Friday, November 17, 2017

SystemPlus Reveals that iPhone X IR Imager is SOI-based

EETimes publishes Junko Yoshida's article based on Yole Developpement and SystemPlus Consulting analysis of Apple iPhone X TrueDepth design. The biggest surprise is that ST IR imager is using SOI process, said to be the first such sensor in mass production:

SystemPlus and Yole "deduced that silicon-on-insulator (SOI) wafers are being used in near-infrared (NIR) imaging sensors. They noted that SOI has played a key role in improving the sensitivity of NIR sensors — developed by STMicroelectronics — to meet Apple’s stringent demands.

Pierre Cambou, activity leader for imaging and sensors at Yole Développement, called the SOI-based NIR image sensors “a very interesting milestone for SOI.”

Apple’s adoption of ST’s NIR sensors marks the debut of SOI in mass production for image sensors, noted Cambou. “Image sensors are characterized by large surface due to the physical size of light. Therefore, this is a great market to be in for a substrate supplier” like Soitec, he added.

Yole and System Plus Consulting found inside ST’s NIR sensor “the use of silicon-on-insulator (SOI) on top of deep-trench isolation (DTI).” DTI is deployed to prevent leakage between photodiodes. Apple reportedly etched literal trenches between each one, then filled the trenches with insulating material that stops electric current.

Optically speaking, Cambou explained that SOI wafers are advantageous because the insulator layer functions like a mirror. “Infrared light penetrates deeper, and it reflects back to the active layer,” he noted. Electrically speaking, Cambou noted, SOI improves NIR’s sensitivity largely because it’s good at minimizing leakage within the pixel. The improved sensitivity provides good image contrast.

Asked if ST’s NIR sensors are using FD-SOI or SOI wafers, Cambou said that the research firms couldn’t tell.

Asked about surprises unearthed by the teardown, Cambou cited the size of ST’s NIR sensor chip. It measures 25mm2, and has only 1.4 megapixels due to the large 2.8-μm pixel size.

Google Applies for RGB-Z Sensor Patent

Google patent application US20170330909 "Physical Layout and Structure of RGBZ Pixel Cell Unit For RGBZ Image Sensor" by Chung Chun Wan and Boyd Albert Fowler is a continuation from PCT filing of WO/2016/105664 in 2014. The application proposes a 5T pixel for ToF imaging intermixed with 4T or 5T RGB pixels:

Thursday, November 16, 2017

Perovskite Materials for Foveon-like Pixels A group of researchers from Empa and ETH Zurich publish a paper in Nature called "Non-dissipative internal optical filtering with solution-grown perovskite single crystals for full-colour imaging" by Sergii Yakunin, Yevhen Shynkarenko, Dmitry N Dirin, Ihor Cherniukh & Maksym V Kovalenko. The crystals of semiconducting methylammonium lead halide perovskites (MAPbX3, where MA=CH3NH3+, X=Cl−, Br− and Br/I−) are used as absorbers for full-color Foveon-like stacked imaging:

(a) Bayer color sensor design. (b) Vertically stacked color sensor design.
(c) Schematic of the crystal structure of hybrid perovskites
— materials with high optical absorption, efficient charge transport, and
bandgap tunability. (d) Photograph of (from left to right) typical MAPbCl3,
MAPbBr3 and MAPb(Br/I)3 single crystals. (e) Measured light absorption
of each perovskite SC used in a stack.
(a) Sketch of stacked SC photodetector.
(b) Photograph of the prototype detector assembled from three SCs
stacked on a chip carrier. (c) Normalized photoconductivity spectra
of the individual SCs in the stacked detector presented in b.

Embedded Image and Vision Processing

Yole Developpement report on Embedded Image and Vision Processing says:

"The image signal processor (ISP) market offers a steady compound annual growth rate (CAGR) of 6.3%, making the total market worth $4,400M in 2017. Meanwhile, the vision processor market is exploding, with a 30.7% CAGR and a market worth $653M in 2017!

The main goal of this report is to understand what is happening with the emergence of AI. Even if it is not a new technology, thanks to technological factors AI has made a spectacular entry into vision systems.

The AI market is therefore expected to reach $35B in 2025 with an estimated CAGR at 50% per year from 2017-2025.

Wednesday, November 15, 2017

Sony Proposes 1D Curved Sensor for Copy Machines

Sony patent application US20170323915 "Semiconductor device and method of manufacturing the same, semiconductor module, and electronic device" by Kiyohisa Tanaka finds another application for curved sensors - improving the resolution of copy machines and document scanners. The big advantage of this application is that it should not support optical zoom:

More about Sony 7.42MP Automotive Sensor

Nikkei publishes a 4-page article on Sony 1/1.7-inch IMX324 ADAS sensor. Sony says "We will sell the product with intent to achieve 100% share (of the market for image sensors designed for sensing cameras to be attached to the front side of vehicle)."

The main points are:

  • Its power consumption at full 7.42MP resolution 40fps is 500-600mW, which is the industry's smallest, according to Sony.
  • The new sensor has the highest sensitivity in the industry and is the industry's first automotive image sensor that features security functions, Sony said.
  • Sony started to contact Mobileye from an early stage of the development of the new product and responded to many demands of Mobileye.
  • However, the new product was developed not only for Mobileye. The specifications required by Mobileye are "commonly-required specifications," Sony said.
  • Sony is to ship samples in November 2017 and to start volume production in June 2018.
  • Sony uses a laminated stacked design, the first laminated-type automotive image sensor, the company said. "We applied a process that is two or three generations more advanced that the processes used for existing automotive image sensor products."
  • Sony improved the sensitivity by using an RCCC CFA. Image recognition is possible with Mobileye's without using all of the RGB colors.

Tuesday, November 14, 2017

Newsight Imaging and LeiShen Intelligent Partner to Deliver "a Game Changing Automotive LiDAR"

BusinessWire: Newsight Imaging announces a partnership with LeiShen Intelligent to deliver V-LiDAR, a 3D pulsed LiDAR for automotive applications. Newsight's patent-pending eTOF (Enhanced Time-of-Flight) bridges the gap between short-distance iTOF and the 200m distance automotive requirement by extending the DR while retaining high accuracy.

Design of the V-LiDAR is the result of close collaboration between LeiShen and Tier-1 and Automotive OEMs. It is real solid-state (no moving parts, No MEMS), high resolution (VGA and above), with range and accuracy that meet the automotive industry definition, and with the appropriate ISO certifications.

LeiShen Intelligent has long valued core technologies and is committed to delivering advanced LiDAR systems. The V-LiDAR™ performs well on distance, speed and reliability measures. It will be a revolutionary product with excellent performance and low costs. The program will constitute a good example of cooperation between Chinese and Israeli companies,” said Bernie Hu, CEO of LeiShen.

"The Newsight-LeiShen partnership creates a very strong brand positioning in the automotive market," said Eli Assoolin, CEO of Newsight Imaging: "Newsight's proven capability of creating very advanced and sensitive integrated CMOS Sensors, together with LeiShen’s exceptional knowledge and experience in LiDAR design, will surely make this product highly attractive for a growing number of automotive makers, offering "best in class" implementation of their requirements, such as range, real solid-state, accuracy, power and price."

Bloomberg: Apple Plans ToF Rear Camera in 2019 iPhone

According to Bloomberg sources, Apple is working on a rear-facing ToF 3-D sensor for the iPhone in 2019, primarily targeting AR applications.

More about Omnivision Nyxel Technology

EEJournal, ElectronicDesign publish more explanations about how Omnivision Nyxel IR technology works:

"The Nyxel technology adds three pieces to the puzzle. The first is increasing the thickness of the silicon, which allows the photons to travel further in the pixel cell and enables more electron to photon conversion hence a brighter image. The second is essentially putting each cell into its own deep trench with barriers between cells to avoid photon travel to the neighboring pixels and prevent crosstalk. The other is to add a layer on the surface that absorbs [scatters] the maximum amount of light. This combination provides a longer path, allowing the sensor to detect more photons and improve the overall performance of the system."

There is also a Chinese-language article on EDNChina site adding some numbers to the story:

"Now that we have a 50% market share in the security market, security products last year accounted for about 20-25% of the company's total revenues, its growth rate is much higher than the phone," OmniVision VP of China Chen Jiawang said.

"We increased the silicon layer from 4 microns to 6 microns, absorbing more photons, converting to more electrical signals and improving imaging efficiency," explained Chen Jiawang.

The technology has been successfully deployed on 12-inch wafers, while 8-inch wafers are said to be unusable.

Update: Vision Systems Design article quotes Boyd Fowler, Omnivision CTO, explaining the technology details:

"One significant change was doubling the epitaxial layer thickness from about 3 to 6 microns.

When the electrons are generated in the substrate, they need to be collected. This DTI makes sure these electrons can't easily move from the pixel where they are generated to an adjacent pixel, which is critical for effective isolation and enables higher sensitivity, without compromising spatial resolution.

Perhaps most important to the new process is careful management of wafer surface texture to scatter the light as it enters the pixel. By scattering the light, the photons must travel a significantly longer path length.

In this case, the straight path length has been extended from about 3 or 4 microns maximum in our legacy design, to a scattered path of up to 10 or 20 microns with the Nyxel technology.

In the past people have tried to develop better NIR technology, but it was almost always a tradeoff between higher sensitivity and spatial resolution. This technology enables us to give the customer both at the same time.

OmniVision is currently sampling this experimental 2MP Nyxel technology-based product to demonstrate the proof of concept, and has also launched a 5MP product in the security market in October of this year. For 2018, the company has a slew of various resolution Nyxel-based products on the roadmap for the security market throughout Q1 and Q2, and very quickly after that will be looking at products for the machine vision market, AR/VR, automotive and medical applications.

Update #2:
BDTI too publishes an article on Nyxel principles, based on a talk with Lindsay Grant, Omnivision VP of Process Engineering.

Monday, November 13, 2017

Photoneo 3D Technologies Comparison

Photoneo white paper "Parameters​ ​of​ ​3D​ ​sensing​ ​techniques​ ​in​ ​a​ ​nutshell" compares various 3D camera approaches:

Sony Security and Machine Vision/ITS Sensor Videos

Somy publishes a Youtube video on its 5MP IMX335 for security cameras:

...and global shutter sensors for MV applications:

...and ITS applications:

Sony also publishes its vision for future GS sensors:

Leti and EVG Show World's First 300-mm Wafer-to-Wafer Direct Hybrid Bonding with 1um Pitch

PRNewswire: EV Group (EVG) and CEA-Leti present the world's first successful 300-mm wafer-to-wafer direct hybrid bonding with pitch dimension connections as small as 1µm. This breakthrough also achieved copper pads as small as 500nm using EVG's fully automated GEMINI FB XT fusion wafer bonding system. The system achieved overlay alignment accuracy to within 195nm (3-sigma) overall, with mean alignment results well centered below 15nm. Post-bake acoustic microscopy scans of the full 300-mm bonded wafer stack as well as specific dies confirmed a defect-free bonding interface for pitches ranging from 1µm to 4µm with optimum copper density.

"To our knowledge, this is the first reported demonstration of sub-1.5µm pitch copper hybrid bonding feasibility," said Frank Fournel, head of bonding process engineering at Leti. "This latest demonstration represents a real breakthrough and important step forward in enabling the achievement and eventual commercialization of high-density 3D chip stacking."

GEMINI FB XT fusion bonding system from EV Group
with SmartView NT aligner (sub-200nm, 3-sigma accuracy).

Image Sensor Companies in Silicon 60 List

EETimes publishes its "Silicon 60: 60 Emerging Companies to Watch" with just two image sensor related companies:

Chronocam AS (Paris, France) is a startup company founded in 2014 that develops machine vision sensors and systems based on asynchronous pixel sensor technology. The novel architecture creates an image sensor that is close to a biological model and a method of reporting image changes reduces off-chip bandwidth requirements and system power consumption. Chronocam has received seed investment from Robert Bosch Venture Capital and CEA Investissement.

Unispectral Ltd. (Ramat Gan, Israel) is developing a hyperspectral image sensor that can not only be used for spectrometric analysis of materials such as food stuffs but can also capture images in low-light. The sensor is applicable to a wide range of applications such as wearables, digital health, medical imaging, Internet of Things, industrial and agricultural applications. The company is reported to already be in negotiations with smartphone manufacturers for the inclusion of its sensor on next-generation phones. The company was founded in 2016.

Raytrix Receives Large 5-Year Order for its Lightfield Cameras

Kieler Nachtrichten reports that Raytrix receives a $18M-large "five-year order from the world's largest processor manufacturer, whose name may not be named for contractual reasons." For the company that has annual sales of 2.5M euros in 2017, this is quite big leap forward.

Thanks to JB for the pointer!

3 Sensor Types Drive Autonomous Cars

Sensors Magazine publishes ST article "Three Sensor Types Drive Autonomous Vehicles" by Gert Rudolph and Uwe Voelzke:

Sunday, November 12, 2017

Fast Mechanical Cameras

We used to think about electronics as being much faster than mechanics, but some of the world's fastest cameras are still relying on rotating mirrors or galvos, as shown in this Youtube video:

Omnivision Wafer Level Endoscope Camera

Omnivision patent application US20170310890 "Ultra-Small Camera Module With Wide Field Of View, And Associate Lens Systems And Methods" by Tsung Wei Wan, Ting-yu Cheng, Wei-ping Chen, and Chuen-yi Yin, sheds some light on wafer level optics design of a miniature endoscopic camera, possibly the single-chip camera and optics version of this one:

IHS Markit Analyses iPhone X Depth Camera

BusinessWire: IHS Market tears down iPhone X and analyses the cost of its components. The company says about the Face ID depth camera:

TrueDepth sensing: lots of components, many suppliers

“Apple’s Face ID system is very similar in basic functionality to the old Microsoft Kinect system of sensing, which used a flood illuminator, dot projector and infrared camera,” said Jérémie Bouchaud, senior director for MEMS and sensors at IHS Markit. “It’s a complex assembly that uses components from many suppliers.”

The teardown of the iPhone X revealed that its IR camera is supplied by Sony/Foxconn while the silicon is provided by ST Microelectronics. The flood illuminator is an IR emitter from Texas Instruments that’s assembled on top of an application-specific integrated circuit (ASIC) and single-photon avalanche diode (SPAD) detector from ST Microelectronics. Finisar and Philips manufacture the dot projector. IHS Markit puts the rollup BOM cost for the TrueDepth sensor cluster at $16.70.

“The assembly and testing of the TrueDepth system and its individual components is challenging and likely a factor in the production delays,” Bouchaud said. “For instance, the assemblage and test of the Texas Instruments and ST Microelectronics subsystem for the flood illuminator is far from trivial and requires a high number of test equipment pieces.”

Saturday, November 11, 2017

Sony Unveils Medium Format BSI Sensors with 100MP and 150MP Resolutions

SonyAlphaRumors notices Sony page presenting its medium format sensor announcements:

Sony also unveils a IMX533 square image sensor for 360-deg view cameras:

Tricking Apple Face ID: Failures and Successes

In the days since iPhone X release, many people are exploring the limits of its Face ID recognition accuracy. It looks like Apple is well prepared to the obvious ways to attack the Face ID:

Wall Street Journal:



However, in some cases, the Face ID can be successfully fooled, such as here, here, and here.

Friday, November 10, 2017

Yole and SEMI on Automotive Sensor Market

SEMI and Yole Développement publish a joint presentation "Smart Automotive – Latest Trends in LiDAR and Sensors." Few slides on the market trends and forecasts:

Samsung 0.9um Pixel Gets CES 2018 Award

BusinessWire: Samsung 0.9um ISOCELL pixel with Tetracell and remosaic technology has been recognized as CES 2018 Innovation Awards Honoree:

"Samsung ISOCELL Slim 2X7 is a 24 megapixel image sensor with 0.9μm pixels, the smallest pixel in the industry, plus Tetracell and remosaic technology to simulate bigger pixel performance. The small 0.9μm pixel size enables a 24Mp image sensor to be fitted in a thinner camera module, allowing premium smartphones to offer high resolution cameras in a very slim and elegant design."

Thursday, November 09, 2017

Invisage Acquisition by Apple Said to be Confirmed

Techcrunch receives what it believes is Apple's confirmation of acquisition of Invisage:

An Apple spokesperson has confirmed the acquisition to us with its customary statement:“Apple buys smaller technology companies from time to time, and we generally do not discuss our purpose or plans.”

Techcrunch also found other evidences of the acquisition:
  • There are a handful of InVisage employees that are already noting on LinkedIn that they work for Apple. We were able to determine that several more who have not updated their LinkedIn profiles are also working there. Meanwhile, InVisage erased the section of its web site that detailed some of its senior staff (but you can still find those pages through web archiving services).
  • InVisage itself went radio silent on social media and other communications channels in November of last year - this one is incorrect as Invisage has presented its progress at IISW 2017 in June.
  • The legal firm representing InVisage changed in September. It’s now using the same firm that Apple uses for all its patent work.
  • Several people we contacted connected to the company told us they were not at liberty to discuss the acquisition, but in doing so also inadvertently confirmed that it took place.
  • More public evidence of a sale (but not to whom) is that multiple InVisage VC backers now list the company as exited on their web sites.

Few figures from Invisage paper presented at IISW 2017 in Hiroshima, Japan in June 2017:

R53: A QuantumFilm Based QuadVGA 1.5µm Pixel Image Sensor with Over 40% QE at 940 nm for Actively Illuminated Applications.
Lionel Barrow, Nikolai Bock, Aurelien Bouvier, Dario Clocchiatti, Jian Feng, Naveen Kolli, Andras Pattantyus, Vitanshu Sharma, Tzi-Hsiung Shu, Emanuele Mandelli. InVisage Technologies, USA

Thanks to JH and AD for the pointer!

iPhone X Uses ST IR Sensor for Face ID

TechInsights updates its Apple iPhone X teardown report to include Face ID cameras. The IR camera responsible for taking structured light image of the face is confirmed to be made by ST:

The ToF proximity sensor comes from ST too, naturally:

Thanks to GM for the pointer!