Configurations for a metrology table and procedures for operating the metrology table

Abstract

A metrology table configuration includes: rotatably mounted connection (130) arranged to receive a wafer (75) and enable it to rotate about a pivot point (131); a radial axis (110) arranged to radially move the attached rotatably mounted connection (130); at least one balancing mass (115, 125) designed to balance at least one of the radial and rotational movements; and an optic (70, 200) having a stationary section configured to produce a collimated illumination beam.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application 61 / 845,358, filed July 11, 2013, and U.S. Provisional Applications 61 / 865,611 and 61 / 866,015, both filed August 14, 2013, BACKGROUND OF THE DISCLOSURE 1. TECHNICAL FIELD

[0002] The disclosure relates generally to the field of metrology machines, in particular to the design of a metrology table. 2. DISCUSSION OF THE STATE OF THE ART

[0003] The metrology stage allows for appropriate positioning of wafers and optics to enable measurement of specific areas on the wafer. Current metrology stage configurations suffer from various limitations, such as a large footprint, ineffective use of the stage's range of motion, limited stage acceleration due to the large mass to be moved and a stack of axes, limited stage stiffness due to the large axes travel, limited stage flatness at the wafer level, and difficult or limited implementation of the balancing mass, which dissipates most of the stage's momentum directly into the environment. As wafers increase in size, these problems are magnified and exacerbated.

[0004] US 2007 / 0 222 991 A1 relates to a metrology system with a positioning system that enables both linear movement and rotational movement between a wafer and an imaging system.

[0005] DE 39 17 260 A1 discloses a system for inspecting microelectronic elements on a wafer. The wafer is positioned relative to an inspection device by a robot arm capable of angular, rotational, and translational movements.

[0006] US 2005 / 0 184 253 A1 describes a scanning device for a substrate. The substrate is rotatably mounted at one end of a two-part arm. The arm can be used, in particular, to achieve a translational movement of the substrate.

[0007] JP H11 - 121 577 A relates to a wafer inspection system with a robot for handling the wafers. SUMMARY OF REVELATION

[0008] An embodiment of the present disclosure provides configurations of a metrology table comprising: a rotatably mounted joint arranged to receive a wafer and enable rotation thereof about a pivot point; a radial axis arranged to move the attached rotatably mounted joint radially thereto; and optics having a stationary portion configured to generate a collimated illumination beam.

[0009] These, additional and / or other embodiments and / or advantages of the present disclosure are set forth in the following detailed description; may be inferred from the detailed description; and / or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a better understanding of the embodiments of the disclosure and to show how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, throughout which like reference numerals designate corresponding elements or portions.

[0011] In the attached drawings: Fig. Figure 1 is a schematic diagram of a prior art metrology table configuration. Fig. 2 is a schematic diagram of a metrology table configuration according to some embodiments of the disclosure. Fig. 3 is a schematic diagram of a metrology table configuration according to some embodiments of the disclosure. Fig. 4 a schematic representation of the optics according to some embodiments of the disclosure. The Fig. 5A, Fig. 5B are schematic representations of a horizontal and a vertical configuration of the metrology table according to some embodiments of the disclosure. Fig. 6 is a schematic representation of a flowchart illustrating a method according to some embodiments of the disclosure.

[0012] The invention is defined by the claims. DETAILED DESCRIPTION

[0013] With particular reference to the drawings in detail, it is emphasized that the details shown are exemplary only and are for the sole purpose of illustrating the preferred embodiments of the present disclosure. The drawings are therefore presented to provide what is believed to be the most useful and readily understandable description of the principles and conceptual embodiments of the disclosure. In this regard, no attempt is made to show structural details of the disclosure in more detail than is necessary for a fundamental understanding of the disclosure. The description, together with the drawings, will make it clear to those skilled in the art how the various embodiments of the disclosure may be carried out in practice.

[0014] Before at least one embodiment of the disclosure is explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and arrangement of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments or of being practiced or carried out in various ways. Likewise, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be considered limiting.

[0015] Metrology stage configurations and corresponding methods are provided that include a pivotable joint for receiving a wafer and enabling its rotation about a pivot point. The metrology stage further includes a radial axis arranged to move the attached pivotable joint radially thereto. The metrology stage configurations also include optics with a stationary section configured to generate a collimated illumination beam. For example, the optics may be stationary, and the radial axis may be centrally rotated to allow actuation of the stage without requiring additional space or clearance for guidance systems.According to another embodiment, a portion of the optics may be rotatable and configured to receive illumination via mechanical isolation or free space, to receive power and control wirelessly, and to deliver data wirelessly. The disclosed configurations provide more compact and robust stages that can efficiently handle even large wafers. The stage configurations can be horizontal or vertical, with the latter further minimizing the machine's footprint.

[0016] The disclosed disclosure includes configurations and implementations of the machine tables that improve throughput and reduce the machine footprint. The disclosed solutions require less space around the footprint defined by wafer movement, thus providing more compact tables and resulting in more compact machines. The disclosed solution reduces both vibrations within the system and vibrations transmitted to the environment. This is due to the compactness as well as the better arrangement of the moving elements and the balancing masses.

[0017] Fig. Figure 1 is a schematic representation of a prior art metrology table 90 configuration. In the prior art, the movements of the wafer 75 are performed in two linear and mutually perpendicular directions, which are shown in Fig. 1 are indicated by X and Y. The wafer 75 is moved to a position where the area of ​​the wafer to be measured is located under the central and stationary optics 70. The X, Y movements of the wafer are controlled by a guide system 91, which includes external movement guides and fastening means for the wafer 75. A support surface 94 is required to accommodate all possible wafer movements (wafer working paths). It should be noted that in the prior art, in addition to the support surface 94, the table system also requires a periphery around the support surface 94, which houses the guide device 91.Furthermore, the immediate vicinity of the support surface 94, which includes the areas 95 of the square boundary of the support surface 94 and includes common sides with the diameter of the support surface 94, cannot be used for other purposes (e.g., supporting the optics 70) so as not to hinder the operation and free mobility of the guide system 91. This space is thus wasted space on the table.

[0018] As wafer sizes increase, the table travel and the moving mass increase dramatically. Together with the required increase in acceleration, unrealistic high-power electric motors are required, which generate a lot of heat and, in turn, increase the moving mass. Short movements and the settling time require extremely high mechanical stiffness of the table axes, which in turn leads to an increase in the moving mass. These considerations are contradictory to the requirement of a small footprint. The current approach of the orthogonal XY stage is very inefficient in terms of the ratio of the wafer capture to the required footprint, as described above. Fig. 1 shown.

[0019] Disclosed are configurations of the metrology table 100, 150 that include (i) a rotatably mounted connection 130 arranged to receive a wafer 75 and to allow rotation thereof (Θ1, indicated by the arrow Θ2) about a pivot point 131; that include a radial axis 110 arranged to move the rotatably mounted connection 130 attached thereto radially (r) (see Fig. 2 and Fig. 3); and an optic 70 having a stationary section configured to project a collimated illumination beam (see Fig. 4) to generate.

[0020] Fig. 2 is a schematic overview of a configuration for a metrology table 100 according to some embodiments of the disclosure. In the configurations of the metrology table 100, the optics are central and stationary, and all movements are performed by the wafer 75. The configurations of the metrology table 100 further include a central pivoted connection 120 arranged to receive a radial axis 110 and to allow rotation (Θ, indicated by arrow Θ1) about its central pivot point 121. The combination of radial movement R and rotational movements 61, 62 allows movement of the wafer 75 over the entire footprint 94 defined by the radial axis 110 and the central pivoted connection 120 (similar to the footprint extent, as shown in Fig. 1, for the same-sized wafers 75). However, in contrast to configurations of the metrology table 90 according to the prior art, the configurations of the metrology table 100 employ a guide device 91 and can use the freed space for other purposes. Furthermore, the area 105 between the square boundary of the support surface 94 (which is the support surface of the table) and the support surface 94 itself (which corresponds to the wafer movement area) can be used without hindering the operation of the table (in contrast to the respective area 95 from the prior art, which could not be used without hindering the wafer movements along the X and Y axes, see Fig. 1). For example, the 70 optics can be supported (at least partially) in the 105 range, thus enabling the construction of more compact stages.

[0021] It should be noted that the required change in axial movement R is only half of the required X, Y movements in prior art metrology stage 90 configurations. This is achieved by introducing the central rotation Θ1. Furthermore, the additional degree of freedom (Θ1) enables the use of azimuth-sensitive motion algorithms, which reduce the travel time and extent, thus increasing the wafer throughput of the machine. Certain embodiments of the disclosure include such algorithms, as well as algorithms for the efficient conversion of X, Y coordinates to R, Θ1, Θ2 coordinates.

[0022] Each of the movements R and Θ1 (if necessary also Θ2) can be compensated by appropriate balancing masses 115, 125 in order to reduce vibrations and improve the accuracy of the system.

[0023] Fig. Figure 3 is a schematic illustration of a configuration for a metrology stage 150 according to some embodiments of the disclosure. Configurations for the metrology stage 150 combine rotations of a portion of the central optics 200 complemented by movements of the wafer 75 (using an RΘ stage with a stationary radial axis 110).

[0024] Fig. 4 is a schematic representation of optics 200, according to some embodiments of the disclosure.

[0025] The optics 200 may include a rotatable part 220 arranged to receive collimated illumination from a stationary section 210 along an optical axis 60. The collimated illumination may be supplied from the stationary section 210 to the rotatable part 220 via a gap 250 (the gap is filled, for example, with air, vacuum, or other media). The gap 250 decouples the section 210 and the rotatable part 220. The rotatable part 220 is configured to be rotatable (Θ3) about the optical axis 60, such as about the rotation axis 170, and thus covers the footprint 74, which may be configured according to specified requirements (for example, the footprint may have a larger or smaller radius than the wafer 75).In certain embodiments, the rotatable portion 220 can be configured to wirelessly receive power 242 and a controller 234 and to wirelessly deliver data 232, such as via corresponding power supply(s) 240 and communication link(s) 230. In certain embodiments, the transmission of power 242, data 232, and controller 234 can be performed using known protocols. Alternatively or additionally, the transmission of power 242, data 232, and controller 234 can be performed mechanically, such as via multiple through-hole rotary unions.

[0026] The metrology stage 150 configuration thus uses a smaller footprint 94 than the metrology stage 100 configuration (since the radial axis 110 is not rotated) and leaves the area 105 free for use. While the optics 200 must be partially rotated to accommodate all required wafer positions within the smaller footprint 94, the rotation is limited to the small portion 220 of the optics to minimize vibrations and inaccuracies resulting from prior art configurations similar in design to the metrology stage 150 configurations, but which require rotation and / or movement of the entire optical system.

[0027] The configuration of the metrology table 150 further enables the use of multiple measuring heads as a rotatable part 220 without increasing the footprint and potentially allowing for easy head replacement. The configuration of the metrology table 150 may further include a simple linear stage and / or a slider to move the optics between predefined discrete positions, and / or simple sensors may be used for precise positioning of the optical head at predetermined discrete positions.

[0028] The movements R (and possibly also Θ2, Θ3) can be balanced by respective counterweights 115 to reduce vibrations and improve the accuracy of the system. Each of the radial axes 110, the central pivot joint 120, the pivot joint 130, and the rotary axis 170 can be implemented using air bearings to improve the stiffness, flatness, accuracy, and repeatability of the stage. Magnetic levitation can also be used instead of or in combination with the air bearings. Hybrid approaches can also be implemented. Such arrangements can be used to increase stiffness, increase flatness and straightness, eliminate the tolerance buildup factor of stacked axes, and improve stage accuracy, resolution, and repeatability.

[0029] It should be noted that prior art configurations with stationary optics are configured to move along mutually perpendicular X and Y axes, rather than along radial and rotational axes. In contrast, prior art configurations with rotatable wafers also have rotatable and / or linearly movable optics. The former has the disadvantage of a relatively large footprint and an unused periphery of the footprint (occupied by guidance systems and left free to allow the guidance systems to operate), while the latter is complex and slow in the operation of the movable optics, and suffers from inaccuracies due to the movements of the optics.The disclosed disclosure utilizes a radial rotation configuration to maintain the large footprint, but the periphery of the footprint is freed for use and / or the optic is configured to rotate only a small portion to avoid the complexity and inaccuracies involved in moving the entire optic.

[0030] The Fig. 5A and Fig. 5B are schematic illustrations of horizontal and vertical metrology stage configurations, respectively, according to some embodiments of the disclosure. Fig. 5A schematically shows a commonly used configuration 60 with a horizontal wafer stage 80. The configuration 60 may utilize prior art XY wafer stages 90, prior art RO wafer stages with movable optics, or any of the metrology stage configurations 100, 150 disclosed in the present disclosure. The metrology stage configurations 100, 150 illustrate angular movement 120 of the radial axis 110 and / or optical configuration 200 with a stationary main portion 210 and a smaller rotatable portion 220 optically and wirelessly coupled to the stationary portion 210.

[0031] Fig. 5B is a schematic representation of a configuration 260 of a machine with a vertical wafer stage 80. Also in this case, the vertical wafer stage 80 can be configured in any of the above-mentioned stage configurations. This includes both XY and RΘ configurations of the prior art metrology stages 90 and 150 with movable optics, as well as embodiments of the disclosed disclosure with at least partially stationary optics, such as the configuration of the metrology stage 100 with a rotatable radial axis 110 or the configuration of the metrology stage 150 with partially stationary optics 200. Obviously, the wafer stage 80 can be adjusted to its vertical position.

[0032] The machine configurations 60 and 260 include a Z-table 71, which moves the optics 70 vertically in configuration 60 and horizontally in configuration 260. A machine body 62 is made of granite, for example, and includes an optics bridge, for example. An isolation system 64 serves to reduce vibration transmission between the respective machine and the environment, as well as a bench 66 and a floor or pedestal 68.

[0033] In configuration 260, the wafer table 80 is rotated to a vertical position, and the optics 70 are positioned horizontally accordingly. Advantageously, the vertical orientation of the wafer table 80 reduces the space occupied by the metrology machine and increases the machine's throughput. Particularly as wafers become larger, the benefits of the disclosed approach are enhanced. In combination with the table and the optics 100, 150, and 200 configurations disclosed above, the machine's footprint can be maintained even when handling larger wafers. Furthermore, the vertical table position enables more efficient handling of the table's movement and shortens the movement and relaxation time.

[0034] In certain embodiments, the configuration 260 further includes a chuck 262 supporting the wafer table 80 with integrated securing means for securing the wafer against falling in the event of a power or vacuum failure. The chuck 262, such as a vacuum chuck, may have an integrated edge gripping mechanism configured to secure the wafer and prevent the wafer from falling downward in the event of a power failure or vacuum shutdown. The edge grip may be "normally closed" and may only be open when the vacuum and power to the chuck are on. The chuck 262 may be configured to allow leveling of the Z-table to eliminate coarse travel in the vertical direction of the table.

[0035] In certain embodiments, the configuration 260 further includes a component or components 268 of the isolation system in proximity to the vertical wafer stage 80. For example, the components 268 may include linear motors that compensate for and isolate vertical movements and vibrations. The components 268 may be considered remote elements of a distributed isolation system 64. The components 268 may be configured to compensate for relative movements of the chuck 262 and wafer stage 80 with respect to the optics 70, e.g., using feeds from the wafer stage 80 and / or the floor 68. In certain embodiments, the isolation system 64 may be arranged directly on the floor or pedestal 68 with the appropriate leveling mechanism.

[0036] In certain embodiments, the configuration 260 further includes a wafer turning and prealignment mechanism 264 configured to handle the wafers relative to the vertical wafer stage 80. The wafer handling mechanism 264 may be located directly above the optics 70 at the reach level of a standard load / unload robot.

[0037] In certain embodiments, configuration 260 further includes a vertical axis counterweight mechanism 266 configured to cancel gravitational effects of repositioning vertical wafer stage 80. Counterweight 266 is configured to cancel or reduce vibrations caused by vertical movement of wafer stage 80. In certain embodiments, configuration 260 further includes horizontal counterweights to dampen horizontal vibrations as well.

[0038] Advantageously, the vertical arrangement of the wafer table 80 changes the footprint and the vibration constraint of the machine, as different dimensions are used as footprint constraints and to determine interaction with the environment. For example, only one dimension (formerly horizontal) of the wafer table 80 affects the footprint compared to two dimensions (horizontal) in the horizontal configuration. The vertical dimension of the wafer table 80 is added to the dimensions of the optics to give the footprint of the machine in the vertical configuration. The optics 70 or 200 can be configured to reduce the horizontal dimension, such as by folding the optical axes, to reduce the footprint. In the case of multiple optical heads, the travel of the table in this direction can be increased, reducing the impact on the footprint.

[0039] Fig. 6 is an overview flowchart illustrating a method 300 according to some embodiments of the disclosure. The method 300 includes configuring a metrology stage to enable radial and rotational movement of the wafer (step 310) and configuring at least a portion of the respective optics to be stationary (step 320).

[0040] Certain embodiments of the method 300 further include possibly rotating a radial axis of the table (step 330) and configuring the optics to be stationary (step 332).

[0041] Certain embodiments of method 300 further include configuring a portion of the optics to receive collimated illumination from the stationary portion (step 340) and to be rotatable about an optical axis of the collimated illumination. Method 300 may further include configuring the rotatable portion to wirelessly receive power and control and wirelessly deliver data (step 350).

[0042] The method 300 in any of the embodiments may further include a configuration having at least one balancing mass for balancing at least one of the radial and rotational movements (step 360).

[0043] The method 300 may include further steps for operating the configurations of the metrology table 100, 150, and the optics 200. The method 300 may include performing the metrological measurements by radially moving a wafer (step 312) and rotationally symmetrically moving a wafer (step 314) while at least a portion of the respective optics is stationary (step 322).

[0044] The method 300 may include rotating a radial axis of the table while the optics are stationary (step 335).

[0045] Method 300 may include rotating only a portion of the optics about an optical axis of the collimated illumination that receives collimated illumination from the stationary portion (step 345). Method 300 may further include wirelessly supplying power and / or control to the rotatable portion and / or wirelessly receiving data therefrom (step 355).

[0046] In any of the embodiments, the method 300 may further include compensating for at least one of the radial and rotational movements (step 365), such as with balancing masses.

[0047] Advantageously, the disclosed configurations of the metrology table 100, 150 can achieve a minimum machine footprint for the required travel of the table; eliminate the tolerance build-up factor of stacked axes (see Fig.1); improve the table dynamics to reduce travel and relaxation times by reducing the moving masses, lower the table profile or stacking, increase stiffness, and shorten the axis stroke; and improve the overall flatness of the table at the chuck level, especially when air bearings are used. In certain embodiments, the metrology table 100, 150 configurations can be designed to eliminate the tolerance buildup factor of stacked linear axes and improve the overall flatness of the table at the chuck level (especially when air bearings are used). In certain embodiments, the improved table movements and configurations can be used to reduce or even eliminate the coarse Z stroke, so that the Z range is entirely subject to only a fine Z axis.The method 300 may further include leveling the table to eliminate a rough travel vertical to the table.

[0048] The method 300 may further include configuring the machine table to move a wafer mounted thereon horizontally and move the optics perpendicular to the wafer; or configuring the machine table to move the wafer mounted thereon vertically and move the optics perpendicular to the wafer. Either of the above tables may be adapted to either the vertical or horizontal configuration of the wafer table and the corresponding perpendicular configurations of the optics.

[0049] The method 300 may further include designing a metrology machine having a vertical wafer table and horizontal optics (step 370), holding and moving the wafer table vertically (step 375), and positioning the optics horizontally, perpendicular to the wafer table (step 377) to minimize the footprint of the machine by reconfiguring the wafer table and / or the optics (step 380).

[0050] In certain embodiments, method 300 may further provide for the use of multiple optical heads (step 382).

[0051] In certain embodiments, method 300 may further include increasing the travel distance of the wafer to reduce the footprint of the machine (step 385).

[0052] In certain embodiments, the method 300 may further include an isolation system or systems directly on the floor / pedestal (step 390) and / or the insertion of isolation elements adjacent to the wafer table (step 395).

[0053] The method 300 may further include arranging handling elements above the wafer table (step 400) and / or compensating for the influence of gravity with respect to the vertical axis with a balancing mass or balancing masses (step 410).

[0054] The method 300 may further include the use of active or passive balancing masses (step 415) and / or the introduction of balancing masses on horizontal axes (step 417).

[0055] The method 300 may further include securing the wafer against falling in the event of a power or vacuum failure (step 420).

[0056] Certain embodiments include a computer program product comprising a computer-readable storage medium having a computer-readable program configured to control radial and rotational movements of the wafer while at least a portion of the respective optics is held stationary. The computer-readable program may further include a computer-readable program configured to control rotation of a radial axis of the wafer while the optics are held stationary. The computer-readable program may further include a computer-readable program configured to control rotation of a portion of the optics that receives collimated illumination from the stationary portion along an optical axis of the collimated illumination. The computer-readable program may further include a computer-readable program configured to control the rotatable portion, the delivery of power thereto, and the retrieval of data therefrom.The computer-readable program may further include a computer-readable program configured to control movements of the at least one balancing mass to balance at least one of the radial and rotational movements. The computer-readable program may further include a computer-readable program configured to control horizontal movements of the wafer and vertical movements of the optics; or to control vertical movements of the wafer and horizontal movements of the optics, which essentially depends on the configuration of the metrology machine. The computer-readable program may further be configured to control the operation of the vertical or horizontal wafer stage and the associated isolation system, balancing masses, and wafer handling devices for the wafer.

[0057] Certain embodiments include a metrology machine that includes at least one of the configurations of the metrology table 100, 150 and has a corresponding computer program configured to control the metrology table.

Claims

[1] A metrology table configuration includes: rotatably mounted connection (130) arranged to receive a wafer (75) and enable its rotation about a pivot point (131); a radial axis (110) arranged to radially move the attached rotatably mounted connection (130); at least one balancing mass (115, 125) designed to balance at least one of the radial and rotational movements; and an optic (70, 200) having a stationary section configured to produce a collimated illumination beam. [2] The metrology table configuration of claim 1, wherein the optics (70) are fixed and further comprise a central pivoted joint (120) arranged to receive and permit rotation of the radial axis (110). [3] The metrology table configuration of claim 2, wherein the optics (70) are at least partially supported within a rectangular surface that is a base surface of the wafer (75) defined by the radial axis (110) and the central rotatable connection (120). [4] The metrology table configuration of claim 1, wherein the optics (200) further comprises a rotatable part (220) arranged to receive the collimated illumination beam from the stationary section (210) along the optical axis (60) and configured to be rotatable about the optical axis (60). [5] The metrology table configuration of claim 4, wherein the rotatable portion (220) is configured to wirelessly receive power and control and wirelessly deliver data. [6] A configuration for the metrology table according to any one of claims 1-5, further comprising leveling the table to eliminate a rough lifting requirement perpendicular to the table. [7] The metrology table configuration of any one of claims 1-6, wherein the wafer (75) is horizontally movable and the optics (70, 200) are perpendicular to the wafer. [8] The metrology table configuration of any one of claims 1-6, wherein the wafer (75) is vertically movable and the optics (70, 200) are perpendicular to the wafer. [9] A metrology table configuration according to claim 8, comprising a vertical wafer table (80) and an optic (70, 200) arranged perpendicular thereto. [10] The metrology table configuration of claim 9, further comprising a chuck (262) configured to support the vertical wafer table (80) and including a safety means configured to secure the wafer (75) in the event of a power or vacuum failure. [11] The metrology table configuration of claim 9, further comprising an isolation system (64) having a first component positioned directly on the floor (68) or a pedestal supporting the machine, and a second component (268) positioned in close proximity to the vertical wafer table (80) and configured to compensate for relative movements of the wafer table (80) and the optics (70). [12] The metrology table configuration of claim 9, further comprising a wafer turning mechanism and wafer pre-orientation mechanism (264) configured to handle wafers (75) with respect to the vertical wafer table (80). [13] The metrology table configuration of claim 9, further comprising a vertical axis counterbalance mass (266) mechanism configured to cancel gravitational effects upon repositioning of the vertical wafer table (80). [14] A configuration for the metrology table according to any one of claims 9-13, further comprising leveling the table to eliminate a coarse lifting requirement perpendicular to the table. [15] A procedure comprises the steps: • Configuring a metrology table to enable radial and rotational movements of a wafer (75); • Configuring at least one balancing mass (115, 125) to balance at least one of the radial and rotational movements; and • Configuring at least a part (210) of a corresponding optic (70, 200) so that it is fixed. [16] The method of claim 15, further comprising the steps of: • that a rotation of a radial axis (110) of the table is enabled; and • that the optics (70) are configured so that they are stationary. [17] The method of claim 15, further comprising configuring a portion (220) of the optics (200) to receive collimated illumination from the stationary portion (210), to be rotatable about an optical axis (60) of the collimated illumination, and to wirelessly receive power and control and wirelessly deliver data. [18] -The method of any of claims 15-17, further comprising leveling the table to eliminate a rough lifting requirement perpendicular to the table. [19] The method of any of claims 15-18, further comprising configuring the metrology table to move a wafer (75) supported thereon in a horizontal direction and to move the optics (70, 200) perpendicular to the wafer. [20] The method of any of claims 15-18, further comprising configuring the metrology table to move a wafer (75) supported thereon in a vertical direction and to move the optics (70, 200) perpendicular to the wafer. [21] A method according to claim 20, comprising the steps of: • Designing a metrology machine with a vertical wafer table (80) and a horizontal optics (70); • Supporting and moving the wafer table (80) vertically and positioning the optics (70) perpendicular to the wafer table to minimize the footprint of the metrology machine. [22] The method of claim 21, further comprising a plurality of optical heads and increasing the movement of the wafer table (80) to reduce the footprint of the metrology machine. [23] The method of claim 21, further comprising providing at least one component of an isolation system directly on a floor (68) or a pedestal, and providing isolation elements (268) adjacent to the wafer table. [24] The method of claim 21, further comprising providing handling elements for the wafer (75) above the wafer table (80) and compensating for gravitational effects using at least one balancing mass (266). [25] The method of claim 21, further comprising using active or passive balancing masses and introducing balancing masses on the horizontal axes. [26] The method of claim 21, further comprising securing the wafer (75) against falling in the event of a power or vacuum failure. [27] The method of any of claims 21-26, further comprising leveling the table to eliminate a rough lifting requirement perpendicular to the table. [28] A method performs metrological measurements, wherein a wafer (75) is moved radially and rotationally, wherein balancing of at least one of the radial and rotational movements is carried out by using a balancing mass (115, 125), while at least a portion of the corresponding optics (70, 200) is stationary. [29] The method of claim 28, further comprising rotating a radial axis (110) of the table while the optics (70) remain stationary. [30] The method of claim 28, further comprising rotating only a portion (220) of the optics (200) about an optical axis (60) of collimated illumination that receives the collimated illumination from a fixed portion (210). [31] The method of claim 28, further comprising wirelessly delivering power and control to the rotatable portion (220) and wirelessly receiving data therefrom. [32] The method of any of claims 28-31, further comprising moving the wafer (75) horizontally and moving the optics (70, 200) vertically, perpendicular to the wafer (75). [33] The method of any of claims 28-31, further comprising moving the wafer (75) vertically and moving the optics (70, 200) horizontally, perpendicular to the wafer (75). [34] The method of any of claims 28-33, further comprising leveling the table to eliminate a rough lifting requirement perpendicular to the table. [35] A computer program product comprises a computer-readable storage medium with a computer-readable program, the computer-readable program being configured to control radial and rotational movements of a wafer (75) while at least a portion of the respective optics (70, 200) is held stationary, the computer-readable program being further configured to control movements of at least one balancing mass (115, 125) to balance at least one of the radial and rotational movements. [36] The computer program product of claim 35, wherein the computer readable program further comprises a computer readable program configured to control rotation of a radial axis (110) of the wafer (75) while the optics (70) are stationary. [37] The computer program product of claim 35, wherein the computer readable program further comprises a computer readable program configured to control rotation of a portion (220) of the optics (200) receiving the collimated illumination from the fixed portion (210) about an optical axis (60) of the collimated illumination. [38] The computer program product of claim 37, wherein the computer readable program further comprises a computer readable program configured to control delivery of power to and receipt of data from the rotatable portion (220). [39] The computer program product of any of claims 35-38, wherein the computer readable program further comprises a computer readable program configured to control horizontal movements of the wafer (75) and vertical movements of the optics (70, 200). [40] The computer program product of any of claims 35-38, wherein the computer readable program further comprises a computer readable program configured to control vertical movements of the wafer (75) and horizontal movements of the optics (70, 200). [41] A metrology machine comprises at least one configuration for a metrology table according to any one of claims 1-14 and a corresponding computer program product according to any one of claims 35-40, which is designed to control the metrology table.

Images