I wonder that can we create a CMOS camera with GaAs wafer? I know that it is almost impossible to create a single crystal wafer from GaAs but If you create a camera using GaAs wafer and if you are lucky to get some large grans in your camera, in this case is your camera work? Work!!! I mean that camera can look a Frankenstein monster but Since I do not need to see whole pictures, I can work with it. In 4k pixel camera, If I can get 500 working fine pixel that is enough for me.
Dear Sayet
I would like to advise you to introduce your subject in more details to show where are the challenges in your problem.
Is the problem that one grows single crystal Si on a GaAs substrate?
From the principle point of view the two materials are nor lattice matched and so one needs some matching layer between them.
Best wishes
Thanks Aparna and Abdelhalim,
SWIR cameras are the answer to my curiosity. That is good to know that. Thanks
B.R.
Applications of MESFETs were initially in microwave circuits for high frequency performance, generally in the range of 1 to 10 gigahertz. As hole mobility in GaAs is 5 to 10 times higher than it is in Silicon and allows MESFET operation at frequencies higher than can be achieved with Silicon devices.
Thanks Ziad,
The speed is nice to have but density is the key achievement that I would to have in a camera.
The Cryo-EM is a very popular topic in drug discovery. The companies keeps improving their device but i think the current limitation is the detector. The protein structures do not give us much contrast. That's why If we can not improve sample properties, Maybe we can improve detector properties.
Currently, The Cryo-EM is using the fast CMOS detectors which made from Si wafer.The logic is using InGaAs wafer;
We're detecting High energy electrons (300 keV). If you consider how far can electron travel inside the detector before losing all of energy it has, it is to much. We need more electron and hole couple inside the limited area of the pixel (15um) and to not getting any false signal from neighbor pixel, we should limited the spread of the electrons as much as posible.
The better part of using the InGaAs is density. The LET (Linear Energy Transfer) can give us the how much energy can electron lose in the unit square.This number is a function of the density of you detector and the relation is exponential so If we use InGaAs, we can get more signal inside the 15um2 pixel and we can get less noise from neighbor pixels.
I talk about this topic with my colleagues, It looks like it is a well known properties but currently nobody working on it.
Maybe, they are waiting to somebody ask them ''found a way the inseld this SWIR detector to my TEM device. I would like to have it'' . I do not know. This part is not my concern.
Anyway, I get my answer. Thanks everyone for the help.
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