Backside illuminated photosensor element with light pipe and light mirror structures
AssigneeSTMicroelectronics (Crolles 2) SAS
InventorsFrancois Roy, Bastien Mamdy
Life of this patent
Estimating the term…
Abstract
A photosensor is formed within a semiconductor substrate layer having a front side and a back side. An isolation structure delimits an active region of the semiconductor substrate layer which includes a charge collecting region. The front side of semiconductor substrate layer includes a charge transfer circuit. A reflecting mirror is mounted at the back side of the semiconductor substrate layer. The reflecting mirror includes a pupil opening configured to admit light into the active region at the back side. An underside reflective surface of the reflecting mirror is configured to reflect light received from the active region back into the active region.
Claims20
A photosensor, comprising:
- a semiconductor substrate layer having a front side and a back side;
- an isolation structure delimiting an active region of the semiconductor substrate layer;
- a charge collecting region within the active region;
- a charge transfer circuit within the active region at the front side of the semiconductor substrate layer;
- and
- a reflecting mirror mounted at the back side of the semiconductor substrate layer, said reflecting mirror including a pupil opening configured to admit light into the active region at the back side and including an underside reflective surface configured to reflect light received from the active region back into the active region.
A photosensor, comprising:
- a semiconductor substrate layer having a front side and a back side;
- an isolation structure delimiting an active region of the semiconductor substrate layer;
- a charge collecting region within the active region;
- a charge transfer circuit within the active region at the front side of the semiconductor substrate layer;
- an antireflective coating layer mounted to the back side of the semiconductor substrate layer;
- and
- a first layer made of a reflective metal material mounted to the antireflective coating layer, said layer including a pupil opening configured to admit light into the active region at the back side, and wherein an underside reflective surface of said layer is configured to reflect light received from the active region back into the active region.
A photosensor, comprising:
- a semiconductor substrate layer having a front side and a back side;
- an isolation structure delimiting an active region of the semiconductor substrate layer;
- a charge collecting region within the active region;
- a charge transfer circuit within the active region at the front side of the semiconductor substrate layer;
- an antireflective coating layer mounted to the back side of the semiconductor substrate layer;
- and
- a layer made of a reflective metal material mounted to the antireflective coating layer, said layer including a frustoconical aperture filled with a transparent material, said frustoconical aperture defining a reflective conical surface configured to reflect light into the active region at the back side, and wherein an underside reflective surface of said layer is configured to reflect light received from the active region back into the active region.
Dependencies are inferred from the claim text.