Syu H.-JLai H.-HSun R.-LCHING-FUH LIN2022-04-252022-04-2520210277786Xhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85109605292&doi=10.1117%2f12.2586050&partnerID=40&md5=95f73fff464f2b260f83ed9d65967963https://scholars.lib.ntu.edu.tw/handle/123456789/607038Nowadays, infrared (IR) photodetectors are mainly made from compound semiconductors due to the bandgap flexibility. However, compound semiconductors are mostly synthesized by expensive and energy-intensive epitaxy processes. Moreover, compound semiconductors are difficult to integrate with Si-based IC industry. Therefore, we used n-type Si (n-Si) wafers and thin NiSi to combine with localized surface plasmon resonance (LSPR) to form a Schottky IR detector. The incident IR light can induce thermionic effect to generate photocurrent, and the LSPR can enhance the light absorption and improve the photoresponse. The LSPR was created by NiSi covered inverted-pyramid array structures (IPAS) formed on n-Si substrates through photolithography and etching processes. After IPAS were prepared, 10-nm-thick Ni was thermally deposited on the IPAS and then the entire samples were annealed under 500 ℃ in 5 s to form NiSi/n-Si Schottky junctions. Finally, Ti and Au were thermally deposited successively on the NiSi and the back of n-Si wafers to be electrodes. A planar device was also prepared to be a control part. The photodetection ability of the device was examined by a 4.8-μm IR source with 1.8-mW optical power, which is in the absorption range of carbon monoxide. The IR source was turned on/off for each 15 s. Consequently, the planar NiSi/n-Si Schottky photodetector shows average 9.37-μA current change under 4.8-μm IR source illumination in 15 s. However, if 8-μm-period IPAS was used, the average current change improved to 30.9 μA. The response enhancement is 3.30 times of the planar device. ? 2021 SPIENiSiPhotodetectorPhotoresponsePlasmonSchottkySiSilicideSurface plasmon resonanceCarbon monoxideEtchingGold depositsInfrared radiationLight absorptionNickel compoundsPhotocurrentsPhotodetectorsPhotonsPlasmonsSilicidesSilicon wafersThermionic power generationAverage currentsCompound semiconductorsEtching processLocalized surface plasmon resonancePhoto detectionSchottky junctionsSchottky photodetectorsThermionic effects[SDGs]SDG7conference paper10.1117/12.25860502-s2.0-85109605292