Method and apparatus for semiconductor integrated circuit testing and burn-in

Abstract

A burn-in process is provided for a memory array having redundant bits and addressable storage locations. The burn-in process includes the steps of raising the temperature of the memory array to a pre-determined temperature, testing all bits in the array, detecting faulty bits and operable bits, replacing faulty bits with redundant operable bits, correcting any defects in the array in-situ, and lowering the temperature of the memory array to ambient temperature to complete the burn-in process. An apparatus for carrying out the above process is provided that includes a test circuit for generating a test pattern and for applying the test pattern to the memory array so as to test all bits within the memory array. A comparison circuit, coupled to the test circuit and adapted to couple to the memory array, compares an actual response and an expected response of the memory array to the test pattern and detects faulty and operable bits based thereon. A failed address buffer register, coupled to the comparison circuit and to the test circuit, stores an address of each addressable storage location that has a faulty bit. Sparing control logic, coupled to the failed address buffer register and adapted to couple to the memory array, reads out each address stored by the failed address buffer register and replaces each faulty bit with a redundant operable bit.