OmniPixel3 CMOS Image Sensors Architecture - OmniVision

OmniVision Technologies introduced the new 1.75 micron pixel OmniPixel3 architecture. The OmniPixel3 CMOS Image Sensors architecture increase the pixel density and uses leading-edge design rules in conjunction with a dedicated and proprietary 0.11-micron CMOS process.

Howard Rhodes, OmniVision, said:

Our major challenge as we shrink the pixel size is that we have to shrink the photodiode, the area of the sensor that captures light…

As the photodiode shrinks, it becomes increasingly difficult to focus light onto the actual photo sensor, which can result in a loss of performance and image quality. OmniPixel3's proprietary pixel architecture and aggressive design rules enable us to more effectively focus light onto the photo sensor, allowing the pixels to capture significantly more light and thus make more effective use of the smaller pixel's active area. Together with OmniVision's new color filter array technology and zero-gap micro-lens technology, we believe we have the result of excellent sensitivity and superior cross-talk performance…

OmniPixel3 CMOS Image Sensors architecture optimizes pixel symmetry to avoid color distortion and offers improved dynamic range of up to 65dB. This is done by maximizing the efficiency of the photodiode process and pixel design, and implementing a new low-noise pixel and column sense readout.

OmniPixel3 CMOS Image Sensors architecture features ultra low dark current (30 e/sec) and low defect density, making this technology ideal for use in low-light and variable light conditions. The new architecture also include a new transfer gate design process and contact technologies that achieve lag-free operation throughout the signal range. Eliminating read-out lag ensures that no 'ghost images' or unwanted noise are present in the imaging process.

Flashback:
First generation of OmniPixel1

The first generation of  OmniPixel technology was launched in August 2004. OmniPixel technology enabled the first generation of CMOS image sensors that deliver the light sensitivity, resolution, color fidelity and low noise of advanced CCD products, while also providing the proven advantages of CMOS-based solutions: low cost, low power consumption, high integration, wide dynamic range and the flexibility of still-image or video capture.

OmniPixel Image Sensors technology incorporates major advances in every area of sensor technology: pixel design, circuit design, feature set, process technology and materials science. The key is a revolutionary pixel design that maximizes the fill factor of each pixel while minimizing boundary wall height. The result is a very small pixel with excellent light collection. The circuit structure of each pixel virtually eliminates effects such as fixed pattern noise and dark current, ensuring consistently clear and sharp images. OmniPixel CMOS Image Sensors arcitecture comes with premium features such as auto-focus, zooming, panning and mechanical shutter control, allowing OmniPixel sensors to challenge and displace CCDs in mainstream and high-end camera markets.

Flashback:
OmniPixel2, the second generation.

OmniPixel2 CMOS Image Sensors architecture was introduced in September of 2005. It offers just 2.2 micron pixel size, less than a half of the first generation of OmniPixel. The OmniPixel2 CMOS Image Sensors architecture features process and technology improvements on both the sensor and system level that enable better performance per area and a further reduction in overall sensor size. OmniPixel2 features three major technology/process developments that increase the pixel density within a compact sensor size and maximizes the performance of the smaller pixel:

• An increase in fill factor by 40 percent along with more vibrant and truer-to-life color reproduction.
• A pixel design that features higher quantum efficiency and improved full well capacity, which brings significant improvements to the pixel’s dynamic range. The quantum efficiency, which measures how effectively pixels convert the captured photons to electrons, was improved through OmniVision’s new proprietary 0.13 micron process. Process improvements designed to optimize image performance also further increase full well capacity, which means that OmniPixel2 has even better full well capacity than its larger 3.18-micron OmniPixel predecessor.
• A zero-gap micro-lens design, which eliminates the space between the lenses that are placed over each pixel, leading to a more efficient direction of light to the pixel’s active area. This allows the pixels to capture over 20 percent more light, more effectively using the smaller pixel’s active area.

OmniPixel3 architecture is expected to be launched  in Q3 this year

Further reading: OmniVision’s OmniPixel3 CMOS Image Sensors Architecture

About OmniVision Technologies

OmniVision Technologies designs and markets high-performance semiconductor image sensors. Its OmniPixel, OmniPixel2 and CameraChip products are highly integrated single-chip CMOS image sensors for mass-market consumer and commercial applications such as mobile phones, digital still cameras, security and surveillance systems, interactive video games, lap-tops and PCs and automotive and medical imaging systems.