ECEP 443 Digital Integrated Circuits
Lab#1: Physical Design and Layout of CMOS Inverter
Objectives
Upon the completion of this Lab, you should be able to:
1. Use L-edit software to lay out basic CMOS digital circuits,
2. Use T-spice software to analyze static and dynamic
characteristics of CMOS digital circuits.
Requirements
You are required to draw the vertical and horizontal layouts for the
minimum sized symmetric CMOS inverter using the 2um MOSIS
CMOS technology and compare between the two layouts in terms of
the used area, power consumption, DC characteristics, and
propagation delays. Both inverters should have the same dimensions.
The following sections provide the detailed procedures to draw the
layout of the vertical CMOS inverter using L-edit.
Manual Layout
1. Copy the following files into your directory
Technology setup files for MOSIS/Orbit n-well 2.0 micron
process. (Technology
= SCNA, LAMBDA = 1.0 micron)
C\tanner\ledit83\samples\tech\mosis\morbn20.
2. Launch L-Edit
3. Create New File. Create new files by choosing File > New, which opens the
New
File dialog:
4. Replacing the Setup.
File > Replace Setup transfers setup information from a file (the source
file) to the current file (the destination file).
5. Under Setup -> Design
The chosen technology units should be
lambda It should be 1 internal unit for
1/1000 lambda The lambda value
should be 1 microns
Grid -> Grid Display -> Displayed Grid 0.5 locator units
6. Create a new cell. Cell -> New, call it inv
7. Draw 14 x 6 Active Box.
8. Draw two 4 x 4 Metal1 box and put on both sides of Active box.
9. Draw two 2 x 2 Active Contact centered on each Metal 1 box It
looks like.
10. Draw 10 x 2 poly box centered at the active.
11. Draw 18 x 23 N Select.
12. Copy the whole block above, select N Select and click Edit -> Edit
Object, change
N Select to be P Select.
13. Draw 10 x 18 P Select below the Nselect of NMOS.
14. Draw 6 x 6 Active inside the Pselect.
15. Draw 2 x 2 Active Contact inside the Active
16. Extend the Metal1 to Pselect area, it looks like:
17. With the same method draw a Nselect on the top of PMOS
18. Draw 25 x 40 Nwell at PMOS place.
19. Connect following the inverter schematic.
20. Draw 5 x 6 Poly beside the gate of two transistors.
21. Draw 4 x 4 Metal 1 centered in the poly.
22. Draw 2 x 2 Poly Contact centered in the Metal1
23. Click Port on the Toolbar. And draw OUT port. The
dialog jumps out. On Layer: Metal1
Port name: OUT
24. With the same method draw port for IN, VDD, GND. On Layer: Metal1,
Port name:IN/VDD/GND. It looks like
25. Run DRC check
A dialog box
jumps out.
26. If No DRC error, go to next step. If there is any, open the file inv.drc or
click to see the error. If you don’t like the error displayed on the screen,
click on the bar.
27. Extract the file to be SPICE file. Click on the toolbar. A dialog jumps
out. Fill the form as following then click RUN.
28. Launch T-Spice to run simulation. The Spice file looks like
* Circuit Extracted by Tanner Research's L-Edit Version 8.30 / Extract Version 8.30 ;
* TDB File: F:\TA\ece755\ Tutorial\LEDITTut \inv.tdb
* Cell: inv Version 1.24
* Extract Definition File: morbn20.ext
* Extract Date and Time: 09/28/2001 - 10:26
.include "G:\WIN32\ TannerT\models\ml2_20.md"
* Warning: Layers with Unassigned AREA Capacitance.
* <P Base Resistor>
* <N Well Resistor>
* <P Diff Resistor>
* <N Diff Resistor>
* <Poly2 Resistor>
* <Poly Resistor>
* Warning: Layers with Unassigned FRINGE Capacitance.
* <Poly1-Poly2 Capacitor>
* <P Base Resistor>
* <N Well Resistor>
* <P Diff Resistor>
* <N Diff Resistor>
* <Poly2 Resistor>
* <Poly Resistor>
* <Pad Comment>
* Warning: Layers with Zero Resistance.
* <PMOS Capacitor>
* <NMOS Capacitor>
* <Poly1-Poly2 Capacitor>
* <Pad Comment>
* NODE NAME ALIASES
* 1 = IN (-56.5,90)
* 2 = OUT (-11.5,89.5)
* 3 = VDD (-34,119)
* 4 = GND (-34,65)
M1 OUT IN VDD VDD PMOS L=2u W=6u AD=36p PD=24u AS=36p PS=24u
* M1 DRAIN GATE SOURCE BULK (-36 107 -30 109)
M2 GND IN OUT GND NMOS L=2u W=6u AD=36p PD=24u AS=36p PS=24u
* M2 DRAIN GATE SOURCE BULK (-36 74.5 -30 76.5)
* Total Nodes: 4
* Total Elements: 2
* Total Number of Shorted Elements not written to the SPICE file: 0
* Extract Elapsed Time: 0 seconds
.END
Pay attention to the sequence of the MOSFET connection to ensure it is drain,
gate, source and base
29. Add the running command and run simulation.
* Circuit Extracted by Tanner Research's L-Edit Version 8.30 / Extract Version 8.30 ;
* TDB File: F:\TA\ece755\ Tutorial\LEDITTut \inv.tdb
* Cell: inv Version 1.24
* Extract Definition File: morbn20.ext
* Extract Date and Time: 09/28/2001 - 10:26
.include "G:\WIN32\ TannerT\models\ml2_20.md"
* Warning: Layers with Unassigned AREA Capacitance.
* <P Base Resistor>
* <N Well Resistor>
* <P Diff Resistor>
* <N Diff Resistor>
* <Poly2 Resistor>
* <Poly Resistor>
* Warning: Layers with Unassigned FRINGE Capacitance.
* <Poly1-Poly2 Capacitor>
* <P Base Resistor>
* <N Well Resistor>
* <P Diff Resistor>
* <N Diff Resistor>
* <Poly2 Resistor>
* <Poly Resistor>
* <Pad Comment>
* Warning: Layers with Zero Resistance.
* <PMOS Capacitor>
* <NMOS Capacitor>
* <Poly1-Poly2 Capacitor>
* <Pad Comment>
* NODE NAME ALIASES
* 1 = IN (-56.5,90)
* 2 = OUT (-11.5,89.5)
* 3 = VDD (-34,119)
* 4 = GND (-34,65)
M1 OUT IN VDD VDD PMOS L=2u W=6u AD=36p PD=24u AS=36p PS=24u
* M1 DRAIN GATE SOURCE BULK (-36 107 -30 109)
M2 GND IN OUT GND NMOS L=2u W=6u AD=36p PD=24u AS=36p PS=24u
* M2 DRAIN GATE SOURCE BULK (-36 74.5 -30 76.5)
Vin IN GND PULSE (0 5 0 1n 1n 100n
200n) Vdd VDD GND 5
.tran/powerup 5n 500n method=bdf
.print tran v(IN) v(OUT)
* Total Nodes: 4
* Total Elements: 2
* Total Number of Shorted Elements not written to the SPICE file: 0
* Extract Elapsed Time: 0 seconds
.END
