Latchup window tests

This report addresses the very important issue of latchup windows in integrated circuits. This is a serious problem and requires careful consideration in each individual case of system design. Latchup may cause system failure through burnout of the device or through an upset of the circuit in which latchup occurs. The existence of a latchup window was first reported by researchers performing latchup testing of MOS integrated circuits (Refs. 1,2). It was found that latchup would occur in some devices for only a small range of dose rates. At dose rates below a critical value, the device would not experience latchup. A second higher dose rate range was found where latchup would again not occur. These tests were performed using high-energy electrons (Linac) and were performed on CMOS, CD4000 series devices.