Semiconductor device
US4963973A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1989 |
| Grant date | Oct 16, 1990 |
| Priority date | — |
| Expiry date | Mar 13, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/921
Abstract
A semiconductor device has a well region formed in the surface of a substrate, and has semiconductor elements such as MOSFETs and bipolar transistors formed in the well region. The carrier concentration profile of the well region assumes the shape of a valley in the direction of depth thereof, and a minimum point thereof has a concentration of smaller than 5.times.10.sup.15 cm.sup.-3 and is located at a position within 1.6 .mu.m from the surface of the substrate. Preferably, the minimum point should have a concentration of greater than 5.times.10.sup.14 cm.sup.-3 but smaller than 5.times.10.sup.15 cm.sup.-3, and more preferably a concentration of greater than 1.times.10.sup.15 cm.sup.-3 but smaller than 5.times.10.sup.15 cm.sup.-3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.