CMOS-erstatteren
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Det nokså ukjente firmaet InVisage Technologies har annonsert en tilsynelatende svært forlokkende sensorteknologi som, gitt at de holder det de lover, vil kunne revolusjonere sensorteknologien. InVisage lover fire ganger bedre ytelse (underforstått sensitivitet) og dobbelt så stort dynamisk omfang, som på toppen av alt skal bli billigere å produsere enn tradisjonelle sensorer. Undertegnede liker ikke å beskylde noen for løgn, men må innrømme at jeg stiller meg nokså skeptisk til lovnadene denne gangen.
Teknologien baserer seg på en film av såkalte kvantepunkter (quantum dots) som legges på toppen av en tradisjonell silisiumbasert sensor. Denne prosessen kan utføres i romtemperatur, noe som vil redusere kostnaden betraktelig. Mens tradisjonelle silisium-sensorer har lystap på 50% ved deteksjon og et ytterligere signaltap på i form av 50% kvanteeffektivitet (at sensoren bare kan omdanne halvparten av lyset som treffer til elektroner), påstår InVisage at deres sensor ikke har lystap, og at de har oppnådd kvanteeffektivitet på 90-95%. Dermed får man nær en firedobling av sensitiviteten, fordi man registerer praktisk talt alt det innkommende lyset.
InVisage forteller ikke hvordan de har fått til dette i kombinasjon med dobbelt dynamisk omfang; de har ikke sagt noe om hvordan de har fått til økt dynamisk omfang i det hele tatt. Større dynamisk omfang betyr i praksis at man må både kunne registrere signal fra et mindre antall fotoner uten mer støy og/eller registrere flere fotoner uten at sensoren går i metning. Økt sensitivitet betyr nok også at de kan skille signaler fra et lite antall fotoner, men det er lite informasjon å finne om akkurat dette.
I første omgang har InVisage valgt å satse på små sensorer, typisk til mobilkameraer o.l. Det er et naturlig valg, men InVisage påpeker at teknologien kan benyttes til alle sensorer. Det vil naturligvis være en drøm å få f.eks. et kamera som Nikon D3s med to eksponeringstrinn bedre ISO-ytelse og bedre dynamisk omfang!
Forøvrig er det veldig lite håndfast informasjon InVisage presenterer i sin pressemelding, de bruker en variant av et svært populært, men nokså intetsigende begrep - kvantefilm, og de har heller ingen eksempelbilder tatt med denne nye teknologien. Det synes å være et seriøst selskap som står bak dette, men undertegnede ville ikke blitt veldig forbauset om det går slik det gikk med Fleischmann og Pons og deres kald fusjon-forsøk på slutten av 80-tallet...
Den nokså intetsigende pressemeldingen finner du på neste side.
Pressemelding
3/22/10 - InVisage Unveils QuantumFilm Image Sensors
Quantum Dot Material Replaces Silicon; Enables Stunning Image Quality on Mobile Handsets
PALM DESERT, Calif., March 22, 2010, DEMO Spring 2010 – Ushering in a new era of high-performance image sensors, InVisage Technologies, Inc. – a venture-backed start-up that is revolutionizing the way light is captured – today announced QuantumFilm. Harnessing the power of custom-designed semiconductor materials, QuantumFilm image sensors are the world’s first commercial quantum dot-based image sensors, replacing silicon. InVisage delivers 4x higher performance, 2x higher dynamic range and professional camera features not yet found in mobile image sensors. The first QuantumFilm-enabled product, due out later this year, solves the crucial challenge of capturing stunning images using mobile handset cameras.
QuantumFilm was developed by InVisage after years of research under the guidance of notable scientist and InVisage CTO Ted Sargent. The technology is based on quantum dots – semiconductors with unique light-capture properties. QuantumFilm works by capturing an imprint of a light image, and then employing the silicon beneath it to read out the image and turn it into versatile digital signals. InVisage spent three years engineering the quantum dot material to produce highly-sensitive image sensors that integrate with standard CMOS manufacturing processes. The first application of QuantumFilm will enable high pixel count and high performance in tiny form factors, breaking silicon's inherent performance-resolution tradeoff.
"It is becoming increasingly difficult and expensive to develop next-generation image sensors using silicon; essentially, silicon has hit a wall," says Jess Lee, InVisage President and C.E.O. "The fundamental problem is that silicon cannot capture light efficiently, but until now it has been the only option. The disruptive nature of QuantumFilm builds on silicon's success in electronics, and elevates its function using new materials that are engineered from the ground up for light capture."
Silicon-based image sensors – the technology used today for all digital cameras including handheld, professional, mobile phone, security and automotive cameras – capture on average a mere 25 percent of light. QuantumFilm captures between 90-95 percent, enabling better pictures in even the most challenging lighting conditions. This increase in efficiency will deliver improvements across the entire imaging market, allowing QuantumFilm to be the de-facto next generation camera platform. The first target market for QuantumFilm is mobile handsets, where there is the greatest demand for small, high performance image sensors.
Just nanometers in size, the quantum dot-based material is deposited directly on top of the wafer during manufacturing. And unlike silicon-based image sensor technologies such as BSI (back-side illumination) and FSI (front-side illumination), QuantumFilm covers 100 percent of each pixel. The material is added as a final wafer-level process, which allows for easy integration into standard semiconductor foundries. The process - akin to coating a layer of photoresist onto a standard wafer - adds minimal cost on top of the standard layers of silicon processes.
"It is safe to say that the industry spends an average of $1 billion for each new generation of pixel technology, all to achieve a single-digit percentage improvement in image quality," says Tetsuo Omori, senior analyst, Techno Systems Research Co. "The future of imaging is in new materials like QuantumFilm, which will change the competitive landscape and possibly re-ignite the pixel race."
InVisage was founded in 2006 and is led by industry veterans from the image sensor and advanced semiconductor materials industry. It employs 30 people at its Menlo Park headquarters and has received more than $30 million in funding from RockPort Capital, Charles River Ventures, InterWest Partners and OnPoint Technologies. Its technology is protected by 21 patents and patents pending.
QuantumFilm is ideal for a wide range of image-sensing technologies including security cameras, automotive cameras and military applications. The first QuantumFilm image sensors, targeting high-end mobile handsets and smartphones, will sample in Q4 of 2010.
For more information on InVisage Technologies, please visit its newly-launched web site at www.invisageinc.com. InVisage will be demonstrating its new technology at DEMO Spring 2010 in Palm Desert, Calif., on March 22 and 23. InVisage will also be giving a talk about its technology at Image Sensors Europe 2010 on March 24 in London.