Co., Ltd. Electrically conductive ceramic material, a process of producing same, and an electrostatic chuck
US20010011637 * Apr 4, 2001 Aug 9, 2001 Joseph Wytman Compliant wafer chuck
US20020109954 * Dec 4, 2001 Aug 15, 2002 Ngk Insulators, Ltd. Electrostatic chucks and process for producing the same
US8556315 Mar 31, 2010 Oct 15, 2013 Ats Automation Tooling Systems Inc. Vacuum gripper assembly
US9025135 Feb 24, 2010 May 5, 2015 Asml Holding N.V. Shared compliance in a rapid exchange device for reticles, and reticle stage
US20070221335 * Mar 23, 2006 Sep 27, 2007 Recif Technologies Device for contact by adhesion to a glass or semiconductor plate (wafer) surface or the like and system for gripping such a plate comprising such a device
US20090148604 * Nov 14, 2008 Jun 11, 2009 Asml Netherlands B.V. Substrate Processing Apparatus and Device Manufacturing Method
US20100253106 * Mar 31, 2010 Oct 7, 2010 Ats Automation Tolling Systems Inc. Vacuum gripper assembly
US20130077078 * Aug 29, 2012 Mar 28, 2013 Asml Netherlands B.V. Lithographic Apparatus and Substrate Handling Method
WO2010111784A1 * Mar 31, 2010 Oct 7, 2010 Ats Automation Tooling Systems Inc. Vacuum gripper assembly stabilized by springs
WO2010115657A1 * Feb 24, 2010 Oct 14, 2010 Asml Holding N.V. Shared compliance in a rapid exchange device for reticles, and reticle stage
International Classification H01L21/683, B65G49/07, B25J13/08, G03F7/20, B08B1/00, H02N13/00, H01L21/027, H01L21/677, H01L21/304
Cooperative Classification B25J13/089, G03F7/70925, H02N13/00, G03F7/70741, G03F7/7075, H01L21/6833
European Classification G03F7/70N6D, G03F7/70N6B, G03F7/70P8D, H01L21/683C2, H02N13/00, B25J13/08V2