cryogenic CCD operation

[John Geary]

Posted to CCD-world:
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>I have heard that CCDs cannot be operated at extremely cold 
>temperatures (I'm looking at an application which would operate
>around 30K). Does anyone have any information on this?
>What is the failure mechanism? Has anyone tried it? What is the 
>cutoff temperature?  Is there any published research on this topic?

> Tim Hardy
> National Research Council Canada          E-mail: Tim.Hardy at hia.nrc.ca
> Herzberg Institute of Astrophysics        Phone:  (250) 363-0015
> 5071 W. Saanich Road                      FAX:    (250) 363-0045
> Victoria, B.C.   V8X 4M6


One thing that happens at low temps is that many of the dopant atoms
recombine rather than exist in the lattice in an ionized state.  This can
lead to a host of effects, such as turning transistors in lumps of inert
silicon, temporarily erasing of potential wells, and vast increases in the
resistivity of polysilicon phase lines.
Some of these effects may show up at temperatures as high as LN2 (77K).

IR devices which must work at really cold temps are specifically doped for
such operation.


Today's Quip:  "At Microsoft, Quality is Job r99v2.07".

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