Lab 4 - ECE 421L 

Authored by Carlo Lopez-Tello.

Email: lopeztel@unlv.nevada.edu.

September 27, 2013.

  

Lab Description:

In this lab we will layout NMOS and PMOS transistors.

We'll begin with the NMOS.

First, we need to make the schematic, so create a new cell.

Select the NMOS device.

 

../Lab4/NMOSicon.JPG

 

Change the width to 10 and set the model by going to Tools>Simulation(Spice)>Set Spice Model.

 

../Lab4/NMOSsetmodel.JPG

 

Click on "SPICE-Model" and change it to "NMOS".

../Lab4/NMOSsetmodeltoNMOS.JPG

 

Create the following schematic for the NMOS.

To make the symbol simply create a symbol cell with the same name as the schematic, or go to View>Make Icon View.

 

../Lab4/NMOSschem.JPG

 

Make a new layout cell with the same name as the schematic cell.

The NMOS is made of poly between two N+ regions. Therefore, select a NMOS node, two N-active nodes, and one Pwell node for ground.

 

../Lab4/NMOSparts.JPG

 

Change the width of the nodes to 10 to match the schematic.

 

../Lab4/NMOSpartssize.JPG

 

Set the spice model of the NMOS node to match the schematic.

../Lab4/NMOSlaysetmodel.JPG

 

Now connect the parts to make the NMOS. Add metal-1 connections, and export them to match the schematic.

 

../Lab4/NMOSlay.JPG

 

Check your layout: DRC, NCC, and ERC.

 

../Lab4/NMOSerrorcheck.JPG

 

Now, we are going to simulate the I-V characteristics of this NMOS.

Create a new schematic, and add this file(C5_models.txt) to the same directory the jelib is in.

 

../Lab4/NMOSsimshem.JPG

 

The current from vds to ground should look like this.

 

../Lab4/NMOSsimgraph.JPG 

 

Now, we are going to layout a PMOS transistor. The schematic should look like this. remember to set the spice model to "PMOS" 

and to change the width to 20.

 

../Lab4/PMOSschem.JPG

 

Create a new layout cell with the same name. The PMOS is made of poly between two P+ regions, so select a PMOS node,

two P-active nodes, and a N-well node for VDD.

 

 ../Lab4/PMOSparts.JPG

 

Change the width of the nodes, then connect the together ot make the PMOS. Remember set the Spice model,

and export the metal connections to match the schematic.

../Lab4/PMOSlay.JPG

 

Check your design for errors: DRC, ERC, and NCC.

 

../Lab4/PMOSerrors.JPG

 

Create a shematic to simulate the PMOS I-V characteristics.

 

../Lab4/PMOSsimshem.JPG

 

The current from vsd to ground should look like this.

  

../Lab4/PMOSsimgraph.JPG

Backup your work. 

Link to jelib.

 

Return to EE 421L Labs