Lateral high-voltage transistor with vertically-extended voltage-equalized drift region
View Patent ↗A lateral high-voltage device in which conductive trench plates are inserted across the voltage-withstand region, so that, in the on state, the current density vectors have less convergence. This can help reduce on-resistance.
1. A method of operating a lateral semiconductor device, comprising the actions of:
emitting charge carriers from a carrier-emission structure into a voltage-withstand structure; while
equalizing vertical potential within said voltage-withstand structure, by providing therein first and second conductive trench electrodes separated by a volume of semiconductor material;
and wherein said carriers emitted by said carrier-emission structure pass through said first and second conductive trench electrodes.
2. The method of claim 1 , wherein said emitting step uses a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.
3. A method of operating a lateral semiconductor device, comprising the actions of:
emitting charge carriers from a carrier-emission structure into a voltage-withstand structure; and
collecting said charge carriers from said voltage-withstand structure into a charge-collection structure; while
equalizing vertical potential within said voltage-withstand structure, by providing therein first and second conductive trench electrodes separated by a volume of semiconductor material.
4. The method of claim 3 , wherein said emitting step uses a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.
5. A lateral semiconductor device, comprising:
a carrier-emission structure, which can emit charge carriers of a first type;
a voltage-withstand structure, through which carriers emitted by said carrier-emission structure can pass; and
a carrier-collection structure, which receives charge carriers of said first type which have passed through said voltage-withstand structure;
wherein said voltage-withstand structure includes first and second conductive trench electrodes separated by a volume of semiconductor material, all connected in series between said carrier-emission and carrier-collection structures.
6. The device of claim 5 , wherein said voltage-withstand structure extends along a lateral direction of predominant current vector, and said trench electrodes extend both in depth and also laterally normal to said current vector.
7. The device of claim 5 , wherein said carrier-emission structure includes an anode and a semiconductor diffusion abutting said anode.
8. The device of claim 5 , wherein said carrier-emission structure includes a source diffusion, a semiconductor channel which abuts said source diffusion, and a gate which is capacitively coupled to said channel.
9. The device of claim 5 , further comprising an electrical contact which receives carriers emitted by said carrier-emission structure, after said carriers have passed through said voltage-withstand region.
10. The device of claim 5 , further comprising third and fourth trench electrodes which adjoin said semiconductor volume and are insulated from it.