Ultrahigh-density trench capacitors in silicon and their application to integrated DC-DC conversion

Abstract

This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an integrated inductive DC-DC converter based on flip-chipping a 65-nm CMOS active die on a PICS™ (Passive-Integration Connecting Substrate) passive die is described. The PICS die includes high-density (80 nF/mm 2 ) integrated MOS trench capacitors. A converter peak efficiency of 87.5% is achieved at V in =1.2 V, V out =0.95 V, I out =100 mA and 100-MHz switching frequency. The concept enables further integration with sensors, actuators and MEMS.

Reducing substrate noise coupling in a 3D-PICS Integrated Passive Device by localized P+ guard rings

“…The latter are based on RIE-etched arrays of high aspect ratio macro pores. Typical depth extension of those pores into the silicon substrate would be in the order of ~30 to 60µm for the different PICS technologies [1][2]. Compared to 2D silicon integrated capacitor technologies (like MOS or MIM), one foresee that surface deployed by the PICS 3D component into the substrate is rather large, thus potentially leading to critical parasitic capacitance.…”

A 65-nm-CMOS 100-MHz 87%-efficient DC-DC down converter based on dual-die system-in-package integration

“…Bergveld, H. J., Nowak, K., Karadi, R., Iochem, S., Ferreira, J., Ledain, S., ... Pommier, M. (2009). A 65-nm-CMOS 100-MHz 87%-efficient DC-DC down converter based on dual-die system-in-package integration.…”

“…The passive die was designed in the Passive-Integration Connective Substrate (PICS) process [13]- [18]. The PICS process was developed in NXP Semiconductors to integrate passive components such as high-Q inductors, resistors, accurate MIM capacitors, and, in particular, high-density (~30 nF/mm 2 ) MOS 'trench' capacitors for decoupling and filtering.…”

“…This paper follows an alternative approach, where all passives are realized in a low-cost high-density passiveintegration IC process [13]- [15], and the active die is flipchipped on top of the passive die [16]- [18]. The high capacitance density yields a relatively small area for highvalue input and output capacitors.…”

Design a new MEMS tunable capacitors using electro-thermal actuators

“…different types of capacitors, such as trench capacitors with a very high density, can be performed on a silicon wafer (Roozeboom et al 2009). Taking advantage of large inner surface area of the trenches, the area can be increased more than 50 times and capacitance density can be increased up to 70 times more than the planar capacitor (Momose et al 2011).…”