Question about junction temperature (Tj) in hot carrier injection

[e.Horus]

Hello,

I need some urgent help. I am using an online calculator for one of the main CMOS foundaries
in the world. My objective is to determine the life time of a circuits under differnt voltage and
temperature conditions. The problem is that I do not understand some of these terms (which
they ask for) and I also have an additional couple of questions:

For the purpose of Hot carrier injection:

1. What is Tj (junction temperature) is it the sme as the operating temperature? If so why is it that the life time decreases when I enter a lower Tj?

3. what is DC to AC factor?

4. what is cum. fail?

For the purpose of Gate oxide break down;

If I apply the voltage to the gate of a common source and the same voltage to the source of
a common-gate device, which has a higher risk of oxide breakdown?


Thank you greatly for your help

 

[kwkam]

hot carrier temperature effect

It is very hard to define the life time of a IC from foundry data. Since, they only guarantee the transistor will work after some years at some conditions. To check a IC life time, the only way is doing burn-in test with the actual IC .

 

[invent]

hot carrier injection

If i remember correctly, for question 1:


Junction temperature is the temprrature inside the IC.
There is some explanation here: www.allegromicro.com/techpub2/an/an295014.pdf

For lower Tj the electrons along the path of the Hot carrier have less energy and are less exited. Therofore the Hot carrier has less obstacle in its path and more energy to be injected into the oxide.

 

[e.Horus]

ac/dc factor nbti

Thank you for your replies

So if I understand correctly hot carrier injection is more dangerous at low temperature, correct?

 

[invent]

Hot carrier effects

Yes, hot carrier injection is more dangerous at low temperature.