# US 2017/0288044 A1 · Vertical power component

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- Number: US 2017/0288044 A1
- Document ID: US20170288044A1
- Status: Published application
- Kind: A1
- Application number: 15/362,919
- Filed: 2016-11-29
- Published: 2017-10-05
- Earliest claimed: 2016-03-31
- Assignees: STMicroelectronics (Tours) SAS
- Applicants: STMicroelectronics (Tours) SAS
- Inventors: Samuel Menard
- Web page: https://patentgrep.com/patent/US20170288044A1

## CPC

- H10D 18/80: Bidirectional devices, e.g. triacs
- H10D 18/021: {of bidirectional devices, e.g. triacs}
- H10D 64/118: {Electrodes comprising insulating layers having particular dielectric or electrostatic properties, e.g. having static charges}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A vertical power component includes a doped silicon substrate of a first conductivity type. A local well of a second conductivity type extends from an upper surface of the substrate. A passivation structure coats a peripheral region of the upper surface side of the substrate surrounding the well. This passivation structure includes, on top of and in contact with the peripheral substrate region, a first region made of a first passivation material and a second region made of a second passivation material. The second region generates, in a surface region of the substrate in contact with said second region, a local increase of the concentration of majority carriers in the substrate.

## Claims

### Claim 1

A vertical power component, comprising:
a doped silicon substrate of a first conductivity type;
a local well of a second conductivity type extending from an upper surface of the substrate; and
on the upper surface of the substrate, a passivation structure coating a peripheral region of the substrate surrounding the well, said passivation structure comprising, on top of and in contact with said peripheral substrate region, a first region made of a first passivation material and a second region made of a second passivation material, the second region providing, in a surface region of the substrate in contact with said second region, a local increase of concentration of majority carriers in the substrate.

### Claim 2 (depends on 1)

The component of claim 1, wherein the second region is made of phosphosilicate glass (PSG).

### Claim 3 (depends on 1)

The component of claim 1, wherein the first region is made of silicon oxide.

### Claim 4 (depends on 1)

The component of claim 1, wherein the first region is made of lead-filled glass.

### Claim 5 (depends on 1)

The component of claim 1, wherein one of the first and second regions of the passivation structure is a layer coating said peripheral region of the substrate, interrupted by a ring-shaped opening arranged opposite a central portion of said peripheral region of the substrate, the other region of the passivation structure being a ring-shaped strip arranged in said opening.

### Claim 6

A method of manufacturing a vertical power component inside and on top of a doped silicon substrate of a first conductivity type, comprising the steps of:
forming a local well of a second conductivity type extending from an upper surface of the substrate; and
forming, on the upper surface side of the substrate, a passivation structure coating a peripheral region of the substrate surrounding the well, said passivation structure comprising, on top of and in contact with said peripheral substrate region, a first region made of a first passivation material and a second region made of a second passivation material, the second region providing, in a surface region of the substrate in contact with said second region, a local increase of the concentration of majority carriers in the substrate.

### Claim 7 (depends on 6)

The method of claim 6, wherein the second region is made of phosphosilicate glass, the forming of the second region comprising a step of depositing phosphosilicate glass at the surface of said peripheral region of the substrate, followed by a step of annealing at a temperature higher than 500° C.

### Claim 8

A vertical power component, comprising:
a doped silicon substrate of a first conductivity type;
a local well of the second conductivity type extending from an upper surface of the substrate; and
on the upper surface side of the substrate, a passivation structure coating a peripheral region of the substrate surrounding the well, said passivation structure comprising, on top of and in contact with said peripheral substrate region, a first region made of a first passivation material and a second region made of a second passivation material, the second region providing fixed positive charges at the interface with silicon, to cause, in a surface region of the substrate in contact with said second region, a local increase of the concentration of majority carriers in the substrate.

### Claim 9 (depends on 8)

The component of claim 8, wherein the second region is made of semi-insulating polysilicon.

### Claim 10 (depends on 8)

The component of claim 8, wherein the second region is made of silicon nitride.

### Claim 11 (depends on 8)

The component of claim 8, wherein the first region is made of silicon oxide.

### Claim 12 (depends on 8)

The component of claim 8, wherein the first region is made of lead glass.

### Claim 13 (depends on 8)

The component of claim 8, wherein one of the first and second regions of the passivation structure is a layer coating said peripheral region of the substrate, interrupted by a ring-shaped opening arranged opposite a central portion of said peripheral region of the substrate, the other region of the passivation structure being a ring-shaped strip arranged in said opening.

### Claim 14

A method of manufacturing a vertical power component inside and on top of a doped silicon substrate of a first conductivity type, comprising the steps of:
forming a local well of a second conductivity type extending from an upper surface of the substrate; and
forming, on the upper surface side of the substrate, a passivation structure coating a peripheral region of the substrate surrounding the well, said passivation structure comprising, on top of and in contact with said peripheral substrate region, a first region made of a first passivation material and a second region made of a second passivation material, the second region providing fixed positive charges at the interface with silicon, to cause, in a surface region of the substrate in contact with said second region, a local increase of the concentration of majority carriers in the substrate.

### Claim 15 (depends on 14)

The method of claim 14, wherein the second region is made of semi-insulating polysilicon, the forming of the second region comprising a step of depositing semi-insulating polysilicon at the surface of said peripheral region of the substrate, followed by a step of annealing at a temperature in the range from 200 to 400° C., or at a temperature higher than 700° C.

### Claim 16 (depends on 14)

The method of claim 14, wherein the second region is made of silicon nitride, the forming of the second region comprising a step of depositing silicon nitride at the surface of said peripheral region of the substrate, by chemical vapor deposition under a gas flow comprising a mixture of silane and of ammonia, with a ratio of the ammonia content to the silane content smaller than 100 or greater than 900.