AN AUTOMATED ON-CHIP DIRECT WIRING MODIFICATION FOR HIGH-PERFORMANCE LSIS

It has become more important to shorten development periods of high pe rformance computer systems and their LSIs. During debugging of compute r prototypes, logic designers request very frequent LSI refabrication to change logic circuits and to add some functions in spite of their e xtensive logic simulation by several GFLOPS supercomputers. To meet th ese demands, an automated on-chip direct wiring modification system ha s been developed, which enables wire-cut and via-digging by a precise focused ion beam machine, and via-filling and jumper-writing by a lase r CVD machine, directly on pre-redesign (original) chips. This modific ation system was applied to LSI reworks during the development of Hita chi large scale computers M-880 and S-3800, and contributed to shorten system debugging period by four to six months.