A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. In one embodiment of the invention, the incident beam is directed onto the surface to be inspected at an angle slightly offset from perpendicular so that the reflected beam is physically separated from the incident beam. The reflected beam is routed to a detector which converts the intensity of the reflected into an analog signal. The analog signal is sampled and digitized to generate pixel data stored in a buffer. Various analyses are performed on the data including calculating a rate of change in the pixel data. If the rate of change in the pixel data exceeds a selected threshold that indicates a possible defect if it occurs in the data area of the disk.
RELATED APPLICATIONS
Commonly assigned, related applications with Ser. Nos. 08/841,037; 08/840,339; 08/840,351; 08/840,352; 08/840,354; 840,355 and 08/840,358 were filed concurrently with this application.
The present invention makes it possible to easily and additionally write positional information of the defective pixel which is difficult to deal with using an automated writing mode, and that, without using any special writing jig in the case where a new defective pixel is occurred in a solid state image element. Concretely, a solid state image device in which solid state image means of N lines in the vertical direction and M pixels in the horizontal direction is arranged in a matrix comprises display means for displaying a position of a defective pixel occurred at a solid state image means, position selection means manually operated so as to select the position of the defective pixel on the screen of this display means and memory means for memorizing positional information D1 of the defective pixel selected by this position selection means. Therefore, if a new defective pixel is occurred in a solid state image means 11 after shipping the product, positional information which is difficult to deal with using the automated writing mode can be easily and additionally written, for example, in the service section without using any special writing jig.
The present invention is related to a detection system for inspecting a continuous stream of products comprising means for determining the detection system induced variations in its output signal. The detection system comprises a reference element and an intermediate optical element, means for scanning a light beam over the product stream and, via the intermediate optical element, over the reference element and means for converting the light beams re-emitted by the product stream and by the reference element into an electrical signal. The intermediate optical element is positioned such that the light beam successively scans the product stream and at least one region of the reference element, in whatever order. Such detection system and method are of particular use in an apparatus for sorting products, where it is used to inspect products provided to the detection system in a continuous stream.
An optical surface analysis system for scanning the surface of a (silicon) wafer and detect if any residual material is still on the wafer surface in order to determine an appropriate end-point in a polishing process. An Optical Surface Analyzer (OSA), of the present invention, is generally used to identify composition, measure surface area, and measure thickness variations of thin film layers of material. The difference in optical properties (index of refraction) of different materials on the surface allows the system of the present invention to separate different materials on the wafer surface using the histogram plots generated by the OSA. This method is used to detect and make a quantitative assessment regarding the amount of residual material to be removed by the polishing process and, therefore, when an appropriate end-point has been reached in the polishing process.
A system to detect pits in a surface comprises first and second radiation targeting assemblies to target a second radiation beam onto a surface, a first radiation collecting assembly that collects radiation scattered from the surface, a processor coupled to the first radiation collecting assembly, a memory module coupled to the processor and comprising logic instructions which, when executed by the processor, configure the processor to generate a first signal from radiation scattered from the first radiation beam, generate a second signal from radiation scattered from the second radiation beam, record the first signal and the second signal at an array of different positions on the surface, calculate a median value for the first signal and the second signal over the array of different positions on the surface, and use the first signal, the second signal, and the median value to detect pits in the surface.
In one embodiment a system to detect multi-domain regions in the soft under layer of a perpendicular magnetic media comprises a radiation targeting assembly to target a polarized radiation beam onto a surface of a substrate covered by the soft under layer of a perpendicular magnetic media, a radiation collecting assembly that collects radiation reflected from the surface, a processor coupled to the first radiation collecting assembly, and a memory module coupled to the processor. The memory module comprises logic instructions which, when executed by the processor, configure the processor to record signal values from radiation reflected by the radiation beam at different positions on the surface and analyze the signal values to detect a region of multiple magnetic domains in the soft under layer of a perpendicular magnetic media.