Abstract: An optical sensor comprises a first and a second photodiode. Each photodiode comprises a respective light sensitive area. The second photodiode further comprises a wavelength-selective absorption layer arranged to selectively attenuate incident light before the light enters the light sensitive area of the second photodiode. The wavelength-selective absorption layer characterized by a low optical absorption in a wavelength range of 300 to 1100 nm and a high optical absorption in a wavelength range of 200 to 275 nm. The photodiodes are configured to generate respective electrical currents in response to incident light, and the optical sensor is configured to determine a light level based on a discrepancy between the electrical current generated by the first photodiode and the electrical current generated by the second photodiode.

Abstract: A method of forming a photodiode including providing a semiconductor wafer and performing a first doping step to form a first well in the wafer having a first type of doping. The method further includes performing a second doping step to form a second well having a second type of doping, so as to form a pn-junction of the photodiode between the first well and the second well. The method includes performing a shallow trench isolation etch to form a plurality of trenches in a surface of the wafer in the second well, and performing a third doping step by injecting dopants at a first angle relative to the surface of the wafer in order to increase a doping concentration of the second type of doping along the sides of the trenches in the second well. The method includes performing a fourth doping step by injecting dopants at a second angle relative to the surface of the wafer in order to increase a doping concentration of the second type of doping at the bottom of the trenches in the second well.

Abstract: A method of forming a light sensitive semiconductor structure is provided. The method includes providing a semiconductor wafer comprising a semiconductor layer comprising a light sensitive region, providing a gate structure comprising an insulation layer on said semiconductor layer and a polysilicon layer on said insulation layer, providing a contact stop layer on said gate structure, wherein said contact stop layer covers said light sensitive region, providing an etch mask, etching said contact stop layer using said etch mask to form said opening, etching said polysilicon layer using said etch mask, and providing a plurality of metal layers comprising a first metal layer electrically connected to said semiconductor layer and a plurality of dielectric layers between metal layers of said plurality of metal layers.

Abstract: An optical UV sensor comprises: a first photodiode sensitive to light in a first wavelength range and to light in a second wavelength range in the UV spectrum, wherein the second wavelength range comprises longer wavelengths than the first wavelength range, and wherein the first photodiode is configured to output a first signal in response to incident light; a second photodiode sensitive to light in the second wavelength range and comprising an absorption layer having an optical thickness in the range of 10 nm to 250 nm to absorb light in the first wavelength range, while being substantially transparent to light in the second wavelength range, wherein the second photodiode is configured to output a second signal in response to incident light; wherein the optical sensor is configured to output a difference between the first signal and the second signal.

Abstract: A dark reference device comprises: a photodiode comprising an optical active area; a light shield configured to prevent light from entering said optical active area, wherein said light shield comprises first and second overlapping metal covers, and wherein each of said metal covers comprises a plurality of openings overlapping said optical active area.

Abstract: A single photon avalanche diode (SPAD) device comprises: a silicon layer; an active region in said silicon layer for detecting incident light; and a blocking structure overlapping said active region for blocking incident light having a wavelength at least in the range of 200 nm to 400 nm, so that light having said wavelength can only be detected by said SPAD device when incident upon a region of said silicon layer outside of said active region.

Abstract: A dark reference device comprises: a photodiode comprising an optical active area; a light shield configured to prevent light from entering said optical active area, wherein said light shield comprises first and second overlapping metal covers, and wherein each of said metal covers comprises a plurality of openings overlapping said optical active area.

Abstract: A single photon avalanche diode (SPAD) device comprises: a silicon layer; an active region in said silicon layer for detecting incident light; and a blocking structure overlapping said active region for blocking incident light having a wavelength at least in the range of 200 nm to 400 nm, so that light having said wavelength can only be detected by said SPAD device when incident upon a region of said silicon layer outside of said active region.