Research Of On-Chip Inductor Based On TGV Technology

Nowadays,microelectronic devices have entered the nano age,and the integration degree is far beyond the past.Inductor,as the basic unit of electronic components,is far behind the development of microelectronic devices in terms of size reduction.In order to promote the miniaturization and integration of inductors,3D integration technology is used to promote the development of chip inductors.However,silicon,as a traditional substrate material,has low resistance and poor microwave performance,and the processed high resistance silicon substrate costs too much,which is not conducive to the development of 3D integrated microwave devices.Glass is characterized by low cost,high resistance,low dielectric loss,and is compatible with silicon-based processing processes.The Through Glass Vias(TGV)inductor has higher quality factor and microwave performance than the silicon-based inductor.According to the simulation study of HFSS software,the port setting should be driven by wave port and Terminal driven mode,and the size of the outer and inner diameter of the ground electrode should be larger.The topology of the inductor will determine the performance,and the glass material should adopt low dielectric constant and low loss coefficient as far as possible,which is conducive to the improvement of the performance of the glass inductor.The inductor preparation process should be concerned with reducing the metal surface roughness and controlling the shape of the vias and the metal wiring.In this thesis,the glass etching,seed layer preparation,electroplating filling,polishing,surface graphics process for TGV inductor preparation are studied.In addition,this thesis proposes a new preparation method of embedded inductor based on the properties of photosensitive glass materials,and researches on copper corrosion and organic filling of the new process are also carried out.Finally,TGV inductor and glass embedded inductor are prepared according to simulation and process research.The embedded glass inductor has a high inductance density of 193.6 n H/mm~2,which is much higher than the glass inductor without ferromagnetic core.However,due to the uncontrollable copper corrosion process,there are errors between the simulation model and the real fabricated inductor,and the real data and simulation data are quite different.According to the TGV inductor simulation and fabrication research,the TGV on-chip inductor prototype was developed,with inductance value of 10 n H and Q value of 48 and inductance density of 69.6 n H/mm~2.Compared with silicon chip,the Q value is more than double,and the inductance density is more than two times higher than the previous glass inductor,showing a significant advantage.Although the inductance value of TGV inductor in physical test conforms to the simulation data,the Q value is lower than the simulation value,so it is speculated that there is no defect found in the process and it needs to be improved.