3D-IC Technology Characterization and Test Chip Design

With sub-micron silicon processing technology reaching under 30nm, it becomes more difficult for integrated circuits to achieve higher integration through the scaling down of the transistor size. Three-dimensional integrated circuit (3D-IC) technology stacks multiple dies together and connects them using through-silicon vias (TSVs). This is a low cost and highly efficient way to increase integration. TSVs and stacked dies are two major features of the 3D-IC technology. However, the stacked structures using TSV interconnects induce concerns in reliability such as TSV strain effect, heat problem, and TSV coupling at high frequency, etc. The reliability concerns need to be carefully addressed before 3D-IC technologies can be widely adopted by the industry. Many studies have been carried out in this field, but there has not been much significant work done for testing electrical, mechanical and thermal issues of the 3D-IC technology simultaneously on a single test chip. In this work, a test chip including various test structures was designed to study and analyze these issues in a 3D-IC technology. An accurate resistance and capacitance (RC) model of the TSV for low frequency design was developed, high frequency electrical performance of the TSVs was characterized, coupling between TSVs was modeled, and the stress effect and the heat dissipation method were analyzed in the 3D-IC technology. The TSV model could be added to the design kit for future 3D-IC design and other results could be used to improve the reliability of 3D-IC designs and optimize the performance