Patent ID: 6747228
Filing Date: 2004-06-08
Classification: G11C

Abstract:
A method of qualifying and sorting semiconductor devices, comprising:grouping a plurality of semiconductor devices into a test lot; selecting a plurality of device grades and a downgrade path for each selected device grade; selecting a test sequence including a plurality of tests, each test corresponding to at least one device grade of the plurality of device grades; defining an initial selected device grade as a current device grade of the plurality of device grades for the test lot; sorting each semiconductor device in the test lot to a final device grade of the plurality of device grades, the sorting comprising: executing at least one test of the test sequence corresponding to the current device grade of each of the plurality of semiconductor devices; and after each test executed, sequentially sorting each semiconductor device through the plurality of selected device grades along a selected downgrade path and assigning another device grade as the current device grade and reexecuting at least another test until the current device grade is the final device grade or the semiconductor device fails each of the plurality of device grades; and separating the plurality of semiconductor devices from the test lot according to the final device grade of each semiconductor device.