Semiconductor doped region with biased isolated members

Patent metadata

Field	Value
Publication number	US-11830830-B2
Application number	US-202117318556-A
Country	US
Kind code	B2
Filing date	May 12, 2021
Priority date	May 12, 2021
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A microelectronic device includes a doped region of semiconductor material having a first region and an opposite second region. The microelectronic device is configured to provide a first operational potential at the first region and to provide a second operational potential at the second region. The microelectronic device includes field plate segments in trenches extending into the doped region. Each field plate segment is separated from the semiconductor material by a trench liner of dielectric material. The microelectronic device further includes circuitry electrically connected to each of the field plate segments. The circuitry is configured to apply bias potentials to the field plate segments. The bias potentials are monotonic with respect to distances of the field plate segments from the first region of the doped region.

First claim

What is claimed is:

1. A microelectronic device, comprising:
a semiconductor substrate;
a first region of the semiconductor substrate, the first region configured to be at a first operational potential;
a second region of the semiconductor substrate, the second region configured to be at a second operational potential different from the first operational potential;
a doped region in the semiconductor substrate between the first region and the second region;
field plate segments in trenches extending into the doped region, each field plate segment separated from the semiconductor substrate by a dielectric liner, the field plate segments including a first field plate segment next to the first region, a second field plate segment next to the second region, and a third field plate segment between the first field plate segment and the second field plate segment; and
circuitry including a resistor ladder having internal nodes that are electrically coupled to the field plate segments, the circuitry configured to apply a first bias potential to the first field plate segment, apply a second bias potential to the second field plate segment different from the first bias potential, and apply a third bias potential to the third field plate segment, the third bias potential being between the first bias potential and the second bias potential, wherein the first, second, third bias potentials are between the first and second operational potentials.

2. The microelectronic device of claim 1 , wherein
the first bias potential is between the first operational potential and the third bias potential; and
the second bias potential is between the third bias potential and the second operational potential.

3. The microelectronic device of claim 1 , wherein the first, second, third bias potentials are monotonic with respect to distances of the field plate segments from the first region.

4. The microelectronic device of claim 1 , wherein the doped region is part of an active component selected from a group of a metal oxide semiconductor (MOS) transistor, a junction field effect transistor (JFET), a bipolar junction transistor, an insulated gate bipolar transistor (IGBT), a bipolar junction diode, and a Schottky diode.

5. The microelectronic device of claim 1 , wherein the internal nodes are electrically coupled to the field plate segments through buffers.

6. The microelectronic device of claim 1 , wherein the dielectric liner has a thickness of 5 nanometers to 50 nanometers.

7. The microelectronic device of claim 1 , wherein the field plate segments are arranged in seriate alternating rows, each row being perpendicular to a current flow direction of the doped region.

8. The microelectronic device of claim 1 , wherein the field plate segments are arranged in rows and columns, each row being perpendicular to a current flow direction of the doped region, each column being parallel to the current flow direction.

9. The microelectronic device of claim 1 , wherein the field plate segments include a material selected from a group of polycrystalline silicon and a metal.

10. The microelectronic device of claim 1 , wherein the trenches extend through the doped region.

11. The microelectronic device of claim 1 , wherein the doped region extends below bottoms of the trenches.

12. A microelectronic device, comprising:
a substrate having a semiconductor material;
a first region of the semiconductor material;
a second region of the semiconductor material;
a doped region in the semiconductor material between the first region and the second region;
field plate segments in trenches extending into the doped region, each field plate segment separated from the semiconductor material by a trench liner of dielectric material, the field plate segments including a row of first field plate segments nearest the first region, a row of second field plate segments nearest the second region, and a row of third field plate segments between the row of first field plate segments and the row of second field plate segments;
a first interconnect directly coupled to the row of first field plate segments;
a second interconnect directly coupled to the row of second field plate segments;
a third interconnect directly coupled to the row of third field plate segments; and
circuitry electrically coupled to each of the field plate segments, a first bias potential node of the circuitry coupled to the first interconnect, a second bias potential node of the circuitry coupled to the second interconnect, and a third bias potential node of the circuitry coupled to the third interconnect, wherein the first bias potential node, second bias potential node, and the third bias potential node are distinct from each other.

13. The microelectronic device of claim 12 , wherein the circuitry is configured to:
apply a first bias potential to the row of first field plate segments through the first bias potential node;
apply a second bias potential to the row of second field plate segments through the second bias potential node; and
apply a third bias potential to the row of third field plate segments through the third bias potential node.

14. The microelectronic device of claim 13 , wherein the first, second, third bias potentials are monotonic with respect to distances of the field plate segments from the first region.

15. The microelectronic device of claim 13 , wherein:
the first region is configured to be at a first operational potential; and
the second region is configured to be at a second operational potential different from the first operational potential.

16. The microelectronic device of claim 15 , wherein the first bias potential, the second bias potential, and the third bias potential are between the first operational potential and the second operational potential, the third bias potential being between the first bias potential and the second bias potential.

17. The microelectronic device of claim 12 , wherein the circuitry includes a resistor ladder having the first, second, and third bias potential nodes.

18. The microelectronic device of claim 17 , wherein the first, second, and third bias potential nodes are electrically coupled to the field plate segments through buffers.

19. A semiconductor device, comprising:
a semiconductor substrate;
a first region of the semiconductor substrate;
a second region of the semiconductor substrate;
a doped region in the semiconductor substrate between the first region and the second region;
field plate segments in trenches extending into the doped region, each field plate segment separated from the semiconductor substrate by a dielectric liner, wherein the field plate segments includes a first field plate segment proximate the first region, a second field plate segment proximate the second region, and a third field plate segment between the first and second field plate segments; and
circuitry including a resistor ladder having internal nodes that are electrically coupled to the field plate segments, wherein the resistor ladder is configured to apply a first bias potential to the first field plate segment, a second bias potential to the second field plate segment, and a third bias potential to the third field plate segment, and wherein the first, second, and third bias potentials are different from each other.

20. The semiconductor device of claim 19 , wherein the first, second, third bias potentials are monotonic with respect to distances of the field plate segments from the first region.

21. The semicond

Assignees

• Texas Instruments Inc

Inventors

• Sadovnikov Alexei
• Haynie Sheldon Douglas
• Radhakrishna Ujwal

Classifications

• H10W44/241

  for passive devices or passive elements · CPC title

• H10D30/603

  having asymmetry in the channel direction, e.g. lateral high-voltage MISFETs having drain offset region or extended drain IGFETs [EDMOS] · CPC title

• H10W44/401 Primary

  Resistive arrangements (H10W44/20, H10W42/80 take precedence) · CPC title

• H10D64/117 Primary

  Recessed field plates, e.g. trench field plates or buried field plates · CPC title

• H10D64/112

  comprising multiple field plate segments · CPC title