Menu

Discussion Forum

New Discussion
Filtern

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Simulating a MOSFET with silicon nitride as gate dielectric, using semiconductor module

Posted 03.12.2013, 06:14 GMT-5 Semiconductor Devices Version 5.2 5 Replies

Soumendu
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Undefined value found.
- Detail: Undefined value found in the equation residual vector.
There are 24 degrees of freedom giving NaN/Inf in the vector for the variable mod1.N.
at coordinates: (5.84978e-005,-3.33333e-009), (5.84931e-005,-6.66667e-009), (5.12993e-005,-6.66667e-009), (5.13039e-005,-3.33333e-009), (5.03756e-005,-6.66667e-009), ...
There are 24 degrees of freedom giving NaN/Inf in the vector for the variable mod1.P.
at coordinates: (5.84978e-005,-3.33333e-009), (5.84931e-005,-6.66667e-009), (5.12993e-005,-6.66667e-009), (5.13039e-005,-3.33333e-009), (5.03756e-005,-6.66667e-009), ...
There are 24 degrees of freedom giving NaN/Inf in the vector for the variable mod1.V.
at coordinates: (5.84978e-005,-3.33333e-009), (5.84931e-005,-6.66667e-009), (5.12993e-005,-6.66667e-009), (5.13039e-005,-3.33333e-009), (5.03756e-005,-6.66667e-009), ...

While trying to simulate a MOSFET with silicon nitride as the gate dielectric layer, I am getting this error message.
What is the problem here and how to solve it?
5 Replies Last Post 29.12.2016, 21:50 GMT-5
COMSOL Moderator

Hello Soumendu

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Anup Kumar
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 07.07.2014, 06:30 GMT-4
Hey Soumendu,

I am getting a similar error. Did you come up with solution. I am trying to use SiO2 as insulator but it shows a red cross on Materials and SiO2 in the model builder. While using semiconductor module can we use material other than given in semiconductor material like SiO2 or any metal.

Thanks
-Anup Kumar
Hey Soumendu, I am getting a similar error. Did you come up with solution. I am trying to use SiO2 as insulator but it shows a red cross on Materials and SiO2 in the model builder. While using semiconductor module can we use material other than given in semiconductor material like SiO2 or any metal. Thanks -Anup Kumar
Ekaterina Nekrasova
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 15.08.2014, 05:30 GMT-4
Hi, Soumendu
Check mesh in your model (is it too fine?) or maybe this problem is due to missing boundary condition.
Hi, Soumendu Check mesh in your model (is it too fine?) or maybe this problem is due to missing boundary condition.
Ekaterina Nekrasova
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 15.08.2014, 06:02 GMT-4
Hi, Anup
If you add Charge Conservation node related to SiO2 domain, red cross will disappear.

In my opinion, when you use Semiconductor Module, COMSOL think that all domains are semiconductors by definition and for this reason COMSOL ask you to define all parameters required by physics (band gap, electron affinity etc.). But you can include insulator in the model by using Charge Conservation feature. As a result you need to specify only relative permittivity to describe SiO2 (actually relative permittivity or polarization or remanent electric displacement - it's your choice in Charge Conservation settings window -> Electric Field)
Hope this helps!
Hi, Anup If you add Charge Conservation node related to SiO2 domain, red cross will disappear. In my opinion, when you use Semiconductor Module, COMSOL think that all domains are semiconductors by definition and for this reason COMSOL ask you to define all parameters required by physics (band gap, electron affinity etc.). But you can include insulator in the model by using Charge Conservation feature. As a result you need to specify only relative permittivity to describe SiO2 (actually relative permittivity or polarization or remanent electric displacement - it's your choice in Charge Conservation settings window -> Electric Field) Hope this helps!
Rahul Changder
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 21.02.2016, 08:27 GMT-5
I'm trying to simulate MOSFET using explicit SiO2 as gate oxide instead of using thin insulator gate. Although applying charge conservation to SiO2 layer only require dielectric constant of SiO2 to define, but it is not allowing me to use metal contact or terminal on the top surface of SiO2 layer. Also, if I use an extra gate material, it requires all semiconductor parameters, which are not available for metals. So is there any other physics or boundary or domain condition I have to use to simulate?
Please look into it and any suggestion will be highly appreciable.
Thank you,
I'm trying to simulate MOSFET using explicit SiO2 as gate oxide instead of using thin insulator gate. Although applying charge conservation to SiO2 layer only require dielectric constant of SiO2 to define, but it is not allowing me to use metal contact or terminal on the top surface of SiO2 layer. Also, if I use an extra gate material, it requires all semiconductor parameters, which are not available for metals. So is there any other physics or boundary or domain condition I have to use to simulate? Please look into it and any suggestion will be highly appreciable. Thank you,
Vivek Sangwan
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 29.12.2016, 21:50 GMT-5
Hi,

I'm facing a same problem of metal layers simulation in Semiconductor module.

Have you able to solve it?
Hi, I'm facing a same problem of metal layers simulation in Semiconductor module. Have you able to solve it?

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content