FABRICATING ELETRONIC CIRCUITRY UNIT CONTAINING STACKED IC LAYERS HAVING LEAD REROUTING

• Main Authors: GO, TIANG C, MINIHAN, JOSEPH, A, SHANKEN, STUART, N
• Format: Patent
• Language: English
• Published: 10.02.1993
• Edition: 5
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A process and product are disclosed which apply advanced concepts of Z-technology to the field of dense electronic packages. Starting with standard chip-containing silicon wafers (fig. 1, 20), modification procedures are followed which create IC chips (fig. 4, 38) having rerouted gold leads (fig. 4, 30) on top of passivation (fig. 6, 52) (which covers the original silicon (fig. 6, 48) and its aluminum or other metallization (fig. 6, 44)). The modified chips (fig. 4, 38) are cut from the wafers (fig. 1, 20), and then stacked to form multi-layer IC devices (fig. 10b, 60). A stack has one or more access planes (fig. 10c, 64). After stacking, and before applying gold metallization on the access plane, a selective etching step removes any aluminum (or other material) which might interfere with the gold metallization formed on the access planes (figs. 11 and 12). Gold terminal pads (fig. 15, 92) are formed in contact with the terminals of the gold rerouting leads (fig. 15, 66) on the stacked chips, thereby forming gold-to-gold T-connections (fig. 14) for maximum conducting efficiency.