Yield Enhancement of Face-to-Face Cu-Cu Bonding With Dual-Mode Transceivers in 3DICs

When more than one dies are stacked vertically in 3-D integrated circuits (3DICs), the overall system yield degrades significantly. While each die can be tested before stacking, failures in 3DIC interconnects could jeopardize the entire system. In this paper, a dual-mode transceiver is proposed as a built-in-self-test/repair solution to improve the yield of direct face-to-face copper thermocompression bonding (Cu-Cu bonding). The proposed transceiver could improve the Cu-Cu bonding-based interconnect reliability with the introduction of two operation modes: the ohmic mode when Cu-Cu bonding presents low resistance and the capacitive coupling mode when Cu-Cu bonding is showing any sign of failure with high resistance at the bonding interface. Such mode sensing is self-contained in the transceiver itself with the help of the proposed resistance sensor. In this paper, we discuss the modeling of Cu-Cu bonding and the proposed transceiver design with power, latency, jitter, and crosstalk simulations followed by the design guideline for the practical implementation with yield analysis.