Fingernail-sized camera lenses built into mobile devices have come a long way since their inception. After being the first company in the industry to unveil 108 and 200 megapixel CMOS (CIS) image sensors in 2019 and 2021 respectively, Samsung Electronics recently surprised the market again with its ISOCELL HP3 image sensor, a sensor image with 200 million pixels. 0.56 micrometer (μm)-pixels, the smallest pixels in the industry.
Samsung is a leader in image sensor technologies with innovative semiconductor designs capable of capturing stunning images with large amounts of pixels. With the mass production announcement of its ultra-high pixel image sensor, the ISOCELL HP3, the company has commercialized the development of 200MP mobile image sensors with ultra-small pixels.
To learn more about how Samsung developed this industry-leading ultra-high pixel image sensor, Samsung Newsroom spoke with System LSI and Semiconductor Business Developers Myoungoh Ki and Sungsoo Choi. R&D Center respectively who played a leading role in the development of the new ISOCELL HP3.
Smaller and better: the industry’s first company to market 0.56μm pixel
An image sensor is a system semiconductor that converts light that enters the device through the camera lens into digital signals. From digital cameras and smartphones to laptops and cars, image sensors are built into every electronic product that comes with a camera. The ISOCELL HP3 that Samsung recently unveiled is an image sensor that packs 200 million 0.56μm pixels, the smallest pixels in the industry, in 1/1.4″ optical format.1
Since 2019, Samsung has succeeded every year in reducing its pixel size to match the smallest size in the industry. Smaller pixels are needed to keep devices slim.
“With a smaller unit pixel size, the physical size of the sensor and the module can be reduced, which also allows the size and width of the lens to be reduced,” Ki explained. “This can eliminate elements that interfere with the design of the device, such as a protruding camera, and can also reduce power consumption.”
While smaller pixels allow devices to be slimmer, maintaining image quality with smaller pixels is critical. Developed using state-of-the-art technology, the ISOCELL HP3, with a 12% smaller pixel size than the previous ISOCELL HP1 model, can reduce the area of the camera module in a mobile device by up to 20%. . Despite its smaller pixel size, the sensor has been developed using technology that maximizes full well capacity (FWC) and minimizes sensitivity loss. Additionally, new features have been added to the sensor, including all-pixel autofocus capabilities and functions for high-speed video operation, as well as improved color expression.
Increased light absorption and photodiode capability through unique technology capabilities
A smaller pixel size is ideal for creating smaller, thinner devices, but may result in less light entering the device or interference between adjacent pixels. Despite these challenges, Samsung was able to use the smallest pixels in the industry to create an innovative new sensor.
“It’s all down to Samsung’s proprietary technology capabilities,” Ki said. “Samsung’s innovative technology is capable of delivering high performance even in much smaller devices.”
Samsung has managed to create physical walls between thinner and deeper pixels using its proprietary technology called Full Depth deep trench isolation (DTI), ensuring high performance even with 0.56μm. DTI, ISOCELL’s key technology, creates an isolated component between pixels, acting as an insulated wall to prevent light loss and improve optical performance. Developer Choi likened the technology to building a thin barrier between different rooms in a building.
“Simply put, it’s like trying to create a thinner wall between your room and the next room without affecting the level of soundproofing,” Choi explained.
The key to DTI is to create thinner and deeper silicone walls to increase ISO and reduce crosstalk2 since larger isolation components between pixels mean more light loss. By applying this technique to the 0.56μm pixels, Samsung has increased light absorption and optimized photodiode (PD) capacitance. Therefore, the use of ultra-small pixels has become possible since more light per pixel can be stored and processed even with a smaller light receptor area.
Autofocus function for all 200 megapixels provides increased speed and accuracy
Super Quad Phase Detection (QPD) technology, which was first used in the HP3, enables the 200 megapixels to focus by increasing the intensity of the autofocus pixels to 100%. Super QPD provides faster and more accurate autofocus by using a four-pixel lens, allowing measurement of all phase differences of the left, right, top, and bottom sides of the subject being photographed. Not only is autofocus accurate even when it’s dark, but high definition is maintained even when zoomed in.
To solve the problem of poor image quality in low light environments, Samsung has used innovative pixel technology to ensure high quality images. “We used an upgraded version of Samsung’s proprietary Tetra2pixel technology that combines four or sixteen adjacent pixels to function as a single large pixel in low-light environments,” Choi said. Improved pixel technology enables high-resolution shooting in 8K at 30 frames per second (fps) and 4K at 120fps with no loss in field of view. In addition, it is possible to shoot 8K video in ultra-high resolution with the same field of view as when taking photos.
Similar to low light environments, it is also difficult to take photos when there is too much sunlight. In order to combat this problem, a unique technology is needed to adjust the levels of photos to correctly capture an image. “When there is too much or too little light, it is important to increase the dynamic range3 in order to take a natural photo that looks like what we see with our eyes,” Ki said. “Using Smart-ISO Pro technology, which uses two conversion gains, and Stepped High Dynamic Range (HDR)4 function, which turns three frames with different exposures (short exposure, medium exposure and long exposure) into one, it supports HDR photography which creates natural images even when shooting in imperfect lighting conditions, providing optimal results.
Collaboration: the key to overcoming technical limitations and enabling rapid development
During the development of the ISOCELL HP3, the developers faced various technical challenges. “As this was the first product to use Super QPD technology, there was a lot of trial and error when using a new structure that couldn’t be found in trench insulation. deep front (FDTI) existing, and we also ran into issues that we hadn’t anticipated at every stage of development,” Choi said.
Despite such a difficult development process, the new sensor was announced less than a year after the release of the previous model. Both developers attributed the rapid development and release of the product to the collaboration between different teams.
“Whenever we encountered a technical problem, we responded by cooperating closely with different business divisions, our team, and even overseas research centers,” Ki said. “We were able to create synergy by adding know-how to leading products, such as memory chips from the Semiconductor R&D center, logic chips, etc. This new product may be the largest collaborative effort between various departments to date, including employees of the semiconductor R&D center, pixel development team, foundry, SSIR researchers and all advanced development team groups, such as sensor design, pixels, solution, technology, manufacturing and product algorithm.
Pride in our cutting-edge technical prowess: market leader in image sensors
As the image sensor market is expected to grow rapidly due to increased demand for cameras and related product diversification, Samsung is setting the trends for cameras in the mobile image sensor market from new generation by overcoming the limits of pixel miniaturization. Samsung Newsroom asked the two developers what they thought about leading the technical development of the ISOCELL HP3, the industry’s first 200MP image sensor to use 0.56μm pixels.
“I’m very proud of the fact that we’re setting trends in the image sensor market and I’m confident that we will continue to be at the forefront of micropixel technology,” Choi said. “Since the applications of image sensors are becoming more widespread in various industries, such as augmented reality (AR), virtual reality (VR), and automotive industry, in addition to the smartphone industry , we will lead the development of future technologies and markets based on our unique technological capabilities,” said Ki, sharing his future ambitions.
Samsung has successfully created ultra-small devices that capture high-definition images with its innovative image sensor technology. Samsung will continue to lead the image sensor market with its unique innovations, such as the ISOCELL image sensor, which provide optimized and advanced experiences for its users.
1 Diameter of the area captured through the camera lens.
2 Phenomenon where light interferes with the photodiodes of adjacent pixels.
3 The ratio between the lightest and darkest parts of a digital image.
4 A technology that expands the range of brightness by making light parts brighter and dark parts darker, the same way the real human eye sees.