Wednesday, June 21, 2017

TechInsights Survey of Stacked Image Sensors

TechInsights publishes a second blog post based on Ray Fontaine presentation at IISW 2017. This part covers stacked image sensor technology from TSV and oxide bonding to Cu-to-Cu direct bonding in the recent products:

IISW 2017 Awards

IISW 2017 held on May 30-June 2 in Hiroshima, Japan has announced a number of Awards:

2017 Walter Kosonocky Award for the best paper published in 2015-16 goes to

A 0.13 μm CMOS System-on-Chip for a 512 × 424 Time-of-Flight Image Sensor With Multi-Frequency Photo-Demodulation up to 130 MHz and 2 GS/s ADC
Cyrus S. Bamji, Patrick O’Connor, Tamer Elkhatib, Swati Mehta, Barry Thompson, Lawrence A. Prather, Dane Snow, Onur Can Akkaya, Andy Daniel, Andrew D. Payne, Travis Perry, Mike Fenton, and Vei-Han Chan
Microsoft, USA, IEEE JSSC, Vol. 50, No. 1, pp. 303-318, January 2015

Pioneering Achievement Award for Contribution to R&D and commercialization of high-performance and high-resolution CCD image sensors is presented to Tetsuo Yamada:

Exceptional Lifetime Achievement Award Significant Contributions to the Advancement of Solid-State Image Sensors Including the Development Of On-chip Microlens Technology and VOD Structures for anti-blooming is presented to Yasuo Ishihara:

The Best Poster Award goes to:

Fully Depleted, Monolithic Pinned Photodiode CMOS Image Sensor Using Reverse Substrate Bias
Konstantin D. Stefanov, Andrew S. Clarke, James Ivory and Andrew D. Holland. The Open University, UK

Thanks to JN for the docs!

Tuesday, June 20, 2017

Sony Enhances IR Sensitivity by 80% with Pyramidal Structure

Sony publishes an open access paper in Nature Journal "IR sensitivity enhancement of CMOS Image Sensor with diffractive light trapping pixels" by Sozo Yokogawa, Itaru Oshiyama, Harumi Ikeda, Yoshiki Ebiko, Tomoyuki Hirano, Suguru Saito, Takashi Oinoue, Yoshiya Hagimoto & Hayato Iwamoto. From the abstract:

"We report on the IR sensitivity enhancement of back-illuminated CMOS Image Sensor (BI-CIS) with 2-dimensional diffractive inverted pyramid array structure (IPA) on crystalline silicon (c-Si) and deep trench isolation (DTI)... A prototype BI-CIS sample with pixel size of 1.2 μm square containing 400 nm pitch IPAs shows 80% sensitivity enhancement at λ = 850 nm compared to the reference sample with flat surface. This is due to diffraction with the IPA and total reflection at the pixel boundary."

The papers's conclusion:

"A novel BI-CIS with IPA on c-Si surface for light trapping pixel technology is proposed and the prototyping results are demonstrated. Both spectroscopic measurements and demo images show considerable NIR sensitivity enhancement with small spatial resolution degradation. BI-CIS with 400 nm pitch IPA surface and DTI shows 80% improvement in sensitivity, which corresponds to QE of more than 30% at 850 nm for a 3 μm thick c-Si photodetector. Furthermore, it is worth noting that there is still a lot of room for improvement toward the fundamental limit of 4n^2. Additionally, it is important to control surface passivation to minimize the degradation of thermal noise and also further improve pixel isolation to reduce lateral color crosstalk as small as possible."

Monday, June 19, 2017

Intel RealSense CTO Presentation

Augmented World Expo (AWE) publishes a presentation by Intel RealSense group CTO, Anders Grunnet Jepsen:

One of the new RealSense depth cameras

Thanks to ZR for the link!

Samsung CIS Business Update

Samsung Investor Presentation gives interesting details on the company CIS business progress.

The market share data shows the business expansion:

Samsung uses 28nm CIS process, while Sony extends 65nm process life:

Automotive and mobile are high-priority applications:

Sunday, June 18, 2017

Plasmonic Filters Found in Mass Produced Device

SystemPlus reverse engineering of NanoLambda NSP32-V1 spectrometer discovers plasmonic filters inside:

"The NSP32-V1 spectrometer uses a 1024 pixel, 32 x 32, nano-optical filter array to measure the light spectrum, based on a technological breakthrough, the plasmonic filter. This is a metal film perforated with subwavelength hole arrays. It is manufactured within the metal layer of the silicon die, giving a monolithic solution.

The 100μm-high sensor die is assembled in an advanced ball grid array (BGA) package with an optical window for only 500μm height. The other optical parts, the lens and the diffuser, are assembled in a 5.7mm-high module. The module is very small overall, at just 6mm x 6mm x 5.3mm.

Saturday, June 17, 2017

High-Speed Low-Noise Column ADC Architectures Thesis

Shizuoka University, Japan, publishes PhD Thesis "A Study on High-Speed Low-Noise Readout Architectures and Column A/D Converters for CMOS Image Sensors" by Tongxi Wang. The thesis starts with a nice overview of the readout and column-parallel ADC concepts:

A Hybrid Tri-Stage-Pipeline Column ADC (TSP) architecture is proposed to achieve the better trade-offs (implemented in 65nm process):

Another proposal is Folding-Integration/Cyclic Cascaded ADC (FICC) (implemented in 110nm process):

Friday, June 16, 2017

KAIST “K-Eye” Recognizes Faces

KAIST research team led by Prof. Hoi-Jun Yoo developes CNNP chip (CNN Processor), that runs AI algorithms with ultra-low power, and K-Eye, a face recognition system using CNNP. The system was made in collaboration with a start-up company, UX Factory.

The “Always-on” image sensor, can determine if there is a face in its camera range. Then, it can capture frames and set the device to operate only when a face exists, reducing the standby power significantly. CNNP achieved 97% face recognition accuracy while consuming only 0.62mW of power. Both chips were developed by Kyeongryeol Bong, a PhD student under Prof. Yoo and presented at ISSCC in February.

A Youtube video demos the K-Eye operation:

EurekaAlert also publishes a die photo:

Thursday, June 15, 2017

TechInsights Surveys PDAF Technologies

TechInsights starts a new blog post series "A Survey of Enabling Technologies in Successful Consumer Digital Imaging Products" based on Ray Fontaine's presentation at IISW 2017. Part 1 talks about PDAF technologies and is very insightful:

Technavio: Inspection Camera Market is Mostly UV

BusinessWire: Technavio report on automatic production inspection camera market forecasts the market size to reach $1,436.46 million by 2021, at a CAGR of nearly 10%. The largest part of the market is UV cameras:

Presto Sees $500M Opprotunity in CIS Production Management

BusinessWire: Presto Engineering, an outsourced operations provider to semiconductor device manufacturers, now offers a turnkey industrialization service for image sensors.

Larger-volume CIS vendors typically keep their manufacturing operations in-house. However, a fragmented market at medium volumes, perhaps as large as $500M aggregated across all segments, provides significant opportunities for fabless CIS companies who can benefit greatly from outsourced test and characterization solutions.

Presto’s IP750Ex test solution provides a large (80x100mm), uniform (+/-2%), high-intensity illumination field at a range of temperatures. Its highly parallel test capability for complex devices (as large as 32M pixels at speeds up to 200MHz) enables fast ramps without compromising cost-of-test. Its extension into IR and its ability to test 12-, 8- and 6-inch wafers across the full automotive temperature range (-40°C to +150°C) qualifies it uniquely for automotive vision integrated circuits (ICs).

Philippe Rommeveaux, CEO of France-based Pyxalis states, “Pyxalis is very excited to use Presto Engineering and its state-of-the-art imaging platform to test custom image sensors. Local support and interaction make this solution very efficient.

Presto Engineering provides outsourced operations from wafer procurement through final product shipment, and much more. The image sensor program and cleanroom facility are located in Meyreuil, France, near Aix-en-Provence.

Melexis Integrates ToF System onto 2 Chips

Melexis new ToF chipset includes the MLX75023 1/3-inch ToF sensor and the MLX75123 companion IC that embeds many of the external components normally required to develop a 3D vision solution. With this high level of integration, designers no longer need external FPGAs and ADCs thereby reducing size, design cost, product cost and time-to-market.

The MLX75023 ToF sensor is said to offer the world’s smallest pixel at QVGA resolution with 63 dB linear DR and sunlight robustness, thanks to Melexis' advanced pixel technology (15um Softkinetic pixels, that is). The MLX75123 companion chip directly interfaces the sensor IC to a host MCU and provides rapid readout of data from the sensor.

Gaetan Koers, Product Manager for Melexis commented: “We are very excited about the possibilities the launch of this chipset unleashes. The simplicity that it brings to the design process will ensure that more applications will be able to benefit from 3D TOF vision. In this fast-moving technology sector the in-built future proofing will mean that our customers will be able to remain at the leading edge for years to come.

Melexis opens a Youtube channel devoted to its new ToF platform:

Sofradir Designs Large Format MCT Imager for ESA

ALA News: Sofradir designs its first supersize 4MP SWIR sensor with 15um pitch for ESA space observation programs. The ALFA 2Kx2K (Astronomy Large Focal Array) 15µm pitch SWIR detector is said to provide the highest levels of performance in QE, dark current and noise in order to optimize IR observations for astrophysicists. The SWIR detector is based on a compound semiconductor material, mercury cadmium telluride (HgCdTe)and includes a readout circuit (ROIC) with a source follower per detector (SFD) at the input stage.

CIS History

Semiconductor Engineering publishes "CMOS Image Sensors (CIS): Past, Present & Future" article by Sofiane Guissi, staff engineer at Coventor. Among other historical comparisons and tables, there is one from talking about CIS stacking timeline, not including Sony 2017 3-layer CIS mass production milestone:

Wednesday, June 14, 2017

Camera-Radar Fusion

TI publishes a nice video showing a fusion between so different views from an automotive radar and a camera:

Tuesday, June 13, 2017

Omnivision 1/36-inch Sensor Pictures

Omnivision kindly sent me few pictures showing how small the new 1/36-inch OV6948 image sensor is:

More Quad Camera Phones from China

Dual fron and dual rear camera combos appear in more and more low-end camera phones in China. DeviceSpecifications reports that the new Oukitel U22 features 13MP+2MP rear cameras and 8MP+2MP front cameras.

Meanwhile, Doogee comes up with its second quad camera phone, model X30 (see the first one here). The phone features 5MP + 5MP on the front side and 8MP + 8MP on the rear (source: DeviceSpecifications):

Analog Devices Demos SNAP Sensor

EDN publishes a July 2016 video interview with Analog Devices representative showing SNAP image sensing technology:

THine Mass Produces 15m MIPI Extender

BusinessWire: THine has started, from June 2017, mass-production and delivery of THCV241-Q MIPI extender which makes it possible to transmit image data up to 15m by converting MIPI CSI-2 interface to V-by-One HS interface. The 8MP 30fps image data can be transmitted by V-by-One HS with one pair of shielded twisted pair wire or one coaxial wire (or one shielded twisted quad cable). Such extenders are popular in automotive and security cameras.

Features of THCV241-Q:
  • MIPI CSI-2 input (1/2/4lane, 1.2Gbps/lane), V-by-One HS output (1/2lane, 4Gbps/lane)
  • Capable of transmitting image data of 8Mpixel (4K2K) 60fps at the maximum (in case of V-by-One HS 2 lane)
  • Control signal bridge function of GPIO/UART/2 wire serial interface
  • Error detection function including CRC (image data transmission path/control data transmission path)
  • Function of distributing image data (in case of V-by-One® HS 2lane)
  • Follow AEC-Q100 Grade 2

Monday, June 12, 2017

OmniVision Introduces 1/36-inch Imager

PRNewswire: OmniVision introduces the OV6948, one of the world's smallest commercially available image sensors. Initially developed for small-outer-diameter medical endoscopes and catheters, the OV6948 can be designed into a wide range of applications, including dental, veterinary, IoT, industrial, wearable and forensic devices. The OV6948 leverages OmniBSI+ pixel technology in a package that measures just 0.575 mm × 0.575 mm.

The product features:

  • 1/36-inch optical format
  • 200 × 200 pixel capture at 30 frames per second (FPS)
  • Sensitivity: 1000 mV/lux-sec
  • Analog data output with the ability to transmit up to 4 meters with minimal noise
  • 0.575 mm x 0.575 mm package size (4 pads total) for easy integration

The OV6948 is currently sampling and is expected to start mass production in Q2 2018.

ULIS Increases its R&D Budget

ALA: ULIS announces significant increase in its R&D spending for 2017 to reach €15M ($16.8M). The company generated €61.5M ($69.3M) in sales in 2016, a rise of nearly 30% compared to 2015. The new level of R&D investment will represent 20% of its annual sales. Previously, the company pledged 10% of its annual revenue to R&D.

Since its founding in 2002 as a spin-off from CEA-Leti, ULIS has become the second largest producer of microbolometers for defense, surveillance, thermography, firefighting, outdoor leisure and automotive markets. The company that started with 35 staff now employs 200. It has experienced double-digit growth, averaging 20% per year since its inception.

In addition, ULIS has injected €70M ($78.7M) to improve production tools and processes, enabling an increase in volume production from a couple of thousand units per year to several hundred thousand. It will soon deliver its one millionth component.

Saturday, June 10, 2017

Sony Dual Conversion Gain Pixel Layout

Sony patent application US20170148832 "Solid-state image pickup device and method of driving the same" by Kazuyoshi Yamashita reveals the company's dual CG BSI pixel layout: