High reliability polysilicon components

Patent metadata

Field	Value
Publication number	US-11296075-B2
Application number	US-201816118648-A
Country	US
Kind code	B2
Filing date	Aug 31, 2018
Priority date	Aug 31, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

The present disclosure introduces, among other things, an electronic device, e.g. an integrated circuit (IC). The IC includes a semiconductor substrate comprising a first doped layer of a first conductivity type. A second doped layer of the first conductivity type is located within the first doped layer. The second doped layer has first and second layer portions with a greater dopant concentration than the first doped layer, with the first layer portion being spaced apart from the second layer portion laterally with respect to a surface of the substrate. The IC further includes a lightly doped portion of the first doped layer, the lightly doped portion being located between the first and second layer portions. A dielectric isolation structure is located between the first and second layer portions, and directly contacts the lightly doped portion.

First claim

What is claimed is:

1. An integrated circuit, comprising:
an epitaxial layer over a semiconductor substrate, the epitaxial layer having a first conductivity type and a top surface;
a transistor formed in or over the epitaxial layer, the transistor including a polysilicon gate formed in a gate-layer;
a well region having the first conductivity type located within the epitaxial layer, the well region having first and second well portions with a greater dopant concentration than a dopant concentration of the epitaxial layer, the first well portion spaced apart from the second well portion laterally with respect to the top surface;
a lightly doped portion of the epitaxial layer located between the first and second well portions; and
a dielectric isolation structure located between the first and second well portions and directly contacting the lightly doped portion.

2. The integrated circuit of claim 1 , further comprising a passive component formed in the gate-layer and located directly on the dielectric isolation structure.

3. The integrated circuit of claim 2 , wherein the passive component comprises a resistor.

4. The integrated circuit of claim 2 , wherein the passive component comprises polysilicon.

5. The integrated circuit of claim 1 , further comprising a doped buried layer having a second conductivity type within the epitaxial layer, wherein the lightly doped portion is located between the dielectric isolation structure and the doped buried layer.

6. The integrated circuit of claim 1 , further comprising a transistor located within the well region.

7. The integrated circuit of claim 1 , wherein the first conductivity type is p-type.

8. The integrated circuit of claim 1 , further comprising a second dielectric isolation structure within the well region, and electrically isolated conductive structures located on the well region.

9. An integrated circuit, comprising:
a buried layer formed within an epitaxial layer having a top surface and a first conductivity type and located over a semiconductor substrate, the buried layer having a second opposite conductivity type; and
one or more deep wells having the second conductivity type and extending from the top surface to the buried layer; and
a lightly doped region having the first conductivity type, the lightly doped region surrounded by the buried layer and the one or more deep wells;
a shallow well having the first conductivity type within the lightly doped region; and
a dielectric isolation structure abutting the shallow well having the first conductivity type,
wherein the lightly doped region touches the dielectric isolation structure.

10. The integrated circuit of claim 9 , further comprising a passive component formed in a gate-layer and located over the dielectric isolation structure.

11. The integrated circuit of claim 9 , wherein the dielectric isolation structure is a first dielectric isolation structure, and further comprising a second dielectric isolation structure within the well having the first conductivity type.

12. The integrated circuit of claim 9 , wherein the dielectric isolation structure is a first dielectric isolation structure, and further comprising a second dielectric isolation structure outside the well having the first conductivity type.

13. The integrated circuit of claim 12 , wherein the epitaxial layer touches the second dielectric isolation structure.

14. The integrated circuit of claim 9 , wherein the first conductivity type is p-type.

15. The integrated circuit of claim 9 , further comprising a portion of the epitaxial layer located vertically between the buried layer and the semiconductor substrate.

16. The integrated circuit of claim 9 , wherein the lightly doped region is junction-isolated from the epitaxial layer by the buried layer and the one or more deep wells.

17. An integrated circuit, comprising:
a first well having a first conductivity type within an enclosed portion of a lightly doped epitaxial layer having the first conductivity type, the enclosed portion touching and being bounded laterally by deep wells having a second opposite conductivity type and further touching and being bounded vertically by a buried layer having the second conductivity type connecting the deep wells;
a transistor formed in or over the first well and having a polysilicon gate electrode formed in a gate-layer;
a dielectric isolation structure touching the enclosed portion of the lightly doped epitaxial layer; and
a passive component formed in the gate-layer and located over the dielectric isolation structure.

18. The integrated circuit of claim 17 , wherein the dielectric isolation structure touches the first well.

19. The integrated circuit of claim 17 , wherein the passive component includes a polysilicon resistor.

20. The integrated circuit of claim 17 , further comprising a second well having the first conductivity type located between the dielectric isolation structure and one of the deep wells.

21. The integrated circuit of claim 17 , wherein the first conductivity type is p-type.

Assignees

• Texas Instruments Inc

Inventors

• Higgins Robert M
• Edwards Henry Litzmann
• Wu Xiaoju
• Arshad Shariq
• Wang Li
• Davis Jonathan Philip
• Chatterjee Tathagata

Classifications

• H10W10/011 Primary

  of isolation regions comprising dielectric materials · CPC title

• H10W10/10

  Isolation regions comprising dielectric materials · CPC title

• H10D84/0151

  Manufacturing their isolation regions · CPC title

• H10D84/817

  Combinations of field-effect devices and resistors only · CPC title

• H10W10/17

  formed using trench refilling with dielectric materials, e.g. shallow trench isolations · CPC title