Ambient light detector, detector array and method
An ambient light detector, a detector array and a method are disclosed. An ambient light sensor includes a first plurality of sensor elements, where each sensor element is configured to provide a signal in response to a level of illumination and a second plurality of reference elements, each reference element configured to provide a reference signal and each including a blocking element configured to shield the respective reference element from being illuminated, where the first plurality is larger than the second plurality and the first plurality of sensor elements and the second plurality of reference elements are arranged in an array, and where a sensor element and a reference element are laterally arranged on or in a common layer substrate sharing at least one common first contact.
1. An ambient light sensor comprising:
a first plurality of sensor elements, each sensor element configured to provide a signal in response to a level of illumination; and
a second plurality of reference elements, each reference element configured to provide a reference signal and each comprising a blocking element configured to shield the respective reference element from being illuminated,
wherein the first plurality is larger than the second plurality and the first plurality of sensor elements and the second plurality of reference elements are arranged in an array, and
wherein a sensor element and a reference element are laterally arranged on, or in, a common layer substrate and share at least one common first contact.
2. The ambient light sensor of claim 1 , wherein second contacts for the reference elements are arranged on a surface of the reference elements facing the blocking element.
3. The ambient light sensor of claim 2 , wherein the second contacts for the sensor elements and/or the reference elements are arranged on a surface of common layer substrate facing away from the blocking element.
4. The ambient light sensor of claim 1 , wherein second contacts for the sensor elements are arranged on a surface of the sensor elements facing the blocking element.
5. The ambient light sensor of claim 1 , wherein the common contact is arranged on a surface of the common layer substrate facing away from the blocking element.
6. The ambient light sensor of claim 1 , wherein, for a top view onto the light sensor, the blocking element is larger than the respective reference element.
7. The ambient light sensor of claim 1 , wherein the blocking element extends over a portion of a sensor element of the first plurality of sensor elements adjacent to the reference element.
8. The ambient light sensor of claim 7 , wherein the portion of the sensor element covered by the blocking element is between 5% and 50% of a total sensor area of the sensor element.
9. The ambient light sensor of claim 1 , wherein the first plurality is 4 times the second plurality.
10. The ambient light sensor of claim 1 , wherein the sensor elements and the reference elements each comprise a p-doped layer, an n-doped layer and an active area in between configured to generate the signal when being illuminated.
11. The ambient light sensor of claim 1 , wherein the sensor elements and/or the reference elements each comprise a well arranged in the common substrate to form an active layer between the well and the common substrate.
12. The ambient light sensor of claim 1 , wherein the blocking element is arranged distally apart from a main surface of the reference element.
13. The ambient light sensor of claim 1 , wherein the sensor elements and the reference elements are arranged in an array, such that a ratio of sensor elements and reference elements along an edge of the array corresponds to a ratio between the first plurality and the second plurality.
14. The ambient light sensor of claim 1 , wherein each blocking element completely covers the respective reference element and extends laterally between the respective reference element and at least one sensor element of the first plurality of sensor elements.
15. An ambient light detector array comprising:
a first plurality of photodiodes; and
a second plurality of reference diodes, the first plurality being different from the second plurality and arranged laterally to each other such that a ratio of a number of photodiodes and a number of reference diodes along an edge of the array corresponds to a ratio between the first plurality and the second plurality.
16. The ambient light detector array, of claim 15 , wherein the first plurality and the second plurality are arranged to form an N×N pattern, wherein N is an integer larger than 2.
17. The ambient light detector array of claim 15 , wherein each corner of the array comprises a photodiode of the first plurality of photodiodes.
18. The ambient light detector array of claim 15 , wherein the second plurality of reference diodes are arranged in a diagonal across the array.
19. The ambient light detector array of claim 15 , wherein the first plurality of photodiodes is four times larger than the second plurality of reference diodes.
20. A method of forming an ambient light sensor, the method comprising:
providing a layer of a first conductivity type, the layer having a main surface;
forming at least two areas of a second conductivity type on or in the layer laterally adjacent to each other and separated by a first distance;
forming contacts to contact the layer and each of the at least two areas; and
forming a light shield element over one of the at least two areas substantially parallel to the main surface, such that the light shield covers the one of the at least two areas and extends at least along the distance.