Introduction to VLSI Design

Previous step Next step Layout tutorial index Flow diagram


Example: CMOS Inverter Layout

The N-Select Layer


Each diffusion area of each transistor must be selected as being of n-type or p-type. This is accomplished by a defining the "window: of n-type (or p-type) doping (implantation), through a special mask layer called n-select (p-select).

1. Select nselect layer from the LSW.

n select

2. Draw a rectangle extending over the active area by 0.6u (2 lambda) in all directions.

N select

This is it ! Our first transistor is finished, now let us make a few million more of the same :-)



Previous step Next step Layout tutorial index Flow diagram


a production of


VLSI CAD Laboratory


Analog/Digital Microelectronics Group

Cadence is a trademark of Cadence Design Systems, Inc., 555 River Oaks Parkway, San Jose, CA 95134.
Please read this DISCLAIMER

Last Updated by Ilhan Hatirnaz on 11/7/1998