One-chip micro-integrated optoelectronic sensor

• US 6,608,360 B2
• Filed: 12/15/2000
• Issued: 08/19/2003
• Est. Priority Date: 12/15/2000
• Status: Active Grant

• Current Assignee: University of Houston (University of Houston System)
• Original Assignee: University of Houston (University of Houston System)
• Inventors: Berishev, Igor, Starikov, David, Bensaoula, Abdelhak
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): LOUIE, WAI SING
• Application Number:
  US09/738,728
• Publication Number:
  US 20020074553A1
• Time in Patent Office: 977 Days
• Field of Search: 257/449, 257/450, 257/453-456, 257/472, 257/476, 257/481, 438/653
• US Class Current: 257/481
• CPC Class Codes: H01L 31/108 the potential barrier being of the Schottky type
• CPC Class Codes: H01L 31/173 formed in, or on, a common substrate
• CPC Class Codes: H01L 31/1852 comprising a growth substrate not being an AIIIBV compound
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

This disclosure describes one-chip micro-integrated optoelectronic sensors and methods for fabricating and using the same. The sensors may include an optical emission source, optical filter and a photodetector fabricated on the same transparent substrate using the same technological processes. Optical emission may occur when a bias voltage is applied across a metal-insulator-semiconductor Schottky contact or a p-n junction. The photodetector may be a Schottky contact or a p-n junction in a semiconductor. Some sensors can be fabricated on optically transparent substrate and employ back-side illumination. In the other sensors provided, the substrate is not transparent and emission occurs from the edge of a p-n junction or through a transparent electrode. The sensors may be used to measure optical absorption, optical reflection, scattering or fluorescence. The sensors may be fabricated and operated to provide a selected spectrum of light emitted and a multi-quantum well heterostructure may be fabricated to filter light reaching the photodetector.

Claims

1. An optoelectronic device for providing light emission or detection, comprising:

an optically transparent substrate;

an optically transparent semiconductor layer on the substrate, the semiconductor layer being selected from the group of substances consisting of III-V nitride compounds and having a top surface;

an amorphous silicon layer on a first area of the top surface of the semiconductor layer, the amorphous silicon layer having a selected thickness to provide tunneling from a Schottky barrier and produce avalanche electroluminescence and detection;

a layer of metal on the amorphous silicon layer, the metal forming a Schottky barrier and being selected to provide low diffusion rate of the metal through the amorphous silicon layer under conditions of deposition of the layer, and an ohmic contact to the layer of metal; and

an ohmic contact on a second area of the top surface of the semiconductor layer.

2. The device of claim 1 wherein the material of the optically transparent substrate is selected from the group of substances consisting of sapphire, quartz and glass.

3. The device of claim 1 wherein the thickness of the amorphous silicon layer is less than about 200 Angstroms.

4. The device of claim 1 wherein the thickness of the amorphous silicon layer is in the range from about 30 Angstroms to about 50 Angstroms.

5.The device of claim 1 wherein the layer of metal on the amorphous silicon layer is titanium.

5. The device of claim 1 wherein the ohmic contact on the second area of the top surface of the semiconductor is comprised of layers of platinum, nickel and gold.

6. An optoelectronic device, comprising:

an optically transparent substrate;

two or more optically transparent spaced apart semiconductor layers on the substrate, each of the semiconductor layers being selected from the group of substances consisting of 111-V nitride compounds and having a top surface;

an amorphous silicon layer on a first area of the top surface of each of the spaced apart semiconductor layers, each of the amorphous silicon layers having a selected thickness to provide tunneling from a Schottky barrier and produce avalanche electroluminescence and detection;

a layer of metal on each of the amorphous silicon layers, the metal forming a Schottky barrier and being selected to provide low diffusion rate of the metal through the amorphous silicon layer under conditions of deposition of the layer, and an ohmic contact to the layer of metal; and

an ohmic contact on a second area of the top surface of the semiconductor layers.

7. The device of claim 7 wherein the material of the optically transparent substrate is selected from the group of substances consisting of sapphire, quartz and glass.

8. The device of claim 7 wherein the thickness of the amorphous silicon layers is less than about 200 Angstroms.

9. The device of claim 7 wherein the thickness of the amorphous silicon layers is in the range from about 30 Angstroms to about 50 Angstroms.

10. The device of claim 7 wherein the metal in the layer of metal on the amorphous silicon layers is titanium.

11. The device of claim 7 wherein the ohmic contact on the second area of the top surface of the semiconductor layers is comprised of layers of platinum, nickel and gold.

12. The device of claim 7 wherein Schottky contacts form a pattern on the substrate.