MOS diode temp dependence

[tzg6sa]

Hi All,

I tried to find the equations describe the temperature dependence of a MOS diode. Could one of you write me or send a link?

For a fixed current the voltage drop depends on the temperature. The voltage change depends on the overdrive voltage too, with other words the overdrive voltage has a temperature coefficient. The effective temperature coefficient is the weighted sum of the threshold voltage's and the overdrive voltage's temperature coefficient.

If we consider the quadratic equation, than it is the change of mobility with temperature. I am looking for its (basic) modeling.

 

[erikl]

I tried to find the equations describe the temperature dependence of a MOS diode. Could one of you write me or send a link?

... the threshold voltage's and the overdrive voltage's temperature coefficient.

... the change of mobility with temperature ...

... the temperature dependence of the carrier velocity saturation, and a lot more, s. e.g. the excerpt from the Allen+Holberg book below.
All these temperature dependencies are considered in the SPICE models (BSIM3, BSIM4, EKV ...). As there are so many different dependencies, it's not easy to give a simple equation or even a fixed value, because it depends on a lot of technological parameters. A value could be given for a special process, however, but even then it would be valid only for a limited range of the W/L ratio and overdrive voltage.
See the SPICE modeling descriptions how it is calculated there.

 

[tzg6sa]

Thanks!

I hoped, that there are nicer equation for this.

 

[erikl]

Thanks!

I hoped, that there are nicer equation for this.

In the literature values between -1 and -2 mV/K can be found for the MOS temperature coefficient of Vt, s. the excerpts below.

Perhaps this can help?
Rgds, erikl

 

[tzg6sa]

Thanks erikl!

I was just curious how to derive equation to mitigate the temp dependence of a MOS diode. But it looks too cumbersome to carry out calculations. I will just relay myself upon the simulator.