Semiconductor device and its manufacture method
US7605041B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2007 |
| Grant date | Oct 20, 2009 |
| Priority date | — |
| Expiry date | Dec 7, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/0191
Abstract
Multiple kinds of transistors exhibiting desired characteristics are manufactured in fewer processes. A semiconductor device includes an isolation region reaching a first depth, first and second wells of first conductivity type, a first transistor formed in the first well and having a gate insulating film of a first thickness, and a second transistor formed in the second well and having a gate insulating film of a second thickness less than the first thickness. The first well has a first impurity concentration distribution having an extremum maximum value only at the depth equal to or greater than the first depth. The second well has a second impurity concentration distribution which is superposition of the first impurity concentration distribution, and another impurity concentration distribution which shows an extremum maximum value at a second depth less than the first depth, the superposition shows also an extremum maximum value at the second depth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.