A laser imaging system is used to analyze defects on semiconductor wafers that have been detected by patterned wafer defect detecting systems (wafer scanners). The laser imaging system replaces optical microscope review stations now utilized in the semiconductor fab environment to examine detected optical anomalies that may represent wafer defects. In addition to analyzing defects, the laser imaging system can perform a variety of microscopic inspection functions including defect detection and metrology. The laser imaging system uses confocal laser scanning microscopy techniques, and operates under class 1 cleanroom conditions and without exposure of the wafers to operator contamination or airflow. Unlike scanning electron microscopes (SEMs) that have previously been used for defect analysis, the laser imaging system will not damage samples or slow processing, costs significantly less to implement than an SEM, can produce a three dimensional image which provides quantitative dimensional information, and allows sub-surface viewing of defects lying beneath dielectric layers. The laser imaging system is adaptable to cluster or in-situ applications, where examination of defects or structures during on-line processing can be performed.

Laser imaging system for inspection and analysis of sub-micron particles

A method is described for characterizing defects on a test surface of a semiconductor wafer using a confocal-microscope-based automatic defect characterization (ADC) system. The surface to be tested and a reference surface are scanned using a confocal microscope to obtain three-dimensional images of the test and reference surfaces. The test and reference images are converted into sets of geometric constructs, or “primitives,” that are used to approximate features of the images. Next, the sets of test and reference primitives are compared to determine whether the set of test primitives is different from the set of reference primitives. If such a difference exists, then the difference data is used to generate defect parameters, which are then compared to a knowledge base of defect reference data. Based on this comparison, the ADC system characterizes the defect and estimates a degree of confidence in the characterization.

Method for characterizing defects on semiconductor wafers

A mobile, hand-held fingerprint scanner is recharged by a data and power communication interface. The mobile, hand-held fingerprint scanner includes a rechargeable power supply and a data and power communication interface. The rechargeable power supply powers the fingerprint scanner during mobile use. In one example, the rechargeable power supply includes at least one rechargeable battery, a charging circuit, and a voltage regulator circuit. Data and recharging power is carried over the sane interface. A separate plug for power is not needed. The fingerprint scanner can then be inserted quickly and easily in a docking station as only a single data and power communication interface need be coupled. This is particularly advantageous in law enforcement applications where mobile use is important and safety can be compromised if a mobile scanner does not couple to a docking station quickly and easily.

Rechargeable mobile hand-held fingerprint scanner with a data and power communication interface

A method and system of obtaining a ten-print plain impression fingerprint includes scanning a print image, processing the scanned image, separating the processed image into individual fingerprint images, and determining how many print images have been scanned. The method also includes comparing the print image to a previously scanned print image, quality classifying the separated images, indicating a quality classification of the print image based on the classifying step, and determining whether the print image is of a good quality. The system can include a ten-print scanner having a finger guide and a platen used to position four finger slaps onto the platen.

Biometric imaging system and method

A portable fingerprint recognition transmitter that is compact, being less than the size of a cigarette pack, allowing the fingerprint recognition transmitter to be carried by an individual in a pocket or purse. The fingerprint recognition transmitter operates to take the image of the fingerprint and formulates a fingerprint image capable of transmitting through infrared or radio frequency to a receiver having previously stored fingerprint images so as to cause a comparison between the image taken and the image stored for purposes unlocking a security area.

Hand-held fingerprint recognition and transmission device

A wideband holographic information storage system records Fourier holograms on film in rapid succession, each hologram storing 128 bits of data. The hologram fringe pattern is held stationary by varying the reference beam frequency to track the variations of frequency of the signal beam that are caused by acoustic-optic modulation of the signal beam. Holograms are successively recorded in adjacent positions by scanning a light beam across a photosensitive film with a rotating polygonal mirror, the recording light beam being wide enough to cover two facets of the mirror so as to achieve nearly 100% scanning duty cycle. During readout, a readout light beam is steered to compensate for prismatic deflection effects caused by variations in thickness of the film. The direction of the output beam is maintained constant despite a scanning motion of the incident readout beam, by reflecting the output beam a second time from a different facet of the polygonal mirror to compensate the rotational component of beam motion. Clocking of output data is self-synchronized, based upon modulation signals. Acoustically caused defocusing of the light beam is optically corrected. Methods are employed to reduce crosstalk.

Anthony Vander Lugt

Papers

Optical information storage system