On-Chip Electrical Monitor for Critical Mask Alignment
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
An electrical monitor, consisting of a metal line which overlays portions of an isolation groove, is used to detect misalignment of critical masks. The monitor provides a means to screen product at final test for potential reliability problems related to sensitive device structures. The application of the monitor, as described in this article, is for testing metal line integrity over a trench isolation structure. As shown in Fig. 1, the monitor consists of a minimum width metal line passing over a polyimide-filled isolation groove in both the X and Y directions. The monitor may be repeated many times on a given integrated circuit IC chip. Both ends of the metal lines are brought out to external terminals and tested at final test.