Applications of CMOS, NMOS and BJT technologies

[Robotduck]

I took a course this semester that covered BJT (TTL, ECL), NMOS, and CMOS technologies. As I understood that CMOS technology is widely used because of its low static power dissipation.
Now the question is :
1) Do we still use BJT and NMOS technologies? If yes then where? What are the specific applications?
2) Also I read in one of the threads that Military applications do not use CMOS technology. Is it true? If yes then why?
3) Also I read in one of the threads that CMOS technology utilizes less area but as I understood that with each input in CMOS you need 2 transistors so the area is a problem in CMOS technology as compared to NMOS technology? NO?
4) Do we prefer BJT logic circuits at high frequency? If yes then why?

Thank you!

 

[dick_freebird]

1) sure; mostly RF (SiGe and III-V HBTs) and power
(SCRs are a BJT-pair merged; IGBTs, a PMOS and
NPN). Most "CMOS" RF is heavily weighted to NMOS
in the signal chain, CMOS in the control logic.

2) Utter bullsh!t. Spend decades doing rad hard
CMOS and BiCMOS, and people are still pushing
down the geometry roadmap for MIL applications
trying to get rugged at near leading edge nodes.

3) NMOS will have two transistors per inverter,
may be more efficient in wider gates -if- you can
stand inferior L-H drive (wired-AND depletion load).
The break-even between CMOS Idd@freq and
NMOS Istatic+Idd(freq) is an engineering trade
to be made up front. Of course NMOS-only
technologies are few and further from the leading
edge.

4) You're not going to beat a InP HBT for speed.
20+ years ago TRW (now Northrop-Grumman)
was doing >100GHz main clock custom digital on
in-house InP. They don't talk about it to just anyone.
SiGe on CMOS is used for high data rate differential
signaling on the serial side, with CMOS handling
the lower word rate parallel (packetizing, error
correction, etc.) parts of the design. One one job
in the '90s I had to design a 400MHz 3.3V CMOS
fiber optic engine chip, I did it in SOI CMOS and the
customer decided to shop around for a second
source; the only bidder was Maxim with a SiGe
bipolar solution (and they gave a cost & schedule
we had already met and were delivering to).