Abstract:
Systems and methods for determining one or more characteristics of a specimen using radiation in the terahertz range are provided. One system includes an illumination subsystem configured to illuminate the specimen with radiation. The system also includes a detection subsystem configured to detect radiation propagating from the specimen in response to illumination of the specimen and to generate output responsive to the detected radiation. The detected radiation includes radiation in the terahertz range. In addition, the system includes a processor configured to determine the one or more characteristics of the specimen using the output.
Abstract:
Reticles may comprise shading elements (SEs) for locally altering the reticle optical properties. However, such reticles may degrade over time as a result of repeated exposure to radiation in a lithography process, as the radiation may "heal" the SEs. Disclosed are techniques for monitoring a reticle in order to maintain confidence about the reticle's optical properties and the uniformity of patterns on wafers that are to be printed using the reticle. Reticles undergo periodic inspection comprising reticle transmission measurement and/or aerial imaging of the reticle. When such inspection indicates sufficient reticle degradation, the reticle is tagged for correction prior to its subsequent use in a lithography process.
Abstract:
An apparatus for illuminating a target surface, the apparatus having a plurality of LED arrays, where each of the arrays has a plurality of individually addressable LEDs, and where at least one of the arrays is disposed at an angle of between about forty-five degrees and about ninety degrees relative to the target surface, where all of the arrays supply light into a light pipe, the light pipe having interior walls made of a reflective material, where light exiting the light pipe illuminates the target surface, and a controller for adjusting an intensity of the individually addressable light sources.
Abstract:
Reticles may comprise shading elements (SEs) for locally altering the reticle optical properties. However, such reticles may degrade over time as a result of repeated exposure to radiation in a lithography process, as the radiation may "heal" the SEs. Disclosed are techniques for monitoring a reticle in order to maintain confidence about the reticle's optical properties and the uniformity of patterns on wafers that are to be printed using the reticle. Reticles undergo periodic inspection comprising reticle transmission measurement and/or aerial imaging of the reticle. When such inspection indicates sufficient reticle degradation, the reticle is tagged for correction prior to its subsequent use in a lithography process.
Abstract:
One embodiment relates to an apparatus, including a CRT-type gun (for example, 102, or 302, or 510, or 1002, or 1113) and deflectors to generate and scan the electron beam, which utilizes the electron beam for inspection or metrology of a substrate. The apparatus may comprise a portable scanning electron microscope. Another embodiment relates to a method of inspecting a substrate or measuring an aspect of the substrate, where an electron beam is focused using electrostatic lenses formed by metal plates (704) supported by and separated by fused glass beads (706) or other insulating material. Another embodiment relates to a method of obtaining an electron beam image of a surface of a bulk specimen where a portable SEM device is moved to the bulk specimen. Other embodiments and features are also disclosed.
Abstract:
Disclosed are techniques for determining and correcting reticle variations using a reticle global variation map generated by comparing a set of measured reticle parameters to a set of reference reticle parameters. The measured reticle parameters are obtained by reticle inspection, and the variation map identifies reticle regions and associated levels of correction. In one embodiment, the variation data is communicated to a system which modifies the reticle by embedding scattering centers within the reticle at identified reticle regions, thereby improving the variations. In another embodiment the variation data is transferred to a wafer stepper or scanner which in turn modifies the conditions under which the reticle is used to manufacture wafers, thereby compensating for the variations and producing wafers that are according to design.
Abstract:
An apparatus for illuminating a target surface, the apparatus having a plurality of LED arrays, where each of the arrays has a plurality of individually addressable LEDs, and where at least one of the arrays is disposed at an angle of between about forty-five degrees and about ninety degrees relative to the target surface, where all of the arrays supply light into a light pipe, the light pipe having interior walls made of a reflective material, where light exiting the light pipe illuminates the target surface, and a controller for adjusting an intensity of the individually addressable light sources.
Abstract:
To increase inspection throughput, the field of view of an infrared camera can be moved over the sample at a constant velocity. Throughout this moving, a modulation can be provided to the sample and infrared images can be captured using the infrared camera. Moving the field of view, providing the modulation, and capturing the infrared images can be synchronized. The infrared images can be filtered to generate the time delay lock-in thermography, thereby providing defect identification. This filtering can account for the number of pixels of the infrared camera in a scanning direction. For the case of optical modulation, a dark field region can be provided for the field of view throughout the moving, thereby providing an improved signal-to-noise ratio during filtering. Localized defects can be repaired by a laser integrated into the detection system or marked by ink for later repair in the production line.
Abstract:
Various test structures and methods for monitoring or controlling a semiconductor fabrication process are provided. One test structure formed on a wafer as a monitor for a lithography process includes a bright field target (30) that includes first grating structures (32) . The test structure also includes a dark field target (34) that includes second grating structures (36) . The first and second grating structures have one or more characteristics that are substantially the same as one or more characteristics of device structures formed on the wafer. In addition, the test structure includes a phase shift target (38) having characteristics that are substantially the same as the characteristics of the bright field or dark field target except that grating structures (40) of the phase shift target are shifted in optical phase from the first or second grating structures. One or more characteristics of the targets can be measured and used to determine parameter (s) of the lithography process .
Abstract:
Disclosed are systems and methods for modifying a reticle. In general, inspection results from a plurality of wafers or prediction results from a lithographic model are used to individually decrease the dose or any other optical property at specific locations of the reticle. In one embodiment, any suitable optical property of the reticle is modified by an optical beam, such as a femto-second laser, at specific locations on the reticle so as to widen the process window for such optical property. Examples of optical properties include dose, phase, illumination angle, and birefringence. Techniques for adjusting optical properties at specific locations on a reticle using an optical beam may be practiced for other purposes besides widening the process window.