Laser scanning of MOS IC's reveals internal logic states nondestructively
A laser scanning system has been used to observe the internal logic pattern in a MOS LSI device in a nondestructive manner. The laser scanner has also been used to selectively change logic states deep within the device. Pictures of the logic patterns revealed by the scanner are discussed.
A Flying‐Spot Scanner
A flying‐spot scanner used to study the electrical properties of semiconductor materials and devices is described. The instrument automatically deflects a collimated light beam in a raster pattern and focuses the raster on the photosensitive semiconductor surface. The electrical output from the semiconductor is amplified and used to form an image of the photoresponse of the sample on a cathode ray tube. The resolution of the system referred to the sample is about 5 μ.
Observation of surface phenomena on semiconductor devices by a light spot scanning method
Abstract A description of an experimental technique developed for the study of electronic processes on semiconductor device surfaces is given, in connection with its application to Si planar transistors. In this method the whole surface of a diode or a transistor is scanned by a light beam of 10 μ dia. synchronized to which travels the electron beam of a cathode-ray oscilloscope. The signal controlling the vertical deflection of the scope is composed of a raster and a photoresponse signal induced by the illuminating spot. The resulting pattern on the screen is a map-like display of the photoresponse, consisting of 40 complete images per second in our arrangement. This photo-response map is suitable to observe the changes in the surface electronic state due to gas ambient and/or bias conditions. Moreover, the local inhomogeneities on the surface and the spatial and time changes of slow processes such as creep or channel formation can be studied. A short discussion of the apparatus and the performance is given, and as an application, photographs represnting Si n-p-n planar transistor surface properties are presented.