Through Silicon Capacitor co-integrated with TSVs on silicon interposer

• Through Silicon Capacitor (TSC) presented as a new type of decoupling capacitor for integration on Si-interposer.
• Dedicated test vehicle is designed to investigate first process steps of TSC.
• TiN/Al2O3/TiN Metal–Insulator–Metal stack deposited in various deep holes geometries exhibit good deposition conformalities.
• An increase of the capacitance density up to a factor of 6 as been measured between planar and tri-dimensional capacitors.

In this paper the Through Silicon Capacitor (or TSC), a new type of decoupling capacitor integrated on a via bridge silicon interposer is presented. TSC is a tri-dimensional MIM capacitor that goes through the whole thickness of the interposer, developing its capacitive area vertically and whose fabrication process uses most of the step of Through Silicon Via own process. A demonstrator have been designed and fabricated to investigate the first process step of TSC, using a TIN/Al2O3/TiN MIM stack deposited in various TSV geometries, design and process flow are exposed. Morphological characterization has been held to define conformalities of the various deposited materials, proving their viabilities in such geometries. Electrical characterizations of capacitors have shown an increase of the capacitance density up to a factor of 6.

Figure optionsDownload as PowerPoint slide