An enhanced fault model for high defect coverage

Abstract

SUMMARYIn this paper, we propose an enhanced fault model to increase coverage in detecting physical faults in LSI. First, as an alternative to the single stuck-at fault model, we propose the single gate logical fault with Hamming distance 1 (SGLFH1) model, which is capable of generating test pattern sets that detect more defects from the same number of faults. The characteristics of this fault model are discussed and the effectiveness of the test pattern sets generated by it is described. Next we show that the multiple detection test pattern set for single stuck-at faults that is conventionally used to enhance defect coverage does not detect SGLFH1 faults satisfactorily. In addition, the effectiveness of the proposed model is shown by comparing the fault detection ratio of the SGLFH1 test pattern set for physical surrogate faults [1,2] with the corresponding fault detection ratio of the multiple detection test pattern set for single stuck-at faults. © 2001 Scripta Technica, Syst Comp Jpn, 32(6): 3644, 2001