OPTICAL PROXIMITY SENSOR ARRANGEMENT AND METHOD FOR PRODUCING AN OPTICAL PROXIMITY SENSOR ARRANGEMENT

• US 20170250169A1
• Filed: 02/24/2017
• Published: 08/31/2017
• Est. Priority Date: 02/26/2016
• Status: Active Grant

• Current Assignee: ams AG (Ams-Osram AG)
• Original Assignee: ams AG (Ams-Osram AG)
• Inventors: MEHRL, David, STOLTZ, Greg
• Granted Patent: US 10,629,576 B2
• Time in Patent Office: Days
• CPC Class Codes: G01S 17/02 Systems using the reflection of electromagnetic waves other than radio waves G01S17/66 takes precedence
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4813 Housing arrangements
• CPC Class Codes: H01L 25/165 Containers
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 31/02162 for filtering or shielding light, e.g. multicolour filters for photodetectors
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 31/167 the light sources and the devices sensitive to radiation all being semiconductor devices characterised by potential barriers

Abstract

An optical proximity sensor arrangement comprises a semiconductor substrate (100) with a main surface (101). A first integrated circuit (200) comprises at least one light sensitive component (201). The first integrated circuit is arranged on the substrate at or near the main surface. A second integrated circuit (300) comprises at least one light emitting component (301), and is arranged on the substrate at or near the main surface. A light barrier (400) is arranged between the first and second integrated circuits. The light barrier being designed to block light to be emitted by the at least one light emitting component from directly reaching the at least one light sensitive component. A multilayer mask (500) is arranged on or near the first integrated circuit and comprising a stack (501) of a first layer (502) of first elongated light blocking slats (503) and at least one second layer (504) of second elongated light blocking slats (505). The light blocking slats are arranged in the mask to block light, incident on the mask from a first region of incidence (701), and to pass light, incident on the mask from a second region of incidence (702), from reaching the at least one light sensitive component.

Claims

1. An optical proximity sensor arrangement, comprising:

a semiconductor substrate with a main surface;

a first integrated circuit comprising at least one light sensitive component, the first integrated circuit being arranged on the substrate at or near the main surface;

a second integrated circuit comprising at least one light emitting component, the second integrated circuit being arranged on the substrate at or near the main surface;

a light barrier arranged between the first and second integrated circuits, the light barrier being designed to block light to be emitted by the at least one light emitting component from directly reaching the at least one light sensitive component; and

a multilayer mask arranged on or near the first integrated circuit and comprising a stack of a first layer of first elongated light blocking slats and at least one second layer of second elongated light blocking slats, wherein the light blocking slats are arranged in the mask to block light, incident on the mask from a first region of incidence, and to pass light, incident on the mask from a second region of incidence, from reaching the at least one light sensitive component.

2. The optical proximity sensor arrangement according claim 1, wherein

the first region comprises angles of incidence restricted to a cone of incidence defined with respect to a surface normal of the mask, and

the second region comprises angles of incidence restricted greater than those angles of the first region.

3. The optical proximity sensor arrangement according claim 1, wherein

the first and the at least one second layer of elongated light blocking slats have different distances with respect to the main surface,

the light blocking slats from the second layer and the light blocking slats from the first layer are offset with respect to each other and along a direction parallel to the main surface, and

wherein the first and second regions of incidence are a function of the offset of light blocking slats.

4. The optical proximity sensor arrangement according claim 3, wherein

the elongated light blocking slats in the first and the at least one second layer are oriented along their elongation and facing into a common direction, respectively,

pairs of elongated light blocking slats in the first and the at least one second layer are regularly spaced such as to confine trenches along the common direction, respectively, and

the elongated light blocking slats and trenches define channels in the mask, and

the second region of incidence is a function of the opening angle.

5. The optical proximity sensor arrangement according to claim 3, wherein the light blocking slats from the second layer and the light blocking slats from the first layer are offset with respect to each other such that the at least one light sensitive component is at least partly or completely covered when viewed along a surface normal of mask.

6. The optical proximity sensor arrangement according to claim 4, wherein channels defined by the elongated light blocking slats and trenches have a two-sided opening angle.

7. The optical proximity sensor arrangement according to claim 1, wherein

the first layer of first elongated light blocking slats is arranged close to or directly on the at least one light sensitive component, and

the first layer at least partly covers the at least one light sensitive component.

8. The optical proximity sensor arrangement according to claim 1, wherein the elongated light blocking slats are arranged into the first and second layer.

9. The optical proximity sensor arrangement according to claim 1, wherein the mask comprises one or more further second layers each comprising second elongated light blocking slats.

10. The optical proximity sensor arrangement according to claim 9, wherein the second elongated light blocking slats in the one or more further second layers each comprise second elongated light blocking slats having different distances with respect to the main surface and are aligned along a surface normal of the mask.

11. The optical proximity sensor arrangement according to claim 1, wherein the elongated light blocking slats are metal slats and/or glass slats.

12. The optical proximity sensor arrangement according to claim 1, wherein

the at least one light sensitive component is at least partly covered by a field oxide,

the first layer of first elongated light blocking slats is arranged on the field oxide,

the second layer or plurality of second layers are arranged in an interlayer oxide, and

an oxide layer or passivation layer is arranged on a top side of the mask.

13. The optical proximity sensor arrangement according to claim 1, further comprising a lens, wherein

the at least one light sensitive component is placed in a back focal plane of the lens, and

an aperture shield is arranged at or near a top side of the lens, comprising at least one elongated light blocking area and one or more light passing areas confined by the elongated light blocking area.

14. The optical proximity sensor arrangement according to claim 12, wherein the elongated light blocking area comprises a circular or rectangular bond pad of the at least one light emitting component.

15. A method for producing an optical proximity sensor arrangement, comprising the steps of:

providing a semiconductor substrate with a main surface;

providing a first integrated circuit comprising at least one light sensitive component, arranging the first integrated circuit on the substrate at or near the main surface;

providing a second integrated circuit comprising at least one light emitting component, arranging the second integrated circuit on the substrate at or near the main surface;

arranging a light barrier between the first and second integrated circuits, the light barrier being designed to block light to be emitted by the at least one light emitting component from directly reaching the at least one light sensitive component; and

arranging a multilayer mask on or near the first integrated circuit, wherein the mask comprises a stack of a first layer of first elongated light blocking slats and at least one second layer of second elongated light blocking slats, wherein the light blocking slats are arranged in the mask to block light, incident on the mask from a first region of incidence, and to pass light, incident on the mask from a second region of incidence, from reaching the at least one light sensitive component.