Re: Electric and TSMC0.18

[Steven Rubin]

I'm learning to make layouts in Electric for TSMC 0.18 Micron Process. I'm using the
SCMOS_DEEP rules (with lambda of 0.09). Some of the design rules are:

1. Contact size is 0.18 umX 0.18 um (i.e. 2 lmbdaX 2 lmbda);
2. Width of device (minimum) is 0.27um (i.e. 3 lmbda);
3. Aspace space  (minimum) is 0.27 um (i.e. 3 lmbda);
4. Poly to active space (minimum) is 0.09um (i.e. 1 lmbda).

I find they are different from the ones in TSMC0.18 rules (in Cadence), where:

1. Contact size is 0.22 umX 0.22 um;
2. Width of device (minimum) is 0.22um;
3. Aspace space  (minimum) is 0. 28um;
4. Poly to active space (minimum) is 0.10um.

I tried exporting the GDSII files and LEF files from Electric (SCMOS_DEEP) and then importing them
into Cadence (TSMC0.18).  I failed to transfer them because of the differences metioned above. I got
DRC errors in Cadence although DRC passed in Electric. What can I do with the DRC errors in Cadence? 
Is it possible to make layouts in Electric for TSMC 0.18 Process and then transfer them into Cadence
without errors? If yes, which technology (and options) is better in Electric? If not,  I should try making up
a dedicated TSMC 0.18 technology in Electric, although I think it is not easy.

It isn't an issue of Electric vs. Cadence.  Rather, it is a question of which fabrication house you are going to use.  When MOSIS tells you that they are using a 0.18 process, they still ask you to make the gate size 0.2 because they are going to compensate your geometry down to 0.18 before fabrication.  Actually, MOSIS CMOS is able to target many different fab houses, not just TSMC.  So their geometries are more general.

Both Electric and Cadence are willing to draw geometries at any size, but they have to target the same design rule specifications.  Electric's MOSIS CMOS design rules consider everything to be relative to the 0.2 sizes.  Does Cadence?  If not, this explains the trouble.

If you want to scale your Electric designs, you can change the value of lambda before writing GDS.  Then you can get it into Cadence.  But there will surely be small differences in the design rules that still require hand-editing.

   -Steven Rubin