Through Silicon Via (TSV) Defect Modeling, Measurement, and Analysis

Through silicon via (TSV)-based 3-D integrated circuit has introduced the solution to limitlessly growing demand on high system bandwidth, low power consumption, and small form factor of electronic devices. As the system design aims for higher performance, the physical dimensions of the channels are continuously decreasing. With TSV diameter of less than 10 μm and pitch of several tens of micrometers, the I/O count has increased up to the order of tens of thousands for wide bandwidth data transmission. However, without highly precise fabrication process, such small structures are susceptible to a variety of defects. For the first time, in this paper, we propose a noninvasive defect analysis method for high-speed TSV channel. With designed and fabricated test vehicles, the proposed method is demonstrated with S-parameter and time-domain reflectometry measurement results. In addition, we present equivalent circuit models of TSV daisy-chain structures, including the circuit components for open defect and short defect. With characterized dominant factors in each frequency range, S ₁₁ is analyzed to distinguish and locate the defects by the amount of capacitance, resistance, and inductance that the signal experiences. S-parameter measurement sufficiently allows high-frequency defect analysis of TSV channel without destroying the test sample. We experimentally verified the accuracy of the suggested model by comparing the S-parameter results from circuit simulations and measurements. Finally, the model is modified to discuss the effects of open defect and short defect on the electrical characteristics of TSV channel.