Electronics > Projects, Designs, and Technical Stuff

Transistors - die pictures

<< < (152/159) > >>

T3sl4co1l:
Hmm, not so much heavily doped, given the modest breakdown voltages; gold doping likely though?

Could well be higher doping in the connection layers (by extension, substrate -- being the collector connecting layer -- if epitaxial type), forcing recombination near the junctions and reducing switching resistance.

(...Ah yes, "double diffused epitaxial", so that could be.  That is, n+ substrate; n- epitaxy for collector drift region; p (base) then n+ (emitter) diffusions; and, maybe p+ base contact diffusion?, but would that be triple, or can it be done at the same time as emitter?  Not sure.  ...Nah, don't think there's a base contact layer. That checks out then.)

Also I guess an extra "emitter" ring around everything, for guard ring?  I... forget exactly how those work, but that looks like what they've done anyway.

Tim

Wolfgang:
Unglaublich saubere Fertigung. für das Alter. Haben wir Restströme von dem Ding ?
In English, sorry: Very clean manufacturing, indeed. Do we have leakage currents for this part ?

Noopy:

--- Quote from: T3sl4co1l on October 30, 2023, 07:42:56 pm ---Hmm, not so much heavily doped, given the modest breakdown voltages; gold doping likely though?

--- End quote ---

A modest Vce but the Veb is quite low with 5V. Nevertheless, of course there are HF transistors with higher doping concentration.
Gold doping is at least possible but you don´t find a hint in the datasheet.



--- Quote from: T3sl4co1l on October 30, 2023, 07:42:56 pm ---Could well be higher doping in the connection layers (by extension, substrate -- being the collector connecting layer -- if epitaxial type), forcing recombination near the junctions and reducing switching resistance.

(...Ah yes, "double diffused epitaxial", so that could be.  That is, n+ substrate; n- epitaxy for collector drift region; p (base) then n+ (emitter) diffusions; and, maybe p+ base contact diffusion?, but would that be triple, or can it be done at the same time as emitter?  Not sure.  ...Nah, don't think there's a base contact layer. That checks out then.)

--- End quote ---

I agree with your explanation.



--- Quote from: T3sl4co1l on October 30, 2023, 07:42:56 pm ---Also I guess an extra "emitter" ring around everything, for guard ring?  I... forget exactly how those work, but that looks like what they've done anyway.

--- End quote ---

Since the "emitter ring" is in the collector area it generates no real junction. But probably it hat a positive effect...



--- Quote from: Wolfgang on October 30, 2023, 07:48:35 pm ---Unglaublich saubere Fertigung. für das Alter. Haben wir Restströme von dem Ding ?

--- End quote ---

Hello Wolfgang! Some german words?  ;)
The cutoff current is at room temperature <70nA (Vcbo=50V).
Really a nice transistor.  8)

Wolfgang:
I see a datasheet leakage of 70nA maximum, but I am sure its in the picoamps when measured. Any measurements available ?

Noopy:
DMM6500 says 30nA @40V.
But I had to take the open part because I have just this one. It is now open for some days, let´s say one or two weeks.
I tried to keep the transistor away from light.

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod