Light sensor having transparent substrate with lens formed therein

Patent metadata

Field	Value
Publication number	US-9224890-B1
Application number	US-201414328957-A
Country	US
Kind code	B1
Filing date	Jul 11, 2014
Priority date	Jan 26, 2011
Publication date	Dec 29, 2015
Grant date	Dec 29, 2015

Abstract

Light sensor devices are described that have a glass substrate, which includes a lens to focus light over a wide variety of angles, bonded to the light sensor device. In one or more implementations, the light sensor devices include a substrate having a photodetector formed therein. The photodetector is capable of detecting light and providing a signal in response thereto. The sensors also include one or more color filters disposed over the photodetector. The color filters are configured to pass light in a limited spectrum of wavelengths to the photodetector. A glass substrate is disposed over the substrate and includes a lens that is configured to collimate light incident on the lens and to pass the collimated light to the color filter.

First claim

What is claimed is:

1. A light sensor comprising:
a substrate having a surface;
a photodetector formed in the substrate proximate to the surface, the photodetector configured to detect light generated from a single illumination source and to provide a signal in response thereto;
a first color filter disposed over the photodetector and configured to filter light in a first limited spectrum of wavelengths to the photodetector;
a second color filter disposed over the photodetector and configured to filter light in a second limited spectrum of wavelengths to the photodetector;
a third color filter disposed over the photodetector and configured to filter light in a third limited spectrum of wavelengths to the photodetector;
a transparent substrate disposed over the substrate, the transparent substrate including a lens configured to collimate light incident on the lens and to pass the collimated light to at least one of the first color filter, the second color filter, or the third color filter, and
an IR suppression filter disposed between at least one of the first color filter, the second color filter, or the third color filter and the transparent substrate, the IR suppression filter configured to filter infrared light to at least substantially block infrared light from reaching the least one of the first color filter, the second color filter, or the third color filter.

2. The light sensor as recited in claim 1 , further comprising a first conductive layer and a second conductive layer and a through-substrate via configured to provide an electrical interconnect with the photodetector.

3. The light sensor as recited in claim 1 , wherein the photodetector comprise at least one of photodiodes or phototransistors.

4. The light sensor as recited in claim 1 , wherein the first color filter is stacked over or adjacent to the second color filter, and the second color filter is stacked over or adjacent to the third color filter.

5. The light sensor as recited in claim 1 , wherein the lens is configured as at least one of a Fresnel lens, a ball lens, a diffractive lens, a diffractive optics element, or a gradient-index optics lens.

6. The light sensor as recited in claim 1 , wherein the transparent substrate comprises a glass substrate.

7. The light sensor as recited in claim 1 , wherein the second color filter is disposed over the first color filter in a stacked configuration.

8. The light sensor as recited in claim 7 , wherein the third color filter is disposed over the second color filter in a stacked configuration.

9. The light sensor as recited in claim 1 , wherein the lens is disposed directly over at least one of the first color filter, the second color filter, or the third color filter.

10. A process comprising:
forming one or more color filters over a passivation layer of a wafer, the passivation layer formed over a surface of the wafer, the wafer including at least one photodetector formed therein, the at least one photodetector configured to detect light generated from a single illumination source and to provide a signal in response thereto, the one or more color filters disposed over the photodetector, the one or more color filters configured to pass light in a limited spectrum of wavelengths to the photodetector;
forming an adhesive material over the passivation layer and the one or more color filters;
forming an IR suppression filter over the one or more color filters, the IR suppression filter configured to filter infrared light to at least substantially block infrared light from reaching the at least one color filter;
positioning a transparent substrate over the wafer, the transparent substrate including a lens configured to collimate light incident on the lens, the IR suppression filter disposed between the at least one color filter and the transparent substrate; and
forming a through-substrate via in the wafer to provide an electrical interconnect with the at least one photodetector.

11. The process as recited in claim 10 , wherein forming one or more color filters further comprises forming a first color filter over or adjacent to a second color filter, wherein the second color filter is formed over or adjacent to a third color filter.

12. The process as recited in claim 11 , wherein the first color filter is configured to filter light in a first limited spectrum of wavelengths to a photodetector formed in the wafer, the second filter is configured to filter light in a second limited spectrum of wavelengths to the photodetector, and the third color filter is configured to filter light in a third limited spectrum of wavelengths to the photodetector.

13. The process as recited in claim 10 , further comprising forming an edge trim region about an edge of the substrate.

14. The process as recited in claim 10 , wherein forming a through-silicon via further comprises forming a hardmask layer over the wafer, depositing a photoresist layer over the hardmask layer, patterning a selected region of the photoresist layer, etching the selected region to form the through-silicon via.

15. The process as recited in claim 10 , wherein the one or more color filters comprise a color absorption filter.

16. The process as recited in claim 10 , wherein the lens is configured as at least one of a Fresnel lens, a ball lens, a diffractive lens, a diffractive optics element, or a gradient-index optics lens.

Assignees

• Maxim Integrated Products

Inventors

• Kerness Nicole D
• Samoilov Arkadii V
• Wang Zhihai
• Jones Joy T

Classifications

• H10W72/20

  Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps · CPC title

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title

• H10F77/337

  using interference filters, e.g. multilayer dielectric filters · CPC title

• H10F71/00

  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) · CPC title

• H10F39/811

  Interconnections · CPC title