Quick doubts on FinFET

Thread Starter

genxium

Joined Feb 13, 2011
1
There're many articles and videos in the internet saying that FinFET has a big advantage in transistor density, however it's difficult for me to find an example about how one FinFET's fins are actually connected to other electrodes such that the density is increased compared to using MOSFET.

I did find some convincing reasons for the density advantage claim (and I believe it's true in real life too)
  • FinFET is less susceptible to short-channel leakage current, thus takes a smaller area than a MOSFET alternative (w.r.t. same noise requirements)
  • FinFET has smaller gate width and length such that even several fins added up to a single source/drain it still has smaller area than a MOSFET alternative
However, I couldn't find proof or disproof on whether or not the "source fins" of a same FinFet be connected to different electrodes, e.g. if a single FinFET has 5 fins on the "source" side, can each of them be connected to different electrodes (as shown in the figure below)?

Ys6Zp5argP.png

If yes is there an example of such use case? Or otherwise what's the technical blocker or disadvantage of doing so (e.g. maybe it's difficult to manufacture conductive paths at the same resolution as the fins)?
 

dl324

Joined Mar 30, 2015
16,845
However, I couldn't find proof or disproof on whether or not the "source fins" of a same FinFet be connected to different electrodes, e.g. if a single FinFET has 5 fins on the "source" side, can each of them be connected to different electrodes (as shown in the figure below)?
All of the sources and drains are connected together via a diffusion layer.
1672246861917.png
 

MisterBill2

Joined Jan 23, 2018
18,167
Unless you are involved with the design and manufacture of transistors, the inside details are not what matters, but rather the data sheet values and specifications.
And I do not trust anything that is on youtoob. (the cartoon channel.)
Go to the manufacturer's site and read what they have to claim as the benefits, rather then on the cartoon channel.
 

shortbus

Joined Sep 30, 2009
10,045
And I do not trust anything that is on youtoob. (the cartoon channel.)
Go to the manufacturer's site and read what they have to claim as the benefits, rather then on the cartoon channel.
I guess you have never seen the videos on Youtube posted by the manufacturers of things. Mostly it's the people doing things with electronics that are cartoons.
 

Tonyr1084

Joined Sep 24, 2015
7,852
Mostly it's the people doing things with electronics that are cartoons.
Have seen a lot of dead bug builds that work for the video but I have to wonder how long they last. Likely with poor assembly technique and a lack of proper engineering behind any of the circuits I'd agree that a lot of what is on YouBoob is exactly that - junk videos. I've put a few videos on there. But I've never put anything like "Free Energy" or other fake or misleading videos that can lead a person to try something harmful or even dangerous. However I LOVE watching the boobs on YouTube. Don't believe me? Go check out my posts in the jokes thread.
 

shortbus

Joined Sep 30, 2009
10,045
Have seen a lot of dead bug builds that work for the video but I have to wonder how long they last.
I don't think the dead bug technique was bad. There were a lot of things done that way before laser printers made home made PCB's easy. The unetched PCB board also makes a great ground plane that many things need.
 

dl324

Joined Mar 30, 2015
16,845
Have seen a lot of dead bug builds that work for the video but I have to wonder how long they last.
There's nothing inherently unreliable about dead bug builds as long as you don't abuse them. Almost all of the circuit prototypes I made while I was a technician at HP Labs were dead bug style. I remember one where I gold plated the PCB and black anodized all of the heat sinks on the final build to make it look "better".
 

MisterBill2

Joined Jan 23, 2018
18,167
I recall seeing that "dead bug" style extended into 3D constructions in the lab area of one place I worked. They were known as "Kissel Balls", after the engineer who started building them. I always wondered what became of Mister William Kissel of department 7430.
 
Top