Method of manufacturing a semiconductor device by forming at least three regions of different lifetimes of carriers at different depths
US5250446A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Oct 9, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/128
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A mixture of at least two types of charged particles of ions having the same value obtained by dividing the electric charge of an ion by the mass of the ion, i.e., a mixture of charged particles including hydrogen molecular ions H.sub.2.sup.+ and deuterium ions D.sup.+, is accelerated in a charged particle accelerator. Since the mass spectrograph unit in the accelerator cannot divide the hydrogen molecular ions H.sub.2.sup.+ and the deuterium ion D.sup.+, both ions are accelerated together. When the hydrogen molecular ion H.sub.2.sup.+ collides against a silicon substrate, it is divided into two hydrogen ions 2H.sup.+. Since the hydrogen ion H.sup.+ and the deuterium ion D.sup.+ have different ranges in silicon, two regions including a great number of crystal defects are formed in the silicon substrate in one ion irradiating step. As a result, at least three regions of different lifetimes of carriers are formed at different depths of the semiconductor substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.