Vertical fuse device
US5436496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Feb 14, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A vertical fuse structure including a lightly-doped shallow emitter 30 provides improved fusing characteristics. The structure includes a buried collector 14, an overlying base 30, and an emitter 44 above the base 30. In one preferred embodiment, the emitter 44 extends about 0.2 microns from the upper surface and has a dopant concentration of about 8.times.1019 atoms of arsenic per cubic centimeter at the surface. A lightly doped base region 30 extends for about 0.46 microns below the emitter 44 to the collector 14. The upper surface of emitter 44 includes a metal contact 60. Heating the metal 60/emitter 44 interface to its eutectic melting point using a current or voltage pulse causes the aluminum to short through the emitter 44 to the base 30. Shorting the emitter programs the fuse. A second preferred embodiment uses polysilicon as an interconnecting medium. Mass transport of aluminum atoms through the polysilicon allows aluminum to collect at an interface between the polysilicon and an underlying single crystal silicon layer. Aluminum atoms are supplied from a contact metal. A barrier metal between the contact metal and an underlying polysilicon contact to the emitter is not pre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.