Back to results
US 6,207,998 B1Granted
Semiconductor device with well of different conductivity types
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsSatoshi Kawasaki, Mikio Asakura, Kenji Tokami
Life of this patent
Estimating the term…
Abstract
An MOS capacitor is provided in the proximity of the boundary between a P well and an N well formed of a bottom N well and an N well. Accordingly, the proximity of the boundary corresponding to the so-called dead space can be used effectively.
Claims16
A semiconductor device comprising:
- a first well of a first conductivity type;
- a second well of a second conductivity type, surrounding and in contact with a side portion and a bottom portion of said first well, and including a bottom well provided at a bottom region;
- a third well of the first conductivity type formed in contact with said second well, and adjacent to said first well with said second well therebetween;
- and
- an MOS capacitor located at a boundary region between said second well and said third well, including an electrode formed on said third well with an insulation film therebetween, and an impurity region formed at a surface of said third well, receiving a predetermined voltage.
2 more elements
A semiconductor device comprising:
- a first well of a first conductivity type;
- a second well of a second conductivity type, surrounding and in contact with a side portion and a bottom portion of said first well, and including a bottom well provided at a bottom region;
- a third well of the first conductivity type formed in contact with said second well, and adjacent to said first well with said second well therebetween;
- an isolation insulator located at the boundary region between the second well and the third well, and
- an MOS capacitor including an electrode formed on said third well with an insulation film therebetween, and in contact with said isolation insulator, and an impurity region formed at a surface of said third well, receiving a predetermined voltage.
2 more elements
Dependencies are inferred from the claim text.