ON Semi’s advanced CMOS process expertise enables groundbreaking image sensor for astronomy

The 16 megapixel H4RG-15, which consists of Teledyne’s HgCdTe detector material hybridised to a CMOS readout circuit, is the largest sensor ever produced for infrared astronomy. An enabling technology in the development of the H4RG-15 is the ability to fabricate and reliably yield the 63 mm x 63 mm stitched CMOS ROIC using ON Semiconductor’s proprietary 180 nanometre process technology. The ROIC is so large that only four die fit onto a 200 mm wafer.

The high yield for these ELS ROICs can be attributed to the expertise and yield improvement efforts made by ON Semiconductor’s wafer fabrication team in collaboration with its Custom Foundry Division. The H4RG-15 readouts were manufactured at ON Semiconductor’s wafer manufacturing facility located in Gresham, Oregon. With this project, ON Semiconductor has demonstrated that it can successfully produce the H4RG-15 with the yield required for this next generation sensor.

The H4RG-15 sensor has been installed at the University of Hawaii’s observatory on Mauna Kea to confirm the performance of the sensor under telescope observing conditions. “The resolution with which images can be captured using this new sensor system represents a major step forward in the progression of IR astronomy,” said Dr. Donald Hall of the Institute for Astronomy at the University of Hawaii, who is the principal investigator for the NSF-funded H4RG-15 development program.

The H4RG-15 is the next step in the highly successful HxRG family of image sensors that Teledyne has developed and delivered to the leading astronomical observatories, on ground and in space, including the Hubble Space Telescope, the James Webb Space Telescope, and every major ground-based observatory.

“The H4RG-15 is critical to the next generation of ground-based telescopes. The 30-meter class Extremely Large Telescopes and future space missions will be designed around the H4RG-15,” stated Richard Blank, Teledyne’s senior program manager for the H4RG-15. “We greatly value our partnership with ON Semiconductor, which has been critical to the successful development of the H4RG-15,” added James Beletic, Vice President of Space & Astronomy at Teledyne Imaging Sensors.

“The success of the H4RG-15 ROIC is an important validation of the capabilities of our company’s foundry services in addition to our process capabilities in CMOS imaging,” adds Rocke Acree, Business Unit Manager, Custom Foundry Division at ON Semiconductor. “The H4RG-15 ROIC produced for Teledyne Imaging Sensors is one of the largest CMOS chips ever made. The innovative stitching process ON Semiconductor utilised for the project enables the production of sensors with far greater physical size to be developed from smaller building blocks. It demonstrates both the versatility and the depth of the technical capabilities we can offer to the market, for even the most demanding of application requirements.”