# US 2020/0403103 A1 · High voltage diode on soi substrate with trench-modified current path

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- Number: US 2020/0403103 A1
- Document ID: US20200403103A1
- Status: Published application
- Kind: A1
- Application number: 16/450,298
- Filed: 2019-06-24
- Published: 2020-12-24
- Earliest claimed: 2019-06-24
- Assignees: Semiconductor Components Industries, LLC
- Applicants: Semiconductor Components Industries, LLC
- Inventors: Jaroslav PJENCAK; Moshe AGAM; Johan Camiel Julia JANSSENS
- Web page: https://patentgrep.com/patent/US20200403103A1

## CPC

- H10D 8/00: Diodes (variable-capacitance diodes H10D1/64; gated diodes H10D12/00)
- H10D 8/01: Manufacture or treatment
- H10D 8/20: Breakdown diodes, e.g. avalanche diodes
- H10D 8/422: {PN diodes having the PN junctions in mesas}
- H10D 62/115: {Dielectric isolations, e.g. air gaps}
- H10D 64/111: {Field plates}
- H10P 90/1906: {Preparing SOI wafers}
- H10W 10/014: {using trench refilling with dielectric materials, e.g. shallow trench isolations}
- H10W 10/021: {of air gaps}
- H10W 10/051: {of isolation region based on field-effect}
- H10W 10/061: {using SOI processes together with lateral isolation, e.g. combinations of SOI and shallow trench isolations}
- H10W 10/17: formed using trench refilling with dielectric materials, e.g. shallow trench isolations
- H10W 10/181: {Semiconductor-on-insulator [SOI] isolation regions, e.g. buried oxide regions of SOI wafers}
- H10W 10/20: Air gaps
- H10W 10/50: Isolation regions based on field-effect
- H10D 30/657: {having substrates comprising insulating layers, e.g. SOI-LDMOS transistors}
- H10D 62/126: {Top-view geometrical layouts of the regions or the junctions}
- H10D 64/117: {Recessed field plates, e.g. trench field plates or buried field plates}
- H10D 64/62: Electrodes ohmically coupled to a semiconductor
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A semiconductor device may include a Silicon on Insulator (SOI) substrate, and a diode formed on the SOI substrate, the diode including a cathode region and an anode region. The semiconductor device may include at least one breakdown voltage trench disposed at an edge of the cathode region, and between the cathode region and the anode region.

## Claims

### Claim 1

A semiconductor device, comprising:
a Silicon on Insulator (SOI) substrate;
a diode formed on the SOI substrate, the diode including a cathode region and an anode region; and
at least one breakdown voltage trench disposed at an edge of the cathode region, and between the cathode region and the anode region.

### Claim 2 (depends on 1)

The semiconductor device of claim 1, wherein the at least one breakdown voltage trench is adjacent to the cathode region, and extends beyond the cathode region in a direction of the insulator of the SOI substrate.

### Claim 3 (depends on 2)

The semiconductor device of claim 2, wherein the at least one breakdown voltage trench extends in the direction of the insulator and leaves a current path through the SOI substrate between the cathode region and the anode region.

### Claim 4 (depends on 1)

The semiconductor device of claim 1, wherein the at least one breakdown voltage trench includes at least two breakdown voltage trenches, including a first breakdown voltage trench at the edge of the cathode region, and a second breakdown voltage trench between the first breakdown voltage trench and the anode region.

### Claim 5 (depends on 4)

The semiconductor device of claim 4, wherein the second breakdown voltage trench is adjacent to the anode region and extends beyond the anode region in a direction of the insulator of the SOI substrate.

### Claim 6 (depends on 1)

The semiconductor device of claim 1, wherein the anode region includes a region of opposite doping type that is shorted to an anode of the diode, the anode acting as base of a lateral Bipolar Junction Transistor (BJT), with the region of opposite doping type acting as collector of the lateral BJT.

### Claim 7 (depends on 1)

The semiconductor device of claim 1, wherein the at least one breakdown voltage trench includes an insulating material with an airgap formed therein.

### Claim 8 (depends on 1)

The semiconductor device of claim 1, further comprising a vertical field plate disposed at an opposing edge of the cathode region as the breakdown voltage trench.

### Claim 9 (depends on 8)

The semiconductor device of claim 8, wherein the vertical field plate is electrically connected to the cathode region.

### Claim 10 (depends on 8)

The semiconductor device of claim 8, wherein the vertical field plate includes a first deep trench isolation structure adjacent to the cathode region that, together with a second deep trench isolation structure isolating the diode from at least one other circuit element formed in the SOI substrate, forms a pocket in which epitaxial material of the SOI substrate is maintained at a same potential as the cathode region.

### Claim 11

A semiconductor device, comprising:
a substrate;
a diode formed in the substrate, the diode including a cathode region and an anode region;
at least one trench insulator adjacent to the cathode region that defines a diode current path around the at least one trench insulator that traverses the substrate between the cathode region and the anode region.

### Claim 12 (depends on 11)

The semiconductor device of claim 11, wherein the substrate includes a Silicon on Insulator (SOI) substrate, and further wherein the at least one trench isolator extends beyond the cathode region in a direction of the insulator of the SOI substrate.

### Claim 13 (depends on 11)

The semiconductor device of claim 11, wherein the diode current path is a reverse current occurring at a breakdown voltage of the diode.

### Claim 14 (depends on 11)

The semiconductor device of claim 11, wherein the at least one trench insulator includes at least two trench insulators, including a first trench insulator at an edge of the cathode region, and a second trench insulator between the first trench insulator and the anode region.

### Claim 15 (depends on 13)

The semiconductor device of claim 13, wherein the substrate includes a Silicon on Insulator (SOI) substrate, and further wherein the second trench insulator is adjacent to the anode region and extends beyond the anode region in a direction of the insulator of the SOI substrate.

### Claim 16 (depends on 11)

The semiconductor device of claim 11, wherein the anode region includes a region of opposite doping type that is shorted to an anode of the diode, the anode acting as base of a lateral Bipolar Junction Transistor (BJT), with the region of opposite doping type acting as collector of the lateral BJT.

### Claim 17 (depends on 11)

The semiconductor device of claim 11, further comprising a vertical field plate disposed at an edge of the cathode region opposed to an edge of the cathode region that is adjacent to the at least one trench insulator, the vertical field plate being electrically connected to the cathode region.

### Claim 18 (depends on 11)

The semiconductor device of claim 11, further comprising a vertical field plate that includes a first deep trench isolation structure adjacent to the cathode region, which, together with a second deep trench isolation structure isolating the diode from at least one other circuit element formed in the SOI substrate, forms a pocket in which epitaxial material of the SOI substrate is maintained at a same potential as the cathode region.

### Claim 19

A method of making a semiconductor device, comprising:
forming a Silicon on Insulator (SOI) substrate;
forming a breakdown voltage trench in the SOI substrate;
forming a diode in the SOI, including forming a cathode region of the diode adjacent to the breakdown voltage trench, with the breakdown voltage trench between the cathode region and the anode region.

### Claim 20 (depends on 1)

The method of claim 1, further comprising:
forming a deep trench isolation (DTI) structure in the SOI substrate in a position to isolate the diode from at least one other circuit element formed in the SOI substrate,
wherein the forming the breakdown voltage trench and the forming the DTI structure are performed during a trench etching process.