Silicon interposers with integrated passive devices, an excellent alternativ to discrete components

摘要

A new way of designing high density silicon capacitors that are intended to be co-integrated with TSV for advanced silicon interposers is presented. This new kind of design; called “mosaic” enables to manufacture IPDs with capacitor density up to 500nF/mm2 while maintaining ultra low ESR. PICS™ “mosaic” capacitors implement localized elements set in parallel on a grid that behave as a parallel network and exhibit the following characteristics: •· The global “mosaic” capacitor has a linear dependency with CGlobal=N∗CLocal where N is the number of repetitions of the localized element and CLocal its capacitance • ESR and ESL have an inverse dependency with N : LGlobal=LLocal/N and ESRGlobal=ESRLocal/N. • Thanks to the 1/N variation of both ESL and ESR; and the N∗C variation of the global capacitance, the products ESR∗C and ESL∗C are nearly constant which respectively means that the cutoff and SRF of the device are also constant, whatever the N value is. The global capacitor performances (like SRF) are driven by the most elementary building block and almost independent from the capacitor size.