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kennycs New Member Offline Posts: 8	viarations of poly resisitor May 14^th, 2010, 9:37pm when I simulate circuits with both mosfet and poly resistor ,I am confused how to set the corner. As we know we can choose TT, SS, FF for mosfet ,and RMIN, RMAX, RTYP for poly resistor. However, I want to know whether the corner of poly resistor is independent with the one of mosfet ,or not ? thanks!
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Geoffrey_Coram

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Re: viarations of poly resisitor
Reply #1 - May 17^th, 2010, 5:06am

I would expect the delta-L and delta-W of the poly resistors to be correlated with delta-L and delta-W of the poly gates of the MOS devices. However, I don't know whether this over/under-etch is the most important source of statistical variation. Probably the threshold voltage shift and oxide thickness variation are more important.

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littlej New Member Offline Posts: 1 Shanghai	Re: viarations of poly resisitor Reply #2 - May 25^th, 2010, 12:06am RES model is indepedant with mosfet and other devices. You can use lib TT_RES/SS_RES/FF_RES.
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Geoffrey_Coram Senior Fellow Offline Posts: 1998 Massachusetts, USA	Re: viarations of poly resisitor Reply #3 - May 25^th, 2010, 6:06am littlej - the model files may show that RES model is independent of MOS model, but I'm sure that's not completely true in actual silicon.
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aLittleKnowledge

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Re: viarations of poly resisitor
Reply #4 - Jul 13^th, 2010, 3:57am

Variations of MOSFET gate length do correlate with variations in poly-resistor width. However, MOSFET length is also affected by sidewall oxide dimensions, and in many processes the poly-resistor is not at the same height as the gate, so the photo-effects will be different.
There is some small correlation between resistivity and VT. So far as I know there are no other correlations between these devices.

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love_analog Senior Member Offline Posts: 101	Re: viarations of poly resisitor Reply #5 - Aug 7^th, 2010, 1:48pm I don't think Resistor and gate will correlate that well. Typically we make the resistor wider so mitigate the delta(W) effect. most of resistor variation comes from the variation in resistivity.
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