Abstract Coded indicia are placed on the surface of a piece of semiconductor material by etching discrete areas on the material. These indicia represent a numerical code which is physically represented by the etching or nonetching of predetermined ones of said discrete areas. The attenuation or enchancement of radiant flux transmitted or reflected by an etched area differs from that of the radiant flux transmitted or reflected by a nonetched area. Radiant energy is directed onto these indicia, and the transmitted or reflected radiant flux from the areas containing these indicia is measured to determine the change (i.e., attenuation or enhancement) of the radiant flux and to provide a numerical output indication corresponding to the indicia.
A system for identifying a piece of semiconductor material, comprising: a. a plurality of discrete areas on said piece, some of said areas being etched and some of said areas being nonetched to correspond to a numerical code; b. means for irradiating each of said areas to yield radiation in respectively different amounts from said etched areas and said nonetched areas; c. output means for receiving said yielded radiation and for generating electrical signals corresponding to said numerical code in response to said radiation; and d. wherein all of said discrete areas are located in a single circular band located near the periphery of the surface of said piece.
Claim 2
Independent Claim
109 words
A system for identifying a piece of semiconductor material, comprising: a. a plurality of discrete areas on said piece, some of said areas being etched and some of said areas being nonetched to correspond to a numerical code; b. means for irradiating each of said areas to yield radiation in respectively different amounts from said etched areas and said nonetched areas; c. output means for receiving said yielded radiation and for generating electrical signals corresponding to said numerical code in response to said radiation; and d. wherein all of said discrete areas are located in a single circular band located near the periphery of the surface of said piece.
Claim 3
Dependent Claim
26 words
A system according to claim 1 wherein each of the etched ones of said discrete areas is bounded by lines extending radially across said circular band.