A novel bitmap analysis technique - test sensitivity intensity bitmap

Bitmapping is a common tool used for analysis and device characterisation on volatile and non-volatile memory in integrated circuits. The tester normally provides the electrical failing address and the analyst will use a scramble table to convert the electrical failing address to the physical failing address. A software may be used to descramble the electrical failing addresses and then display the physical location of the failure using simple graphics. In this paper, a novel bitmap technique is presented. Instead of just displaying the X,Y physical location of the failure, which is basically two dimensions, this bitmap technique takes it a step further. The new bitmap technique 'test sensitivity intensity (TSI) bitmap' is a graphical combination of all the listed tools. The idea of using a graphical bitmap was to make it easier to visualise the failure and the pattern of the failure as test conditions change from relaxed conditions to very stringent conditions, compared to a simple data dump memory display.