# US 10,872,996 B2 · Semiconductor device and method of forming the same

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- Number: US 10,872,996 B2
- Document ID: US10872996B2
- Status: Granted
- Kind: B2
- Application number: 16/265,246
- Filed: 2019-02-01
- Published: 2019-05-30
- Granted: 2020-12-22
- Earliest claimed: 2015-07-06
- Assignees: The Hong Kong University of Science and Technology
- Applicants: The Hong Kong University of Science and Technology
- Inventors: Qinglin He; Ying Hoi Lai; Yi Liu; Iam Keong Sou
- Web page: https://patentgrep.com/patent/US10872996B2

## CPC

- H10F 30/227: the potential barrier being a Schottky barrier
- H10D 62/82: Heterojunctions
- H10D 62/86: being Group II-VI materials, e.g. ZnO
- H10F 10/16: Photovoltaic cells having only PN heterojunction potential barriers
- H10F 71/00: Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00)
- H10F 77/12: Active materials
- H10F 77/16: Material structures, e.g. crystalline structures, film structures or crystal plane orientations
- H10F 77/206: {for devices having potential barriers}
- H10F 77/254: {comprising a metal, e.g. transparent gold}
- H10P 74/238: {comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement}
- H10D 62/812: {Single quantum well structures}
- H10F 77/124: comprising only Group III-V materials, e.g. GaAs
- H10P 14/22: using physical deposition, e.g. vacuum deposition or sputtering
- H10P 14/2911: {Arsenides}
- H10P 14/3436: {being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds}
- H10P 14/3452: {Microstructure}
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A UV radiation detector includes: a diode including a substrate having a first side and a second side, the first side and the second side being located on opposing faces of the substrate, an active layer including rocksalt phase crystalline structure CaS disposed on the first side of the substrate, an electrical contact disposed on the second side of the substrate, and a semi-transparent conducting layer disposed on the active layer; and a circuit connecting the semi-transparent conducting layer and the electrical contact. The UV radiation detector detects radiation having a wavelength between 200 and 280 nm.

## Claims

### Claim 1

A UV radiation detector comprising:
a Schottky-barrier diode, the Schottky-barrier diode comprising:
a substrate having a first side and a second side, the first side and the second side being located on opposing faces of the substrate;
a calcium sulfide (CaS) rocksalt phase crystalline layer as an active material grown on the first side of the substrate;
an electrical contact disposed on the second side of the substrate; and
a semi-transparent conducting layer disposed on the CaS rocksalt phase crystalline layer; and
a circuit connecting the semi-transparent conducting layer and the electrical contact,
wherein the UV radiation detector detects radiation having a wavelength between 200 and 280 nm,
wherein the Schottky-barrier diode has an external quantum efficiency of at least 19% at a wavelength of 235 nm when operated in zero-bias mode.

### Claim 2 (depends on 1)

The UV radiation detector according to claim 1, wherein the substrate has a lattice constant of 5.69 Å.

### Claim 3 (depends on 1)

The UV radiation detector according to claim 1, wherein the CaS rocksalt phase crystalline layer is between 20-50 nm thick.

### Claim 4 (depends on 1)

The UV radiation detector according to claim 1, wherein the substrate is an n+-GaAs substrate.

### Claim 5 (depends on 1)

The UV radiation detector according to claim 1, wherein the semi-transparent conducting layer is a 10 nm thick layer of gold.