Semiconductor substrate containing bulk micro-defect
US5502331A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1995 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | May 19, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D62/83
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The semiconductor substrate is manufactured by growing a semiconductor crystal in accordance with CZ method; forming a substrate from the semiconductor crystal; and heat treating the formed substrate at 1150.degree. C. or higher for 30 min or longer in non-oxidizing atmosphere (e.g., 1200.degree. C. for 1 hour in hydrogen gas). In the formed wafer, the density of bulk micro-defects is 5.times.10.sup.2 to 5.times.10.sup.6 pieces per cm.sup.-3 in the surface area, but 5.times.10.sup.7 pieces per cm.sup.-3 or more in an 20 .mu.m or deeper from the surface. To confirm the depth profile of BMD density, the substrate is further heat treated at 780.degree. C. for 3 hours in oxygen atmosphere and successively at 1000.degree. C. for 16 hours in oxygen atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.