Thursday, February 13, 2014
Samsung ISOCELL Details Presented
Android Authority publishes Samsung slides. The web site says that "ISOCELL is actually the commercial name of what Samsung calls 3D-Backside Illuminated Pixel with Front-Side Deep-Trench Isolation (F-DTI) and Vertical Transfer Gate (VTG)." The slides below refer to a pixel size of 1.12um. More slides are at Android Authority site.
It looks like exactly what has been developed by STM!! What is the fundamental difference compared to DTI_VTX of STM please?
ReplyDeleteIndeed similar. STM presented a similar work at IISW '11. I remember the presenter did not answer the question about the noise which, I suppose, was high.
DeleteBTW, is it really helpful that large full well at such small pixel pitch? You need long integration time to fill it up. Tripod makers will be happy :)
See also US2011/0096208 "Image Sensor with Vertical Transfer Gate" by STM
DeleteRegarding the vertical transfer gate, Omnivision and KETRI patent applications were published at about the same time:
Deletehttp://image-sensors-world.blogspot.co.il/2011/04/vertical-transfer-gates-proposed-by.html
Links to that post give earlier references dated all the way back to 2005. Also, Sony presented its vertical transfer gate on the recent IEDM.
I remember the VTG work at Samsung started around 2009 but I don't recall the origin of the idea. It is quite possible it was conceived independently. A trench CCDs with high full well capacity was proposed in 1989 (by me, IEEE EDL 10(5) p 177) and certainly the Mitsubishi patent for IR Schottky barrier photodetectors predated that by a year even if for something quite different. I was not aware of that patent in 1988 when we were conceiving the trench CCD, and I don't recall the Samsung guys (I was part of that team) discussing any prior art when we were doing the VTG R&D. And, as commented in this blog in April 2011, the KETRI and Omnivision patent apps were filed within 2 weeks of each other, probably with each party unaware of the other.
ReplyDeleteIt is an interesting aspect of the inventive process that some solutions are conceived of nearly simultaneously by different groups. It does make one wonder if the solution was thus "obvious" to one ordinarily skilled in the art. I don't think so but it is something to contemplate.
Samsung have been building DRAM with vertical gates (In DRAM world they are known as RCAT 'recessed channel array transistors') since ~2005 see http://micromagazine.fabtech.org/archive/05/07/chipworks.html The concept for DRAM and CIS is identical higher Leff providing lower leakage.
ReplyDeleteSony have been producing BSI sensors with vertical gates for a couple of years, Ray Fontaine from Chipworks presented an image from the WX100 at IISW last year :-http://www.chipworks.com/components/com_wordpress/wp/wp-content/uploads/2013/08/Fontaine_Innovative-Technology-Elements-for-Large-and-Small-Pixel-Imaging-Devices.pdf
The WIN here is obviously Samsung's over 20yrs of CMOS fabrication experience. Something Sony unwittingly got cheap on after selling off their foundry business. That Sir Howard Stringer cheap cost saving measure was absolute tom foolery at it's finest. Now they are hurriedly going back into the CMOS foundry business, buying up foundries and hiring new R&D people, since they've been obviously resting on their laurels, acting like they didn't have any competition.
ReplyDeleteTo the contrary..... Samsung has been spending Mega Bucks over the same time period and it's finally paying off. Even though this writer and most people online aren't aware of this fact. Samsung has already been the largest CMOS fabricator in the World for awhile. Sony is now #2 thanks to all the wonderful cost saving measures by Sir Stringer that never did any good and failed to keep in the #1 Electronics Conglomerate in the World Lead!
Now playing Catch-Up to #1 Samsung will have them not only losing Samsung business, but possibly Apple's too. Which would be a castastrophe of major proportions for Kaz Harai failing to move quick enough to stop the R&D funds bleeding out through their CameraCMOS sensors! ;-P
btw.... it's the integrated field array Autofocus (AF) sensors within ISOCELL for mobiles, along with it's Samsung's foundry expertize that has ISOCELL headed for dominating the mobile device market right now over Sony BSI!