[26a-E301-1~9] 3.13 Semiconductor optical devices

△ [26a-E301-9] Improvement of near-infrared sensitivity of silicon image sensors by quasi-resonance of surface plasmon

〇Takahito Yoshinaga¹, Kazuma Hashimoto¹, Nobukazu Teranishi^2,3, Atsushi Ono^1,2 (1.Shizuoka Univ., 2.RIE, Shizuoka Univ., 3.Univ. of Hyogo)

Keywords:plasmon, image sensor, photodetector

The research purpose is the improvement of near-infrared sensitivity of silicon CMOS image sensors. We propose an optical confinement in the silicon absorption layer under the quasi-resonance of surface plasmon. The incident light diffracts through the absorption layer at a diffraction angle nearly 90°, which increases the effective propagation distance and improves the silicon absorption. In simulation, the integrated absorption rate of 3-µm-thick silicon reached 31.3% at a wavelength of 940 nm, which was about 8.7-fold of sensitivity improvement by optical confinement.