Nanoelectronics Computation Laboratory - NCL

Welcome to the Nanoelectronics Computation Laboratory of the Dept of Electrical Engineering. This lab facilitates running TCAD simulations at a transistor level and also simulations related to on-chip interconnects. TCAD stands for Technology CAD, the technology aspect implying process/material technology. In other words, TCAD tools let you simulate the effects of process and material related parameters (etch rate, material work function, channel doping, physical models (and their controlling parameters) for various physical effects like recombination/generation, band-to-band tunneling, etc), by spatially solving the key partial differencial equations that govern the physics of semiconductor devices and on-chip interconnects.

In line with trends at leading institutions, it is intentionally not being named as a TCAD Lab because it is not intended to be limited to TCAD alone, but rather grow in time to develop expertise in development of algorithms/software/numerical-techniques also, all in areas related to semiconductors. These are areas like the development of custom-developed, homegrown simulators for device simulation including but not limited to Monte Carlo simulators, etc as also sundry areas related to EDA algorithms like parameter extraction, circuit simulators, Boolean minimization, synthesis, etc.

The TCAD tools that we have in this lab are Synopsys Sentaurus and Synopsys Raphael. The former is a TCAD tool for transistors while the latter is a field-solver intended primarily for on-chip interconnects. Simulations can be either 2D or 3D.

Pools of Machines

We presently have two 3D licenses and three 2D licenses for the TCAD tools. It is our understanding that these license limits are at an individual executable level. In other words, running svisual to visualize a 3D structure and running a 3D simulation using sdevice does not count as 2 licenses. Rather, it counts as 1 license of each. This is what has been informed to us by our designated support agency Eigen Technologies, this undcerstanding needs to be ascertained.

Due to the limited number of licenses, we have defined 2 pools of machines along with the specified user-machine allocation shown below so as to load-balance the machines appropriately:

1. Pool#1 for 2D simulations:
   1. eleclab-tcad02.snu.in: Bhavith Dulipalla, Kiran G
   2. eleclab-tcad03.snu.in: S. Bhanoday
   3. eleclab-tcad04.snu.in: Dr Amitabh Chatterjee and Dr Venkatnarayan Hariharan
2. Pool#2 for 3D simulations:
   1. eleclab-tcad01.snu.in: Krishna Madhur Akella, Jyothi Pillai, Dr Jitendra Prajapati

Pool#2 obviously comprises beefier machines. Per Synopsys [httphttps://solvnetplus.synopsys.com/s/article/Choosing-Hardware-OS-for-Running-TCAD-Sentaurus-Tools:// SOLVNET Article# 000033256] dated April 2021, 3D simulations need minimum 128GB RAM, a CPU with 10 or more cores and ample L2 cache, a graphics card with 5GB video memory (VRAM). On the other hand, 2D simulations need only 16-32GB RAM and a graphics card with 2GB VRAM.

As of Mar 2022, the above machines are physically located in the EED's Microwave Lab in C-Block 2nd floor. This is a temporary arrangement, and they will eventually be moved to a dedicated NCL Lab in hC-Block 1st floor.

Remote Connectivity

For best performance and productivity, one is encouraged to work by being physically present in the lab. But the machines can also be accessed remotely using Windows Remote Desktop Connection software (RDC). The “.snu.in” suffix is not needed when connecting from within the SNU network (hostels, other labs, faculty cabins, etc). If one wishes to connect from outside the SNU campus, then one will need VPN access from SNU IT.

Useful RDC Settings

• To enable ALT-TAB to work as we usually expect: Click RDP -> Show Options -> Local Resources tab -> For "Apply Windows key combinations" select the option "On this computer".
• To copy/paste clipboard contents from Unix to Unix:
  • Using mouse: Select on Unix and then paste by clicking middle-mouse button
  • Using keyboard (KB): Select on Unix and click ctrl-shift-c, and then paste using ctrl-shift-v
• To copy/paste from Unix to Windows:
  • Select on Unix and type ctrl-shift-c
  • Then go to target Windows application and paste as usual in Windows (using mouse/KB/whatever)
• To copy/paste from Windows to Unix:
  • Copy as usual in Windows (using mouse/KB/whatever)
  • On Unix press ctrl-shift-v

Kindly note:

1. • You can only access one desktop at a given time.
   • If you do not logoff your desktop and simply disconnect or close the application, the system will initiate a logoff after 5 mins.
   • You may go through the Do's and Don't for using the VDI platform at: