Method to suppress boron penetration in P+ mosfets
US6103582A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1998 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Aug 13, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/28035
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
With the growing practice of doping gates for MOSFETs with boron, problems have been encountered due to later diffusion of the boron into the active region. To block this, argon ions are implanted into the gate pedestal material prior to doping it with boron. The damage caused by the argon ions results in traps that getter the boron atoms, behaving in effect as a diffusion barrier. The invention is directed specifically to gate pedestals that are less than about 3000 Angstroms thick. Under these conditions it has been determined that the implantation energies of the argon ions should not exceed 80 keV. It is also important that the dosage of argon be in the range from 1.times.10.sup.15 to 1.times.10.sup.16 per cm.sup.2. Preferably doses in excess of 5.times.10.sup.15 should be used as they also lead to improvements in subthreshold swing and hot carrier immunity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.