KIST, 값싼 실리콘으로 적외선 감지…광감도 1.8~3배 높였다

Translation

The Korea Institute of Science and Technology (KIST) announced on 22 September that a team led by Dr Lee In-ho and Dr Park Min-chul of the Quantum Technology Research Group at its Next-Generation Semiconductor Research Institute had developed a short-wavelength infrared image sensor compatible with existing silicon semiconductor processes. Existing sensors use expensive compound semiconductors, so manufacturing costs are high and compatibility with silicon processes is low. The team used 'hot carriers', high-energy electrons generated when metal absorbs infrared light: the principle is that hot carriers cross the barrier between the metal and the silicon and thereby create an electrical signal. The problem of detection performance falling because infrared light is reflected was improved with an anti-reflection coating (QARC) that stacks amorphous silicon on an ultra-thin copper electrode about 10 nanometres thick. As a result, photosensitivity improved 1.8 to 3 times over the existing structure depending on the electrode material, and actual short-wavelength infrared imaging was achieved. The findings were published in the international journal 'Advanced Science' in April.