Dopant activation of heavily-doped semiconductor by high current densities
US5882953A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1996 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jul 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/479
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Dopant activation in heavily boron doped p.sup.+ --Si is achieved by applying electric current of high density. The p.sup.+ --Si was implanted by a 40 KeV BF.sup.2+ at an ion intensity 5.multidot.10.sup.15 ions per cm.sup.2 and annealed at 900.degree. C. for 30 minutes to obtain a partial boron activation according to conventional processing steps. To obtain additional activation and higher conductivity, current was gradually applied according to the invention to a current density of approximately 5.times.10.sup.6 A/cm.sup.2 was realized. The resistance of the p.sup.+ --Si gradually increases and then decreases with a precipitous drop at a threshold current. The resistance was reduced by factor of 5 to 18 times and was irreversible if an activation current threshold was reached or exceeded. The high-current-density-dopant activation occurs at room temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.