Integrated coil inductors for IC devices
US6492708B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2001 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Mar 14, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F17/0033
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A means for fabrication of solenoidal inductors integrated in a semiconductor chip is provided. The solenoidal coil is partially embedded in a deep well etched into the chip substrate. The non-embedded part of the coil is fabricated as part of the BEOL metallization layers. This allows for a large cross-sectional area of the solenoid turns, thus reducing the turn-to-turn capacitive coupling. Because the solenoidal coils of this invention have a large diameter cross-section, the coil can be made with a large inductance value and yet occupy a small area of the chip. The fabrication process includes etching of a deep cavity in the substrate after all the FEOL steps are completed; lining said cavity with a dielectric followed by fabrication of the part of the coil that will be embedded by deposition of a conductive material metal through a mask; deposition of dielectric and planarization of same by CMP. After planarization the fabrication of the remaining part of the solenoidal coil is fabricated as part of the metallization in the BEOL (i.e. as line/vias of the BEOL). To further increase the cross section of the solenoidal coil part of it may be built by electrodeposition through a ma…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.