Ultralow-Capacitance Through-Silicon Vias With Annular Air-Gap Insulation Layers
Ultralow-Capacitance Through-Silicon Vias With Annular Air-Gap Insulation Layers
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具有环形气隙绝缘层的超低电容硅通孔
DOI：
10.1109/ted.2013.2244895
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发表时间：
2013-04-01
影响因子：
3.1
通讯作者：
Wang, Zheyao
中科院分区：
文献类型：
--
作者：
Chen, Qianwen;Huang, Cui;Wang, Zheyao
低电容对于硅通孔（TSV）的电性能至关重要。本文报道了超低电容硅通孔硅通孔的发展和电特性，这种硅通孔。通过开发一种牺牲技术成功地制造了气隙TSV，该牺牲技术使用无空隙填充和选择性蚀刻围绕铜插头的环形苯并环丁烯聚合物包层。测试了电容和漏电流，以表征其电气性能。空气的最低有效介电常数使得气隙TSV的电容低至24 fF，并且电容密度比常规SiO2内衬TSV的电容密度低一个数量级以上。在40 V时，对衬底的漏电流为3 ×10-13 A，并且在40次循环的热冲击测试后没有发生漏电流劣化。初步结果表明，新的空气间隙结构和空气间隙在减少TSV电容的功效。
Low capacitance is critical to the electric performance of through-silicon vias (TSVs). This paper reports the development and electrical characterization of ultralow-capacitance TSVs which use air gaps to replace the conventional silicon dioxide as the insulation layers. The air-gap TSVs are successfully fabricated by developing a sacrificial technology which uses void-free filling and selective etching of an annular benzocyclobutene polymer cladding that surrounds copper plugs. The capacitance and the leakage current are tested to characterize the electrical performance. The lowest effective dielectric constant of the air enables the capacitance of the air-gap TSVs to be as low as 24 fF, and the capacitance density is more than one order of magnitude lower than that of conventional SiO2 liner TSVs. The leakage current to the substrate is 3 ×10-13 A at 40 V, and no leakage current degradation occurs after a 40-cycle thermal shock test. The preliminary results demonstrate the new air-gap structure and the efficacy of air gaps in reducing TSV capacitance.