Improved near-infrared sensitivity of a back-side illuminated image sensor with a metal reflector

IEICE Electronics Express

Shozo Morita¹  Yutaka Arima¹  Tetsuya Ariyoshi¹  Akiyoshi Baba¹ 

[1] Center for Microelectronic Systems, Kyushu Institute of Technology

关键词: near-infrared light;    higher sensitivity;    back-side illumination;    Deep-RIE;    metal reflector;   

DOI  :  10.1587/elex.6.341

学科分类：电子、光学、磁材料

来源: Denshi Jouhou Tsuushin Gakkai

【 摘 要 】

References(4)Cited-By(2)To improve the near-infrared sensitivity of an image sensor that has a conventional pixel structure, we made use of the metal wiring layer as a reflector in addition to the method of back-side illumination from the etched back surface of the sensor. We fabricated an image sensor that has a remaining silicon substrate thickness of 32 ± 4µm and evaluated the spectral sensitivity. For 830nm light, the sensitivity is about the same as for front-side illumination. For a wavelength of 970nm, the sensitivity was 2.2 times as high as for front-side illumination. The image sensor with reflector has about 30% higher sensitivity than without the reflector.

【 授权许可】

Unknown