Hardness Assurance Latchup Test Procedure.

This test procedure defines the detailed requirements for gamma dose rate testing of semiconductor integrated circuits to determine if they are susceptible to radiation-induced latchup. This test is not deleterious, and devices which have been subjected to and passed the test may be used as production hardware. There are two types of radiation-induced latchup 1 a hard latchup, and 2 an incipient latchup. A hard latchup is a sustained functional failure. The erroneous operational condition can be stopped by cycling bias power if burnout has not occurred in the interim. Incipient latchup is characterized by a functional failure which is not sustained, but which lasts longer than can be explained by normal circuit time constants. Identification of a latchup-susceptible IC is accomplished by identifying erroneous operating states immediately after radiation exposure by exercising the device with a functional test.