A high-efficiency CMOS image sensor with air gap in situ MicroLens (AGML) fabricated by 0.18-μm CMOS technology

The air gap in situ microlens (AGML) above-pixel sensor with 0.18-μm CMOS image sensor technology has been successfully developed to dramatically improve the optical crosstalk and pixel sensitivity. We demonstrated excellent crosstalk diminution with the structure on small pixels. Compared with conventional 2.8 μm square pixel, adopting the AGML can reduce the optical crosstalk up to 64%, and provide 21% in enhancement of photosensitivity at 0/spl deg/ incident angle. Furthermore, under 20/spl deg/ incident angle the optical crosstalk reduction and sensitivity enhancement are increased to 89% and 122%, respectively. Therefore, the AGML structure makes pixel size be further scaled down to less than 2.8 μm square and maintain good performance.