TSV转接板空腔金属化与再布线层一体成型技术

Integrated Forming Technology of Cavity Metallization and Redistribution Layer of TSV Interposer

为满足射频微波应用的需求并实现三维异质集成,提出了一种带有大尺寸空腔结构的硅通孔(TSV)转接板,研究了其空腔金属化与表面金属再布线层(RDL)一体成型技术。首先,刻蚀空腔并整面沉积一层2μm厚的SiO2;然后,在不损伤其他部分绝缘层的条件下,通过干法刻蚀完成TSV背面SiO2刻蚀;最后,通过整面电镀实现空腔金属化和RDL一体成型,并通过金属反向刻蚀形成RDL。重点研究了对TSV背面SiO2刻蚀时对空腔拐角的保护方法,以及在形成表面RDL时对空腔侧壁金属层的保护方法。最终获得了带有120μm深空腔的TSV转接板样品,其中空腔侧壁和表面RDL的金属层厚度均为8μm。

To meet the requirements of RF&microwave applications and to achieve 3 D heteroge-neous integration,a new type of trough silicon via(TSV)interposer with large size cavity structure was proposed.The integrated forming technology of cavity metallization and surface metal redistribution layer(RDL)was studied.Firstly,the cavity was etched and a layer of SiO2 with the thickness of 2μm was deposited on the whole surface.Then,the backside SiO2 etching of TSV was completed by dry etching without damaging the other insulation layers.Finally,the cavity metallization and RDL were formed integrally by the whole surface plating and the RDL was formed by reverse metal etching.The protection method for the corners of cavity when the backside SiO2 etching of TSV was studied,and the protection method for the metal layer on the cavity side wall during the formation of RDL was also emphatically studied.At last,TSV interposer samples with the cavity depth of 120μm were obtained,and the thicknesses of metal layer on the side wall of the cavity and on the surface RDL were both 8μm.