Solid-State Photodetector Pixel and Photodetecting Method

Abstract

A pixel is formed in a semiconductor substrate (S) with a plane surface for use in a photodetector. It comprises an active region for converting incident light (In) into charge carriers, photogates (PGL, PGM, PGR) for generating a lateral electric potential (Φ(x)) across the active region, and an integration gate (IG) for storing charge carriers generated in the active region and a dump site (Ddiff). The pixel further comprises separation-enhancing means (SL) for additionally enhancing charge separation in the active region and charge transport from the active region to the integration gate (IG). The separation-enhancing means (SL) are for instance a shield layer designed such that for a given lateral electric potential (Φ(x)), the incident light (In) does not impinge on the section from which the charge carriers would not be transported to the integration gate (IG).

1 - 46 . (canceled) 
     
     
         47 . A method for sensing a chemical and/or biochemical substance, comprising:
 illuminating the substance with modulated electromagnetic radiation, causing the electromagnetic radiation to interact with the substance or indirectly through a transducer, and   detecting electromagnetic radiation from substance, with a photodetector that comprises an active region for converting incident electromagnetic radiation into charge carriers and an integration region for storing the charge carriers synchronously with the modulation of the modulated electromagnetic radiation.   
     
     
         48 . The method according to claim  37 , wherein the substance is deposited on a sensing pad arranged on a surface of a planar waveguide. 
     
     
         49 . The method according to claim  37 , wherein the interaction comprises luminescence, and luminescent radiation emitted by the substance is detected. 
     
     
         50 . The method according to claim  38 , wherein the sensing pad is illuminated by a resonant electromagnetic field excited in the waveguide, and luminescent radiation that does not excite a resonant electromagnetic field in the waveguide is detected. 
     
     
         51 . The method according to claim  38 , wherein the sensing pad is illuminated by a first resonant electromagnetic field excited in the waveguide, and electromagnetic radiation that excites a second resonant electromagnetic field in the waveguide is detected. 
     
     
         52 . The method according to claim  41 , wherein the sensing pad comprises a diffraction grating structure. 
     
     
         53 . The method according to claim  42 , wherein electromagnetic radiation is coupled into the waveguide and coupled out of the waveguide by the same grating structure comprised in the sensing pad. 
     
     
         54 . The method according to claim  42 , wherein electromagnetic radiation is coupled into the waveguide by a first grating structure and coupled out of the waveguide by a second grating structure that is not identical with the first grating structure, and the sensing pad comprises the first or the second grating structure. 
     
     
         55 . The method according to claim  44 , wherein the sensing pad comprises the first grating structure, a beam of electromagnetic radiation is coupled into the waveguide under a constant, well-defined incoupling angle (θ in ), the wavelength (λ) of the beam is periodically modulated, the modulation being triggered by a camera performing the detection, and an intensity of outcoupled electromagnetic radiation is detected by the camera. 
     
     
         56 . The method according to claim  44 , wherein the sensing pad comprises the second grating structure, electromagnetic radiation is coupled into the waveguide under a limited range of incoupling angles, the wavelength (λ) of the beam is periodically modulated, the modulation being triggered by a camera performing the detection, and a position-dependent phase of an outcoupled beam of electromagnetic radiation is detected by the camera.