METHOD OF MANUFACTURING A POWERFUL PHOTODETECTOR Russian patent published in 2019 - IPC H01L31/18 

FIELD: physics.

SUBSTANCE: invention can be used to create microwave photo detectors based on GaAs/Al_xGa_1-xAs epitaxial structures sensitive to radiation at a wavelength of 810–860 nm. Method consists in creating a photosensitive area and a contact pad for bonding outside the photosensitive area on a semiconductor substrate, forming an antireflection coating and frontal ohmic contact tires 4–10 microns wide on the photosensitive area. Tires of frontal ohmic contact are performed by deposition of a three-layer coating consisting of a lower layer of silver, a layer of gold and an upper layer of silver. Create a rear ohmic contact, form a mesa-structure, blacken the top silver layer of frontal ohmic contact tires by processing the photodetector in a solution based on sodium sulfide, sodium hydroxide and sodium sulfite for 15–30 seconds or in a solution based on FeCl₃ within 5–15 s.

EFFECT: invention provides the possibility of manufacturing a photodetector (laser radiation fed over an optical fiber) having an increased operating power, an increased degree of absorption of the incident radiation and a lower value of the reflection coefficient of the radiation, and, as a consequence, a reduced fraction of the radiation incident upon reflection from the photo detector in the optical fiber, moreover, since laser radiation is supplied to a photodetector via an optical fiber, this ensures that the radiation is focused on the photosensitive area of the photodetector and, accordingly, prevents the emission and reflection of radiation from the contact pads.

3 cl, 6 dwg