Fortune: A New Fault-Tolerance TSV Configuration in Router-Based Redundancy Structure

In three-dimensional integrated circuits (3D-ICs), through silicon via (TSV) is a critical technique in providing vertical connections. However, yield is one of the key obstacles to adopt the TSV-based 3D-ICs technology in the industry. Various fault-tolerance structures using redundant TSVs to repair faulty functional TSVs have been proposed in the literature for yield and reliability enhancement. However, the TSV repair paths under delay constraint cannot always be generated due to the lack of appropriate repair algorithms. In this article, we propose an effective TSV repair strategy for the router-based TSV redundancy architecture, taking into account the delay overhead. First, we prove that the router-based fault-tolerance structure configuration (RFSC) with the delay constraint is equivalent to the length-bounded multicommodity flow (LBMCF) problem. Then, an integer linear programming (ILP) formulation with acceptable scalability is presented to solve the LBMCF problem. The experimental results demonstrate that, compared with state-of-the-art fault-tolerance designs, the proposed ILP model can provide higher yield and lower delay overhead.

I. Introduction

As device feature sizes continue to rapidly decrease, the interconnecting delay is becoming a bottleneck limiting IC performance. The three-dimensional integrated circuits (3D-ICs) technology involving vertically stacking multiple dies connected by through silicon vias (TSVs) provides a promising way to alleviate the interconnecting problem and achieves a significant reduction in chip area, wire length, and interconnect power [1]. Study indicates that the average wire length of a 3D-IC varies according to the square root of the number of layers. Moreover, 3D-ICs have the potential for heterogeneous integration, which is essential for the More than Moore (MtM) technology. 3D integration has already seen several commercial applications in the form of 3D memory but there are still existing significant open problems in both academia and industry [2]. In this work, we will focus on the TSV reliability problem.