摘要:
Optimization of optical parametric models for structural analysis using optical critical dimension metrology is described. A method includes determining a first optical model fit for a parameter of a structure. The first optical model fit is based on a domain of quantities for a first model of the structure. A first near optical field response is determined for a first quantity of the domain of quantities and a second near optical field response is determined for a second, different quantity of the domain of quantities. The first and second near optical field responses are compared to locate a common region of high optical field intensity for the parameter of the structure. The first model of the structure is modified to provide a second, different model of the structure. A second, different optical model fit is determined for the parameter of the structure based on the second model of the structure.
摘要:
A system and method for managing entitlements in a multi-tenant database system. In one embodiment, a method includes receiving service level definitions for one or more entitlements, and maintaining the one or more entitlements. The method further includes verifying if one or more users are eligible for the one or more entitlements, and enforcing the one or more entitlements based on the service level definitions.
摘要:
A method and inspection system to inspect a first pattern on a specimen for defects against a second pattern that is intended to be the same where the second pattern has known responses to at least one probe. The inspection is performed by applying at least one probe to a point of the first pattern on the specimen to generate at least two responses from the specimen. Then the first and second responses are detected from the first pattern, and each of those responses is then compared with the corresponding response from the same point of the second pattern to develop first and second response difference signals. Those first and second response difference signals are then processed together to unilaterally determine a first pattern defect list.
摘要:
A semiconductor wafer inspection system and method is provided which uses a multiple element arrangement, such as an offset fly lens array. The preferred embodiment uses a laser to transmit light energy toward a beam expander, which expands the light energy to create an illumination field. An offset fly lens array converts light energy from the illumination field into an offset pattern of illumination spots. A lensing arrangement, including a first lens, a transmitter/reflector, an objective, and a Mag tube imparts light energy onto the specimen and passes the light energy toward a pinhole mask. The pinhole mask is mechanically aligned with the offset fly lens array. Light energy passing through each pinhole in the pinhole mask is directed toward a relay lens, which guides light energy onto a sensor. The offset fly lens array corresponds to the pinhole mask. The offset pattern of the offset fly lens array is chosen such that spots produced can be recombined into a continuous image, and the system utilizes a time delay and integration charge coupled device for rapid sensing along with an autofocus system that measures and cancels topological features of the specimen.
摘要:
A variable modulated transfer function (MTF) design employing a variable gate voltage source for use in inspecting specimens is disclosed. The design applies a variable gate voltage to each pixel of a sensor, wherein applying the variable gate voltage to each pixel adjusts the MTF of the pixel. MTF adjustment improves adverse effects encountered during inspection, such as aliasing and maintaining contrast.
摘要:
Disclosed is a method for detecting electrical defects on test structures of a semiconductor die. The test structures includes a plurality of electrically-isolated test structures and a plurality of non-electrically-isolated test structures. The test structures each has a portion located partially within a scan area. The portion of the test structures located within the scan area is scanned to obtain voltage contrast images of the test structures' portions. In a multi-pixel processor, the obtained voltage contrast images are analyzed to determine whether there are defects present within the test structures. In a preferred embodiment, the multi-pixel processor operates with pixel resolution sizes in a range of about 25 nm to 200 nm. In another aspect, the processor operates with a pixel size nominally equivalent to two times a width of the test structure's line width to maximize throughput at optimal signal to noise sensitivity. A computer readable medium having programming instructions for performing the above described methods is also disclosed.
摘要:
Disclosed is a method of inspecting a sample. The sample is illuminated with an incident beam, thereby causing voltage contrast within structures present on the sample. Voltage contrast is detected within the structures. Information from the detected voltage contrast is stored, and position data concerning the location of features corresponding to at least a portion of the stored voltage contrast information is also stored. In a specific embodiment, the features represent electrical defects present on the sample. In another embodiment, the stored position data is in the form of a two dimensional map. In another aspect, the sample is re-inspected and the stored position data is used in analyzing data resulting from the re-inspection.
摘要:
Disclosed is a method of inspecting a sample. At least a portion of the sample is illuminated. Signals received from the illuminated portion are detected, and the detected signals are processed to find defects present on the sample. The processing of the detected signals is optimized, at least in part, based upon results obtained from voltage contrast testing. In one implementation, the illumination is an optical illumination. In another embodiment, the processing comprises automated defect classification, and setup of the automated classification is optimized using the results obtained from voltage contrast testing. In another implementation, the results relate to a probability that a feature present on the sample represents an electrical defect.
摘要:
Disclosed is a method and apparatus for using far field scattered and diffracted light to determine whether a collection of topological features on a surface (e.g., a semiconductor wafer) conforms to an expected condition or quality. This determination is made by comparing the far field diffraction pattern of a surface under consideration with a corresponding diffraction pattern (a "baseline"). If the baseline diffraction pattern and far field diffraction pattern varies by more than a prescribed amount or in characteristic ways, it is inferred that the surface features are defective. The method may be implemented as a die-to-die comparison of far field diffraction patterns of two dies on a semiconductor wafer. The portion of the far field scattered and diffracted light sensitive to a relevant condition or quality can also be reimaged to obtain an improved signal-to-noise ratio.