Samsung develops new image sensor technology for mobile devices

The quality of a digital image is determined by the amount of light that is accurately captured by the individual pixels of the sensor. With the market pressure to increase camera resolution and image quality, without growing the camera size, the pixels have had to shrink, while improving their performance at the same time – a challenging task.

Previous sensor technology developments have focused on improving the light absorption of each pixel, and have progressed pixel technology from FSI (Front Side Illumination) to BSI (Back Side Illumination) which places photodiode at the top to maximize photoelectric efficiency. However, this BSI technology also faced limitations in improving image quality as pixel sizes continued to decrease, Samsung said.

That’s why the company has developed Isocell. The new technology, which is patent pending, isolates the pixels by forming a physical barrier between the neighboring elements. This isolation enables more photons to be collected from the micro-lens and absorbed into the correct pixel’s photodiode while minimizing undesired electrical crosstalk between pixels and allowing expanded full well capacity (FWC).

Compared to conventional BSI pixels, the Isocell pixels decrease the crosstalk by approximately 30 percent, according to Samsung. As a result, it achieves higher color fidelity to reproduce the original color with sharpness and richness, and increases the full well capacity (FWC) by 30 percent which leads to greater dynamic range.

Additionally, an imager designed with Isocell can feature a 20 percent wider chief ray angle (CRA), reducing the height of the camera module. This makes it suitable for slim and small mobile devices.

As the first Samsung image sensor to adopt this new technology, the S5K4H5YB 1/4 inch 8 Megapixel imager is currently sampling to customers with mass production scheduled for Q4 2013.