Hi

I am new to Layout . I want to know the difference between Lambda and Micron rules.

I know that, Lambda it is scalable and Micron it is non scalable (fixed).

I want to know how to convert Lambda to micron and some more details about that.

Dear Sivaraj

I am not very familiar with the topic. But what i can tell is the following. I think !!!

1. The u-Rule means that all width and spacing rules from the foundry is specified as absolute values. i.e. e.g. M1 min width = .8u ; M1M1 min spacing = .14u etc.

By this way the FAB Engineer or physicist has the flexibility to fine tune each of the values resulting in the best silicon implementation of the design in terms of efficiency.

2. By Lambda Rule - Each of the width spacing rules etc. are specified as a multiple. e.g. M1 min width = 2Lambda; M1M1 min spacing = 3Lambda etc.

For example for a .5u process if Lambda is .3u then that then will evaluate to the values of M1 min width = .6u and M1M1 min spacing = .9u

A FAB will fix the values of M1 min Width = 2Lambda and M1M1 min spacing = 3Lambda for all its process.

That means from this fab if u want to do a layout in a .25u process and Lambda is specified as .15 then u can compute the absolute values of the these parameters.

This would mean a FAB Engineer or a physicist does not have the flexibility to fine tune the process but the Designer has the advantage that the can quickly write some automatic codes to generate layout of a .25u process if the layout form the 0.5u is already ready. More suited for huge digital design chips.

Hope it helps

BR
Bharath

hi
refer this link
http://www.ece.virginia.edu/~mrs8n/cadence/tutorial5.html
its cadence tutorial with examples using their CAD tool
* Virtuoso Composer for schematic capture,
* Analog Environment for simulation,
* Virtuoso Layout for layout,
* Diva for DRC (design rule checking).

Hello Shivraj,

The micron unit is fixed for the technology.... This is the minimum available lithography of the technology... You can not change it right?

But, lambda unit is made for the designer's convenience... to draw the layouts properly... Hence, in-order to design the layout conveniently lambda units are usually employed...

According to your selection the layout screen will... adjust the grid.. so, that u can design the layouts as per the DRC(Design Rules) requirements.

for example say for a 0.18um technology i.e 180nm-- right??
we use:

lambda = L(min)/2

This will become 90.. and then its very easier to draw the layout... simply by counting the spacings between the grid... try this in front of the layout design window... then u will understand better and easily...

Try this free software to practice at home...

MICROWIND3.1

Very helpful and easy to use...
cheers..