By Dr. Cameron Chai
Applied Materials, a provider of equipment, software and services for manufacturing advanced flat panel display, solar photovoltaic and semiconductor products, has introduced an innovative new technology for producing backside-illuminated (BSI) image sensors that are utilized in the latest, sophisticated tablet PCs, smartphones and cameras.
The new Applied Producer Optiva CVD system allows manufacturers to deposit conformal, low temperature films that increase the durability and enhance the sensor’s low-light performance. These features increase the device yield leading to lower costs.
The microlenses in the sophisticated image sensors are located exactly above the photodiodes, so as to enhance the ability of each pixel to gather light. The Applied Materials Producer Optiva system covers the microlens with a thin, transparent and tough layer that has the ability to protect the lens from the environment and also reduce scratches and reflections. This CVD allows conformal deposition greater than 95% at temperatures lower than 200 °C. This is critical in sensor fabrication where temperature-sensitive adhesives and polymers are used.
The Applied CVD system can be used for 3D chip packaging, where for through-silicon vias’ it can be utilized for depositing conformal insulating liners. The low temperature in this process plays an important role in protecting the adhesive that is used for bonding the wafer to a temporary carrier.
The vice president and general manager of Applied’s business unit - Dielectric Systems and Modules, Bill McClintock, stated that the low temperature process of the Optiva ran on the company’s fast Producer platform, which will help chipmakers to address the demand for BSI image sensors. By 2014, the market requirement will be around 300 million BSI image sensors, he added.
iSuppli, a market researcher, has stated that the fitment of BSI sensors in expected to go up from 14% in 2010 to three-quarters of all smartphones in 2014. Further, prominent manufacturers are moving to 300 mm wafers for increasing the output. This change will help manufacturers to produce significantly more sensors per wafer.