Abstract:
A Pre-Aligned Metrology System comprising a number of Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules for measuring a target on a wafer. The Pre-Aligned Metrology Assemblies and Pre-Aligned Metrology Modules can reduce the maintenance down time and decrease the cost of ownership (COO).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to optical metrology, and more particularly to improving the optical metrology process using a pre-aligned metrology system that includes pre-aligned metrology assemblies and pre-aligned metrology modules. 
         [0003]    2. Description of the Related Art 
         [0004]    In the manufacture of integrated circuits, very thin lines or holes down to 10 nm or sometimes smaller are patterned into photoresist and then transferred using an etching process into a layer of material below on a silicon wafer. It is extremely important to inspect and control the width and profile (also known as critical dimensions or CDs) of these lines or holes. Traditionally the inspection of CDs that are smaller than the wavelength of visible light has been done using large and expensive scanning electron microscopes (SEM). As the structures patterned get smaller and smaller, the measurement precision and accuracy becomes much higher, and additional measurement data is needed for each wafer for process control. It is a very challenging for SEM to meet the metrology request in these cases. In many cases, manufacturers need to measure CD and profiles immediately after the photoresist has been patterned, a non-destructive metrology is needed to overcome photo-resist damage issues by SEM. For the case of process control or advanced equipment control, the measurement has to be non-destructive and the measurement tool need to be integrated into the process tools, such as wafer track that develops the photoresist or wafer-etching tool. 
         [0005]    One general technique that has promise for integrated CD measurements is Scatterometry using Optical Digital Profilometry (ODP). Exemplary Scatterometry techniques are described in U.S. Pat. No. 6,538,731, entitled “System and Method for Characterizing Macro-Grating Test Patterns in Advanced Lithography and Etch Processes”, by Niu, et al., issued on Mar. 25, 2003, and is incorporated in its entirety herein by reference. Exemplary ODP techniques are described in U.S. Pat. No. 6,433,878, entitled “Method and Apparatus for the Determination of Mask Rules Using Scatterometry”, by Niu, et al., issued on Apr. 13, 2002, and is incorporated in its entirety herein by reference. This technique takes advantage of the fact that small periodic lines or holes diffract an incident light beam, and the properties of the light in each of the diffraction orders carries information of the lines and holes. In practice, the optical properties of zero-th diffraction order that is reflected (or, for transparent samples, transmitted) from the periodic structures are measured with an optical metrology sensor, and measured data is analyzed with as Scatterometry software, such as ODP. Often such parameters are measured versus wavelength, and in some cases, versus angle of incidence on the sample. 
         [0006]    Optical metrology sensor measures the optical properties of the features on a wafer. These optical properties include a fraction of the incident energy reflected and polarization state change. These techniques are described in U.S. Pat. No. 7,064,829, entitled “Generic Interface for an Optical Metrology System”, by Li, et al., issued on Jun. 20, 2006, and is incorporated in its entirety herein by reference. The optical metrology sensor can be designed to sense one or more of this optical properties. For example, a tool that measures energy changes is called a reflectometer, and tools that measure the polarization change are called ellipsometers. The optical metrology sensor typically uses photometric or spectral photometric detectors. For reflectometer, a standard reflector that the reflection is known is needed to deduct the fraction of energy reflected from the feature under test. For ellipsometer, the polarization state of the incident beam is known and stable by design and calibration, and thus standards are not required when the reflectivity is not of interest. The polarization state changes are deduced from the ratios of different Fourier components, thus the absolute light source intensity is not needed. This is often referred to as “self reference”. In either case, the measurement quantity is the optical properties of the feature, and not the intensity of light in the diffraction orders although the optical properties is calculated from the intensities of the diffracted light and standard reflector in reflectometer case. The CD and profile information is obtained from an analysis of the diffraction signal using techniques such regression, library based systems, and machine learning systems such as those based on neural net techniques. 
         [0007]    An optical metrology sensor involves directing an incident beam in one or most polarization state at a feature on a wafer, measuring the resulting diffraction signals, and measuring the signal from standard reflector in reflectometer case, the measured signs are first analyzed to find the optical properties of the feature, namely reflectivity or polarization state changes. The measured optical properties of the feature are analyzed to determine various characteristics of the feature. In semiconductor manufacturing, optical metrology is typically used for quality assurance, process control, and equipment control. For example, after fabricating a periodic grating in proximity to a semiconductor chip on a semiconductor wafer, an optical metrology system is used to determine the profile of the periodic grating. By determining the profile of the periodic grating, the quality of the fabrication process utilized to form the periodic grating, and by extension the semiconductor chip proximate the periodic grating, can be evaluated. Further more, the measured dimensions of features can be used to control the process equipment work conditions. 
         [0008]    An integrated CD measurement tool must be both fast and compact, and must be non-destructive to the wafer under test. The wafer may also be loaded into the measurement tool at an arbitrary angle creating further complications for instruments that have a preferred measurement orientation with respect to certain wafer features. 
         [0009]    Most of the optical metrology systems for CD measurement are stand-alone tools that are used as off-line application for monitoring the process. As the semiconductor roadmap goes to smaller and smaller nodes, more and more challenges on semiconductor process control to meet very tight tolerance while the structure becomes smaller. Integrated metrology tools are needed to measure the structures made on the wafer, and use the measured data for optimizing the process tools that the structures on the wafer has been made, or for adjusting the process tool conditions that the wafer is going to be further processed. For an integrated metrology tools, the reliability and availability need to be much higher than for off line tools, and the maintenance time needs to be significantly shorter than an off line tool. 
       SUMMARY OF THE INVENTION 
       [0010]    The invention presents a Pre-Aligned Metrology Assembly that can be used in an integrated metrology sensor (IMS) that is configured using a plurality of Field Replaceable Units (FRUs). The invention presents a Pre-Aligned Metrology Assembly that is compact and well suited for integration into a compact IMS. The IMS can include one or more Pre-Aligned Metrology Assemblies, and the IMS can be used to measure structures 50 nm wide or smaller. The Pre-Aligned Metrology Assembly can be pre-aligned and calibrated so that it can be swapped in the field with minimum amount of time. The Pre-Aligned Metrology Assembly can be swapped as part of scheduled maintenance to improve the reliability and availability of the IMS. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: 
           [0012]      FIG. 1  depicts an exemplary optical metrology system in accordance with embodiments of the invention; 
           [0013]      FIG. 2  illustrates a simplified block diagram of a Metrology Assembly and a simplified block diagram of a test subsystem in accordance with embodiments of the invention; and 
           [0014]      FIG. 3  illustrates an exemplary flow diagram of an alignment procedure for a Metrology Assembly in accordance with embodiments of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Reliability, availability, and performance are the most important parameters for semiconductor equipments in a modern fabrication environment. Many semiconductor manufacturers use optical metrology systems for thin-film and optical CD measurements that include stand-alone tools, and use off-line applications for process monitoring. As the semiconductor roadmap goes to smaller and smaller nodes, the tightened tolerances associated with the smaller structures become more challenging to obtain and verify using semiconductor process control applications. Thus, integrated metrology tools are required to meeting measurement time and accuracy on the smaller structures made on the wafer. In addition, the measured data from the integrated metrology sensor (IMS) can be used either to optimize the process tools that are being used to create the structures on the wafer, or to adjust the process tool conditions that are being used to further process the wafer. When the metrology tool is integrated as in-line equipment, much higher reliability and availability are needed because a faulty in-line tool can cause throughput problems in the associated production line. 
         [0016]    The present invention provides a Pre-Aligned Metrology Assembly to improve tool reliability and to reduce the time to repair or maintain an in-line metrology tool and provide improved tool availability. Pre-Aligned Metrology Assembly can be more easily applied when a new metrology tool is designed and constructed. The entire metrology system can be separated into many Pre-Aligned Metrology Assemblies, and each one of the Pre-Aligned Metrology Assemblies can be assembled, aligned, calibrated, installed, and/or replaced with a minimum amount of system level adjustment. 
         [0017]    The inventor believes that an improved IMS can be designed and built using compact Pre-Aligned Metrology Assemblies. The inventor believes that the use of Pre-Aligned Metrology Assemblies in an IMS can minimize and/or substantially eliminate system level alignment, diagnostic and calibration procedures that are presently required after a scheduled maintenance is performed, and after a repair of a system failure. 
         [0018]    The invention can provide apparatus and methods for processing wafers using Pre-Aligned Metrology Assemblies having processing recipes and processing models associated therewith and the Pre-Aligned Metrology Assemblies can be used in real-time and non-real-time processing sequences that can include Double-Patterning (D-P) processing sequences, Double-Exposure (D-E) processing sequences, or other multi-step processing sequences. The D-P processing sequences can include one or more lithography-related procedures, one or more scanner-related procedures, one or more etch-related procedures, one or more deposition-related procedures, one or more measurement-related procedures, or one or more inspection-related procedures, or any combination thereof. 
         [0019]    One or more multi-dimensional target structures having one or more identifiable features can be provided at various locations on a test wafer and can be used to align a non-aligned Metrology Assembly. 
         [0020]    As structure sizes decrease below the  65  nm node, accurate processing and/or measurement data becomes more important and more difficult to obtain. Multi-step procedures can be used to more accurately process and/or measure these ultra-small devices and structures. The data from a D-P procedure can be compared with the accuracy, warning, and/or error limits, when a limit is exceeded, an alarm can be generated indicating a processing problem, and real-time correction procedures can be performed. 
         [0021]      FIG. 1  shows an exemplary block diagram of an optical metrology system in accordance with embodiments of the invention. In the illustrated embodiment, an Integrated optical Metrology Sensor (IMS)  100  is shown that can comprise a platform subsystem  103 , an alignment subsystem  102  coupled to the platform subsystem  103 , an alignment sensor  104  coupled to the alignment subsystem  102 , and these subsystems can be configured to align the wafer  101 . One or more optical outputs  106  from the lamp subsystem  105  can be transmitted to an illuminator subsystem  110 . One or more optical beams  111  can be sent from the illuminator subsystem  110  to a selector subsystem  115 . The selector subsystem  115  can provide one or more optical beams  116  to a beam generator subsystem  120 . In addition, a reference subsystem  125  can provide one or more reference beams to and/or exchange data with the beam generator subsystem  120  using path  126 . 
         [0022]    The Integrated Metrology Sensor (IMS)  100  can comprise a first selectable reflection subsystem  130  that can be used to direct one or more outputs  121  from the beam generator subsystem  120  as first outputs  131  when operating in a first mode “HIGH” or as second outputs  132  when operating in a second mode “LOW”. When the first selectable reflection subsystem  130  is operating in the first mode “HIGH”, one or more of the outputs  132  from the first selectable reflection subsystem  130  can be directed to a first reflection subsystem  140 , and one or more outputs  141  from the first reflection subsystem  140  can be directed to a high angle focusing subsystem  145  , When the first selectable reflection subsystem  130  is operating in the second mode “LOW”, one or more of the outputs  132  from the first selectable reflection subsystem  130  can be directed to a low angle focusing subsystem  135 . Alternatively, other modes may be used and other configurations may be used. 
         [0023]    When the IMS  100  is operating in the first mode “HIGH”, one or more of the outputs  146  from the high angle focusing subsystem  145  can be directed to the wafer  101 . For example, a high angle of incidence can be used. When the IMS  100  is operating in the second mode “LOW”, one or more of the outputs  136  from the low angle focusing subsystem  135  can be directed to the wafer  101 . For example, a low angle of incidence can be used. Alternatively, other modes may be used and other configurations may be used. 
         [0024]    The IMS  100  can comprise a high angle collection subsystem  155 , a low angle collection subsystem  165 , a second reflection subsystem  150 , and a second selectable reflection subsystem  160 . 
         [0025]    When the IMS  100  is operating in the first mode “HIGH”, one or more of the outputs  156  from the wafer  101  can be directed to the high angle collection subsystem  155 . For example, a high angle of incidence can be used. In addition, the high angle collection subsystem  155  can process the outputs  156  obtained from the wafer  101  and high angle collection subsystem  155  can provide outputs  151  to the second reflection subsystem  150 , and the second reflection subsystem  150  can provide outputs  152  to the second selectable reflection subsystem  160 . When the second selectable reflection subsystem  160  is operating in the first mode “HIGH” the outputs  152  from the second reflection subsystem  150  can be directed to the analyzer subsystem  170 . For example, one or more blocking elements can be moved allowing the outputs  152  from the second reflection subsystem  150  to pass through the second selectable reflection subsystem  160  with a minimum amount of loss. 
         [0026]    When the IMS  100  is operating in the second mode “LOW”, one or more of the outputs  166  from the wafer  101  can be directed to the low angle collection subsystem  165 . For example, a low angle of incidence can be used. In addition, the low angle collection subsystem  165  can process the outputs  166  obtained from the wafer  101  and low angle collection subsystem  165  can provide outputs  161  to the second selectable reflection subsystem  160 . When the second selectable reflection subsystem  160  is operating in the second mode “LOW”, the outputs  162  from the second selectable reflection subsystem  160  can be directed to the analyzer subsystem  170 . 
         [0027]    When the IMS  100  is operating in the first mode “HIGH”, high incident angle data from the wafer  101  can be analyzed using the analyzer subsystem  170 , and when the IMS 100  is operating in the second mode “LOW”, low incident angle data from the wafer  101  can be analyzed using the analyzer subsystem  170 . 
         [0028]    The IMS  100  can include one or more measurement subsystems  175  that can receive inputs from the analyzer subsystem  170 . One or more of the measurement subsystems  175  can include one or more spectrometers. For example, the spectrometers can operate from the Deep-Ultra-Violet to the visible regions of the spectrum. 
         [0029]    The IMS  100  can include one or more camera subsystems  180 , one or more illumination, and imaging subsystems  185  coupled to one or more of the camera subsystems  180 . In addition, the IMS  100  can also include one or more illuminator subsystems  184  that can be coupled to one or more of the imaging subsystems  185 . 
         [0030]    In some embodiments, the IMS  100  can include one or more auto-focusing subsystems  190 . Alternatively, other focusing techniques may be used. 
         [0031]    One or more of the controllers (not shown) in one or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185  and  190 ) can be used when performing real-time or non-real-time procedures. A controller can receive real-time or non-real-time data to update subsystem, processing element, process, recipe, profile, image, pattern, and/or model data. One or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185  and  190 ) can exchange data using one or more Semiconductor Equipment Communications Standard (SECS) messages, can read and/or remove information, can feed forward, and/or can feedback the information, and/or can send information as a SECS message. 
         [0032]    Those skilled in the art will recognize that one or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 , and  190 ) can include computers and memory components (not shown) as required. For example, the memory components (not shown) can be used for storing information and instructions to be executed by computers (not shown) and may be used for storing temporary variables or other intermediate information during the execution of instructions by the various computers/processors in the IMS  100 . One or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 , and  190 ) can include the means for reading data and/or instructions from a computer readable medium and can comprise the means for writing data and/or instructions to a computer readable medium. The IMS  100  can perform a portion of or all of the processing steps of the invention in response to the computers/processors in the processing system executing one or more sequences of one or more instructions contained in a memory and/or received using a computer-readable medium. Such instructions may be received from another computer, a computer readable medium, or a network connection. In addition, one or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 , and  190 ) can comprise control applications, Graphical User Interface (GUI) components, and/or database components. For example, the control applications can include Advanced Process Control (APC) applications, Fault Detection and Classification (FDC), and/or Run-to-Run (R2R) applications. In some embodiments, APC applications, FDC applications, and/or R2R applications can be performed using multi-angle metrology procedures. 
         [0033]    In some embodiments, the IMS  100  can include Optical Digital Profilometry (ODP) elements (not shown), and ODP elements/systems are available from Timbre Technologies Inc. (a TEL company). Alternatively, other data analysis elements may be used. For example, ODP techniques can be used to obtain real-time data that can include critical dimension (CD) data, gate structure data, thickness data, and the wavelength ranges for the ODP data can range from less than approximately 45 nm to greater than approximately 900 nm. Exemplary ODP elements can include Optical Digital Profilometry Profiler Library elements, Profiler Application Server (PAS) elements, and other ODP Profiler Software elements. The ODP Profiler Library elements can comprise application specific database elements of optical spectra and its corresponding semiconductor profiles, critical dimensions (CDs), and film thicknesses. The PAS elements can comprise at least one computer that connects with optical hardware and computer network. The PAS elements can be configured to provide the data communication, ODP library operation, results generation, results analysis, and results output. The ODP Profiler Software elements can include the software installed on PAS elements to manage measurement recipe, ODP Profiler library elements, ODP Profiler data, ODP Profiler search/match results, ODP Profiler calculation/analysis results, data communication, and PAS interface to various metrology elements and computer network. 
         [0034]    The IMS  100  can use polarizing reflectometry, spectroscopic ellipsometry, spectroscopic reflectometry, or other optical measurement techniques to measure accurate feature profiles, accurate CDs, and multiple layer film thickness of a wafer. The integrated data process (ODP) can be executed as an integrated data analyzer in an integrated group of subsystems. In addition, the integrated group (iODP) that consists of IMS  100  and data analyzer (ODP) into a process tool eliminates the need to break the wafer for performing the analyses or waiting for long periods for data from external systems. iODP techniques can be integrated with TEL processing systems and/or lithography systems and etch systems to provide real-time process monitoring and control. 
         [0035]    An exemplary ODP is described in U.S. Pat. No. 6,943,900, entitled GENERATION OF A LIBRARY OF PERIODIC GRATING DIFFRACTION SIGNAL, by Niu, et al., issued on Sep. 13, 2005, and is incorporated in its entirety herein by reference. 
         [0036]    Simulated diffraction signals with ODP can be generated by applying Maxwell&#39;s equations and using a numerical analysis technique to solve Maxwell&#39;s equations. For example, various numerical analysis techniques, including variations of rigorous coupled wave analysis (RCWA), can be used with multi-layer structures. For a more detail description of RCWA, see U.S. Pat. No. 6,891,626, titled CACHING OF INTRA-LAYER CALCULATIONS FOR RAPID RIGOROUS COUPLED-WAVE ANALYSES, filed on Jan. 25, 2001, issued May 10, 2005, which is incorporated herein by reference in its entirety. 
         [0037]    An alternative procedure for generating a library of simulated-diffraction signals can include using a machine learning system (MLS). Prior to generating the library of simulated-diffraction signals, the MLS is trained using known input and output data. For example, the MLS may be trained with a subset of the D-P library data. In one exemplary embodiment, simulated diffraction signals can be generated using a MLS employing a machine learning algorithm, such as back-propagation, radial basis function, support vector, kernel regression, and the like. For a more detailed description of machine learning systems and algorithms, see “U.S. patent application Ser. No. 10/608,300, titled OPTICAL METROLOGY OF STRUCTURES FORMED ON SEMICONDUCTOR WAFERS USING MACHINE LEARNING SYSTEMS, filed on Jun. 27, 2003, which is incorporated herein by reference in its entirety. 
         [0038]    In various embodiments, one or more of the subsystems ( 105 ,  110 ,  115 ,  120 ,  125 ,  130 ,  135 ,  140 ,  145 ,  150 ,  155 ,  160 ,  165 ,  170 ,  175 ,  180 ,  185 , and  190 ) can perform evaluation procedures, inspection procedures, temperature control procedures, measurement procedures, alignment procedures, verification procedures, and/or storage procedures on one or more wafers. For example, wafer data that can include wafer temperature, wafer thickness, wafer curvature, layer thickness, wafer uniformity, pattern data, damage data, or particle data, or any combination thereof. In addition, controller  195  can determine if the wafer has been processed correctly or if a rework procedure is required. 
         [0039]      FIG. 2  illustrates a simplified block diagram of a Multi-Angle Assembly and a simplified block diagram of a test subsystem in accordance with embodiments of the invention. In the illustrated embodiment, a Metrology Assembly  400  is shown that includes a first set of source elements  200  and a first set of receiving elements  300 . In some examples, the source elements  200  can include one or more focusing elements, and the receiving elements  300  can include one or more collecting elements. Alternatively, other source elements and/or receiving elements may be used. The Metrology Assembly  400  is shown coupled to a test chamber  410  using one or more attachment elements  25 , one or more attachment devices ( 26  and  27 ) and one or more alignment devices  28 . For example, first pre-aligned output wall  270  and second pre-aligned input wall  370  in the Metrology Assembly  400  can be coupled to the first alignment wall  425  and the second alignment wall  435  in the test chamber  410 . Alternatively, other configurations may be used. 
         [0040]    The source elements  200  can include a source chamber  205  having one or more attachment elements  25 . The source chamber  205  can be a sealable structure that can be evacuated and back-filled with a low-pressure gas, such as nitrogen. Alternatively, a back-filling procedure may not be required. 
         [0041]    The source elements  200  can include a first input optical element  210  that can include an illumination pinhole  222 , and the first input optical element  210  can be mounted and aligned in a first pre-aligned input wall  223  having a pre-aligned angle  224 . For example, the illumination pinhole  222  can include material that is optically transparent to a first set of wavelengths. In alternate embodiments, the first input optical element may include a lens or a polarizer. The pre-aligned angle  224  can vary from approximately 85 degrees to approximately 95 degrees. A preferred value can be 90.0 degrees. The first input optical element  210  can be configured for coupling to optical windows or optical fibers. 
         [0042]    The source elements  200  can include a movable shutter element  220  and an attachment element  221 . For example, the movable shutter element  220  can be moved to intercept and turn-off one or more of the internal source beams ( 211 ,  212 , and  213 ) that can be aligned or non-aligned. Alternatively, the movable shutter element  220  may not required. The attachment element  221  can comprise one or more coupling elements and can be coupled to an inside wall of the source chamber  205 . The movable shutter element  220  and an attachment element  221  can be coupled to a controller  235 . In an alternate embodiment, the movable shutter element  220  may include a polarizing element. 
         [0043]    The source elements  200  can include a moveable ultra-violet (UV) cutoff filter  225  and an attachment element  226 . For example, the movable ultra-violet cutoff filter  225  can be moved to intercept and remove the UV wavelengths from one or more of the internal source beams ( 211 ,  212 , and  213 ) that can be aligned or non-aligned. Alternatively, the movable ultra-violet cutoff filter  225  may not required. The attachment element  226  can comprise one or more coupling elements and can be coupled to an inside wall of the source chamber  205 . The movable ultra-violet cutoff filter  225  and an attachment element  226  can be coupled to a controller  235 . In an alternate embodiment, the movable ultra-violet cutoff filter  225  may include a different filter element. 
         [0044]    The source elements  200  can include a moveable measurement device  230  and an attachment element  231 . For example, the movable measurement device  230  can be moved to intercept and measure one or more of the internal source beams ( 211 ,  212 , and  213 ) that can be aligned or non-aligned. Alternatively, the movable measurement device  230  may not be required. The attachment element  231  can comprise one or more coupling elements and can be coupled to an inside wall of the source chamber  205 . The movable measurement device  230  and the attachment element  231  can be coupled to a controller  235 . 
         [0045]    In addition, the source elements  200  can include one or more fixed measurement devices  236  that can be used to measure residual light in the source chamber  205 . The fixed measurement devices  236  can be coupled to the controller  235 , and can be positioned to measure misaligned beams. Alternatively, the fixed measurement devices may not be required. 
         [0046]    The source elements  200  can comprise a first reflecting element  240  that can include one or more first highly-efficient reflecting surfaces  241  that can be used as an illumination aperture stop. The first reflecting element  240  can be coupled to a first adjusting structure  245  and the first adjusting structure  245  can position the first reflecting element  240  at a first angle  242 . The first highly-efficient reflecting surfaces  241  can include one or more convex surfaces that can receive the first aligned internal source beam  211  and create a second aligned internal source beam  212 . The first highly-efficient reflecting surfaces  241  can include one or more highly polished surfaces. The first reflecting element  240  and/or the first adjusting structure  245  can be coupled to a controller  235 . 
         [0047]    In some examples, the first adjusting structure  245  can include mechanical adjustment devices (not shown), and mechanical adjustments can be made to change the first angle  242  during the alignment and/or testing procedures before the source chamber  205  is sealed. In other examples, the first adjusting structure  245  can include electronic adjustment devices (not shown), and electronic adjustments can be made before and after the source chamber  205  is sealed. Electronic adjustments can be made to change the first angle  242  during system operations, and the controller  235  can be programmed to change the first angle  242  in order to compensate for drift and/or system variations. In addition, when a new light source is installed, the controller  235  can be programmed to compensate for the lamp-to-lamp variations and a system level alignment may not be required. The first angle  242  can vary from approximately  45  degrees to approximately  80  degrees. 
         [0048]    The source elements  200  can comprise a second reflecting element  250  that can include one or more second highly-efficient reflecting surfaces  251  that can be used as a focusing element. The second reflecting element  250  can be coupled to a second adjusting structure  255  and the second adjusting structure  255  can position the second reflecting element  250  at a second angle  252 . The second highly-efficient reflecting surfaces  251  can include one or more concave surfaces that can receive the second aligned internal source beam  212  and create a third aligned internal source beam  213 . The second highly-efficient reflecting surfaces  251  can include one or more highly polished surfaces. The second reflecting element  250  and/or the second adjusting structure  255  can be coupled to a controller  235 . 
         [0049]    In some examples, the second adjusting structure  255  can include mechanical adjustment devices (not shown), and mechanical adjustments can be made to change the second angle  252  during the alignment and/or testing procedures before the source chamber  205  is sealed. In other examples, the second adjusting structure  255  can include electronic adjustment devices (not shown), and electronic adjustments can be made before and/or after the source chamber  205  is sealed. Electronic adjustments can be made to change the second angle  252  during system operations, and the controller  235  can be programmed to change the second angle  252  in order to compensate for drift and/or system variations. In addition, when a new light source is installed, the controller  235  can be programmed to compensate for the lamp-to-lamp variations and a system level alignment may not be required. The second angle  252  can vary from approximately 45 degrees to approximately 80 degrees. 
         [0050]    The source elements  200  can comprise a reference detector  265  that can be used to measure a reference beam  266 . The reference detector  265  can be coupled to an inside wall of the source chamber  205 , and the reference detector  265  can be coupled to a controller  235 . During some alignment and test procedures, the optical test source  80  can be programmed to provide one or more reference beams  266 . 
         [0051]    The source elements  200  can comprise a first output optical element  260  that can include one or more low-loss polarizing components  261 . The first output optical element  260  can be mounted and aligned in a first opening  271  in a first pre-aligned output wall  270  that can be configured for attaching the first Metrology Assembly  400  to the test chamber  410  or to an IMS  100 , such as shown in  FIG. 1 . Alternatively, the polarizing components may not be required. The first output optical element  260  can include one or more low-loss polarizing components  261  that can be used to receive the third aligned internal source beam  213  and create a first incident beam  215  having a first incident angle  216 . The first incident angle  216  can measured relative to a normal vector  418  and can vary from approximately 15 degrees to approximately 80 degrees. The first output optical element  260  can be coupled to a controller  235  when the first output optical element  260  includes adjustable components, such as a polarizer. The first output optical element  260  can be configured for coupling to optical windows or optical fibers. 
         [0052]    In some examples, the low-loss polarizing components  261  that can linearly polarize the light, and the polarization can be selected to maximize the sensitivity of the optical measurement to the parameters of the sample. One or more of the polarizing components  261  can provide the S-polarized light. In other examples, polarizing components  261  may be rotated to collect additional measurement data. Alternatively, a rotating waveplate or electro-optic modulator (Pockels or Kerr effect based) could be placed after polarizing components  261  to collect more information on the sample&#39;s properties. 
         [0053]    After a Metrology assembly  400  has been constructed or repaired, one or more pre-alignment procedures can be used to align and/or test the non-aligned assembly to create a pre-aligned assembly. 
         [0054]    During some alignment procedures, an optical test source  80  can be coupled to the source chamber  205  using one or more first coupling elements  81  that can include alignment devices  82 . For example, one or more alignment lasers may be used during alignment and replaced by fastening means after alignment. The optical test source  80  can operate at many different wavelengths and can provide one or more optical test signals  84  that have different polarization angles. The illumination pinhole  222  can be used to establish a first aligned internal source beam  211  using a source signal from the optical test source  80 . In various procedures, the movable shutter element  220  can be aligned and tested; the moveable ultra-violet cutoff filter  225  can be aligned and tested, and the moveable measurement device  230  can be used to measure and/or align the first aligned internal source beam  211 . The first reflecting element  240  can be adjusted to align and/or optimize the second aligned internal source beam  212 , the second reflecting element  250  can be adjusted to align and/or optimize the third aligned internal source beam  213 , and the first output optical element  260  can be adjusted to align and/or optimize the first incident beam  215 . 
         [0055]    In some embodiments, the test subsystem  410  can include one or more motion control subsystems  420 , and the motion control subsystem  420  can be removably coupled at various times and in various places to a test subsystem. In addition, the test chamber  410  can include a process space  404  that can be evacuated during testing and alignment procedures. Alternatively, multiple process spaces may be used. 
         [0056]    The source chamber  205  can be coupled to the test chamber  410 . For example, the source chamber  205  can comprise a first pre-aligned output wall  270  that can be coupled to and aligned with a first alignment wall  425  in the test chamber  410 . The first pre-aligned output wall  270  in the source chamber  205  can have a first pre-aligned angle  272 , the first alignment wall  425  in the test chamber  410  can have a first alignment angle  427 , and the first pre-aligned angle  272  can be substantially equal to the first alignment angle  427 . For example, the first pre-aligned angle  272  and the first alignment angle  427  can vary from approximately  40  degrees to approximately  90  degrees. 
         [0057]    In addition, the first wall  425  in the test chamber  410  can include a first opening  426  that can be aligned with the first opening  271  in the first pre-aligned output wall  270  in the source chamber  205  and can be used to allow the first incident beam  215  to enter the test chamber  410 . In some configurations, an optically transparent window (not shown) can be installed in the first opening  426 . The first incident angle  216  can vary from approximately 15 degrees to approximately 50 degrees relative to a normal vector  418 . In this manner, the first incident angle  216  that is established during the alignment and testing procedures remains correct when the Metrology Assembly  400  is installed in an IMS  100 , such as shown in  FIG. 1 . 
         [0058]    During some alignment procedures, measurement data can be obtained for the source elements  200  using various test wafers  401  in the test chamber  410 . The measurement data for the source elements  200  can include intensity data, wavelength data, incident angle data, polarization data, transmission data, reflection data, and diffraction data. Alternatively, other measurement devices (not shown) may be used to simulate a wafer. 
         [0059]    In some embodiments, the receiving elements  300  can include a receiver chamber  305  having one or more attachment elements  25 . The receiver chamber  305  can be a sealable structure that can be evacuated and back-filled with a low-pressure gas, such as nitrogen. Alternatively, a back-filling may not be required. 
         [0060]    The receiving elements  300  can comprise a second input optical element  360  that can include one or more low-loss polarizing components  361 . The second input optical element  360  can be mounted and aligned in a second opening  371  in a second pre-aligned input wall  370  that is configured for attaching the Metrology Assembly  400  to the test chamber  410  or to an IMS ( 100 ,  FIG. 1 ). Alternatively, the polarizing components may not be required. The second input optical element  360  can include one or more low-loss polarizing components  361  that can be used to receive the first reflection beam  315  having a first reflection angle  316  and create a first aligned internal received beam  311 . The first reflection angle  316  can measured relative to a normal vector  418  and can vary from approximately 45 degrees to approximately 80 degrees. The second input optical element  360  can be coupled to a controller  335  when the second input optical element  360  includes adjustable components, such as a polarizer. The second input optical element  360  can be configured for coupling to optical windows or optical fibers. 
         [0061]    In addition, the receiving elements  300  can comprise a first reflecting element  350  that can include one or more third highly-efficient reflecting surfaces  351  that can be used as a collecting element. The first reflecting element  350  can be coupled to a first adjusting structure  355  and the first adjusting structure  355  can position the first reflecting element  350  at a first angle  352 . The third highly-efficient reflecting surfaces  351  can include one or more concave surfaces that can receive the first aligned internal received beam  311  and create a second aligned internal received beam  312 . The third highly-efficient reflecting surfaces  351  can include one or more highly polished surfaces. The first reflecting element  350  and/or the first adjusting structure  355  can be coupled to a controller  335 . 
         [0062]    In some examples, the first adjusting structure  355  can include mechanical adjustment devices (not shown), and mechanical adjustments can be made to change the first angle  352  during the alignment and/or testing procedures before the receiver chamber  305  is sealed. In other examples, the first adjusting structure  355  can include electronic adjustment devices (not shown), and electronic adjustments can be made before the receiver chamber  305  is sealed and after the receiver chamber  305  is sealed. Electronic adjustments can be made to change the first angle  352  during system operations, and the controller  335  can be programmed to change the first angle  352  in order to compensate for drift and/or system variations. In addition, when a new light source is installed, the controller  335  can be programmed to compensate for the lamp-to-lamp variations and a system level alignment may not be required. The first angle  352  can vary from approximately 45 degrees to approximately 80 degrees. 
         [0063]    The receiving elements  300  can comprise a reference detector  365  that can be used to measure a reference beam  366 . The reference detector  365  can be coupled to an inside wall of the receiver chamber  305 , and the reference detector  365  can be coupled to a controller  335 . During some alignment and test procedures, the optical test source  80  can be programmed to provide one or more reference beams  366 . 
         [0064]    The receiving elements  300  can comprise a second reflecting element  340  that can include one or more fourth highly-efficient reflecting surfaces  341  that can be used as an illumination aperture stop. The second reflecting element  340  can be coupled to a second adjusting structure  345  and the second adjusting structure  345  can position the second reflecting element  340  at a second angle  342 . The fourth highly-efficient reflecting surfaces  341  can include one or more convex surfaces that can receive a second aligned internal received beam  312  and create a first aligned internal received beam  311 . The fourth highly-efficient reflecting surfaces  341  can include one or more highly polished surfaces. The second reflecting element  340  and/or the second adjusting structure  345  can be coupled to a controller  335 . 
         [0065]    In some examples, the second adjusting structure  345  can include mechanical adjustment devices (not shown), and mechanical adjustments can be made to change the second angle  342  during the alignment and/or testing procedures before the receiver chamber  305  is sealed. In other examples, the second adjusting structure  345  can include electronic adjustment devices (not shown), and electronic adjustments can be made before and/or after the receiver chamber  305  is sealed. Electronic adjustments can be made to change the second angle  342  during system operations, and the controller  335  can be programmed to change the second angle  342  in order to compensate for drift and/or system variations. In addition, when a new light source is installed, the controller  335  can be programmed to compensate for the lamp-to-lamp variations and a system level alignment may not be required. The second angle  342  can vary from approximately 45 degrees to approximately 80 degrees. 
         [0066]    The receiving elements  300  can include a second output optical element  310  that can include an output pinhole  322  that is configured to establish a measurement beam  89 , and the second output optical element  310  can be coupled to a second pre-aligned output wall  323  having a pre-aligned angle  324 . For example, the output pinhole  322  can include material that is optically transparent to a first set of wavelengths, and the pre-aligned angle  324  can vary from approximately 85 degrees to approximately 95 degrees. A preferred value can be 90.0 degrees. In addition, the output pinhole  322  can be larger than the illumination pinhole  222 . 
         [0067]    In other embodiments, the receiving elements  300  can include a moveable measurement device  330  and an attachment element  331 . For example, the movable measurement device  330  can be moved to intercept and measure one or more of the internal received beams ( 311 ,  312 , and  313 ) that can be aligned or non-aligned. Alternatively, the movable measurement device  330  may not be required. The attachment element  331  can comprise one or more coupling elements and can be coupled to an inside wall of the receiver chamber  305 . The movable measurement device  330  and the attachment element  331  can be coupled to a controller  335 . In addition, the receiving elements  300  can include one or more fixed measurement devices  336  that can be used to measure residual light in the receiver chamber  305 . The fixed measurement devices  336  can be coupled to the controller  335 , and can be positioned to measure misaligned beams or internal light intensity. Alternatively, the fixed measurement devices may not be required. 
         [0068]    In other examples, the receiving elements  300  can include a moveable ultra-violet UV cutoff filter  325  and an attachment element  326 . For example, the movable ultra-violet UV cutoff filter  325  can be moved to intercept and remove the UV wavelengths from one or more of the internal received beams ( 311 ,  312 , and  313 ) that can be aligned or non-aligned. Alternatively, the movable ultra-violet UV cutoff filter  325  may not required. The attachment element  326  can comprise one or more coupling elements and can be coupled to an inside wall of the receiver chamber  305 . The movable ultra-violet UV cutoff filter  325  and an attachment element  326  can be coupled to a controller  335 . In an alternate embodiment, the movable ultra-violet UV cutoff filter  325  may include a different filter element. 
         [0069]    In still other example, the receiving elements  300  can include a movable shutter element  320  and an attachment element  321 . For example, the movable shutter element  320  can be moved to intercept and turn-off one or more of the internal received beams ( 311 ,  312 , and  313 ) that can be aligned or non-aligned. Alternatively, the movable shutter element  320  may not be required. The attachment element  321  can comprise one or more coupling elements and can be coupled to an inside wall of the receiver chamber  305 . The movable shutter element  320  and an attachment element  321  can be coupled to a controller  335 . In an alternate embodiment, the movable shutter element  320  may include a polarizing element. 
         [0070]    After the Metrology Assembly  400  has been constructed or repaired, one or more alignment procedures can be used to align and/or test a non-aligned assembly to create a Pre-Aligned Assembly. 
         [0071]    During some pre-alignment procedures, a measurement subsystem  85  can be coupled to the receiver chamber  305  using one or more second coupling elements  86  that can include alignment devices  87 . For example, one or more alignment lasers may be used during alignment and replaced by fastening means after alignment. The output pinhole  322  can be used to create a measurement beam  89  using the third aligned internal received beam  313 . The measurement subsystem  85  can be used to measure the measurement beam  89 . The measurement subsystem  85  can include a number of different devices that can be coupled to the receiver chamber  305  during various measurement procedures. The measurement subsystem  85  can operate over a wavelength range from approximately 190 nm to approximately 1000 nm and a polarization angle range from zero degrees to three-hundred-sixty degrees. For example, the measurement subsystem  85  can include one or more spectrometers, and the spectrometers can operate from the Deep-Ultra-Violet to the visible regions of the spectrum. 
         [0072]    In various procedures, the movable shutter element  320  can be aligned and tested; the moveable ultra-violet UV cutoff filter  325  can be aligned and tested, and the moveable measurement device  330  can be used to measure and/or align the third aligned internal received beam  313 . The second input optical element  360  can be adjusted to align and/or optimize the first aligned internal received beam  311 , the first reflecting element  350  can be adjusted to align and/or optimize the second aligned internal received beam  312 , and the second reflecting element  340  can be adjusted to align and/or optimize the third aligned internal received beam  313 . 
         [0073]    In addition, the second alignment wall  435  in the test chamber  410  can include a second opening  436  that can be aligned with the second opening  371  in the second pre-aligned input wall  370  and can be used to allow the reflection beam  315  to pass through and exit the test chamber  410 . In some configurations, an optically transparent window (not shown) can be installed in the second opening  436  in the test chamber  410 . The first reflection angle  316  can vary from approximately  15  degrees to approximately  50  degrees relative to the normal vector  418 . 
         [0074]      FIG. 3  illustrates an exemplary flow diagram of an alignment procedure for a Metrology Assembly in accordance with embodiments of the invention. For example, the alignment procedure for a Metrology Assembly  400  can be performed using pre-aligned test fixture and a non-aligned assembly. 
         [0075]    In  510 , a Metrology Assembly  400  can be coupled to a test chamber  410  using one or more attachment elements  25 , one or more attachment devices ( 26  and  27 ) and one or more alignment devices  28 . A first pre-aligned output wall  270  and a second pre-aligned input wall  370  in the Metrology Assembly  400  can be aligned with and coupled to a first alignment wall  425  and a second alignment wall  435  in the test chamber  410 . The first pre-aligned output wall  270  can have a first pre-aligned angle  272 , and the first alignment wall  425  can have a first alignment angle  427  that is substantially equal to the first pre-aligned angle  272 . The second pre-aligned input wall  370  can have a second pre-aligned angle  372 , and the second alignment wall  435  can have a second alignment angle  437  that is substantially equal to the second pre-aligned angle  372 . 
         [0076]    In  515 , an optical test source  80  can be coupled to the first pre-aligned input wall  223  in the source chamber  205  using one or more first coupling elements  81  and one or more alignment devices  82 . The first pre-aligned input wall  223  can include a first input optical element  210  having an illumination pinhole  222 . 
         [0077]    In  520 , a first measurement subsystem  85  can be coupled to the second pre-aligned output wall  323  in the receiver chamber  305  using one or more second coupling elements  86  and one or more alignment devices  87 . The second pre-aligned output wall  323  can include a second output optical element  310  having an output pinhole  322 . 
         [0078]    In  525 , a first incident beam  215  can be established using the source elements  200 . In some examples, a first aligned internal source beam  211  can be established in the source chamber  205 , and the optical test source  80  can provide a test signal having a first wavelength and a first polarization angle. For example, the optical test source  80 , the first pre-aligned input wall  223 , and the illumination pinhole  222  can be configured to operate using a first set of wavelengths that can vary from approximately 190 nm to approximately 1000 nm. Then, a second aligned internal source beam  212  can be established in the source chamber  205 . A first highly-efficient reflecting surface  241  can be movably mounted to a first adjusting structure  245  that is rigidly coupled a first chamber wall, and the first adjusting structure can be configured to position the first highly-efficient reflecting surface  241  at a first angle  242  to receive the first aligned internal source beam  211  and to establish the second aligned internal source beam  212 . Next, a third aligned internal source beam  213  can be established in the source chamber  205 . A second highly-efficient reflecting surface  251  can be movably mounted to a second adjusting structure  255  that is rigidly coupled a second chamber wall, and the second adjusting structure can be configured to position the second highly-efficient reflecting surface  251  at a second angle  252  to receive the second aligned internal source beam  212  and to establish the third aligned internal source beam  213 . Lastly, the third aligned internal source beam  213  is sent through a first output optical element  260  that can include a polarizer, and the first incident beam  215  can be established. 
         [0079]    In  530 , the first incident beam  215  can be directed to a test wafer  401  in a test chamber  410  and a first reflection beam  315  can be sent from the test wafer  401  in a test chamber  410 . The first incident beam  215  and the reflection beam  315  can be aligned using wavelengths between approximately 190 nm and approximately 900 nm, and polarization angles from zero degrees to three-hundred sixty degrees. 
         [0080]    In  535 , the first reflection beam  315  can be processed using one or more of the receiving elements  300 . A first aligned internal received beam  311  can be established in the receiver chamber  305 , and a second input optical element  360  can be configured to convert the reflection beam  315  into the first aligned internal received beam  311 . For example, the second input optical element  360  can comprise a polarizer. Next, a second aligned internal received beam  312  can be established in the receiver chamber  305 . A third highly-efficient reflecting surface  351  can be movably mounted to a first adjusting structure  355  that is rigidly coupled a first chamber wall, and the first adjusting structure can be configured to position the third highly-efficient reflecting surface  351  at a first angle  352  to receive the first aligned internal received beam  311  and to establish the second aligned internal received beam  312 . Then, a third aligned internal received beam  313  can be established in the receiver chamber  305 . A fourth highly-efficient reflecting surface  341  can be movably mounted to a second adjusting structure  345  that is rigidly coupled a second chamber wall, and the second adjusting structure can be configured to position the fourth highly-efficient reflecting surface  341  at a second angle  342  to receive the second aligned internal received beam  312  and to establish the third aligned internal received beam  313 . Lastly, a measurement beam  89  can be established using a second output optical element  310  that can include an output pinhole  322  that is configured to establish the measurement beam  89 . 
         [0081]    In  540 , measurement data can be obtained for the measurement beam  89  using the first measurement subsystem  85 . The measurement data can be used to determine the alignment error associated with the first incident beam  215  and the first reflection beam  315 . 
         [0082]    In  545 , a query can be performed to determine if the alignment error is less than a first alignment error limit. When the alignment error is less than a first alignment error limit, procedure  500  can branch to  550 . When the alignment error is not less than a first alignment error limit, procedure  500  can branch to  555 . 
         [0083]    In  550 , the Metrology Assembly  400  can be identified as a “Pre-Aligned Metrology Assembly”. 
         [0084]    In  555 , one or more corrective actions can be performed. 
         [0085]    Data can be sent from and/or received by the Pre-Aligned Metrology Assembly, and data can be passed to the Pre-Aligned Metrology Assembly in real-time as real-time variable parameters, overriding current recipe or model default values, improving the alignment time for the tool, and improving the measurement accuracy. The Pre-Aligned Metrology Assembly can be used with a library-based system, or regression-based system, or any combination thereof. 
         [0086]    Reliability, availability, throughput, and performance are the most important parameters for semiconductor equipments. Typically, most of the optical metrology systems for thin-film and CD measurement are performed using stand-alone equipment and off-line applications for process monitor. As the semiconductor roadmap goes to smaller and smaller nodes, the tightened tolerances provide additional challenges on semiconductor process control. Pre-Aligned Optical Metrology Systems that are designed using Pre-Aligned Metrology Assemblies and Pre-Aligned Optical Metrology Modules can be used to more accurately measure the smaller structures created on the wafer, and use the measured data either for optimize the process tools that the structures on the wafer has been made, or for adjust the process tool conditions that the wafer is going to be further processed. This is true especially for the incident angle  216  determination. In prior art, the angle  216  is determined with fitting the measurement data with all other system parameters. As the results of correlation between different parameters, the uncertainty of the data fitting process is large, and thus the whole system measurement uncertainty is large and it is very difficulty to meet the requirement of current and further applications. For this invention, the incident angle  216  is pre-determined when the module is aligned, and a test fixture can be used to measure the incident angle during alignment. In this way, the incident angle  216  is determined independent of other system parameters, and the uncertainty is very small, thus the whole system has much higher measurement accuracy. 
         [0087]    Pre-Aligned Metrology Assemblies and Pre-Aligned Optical Metrology Modules can be used to improve tool reliability, to reduce the time to repair, and to provide improved tool availability. Pre-Aligned Metrology Assemblies and Pre-Aligned Optical Metrology Modules can easily be integrated when new equipment is designed. Each one of the Pre-Aligned Metrology Assemblies and/or Pre-Aligned Optical Metrology Modules can be assembled, aligned, calibrated, and swapped each other with a minimum amount of system level adjustment. 
         [0088]    Those skilled in the art will recognize that one or more of the controllers ( 235 ,  335 , and  435 ) can include microprocessors and memory components (not shown) as required. For example, the memory components (not shown) can be used for storing information and instructions to be executed by microprocessors (not shown) and may be used for storing temporary variables or other intermediate information during the execution of instructions by the various computers/processors. One or more of the controllers ( 235 ,  335 , and  435 ) can include the means for reading data and/or instructions from a computer readable medium and can comprise the means for writing data and/or instructions to a computer readable medium. The controllers ( 235 ,  335 , and  435 ) can perform a portion of or all of the processing steps of the invention in response to the computers/processors executing one or more sequences of one or more instructions contained in a memory and/or received using a computer-readable medium. Such instructions may be received from another computer, a computer readable medium, or a network connection. For example, one or more of the controllers ( 235 ,  335 , and  435 ) can perform Advanced Process Control (APC) applications, Fault Detection and Classification (FDC) applications, Run-to-Run (R2R) applications, D-P procedures, D-E procedures, and/or library procedures. 
         [0089]    For example, the attachment elements and the alignment devices can be configured to allow the Pre-Aligned Metrology Modules and Subsystems to be quickly coupled to and/or decoupled from one or more test benches used for testing and/or aligning. 
         [0090]    Preventive maintenance procedures can be established for the Pre-Aligned Metrology Modules, and the preventive maintenance procedure can be based on the expected lifetime for one or more of the components. 
         [0091]    In some embodiments, the Pre-Aligned Metrology Assembly can include integrated Optical Digital Profilometry (iODP) elements (not shown), and iODP elements/systems are available from Timbre Technologies Inc. (a TEL company). Alternatively, other metrology systems may be used. 
         [0092]    The Pre-Aligned Metrology Assembly can use polarizing reflectometry, spectroscopic ellipsometry, spectroscopic reflectometry, or other optical measurement techniques to measure accurate device profiles, accurate CDs, and multiple layer film thickness of a wafer. The integrated metrology process (iODP) can be executed as an integrated process in an integrated group of subsystems. In addition, the integrated process eliminates the need to break the wafer for performing the analyses or waiting for long periods for data from external systems. iODP techniques can be used with the existing IMS for inline profile and critical dimension (CD) measurement, and can be integrated with TEL processing systems and/or lithography systems to provide real-time process monitoring and control. 
         [0093]    Data from the Pre-Aligned Metrology Assembly can include measured, predicted, and/or simulated data, and the data can be stored using processing, wafer, lot, recipe, site, or wafer location data. In some cases, one or more “golden” assemblies and/or modules can be used in verification procedures. 
         [0094]    Although only certain embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention. 
         [0095]    Thus, the description is not intended to limit the invention and the configuration, operation, and behavior of the present invention has been described with the understanding that modifications and variations of the embodiments are possible, given the level of detail present herein. Accordingly, the preceding detailed description is not mean or intended to, in any way, limit the invention - rather the scope of the invention is defined by the appended claims.