Semiconductor device comprising an ESD protection device, an ESD protection circuitry, an integrated circuit and a method of manufacturing a semiconductor device
View Patent ↗A semiconductor device includes an ESD protection device. In a N-well, two P+ doped regions form a collector and emitter of a parasitic transistor of the ESD protection device. The N-well area between the P+ doped regions, forms a base of the parasitic transistor. At some distance away from the P+ doped regions an N+ doped region is provided. The N-well in between the N+ doped region and base of the transistor forms a parasitic resistor of the ESD protection device. The N+ doped region and the emitter of the transistor are coupled to each other via an electrical connection. The ESD protection device has a limited snapback behaviour and has a well-tunable trigger voltage.
1. A semiconductor device comprising an ESD protection device for protecting an integrated circuit on the semiconductor device against ESD event received by the integrated circuit, the ESD protection device comprising:
an N-well region arranged in a semiconductor substrate of the semiconductor device and having a surface at a first side of the substrate;
a first P+ doped region that abuts the N-well region for forming a collector of a parasitic transistor;
a second P+ doped region that abuts the N-well region for forming an emitter of the parasitic transistor, the second P+ doped region being separated from the first P+ doped region by a first portion of the N-well region;
a N+ doped region that abuts the N-well region for providing an electrical contact with the N-well region, the N+ doped region being arranged at a larger distance from the first P+ doped region than from the second P+ doped region, the N+ doped region being separated from the second P+ doped region by a second portion of the N-well region; and
an electrical connection between the second P+ doped region and the N+ doped region, the electrical connection being arranged in one or more layers which are arranged at the first side of the substrate,
wherein no gate is present in a layers manufactured at the first side of the substrate above the first portion of the N-well region, the first side of the semiconductor substrate is unsilicided at the first portion of the N-well region, a P+ doping of the first P+ doped region and the N-well doping are configured to obtain a predefined trigger voltage for triggering the operation of the ESD protection device.
2. A semiconductor device according to claim 1 , wherein the first P+ doped region, the second P+ doped region and the N+ doped region are silicided at the first side of the substrate, the first portion of the N-well region is not silicided.
3. A semiconductor device according to claim 1 , wherein the predefined trigger voltage is in between 5 and 15 volts.
4. A semiconductor device according to claim 1 , wherein the ESD protection device is configured to have a snapback voltage between 0 volt and 1 volt, wherein the snapback voltage of the ESD protection device is expressed as an amount by which the voltage across the ESD protection device is reduced after a start of the operation of the ESD protection device when the voltage across the ESD protection device has reached the predefined trigger voltage.
5. A semiconductor device according to claim 1 , wherein the sheet resistance of the N-well region is at least 150 Ohms/sq.
6. A semiconductor device according to claim 1 , wherein the P+ doping of at least the first P+ doped region is higher than 1·1019 atoms/cm3.
7. A semiconductor device according to claim 1 , wherein the N-well region is isolated from neighbouring structures.
8. A semiconductor device according to claim 7 , wherein the N-well region is isolated by Deep Trench Isolation.
9. A semiconductor device according to claim 1 , wherein the second P+ doped region is in between the first P+ doped region and the N+ doped region.
10. A semiconductor device according to claim 1 , wherein the electrical connection is also coupled to an I/O pad of the semiconductor device for allowing the ESD protection device to catch ESD events received by the I/O pad.
11. A semiconductor device according to claim 1 , wherein the first P+ doped region is electrically coupled to a ground voltage.
12. A semiconductor device according to claim 1 , wherein the semiconductor substrate is P doped.