Hey there!
I'm struggling to find commercial transistors that could be used in cryo(liquid argon, about 88K). I want to do a HBT, CMOS hybrid charge amplifier and I'm struggling to find the right components, especially with the MOSFETs. According to our brother chatgpt most commercial discrete smd mosfet are of the bulk type, yet the bulk type is a lot more sensitive to cryo, so I'd like to have soi or finfet stand-alone discrete mosfet. now when I look for "finfet" or "soi", I can't find anything, not even in the datasheet. So I come here to ask if anyone has any recommendations on components that work at cryogenic temperatures, or if someone knows where I can search more accurately.

Thank you in advance,
Best wishes sascha from the lab

 

For charge sensitive amplifiers, we use 2N4416 JFET in TO-72 metal cans. The transistor itself is not cooled in the cryostat, only the detector crystal.

 

For charge sensitive amplifiers, we use 2N4416 JFET in TO-72 metal cans. The transistor itself is not cooled in the cryostat, only the detector crystal.

Thank you very much! i'll see what i can do with them. the original design also used JFETs, but since they decay exponentially in performance from about 100K downwards, i thought it made more sense to use MOS and HBT, since the preamp has to be 4 meters down the cryostat, and cannot be at RT. but maybe if yours perform well, and if the doping is high enough they might bend the corner, so i'll give them a try. thank you very much for your answer!