TinyFlow Design Rules Manual (v0.3)

Adapted from MOSIS Scalable CMOS (SCMOS) Revision 8.0 (Technology: SCN6M DEEP) (https://www.southampton.ac.uk/~bim/notes/ice/DesignRules/scmos-main.html#tech-codes)

Authors: Vayun Tiwari

Last updated: January 27th, 2026

nwell

Rule	Description	\(\lambda\)
1.1	Minimum width	12
1.3	Minimum spacing between wells at same potential	6

active

Rule	Description	\(\lambda\)
2.1	Minimum width	3
2.2	Minimum spacing	3
2.3	Source/drain active to well edge	6
2.4	Substrate/well contact active to well edge	3
2.5	Minimum spacing between non-abutting active of different implant	4

poly

Rule	Description	\(\lambda\)
3.1	Minimum width	2
3.2	Minimum spacing over field	3
3.2a	Minimum spacing over active	4
3.3	Minimum gate extension of active	3
3.4	Minimum active extension of poly	4
3.5	Minimum field poly to active	1

pselect & nselect

Rule	Description	\(\lambda\)
4.1	Minimum select spacing to channel of transistor to ensure adequate source/drain width	3
4.2	Minimum select overlap of active	2
4.3	Minimum select overlap of contact	2
4.4	Minimum select width and spacing (P and N-select may coincident, but must not overlap)	4

contact to poly

Rule	Description	\(\lambda\)
5.1	Exact contact size	2×2
5.2	Minimum poly overlap	2
5.3	Minimum contact spacing	4
5.4	Minimum spacing to gate of transistor	2

contact to active

Rule	Description	\(\lambda\)
6.1	Exact contact size	2×2
6.2	Minimum active overlap	2
6.3	Minimum contact spacing	4
6.4	Minimum spacing to gate of transistor	2

metal1

Rule	Description	\(\lambda\)
7.1	Minimum width	3
7.2	Minimum spacing	3
7.3	Minimum overlap of contact or via	1
7.4	Minimum spacing when either metal line is wider than 10 lambda	6
7.5	Minimum area	25 \(\lambda\)2

metal1 label

Rule	Description	\(\lambda\)
label.1	Track alignment	-
label.2	Minimum metal1 overlap	4 \(\times\) 4

prboundary

Rule	Description	\(\lambda\)
prboundary.1	Minimum spacing to active (does not apply to well-tap active)	2
prboundary.2	Minimum spacing to metal1 (does not apply to metal1 VDD/VSS rails)	2
prboundary.3	Minimum spacing to poly	2

*these rules ensure DRC-clean abutment between adjacent standard cells during place & route

via12 & above

coming in v1