Smaller camera sensors with ISOCELL plus technology

Digital camera sensor technology improved in moving from BSI -BackSide Illuminated sensors to ISOCELL. Now ISOCELL is improving providing better low light sensitivity. Credit: Samsung

The sensor size in a digital camera has a lot to do with the overall quality of the photos that can be taken. Once you fix the size you can play with the number of pixels and their size. You want more resolution (more pixels) you have to have smaller pixels, you want to capture more light so that low light situations (like night time) can be handle then you increase the pixel size but then you will have lower resolution.

This tradeoff is particularly though in smartphones where the space for the camera is small (it is not actually the planar surface, it is the fact that the bigger the sensor the “thicker” the optical part and hence the phone…).

One trick to increase the sensor size without increasing the thickness is to have several sensors and let the software combine the images captured by the sensors (this is increasingly done by top of the line smartphones that are embedding 2 sensors -even 3- and also by digital camera like Light 16 that has 16 sensors).

A different approach, more difficult, is to increase the performance of the sensors at the pixel level.  This is what Samsung has done moving in 2013 from the BSI (BackSide Illuminated) sensor to the ISOCELL sensor with a technology able to control the cross flow of photons from one pixel to the pixels nearby. That allowed the decrease of size of the boundary between pixels and therefore the relative increase of pixel size at a given resolution.

Now Samsung has announced an improvement to its ISOCELL technology, ISOCELL plus, that increases the effectiveness of the separation between pixels by using a special coating material on the sensor leading to an increase of density of the order of 30%, meaning that future smartphone sensors may pack as many as 20 million pixels. Alternatively, manufacturers may go for even thinner smartphones keeping today resolution (in the order of 10-12 Mpixels).

ISOCELL plus has been developed by Samsung in cooperation with Fujitsu resulting in an improved light sensitivity of 15% (better night time pictures) with a single pixel dimension of 0.8µm.

The trend towards the use of multiple sensors and image stacking will continue even with the new sensor technology and it is likely to be further perfected in the coming years. The progress in software has already killed the point and shoot camera market and quite a few observers are betting that it will eventually kill the professional camera market as well by the end of the next decade for areas like industrial photography, landscape photography and wedding photography whilst for wildlife photography where “long lenses” are needed it might take much more time for the replacement of professional cameras.

About Roberto Saracco

Roberto Saracco fell in love with technology and its implications long time ago. His background is in math and computer science. Until April 2017 he led the EIT Digital Italian Node and then was head of the Industrial Doctoral School of EIT Digital up to September 2018. Previously, up to December 2011 he was the Director of the Telecom Italia Future Centre in Venice, looking at the interplay of technology evolution, economics and society. At the turn of the century he led a World Bank-Infodev project to stimulate entrepreneurship in Latin America. He is a senior member of IEEE where he leads the New Initiative Committee and co-chairs the Digital Reality Initiative. He is a member of the IEEE in 2050 Ad Hoc Committee. He teaches a Master course on Technology Forecasting and Market impact at the University of Trento. He has published over 100 papers in journals and magazines and 14 books.