With emerging markets developing for augmented reality (AR), virtual reality (VR), facial-recognition security systems, advanced human/machine interfaces and other 3D imaging applications, the need for 3D camera systems is booming. These 3D cameras require CMOS image sensors that are capable of working in the near-infrared (NIR) spectrum.
In 2018, a towering wave of 3D imaging and sensing products is expected to hit world markets, according to the research firm Yole Développement. The tremendous market growth of 37.7 percent CAGR is forecast for the coming years, reaching $9 billion in sales by 2022.
To meet this enormous and sustained market demand, material solutions are needed to cost-efficiently mass produce the advanced front-side imagers that drive 3D image sensors. A new generation of silicon-on-insulator (SOI) wafer technology called Imager-SOI offers both the performance and the high-volume availability to meet customers’ needs and accelerate the development of new 3D imaging products.
This new flavor of SOI extends the operating range of high-resolution, silicon-based CMOS image sensors into the NIR spectrum by solving several key challenges. For example, Imager-SOI is capable of light trapping, effectively eliminating the problem of silicon’s high transparency to infrared light. As a result, the quantum efficiency of sensor ICs is enhanced significantly.
In addition, the SOI wafer’s buried oxide (BOx) layer enables complete pixel isolation. This greatly improves ICs’ signal-to-noise ratios in the NIR spectrum by reducing crosstalk.
The BOx layer, whose thickness can be tightly controlled from 15nm to 150nm, also serves as a diffusion barrier to prevent metal contamination. The epi-ready top-silicon layer can have a thickness ranging from 50 nm to 200 nm.
These performance attributes of the newest SOI technology enable innovative 3D sensor designs that are revolutionizing imaging for high-volume consumer electronics.