Unknown east German chips - high resolution die shots - is anyone able to identify?

[Tesla44289]

Hi,

About a year ago I acquired some unlabeled prototype chips from east German production. I worked at an experimental fab until recently and they let me use the Olympus Semiconductor microscope to take some high resolution die shots of them (which I unfortunately had to compress quite a lot due to the forum's file size limitation). They fare really well as wallpapers on my devices, however I haven't managed to identify them...


I know it is fairly improbable that anyone is able to make out what kinds of chips they are, but if anyone has an idea pleas let me know!

Cheers from Germany
Milan

 

[philpem]

Those are some nice die shots!

The AMX14 looks like some kind of test device. There are some tracks going from bond pads on one side of the chip to the other, which I guess would be useful for measuring metal layer resistance. That said, it looks like the silicon is doped underneath - so they could well be FETs. There seem to be a lot of large transistors and transistor arrays on the chip, and it's very sparsely populated - which is why I think it's a test chip. The purpose of such devices is to characterise the manufacturing process.

The AM400A is a mystery. It looks like it was made with a similar process to the AMX14, but is far more complex. There are a lot of polysilicon resistors and bipolar transistors, so my guess is it's either some kind of bipolar RTL, DTL or TTL chip, or an analog chip. Looks like a 2-metal (two metal layers) process, so probably quite late in the lifespan of the GDR.

You might want to have a look around the other die shots on https://siliconpr0n.org/archive/doku.php and see if you can find something which looks similar. The text especially might give away who the fab (or at least the designer) was.

 

[Chuck(G)]

I think I've found a bug in the AM400 die:

 

[Tesla44289]

You might want to have a look around the other die shots on https://siliconpr0n.org/archive/doku.php and see if you can find something which looks similar. The text especially might give away who the fab (or at least the designer) was.

That sounds good, I'll look through those, thanks! I've also dropped John a mail in order to get the pics uploaded to the database.