Mfr. of integrated circuits - applying temp. voltage test before conductive layer structuring to reduce costs

摘要

Intergrated circuits on the basis of monocrystalline silicon, e.g. consisting of MOSFET's, have to undergo a test at a raised temp. (125 deg.C, 14 V for 40 h) to sort out sound and defective units. Instead of at the end of the manufacturing cycle, it is suggested to carry out this test before the conductive layer is structural, using a conductive layer of doped polycrystalline silicon or metal. The result is a considerable cost reduction because the housings used for the scrapped units cannot be re-used.