Method and apparatus for personalization of semiconductor

Abstract

A system for making small modifications to the pattern in standard processed semiconductor devices. The modifications are made to create a small variable part of the pattern against a large constant part of the same pattern. In a preferred embodiment the exposure of the variable and constant parts are done with the same wavelength in the same combined stepper and code-writer. The invention devices a way of writing variable parts of the chip that is automatic, inexpensive and risk-free. A system for automatic design and production of die-unique patterns is also shown.

1 - 18 . (canceled)  
   
   
       19 . A control system for controlling a stepper to personalize at least one die on a wafer characterized by 
 a stepper control system initiating the exposure of the exposure field containing the die,    a codewriter control system compiling information about the programming for a particular die,    and a code rasterizing unit for creating a hardware format to be fed to an spatial light modulator (SLM) for a particular die.    
   
   
       20 . A design block for a chip with a chip-unique information, such as a serial number or hidden cryptographic key, characterized in that it comprises 
 a layout block describing the layout of the constant part of the block,    a control block specifying the type of code to be written and the placement of the code,    and a data block, where the contents of the block is described, e.g., by a reference to a database or to a sequence of instruction.    
   
   
       21 . A method for personalization of a die on a wafer comprising 
 exposing to the die a constant part of a pattern, said constant part being used for exposing at least one other die,    and exposing to the same die a variable part of a pattern,    said variable part differing from the corresponding variable part of another die on the wafer, and preferably being a die-unique information, such as a serial number or hidden cryptographic key.    
   
   
       22 . The method according to  claim 21 , wherein said constant and said variable part of said pattern are exposed by different wavelengths.  
   
   
       23 . The method according to  claim 21 , wherein said constant and said variable part of said pattern are exposed by the same wavelengths.  
   
   
       24 . The method according to  claim 21 , wherein said variable part of said pattern is exposed by a computer controlled reticle.  
   
   
       25 . The method according to  claim 24 , wherein said computer controlled reticle is a Spatial Light Modulator (SLM).  
   
   
       26 . The method according to  claim 21 , wherein said constant and said variable part of said pattern are exposed at least partly simultaneously.  
   
   
       27 . The method according to  claim 21 , wherein said constant and said variable part of said pattern are sequentially exposed after each other.  
   
   
       28 . A method for fast correction of position errors in a pattern generator using an analog spatial light modulator (SLM) comprising the steps of 
 measuring the stage position error compared to the correct position,    convolving the bitmap loaded into the SLM by a convolution kernel, whereby said kernel is selected or modified in dependence of the measured position error in order to correct said position error.