Abstract: Methods for the determination of center of focus and process control for a lithographic tool. Diffraction signatures are obtained from a plurality of diffraction structures located within multiple different focus setting fields. Variability of diffraction signatures with each field are determined, by direct analysis or comparison to a library. The variation or uniformity may be represented by any measure, including the standard deviation or the range of values of a chosen feature of a library of theoretical diffraction structures or the variability or uniformity of the diffraction signatures themselves, such as by RMS difference or intensity range. The methods may be used for process control and monitoring of focus drift by determining intra-field variation of diffraction signatures of multiple diffraction structures in a series of wafers.

Abstract: Methods for determination of parameters in lithographic devices and applications by cross-section analysis of scatterometry models, including determination of center of focus in lithography devices and applications. Control methods are provided for process control of center of focus in lithography devices utilizing cross-section analysis.

Abstract: A method of and apparatus for measuring line profile asymmetries in microelectronic devices comprising directing light at an array of microelectronic features of a microelectronic device, detecting light scattered back from the array comprising either or both of one or more angles of reflection and one or more wavelengths, and comparing one or more characteristics of the back-scattered light by examining data from complementary angles of reflection or performing a model comparison.

Abstract: Methods for the determination of center of focus and process control for a lithographic tool. Diffraction signatures are obtained from a plurality of diffraction structures located within multiple different focus setting fields. Variability of diffraction signatures with each field are determined, by direct analysis or comparison to a library. The variation or uniformity may be represented by any measure, including the standard deviation or the range of values of a chosen feature of a library of theoretical diffraction structures or the variability or uniformity of the diffraction signatures themselves, such as by RMS difference or intensity range. The methods may be used for process control and monitoring of focus drift by determining intra-field variation of diffraction signatures of multiple diffraction structures in a series of wafers.

Abstract: Methods for determination of parameters in lithographic devices and applications by cross-section analysis of scatterometry models, including determination of center of focus in lithography devices and applications. Control methods are provided for process control of center of focus in lithography devices utilizing cross-section analysis.

Abstract: A method of pruning a reference library of signatures and corresponding known structure parameter vectors, each signature composed of a reference signal vector, including, for a given reference signal vector, interpolating a parameter vector and deleting the given reference signal vector and the corresponding parameter vector for a sufficiently small interpolation error. Also a method of accessing an indexed reference library of signatures and corresponding known structure parameter vectors, each signature comprising a reference signal vector, including acquiring an unknown signal, calculating an index vector for the unknown signal; determining error between the index vector for the unknown signal and a calculated reference signal index vector of the library; and thereby identifying as a match candidate for the unknown signal a reference signal vector.

Abstract: Methods for metrology of undercut multi-layer diffracting structures, utilizing diffraction signature analysis obtained by means of a radiation-based tool, wherein simulated diffraction signals are generated based on models of undercut multi-layer structures. In one method, comparison to a library is employed. In another method, regression analysis is employed. The undercut parameters, including critical dimension and materials factors, can be altered in the models.

Abstract: Methods for determination of parameters in lithographic devices and applications by diffraction signature difference analysis, including determination of center of focus in lithography devices and applications. Latent image analysis may be employed with exposed but undeveloped lithographic substrates. Control methods are provided for process control of center of focus in lithography devices utilizing diffraction signature difference analysis.

Abstract: Methods for determination of parameters in lithographic devices and applications by diffraction signature difference analysis, including determination of center of focus in lithography devices and applications. Latent image analysis may be employed with exposed but undeveloped lithographic substrates. Control methods are provided for process control of center of focus in lithography devices utilizing diffraction signature difference analysis.

Abstract: A method of and apparatus for measuring line profile asymmetries in microelectronic devices comprising directing light at an array of microelectronic features of a microelectronic device, detecting light scattered back from the array comprising either or both of one or more angles of reflection and one or more wavelengths, and comparing one or more characteristics of the back-scattered light by examining data from complementary angles of reflection or performing a model comparison.

Abstract: The present invention provides methods for determination of parameters in lithographic devices and applications by diffraction signature difference analysis, including determination of center of focus in lithography devices and applications.

Abstract: A method of pruning a reference library of signatures and corresponding known structure parameter vectors, each signature comprising a reference signal vector, comprising: for a given reference signal vector, interpolating a parameter vector assuming that the given reference signal vector and its corresponding parameter vector were deleted from the reference library; and deleting the given reference signal vector and the corresponding parameter vector if an interpolation error between the corresponding parameter vector and the interpolated parameter vector is less than a threshold value.

Abstract: The present invention provides methods for determination of parameters in lithographic devices and applications by diffraction signature difference analysis, including determination of center of focus in lithography devices and applications, such as for photoresist lithographic wafer processing.

Abstract: Manual actuation of a stop/eject button on a computer causes a signal to be sent to both the computer's operating system and to a wireless communication controller. The operating system interprets this signal in a manner analogous to a conventional signal to open the drawer, or door, of a compact disk drive device when a compact disk is not currently present in the drive device. If a compact disk is present in the device, the operating system ignores the signal. In this case, the communications controller operates in a normal fashion to interrupt access to the compact disk, instruct the operating system to unmount the disk, and thereafter eject the disk by opening the drive door.