近红外增强CCD成像器件研究

Study on Near Infrared-enhanced CCD Imaging Sensors

阐述采用背照式CCD工艺,制备一种新型的近红外增强CCD。相比较传统的近红外增强CCD(增加外延层厚度),基于反应离子刻蚀法在该器件背面进行了黑硅制作,在紫外光(波长250nm)到近红外光(波长2500nm)都具有高吸收率,可以增强CCD近红外响应灵敏度。结果表明,在400~1060nm波长范围内,黑硅反射率小于7%,吸收率大于93%。黑硅CCD近红外响应得到增强,与常规CCD相比,在波长950~1060nm的量子效率分别从34%和1%提高到41.8%和16.1%。

A new kind of near infrared CCD was prepared by using back illumination CCD.Compared with the traditional near infrared enhanced CCD(increasing the thickness of the epitaxial layer),black silicon was fabricated on the back of the device by reactive ion etching,black silicon(BS)appears very high absorptance of light from the near-ultraviolet(250 nm)to the near-infrared(2500 nm)wavelength region.And the black silicon detectors are many times more responsivity than conventional silicon detectors in the near infrared.It is indicated that,the reflectance of black silicon,prepared by reactive ion etching,is less than 7%and the absorptance of the sample remains more than 93%in the wavelength from 400 nm to 1060 nm.The near infrared response of CCD is remarkably enhanced by black silicon,Compared to conventional CCD,The quantum efficiencies of these devices at the wavelength of 950 nm and 1060 nm are from 34%and 1%to 41.8%and 16.1%.