8/14/2019 Layout Matching - 5 Kickass Rules!.pdf

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Layout Matching 5 Kickass Rules! Written by Adrian O'Shaughnessy Senior Layout Engineer

Layout Matching 5 Kickass Rules!osted on anuary "#$ %&""byAdrian OShaughnessy

(E )abrication *rocess is not ideal and there)ore de+ice si,es can di))er )ro- -ask si,es. /t's

critical that 0e understand the +arying e))ects o) )abrication and a**ly techni1ues to reduce

-is-atch bet0een de+ices. E2a-*les o) such +ariations include -ask shi)t$ o+er3under etch$

i-*lant shado0ing$ o2ide gradients$ S/$ WE etc.

We need to try and adhere to a set o) layout rules that 0ill try to ensure 0e a+erage the *rocess

+ariation gradients across the -atched structures. hese rules should include the )ollo0ing4

Unit Fingers

Matched de+ices should al0ays be layed out as -ulti*les o) a unit de+ice4

Device Orientation

he orientation o) a de+ice is a critical ele-ent 0hen -atching bet0een de+ices. Matched

de+ices should al0ays ha+e the sa-e orientation4

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8/14/2019 Layout Matching - 5 Kickass Rules!.pdf

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Layout Matching 5 Kickass Rules! Written by Adrian O'Shaughnessy Senior Layout Engineer

Locality

e+ices 0hich re1uire close -atching should be *laced close together as it reduces

-is-atches introduced due to +ariation in *rocess gradients4

Interleaving, cross quaing

/nterlea+ing is a techni1ue 0here t0o or -ore de+ices are 0ea+ed together in the 6 or 7

a2is. (el*s co-*ensate )or -is-atches due to +ariation in *rocess gradients4

Ientical "acent #onuctors $Du%%y Insertion&

u--y de+ices are inserted in the layout so as -atched de+ices are e2*osed to the sa-e

boundary conditions4

F

For more information on IC Mask Design's layout training course 'Advanced Analog Layout',

please visit http:!!!"icmaskdesign"comcoursescourse#aalt

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