Fail Bit Analysis System For Semiconductor Memory Wafers

Abstract

The fail bit data analysis system was developed to shorten the defect analysis time for semiconductor memory products. The system has the following features: (])Feature elicidation by display of wafer scale and detailed analysis by expansion function. (2)Display of fail bit distribution based on design data and transfer of coodinate data to SEM. (3)Data storage by data compression. 1 .Problem Areas in Fail Bit Analysis The analysis of fail bit distribution in semiconductor memory is effective in specifying structural defects in memory-mats and their surrounding circuits. For example,when the fail bits are in a line in the memory -mat as shown in Fig.], a problem in the data read circuit in the horizontal direction is clear.However,the following problems exist in actually implementing fail bit analysis. memory chip