High voltage device
View Patent ↗A device is disclosed. The device includes s substrate prepared with an active device region. The active device region includes a gate. The device also includes a doped channel well disposed in the substrate adjacent to a first edge of the gate. The first edge of the gate overlaps the channel well with a channel edge of the channel well beneath the gate. The first edge of the gate and channel edge defines an effective channel length of the device. The effective channel length is self-aligned to the gate. A doped drift well adjacent to a second edge of the gate is also included.
1. A device comprising:
a substrate prepared with an active device region, wherein the active device region includes a gate, the gate including a gate electrode over a gate dielectric;
a doped channel well disposed in the substrate adjacent to a first edge of the gate, the first edge of the gate overlaps the channel well with a channel edge of the channel well beneath the gate, the first edge of the gate and channel edge beneath the gate define a channel of the device, wherein the channel is displaced from a first heavily doped region adjacent to the first edge of the gate; and
a doped drift well adjacent to a second edge of the gate.
2. The device of claim 1 further comprising spacer on the first edge of the gate, wherein the spacer defines the displacement of the channel from the first heavily doped region.
3. The device of claim 1 wherein the substrate comprises:
a drift isolation region in the doped drift well; and
a doped deep well in the substrate of the active device region encompassing the doped drift well.
4. The device of claim 3 wherein the drift isolation region is disposed under the gate.
5. The device of claim 4 wherein the first and a second heavily doped regions are provided adjacent to the gate, wherein:
the first heavily doped region is disposed in the doped channel well on a source side of the device; and
the second heavily doped region is disposed between the drift isolation region and a device isolation region on a drain side of the device.
6. The device of claim 1 wherein the first edge of the gate corresponds to a channel edge of the gate of the device and a second edge of the gate corresponds to a drain edge of the gate of the device.
7. The device of claim 1 wherein the channel having a channel length that is controlled by ion implantation.
8. The device of claim 7 wherein the ion implantation comprises a tilt angle implant.
9. The device of claim 8 wherein a tilt angle of the ion implantation is about 1-45°.
10. The device of claim 7 wherein the ion implantation comprises multiple tilt angle implants which are rotated about a plane of the substrate.
11. The device of claim 10 wherein a tilt angle of the implant is about 1-45°.
12. The device of claim 7 wherein the ion implantation comprises a quad tilt angle implant which is rotated about a plane of the substrate.
13. A device comprising:
a substrate prepared with an active device region, wherein the active device region includes a gate, the gate including a gate electrode over a gate dielectric;
a doped channel well disposed in the substrate adjacent to a first edge of the gate, wherein the first edge of the gate overlaps the channel well with a channel edge of the channel well beneath the gate, the first edge of the gate and channel edge beneath the gate define a channel of the device, wherein the channel is displaced from a first heavily doped region adjacent to the first edge of the gate;
a doped drift well adjacent to a second edge of the gate; and
a drift isolation region in the doped drift well.
14. The device of claim 13 further comprising a spacer on the first edge of the gate, wherein the spacer defines the displacement of the channel from the first heavily doped region.
15. The device of claim 13 wherein the first edge of the gate corresponds to a channel edge of the gate of the device and a second edge of the gate corresponds to a drain edge of the gate of the device.
16. The device of claim 13 wherein the drift isolation region is disposed under the gate.
17. The device of claim 13 wherein the first and a second heavily doped regions are provided adjacent to the gate, wherein:
the first heavily doped region is disposed in the doped channel well on a source side of the device; and
the second heavily doped region is disposed between the drift isolation region and a device isolation region on a drain side of the device.
18. The device of claim 13 wherein the channel having a channel length that is controlled by ion implantation.
19. The device of claim 18 wherein the ion implantation comprises a tilt angle implant, multiple tilt angle implants or quad tilt angle implant.
20. A semiconductor device comprising:
a substrate prepared with an active device region, wherein the active device region includes a gate, the gate including a gate electrode over a gate dielectric;
first and second heavily doped regions adjacent to first and second edges of the gate;
a doped channel well disposed in the substrate adjacent to the first edge of the gate, wherein the first edge of the gate overlaps the channel well with a channel edge of the channel well beneath the gate, the first edge of the gate and channel edge beneath the gate define a channel of the device, wherein the channel is displaced from the first heavily doped region adjacent to the first edge of the gate; and
a doped drift well adjacent to a second edge of the gate, wherein a drift isolation region is disposed in the doped drift well.