Thermo-mechanical Analysis of an Improved Thermal through Silicon via (ttsv) Struc- Ture

Temperature and thermal stress responses of an improved TTSV structure under the impact of hotspots are numerically analyzed in this paper. A Fin structure is added to the circular TTSV to strengthen the effect of thermo-mechanical mitigation. The nonlinear finite element method (N-FEM) is presented to obtain the coupled thermal and mechanical fields. Running time of the N-FEM algorithm is compared with that of commercial software to indicate its efficiency. The model of state-of-the-art 3D Dynamic Random Access Memory (DRAM) is adopted in our simulation. Besides the single-layer TTSV and TTSV array, the extended case of multi-layer TTSVs is also investigated. To take into consideration the nonlinear effects, the temperature dependent results for the issues of hotspot alignment and liner materials selection are provided, both of which are compared with the corresponding temperature independent results. This paper is aimed to provide some practical guidance to the design of TTSV for effective thermo-mechanical management.