应用于TGV的ICP玻璃刻蚀工艺研究

Formation of Through-Glass Via by Inductively Coupled Plasma Etching

玻璃通孔(TGV)技术被认为是下一代三维集成的关键技术,该技术的核心为深孔形成工艺。感应耦合等离子体(ICP)刻蚀技术是半导体领域中深孔形成的重要手段之一。本文通过正交实验设计方法,研究ICP石英玻璃刻蚀工艺中工作压强、C4F8流量、Ar流量三个工艺参数对深孔刻蚀的影响,探索提高刻蚀速率的优化组合。实验结果表明,C4F8流量对玻璃刻蚀速率有显著影响,并且随着C4F8/Ar流量比减小,侧壁角度垂直性越好。实验为TGV技术开发和应用提供了实验依据。

Here,we addressed etching of fused silica with inductively coupled plasma（ ICP） to develop through-glass via（ TGV） technology,which has a major impact on the next generation three-dimensional integration packaging. The influence of the ICP etching conditions,including but not limited to the pressure and ratio of C4F8/ Ar gas-flow rates,on the etching rate and side-wall steepness was investigated in orthogonal experiment design. The ICP etched holes were characterized with scanning electron microscopy. The results show that the ratio of C4F8/ Ar gasflow rates significantly affects the etching rate and sidewall steepness. For instance,as the ratio decreased,the etching rate decreased but the sidewall became increasingly steeper. Under the optimized etching conditions,the allowable highest etching rate could be 758 nm / min and the holes,50 μm in diameter with nearly vertical sidewall,were obtained,respectively,in the experimental tests.