dxt78
Junior Member
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Posts: 15
Ohio
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Hi all,
I'm trying to characterize a new process, and having trouble extracting unCox. My approach has been to plot ID vs. sqrt(VGS), then find the slope of the curve in the region where I will operate the transistor. Since ID=(1/2)*unCox*(VGS-VT)^2, the slope of the ID vs. sqrt(VGS) curve will be equal to sqrt(1/2*unCox*W/L). The unCox obtained by the above method is approximately 700uA/V^2, which seems reasonable.
My problem arises when I try to use .op in Cadence to confirm the above extracted value for unCox. I print betaeff, which I understand betaeff=(kprime)*W/L. Now, two strange things happen:
1) Cadence is giving the same value of betaeff for transistor of different sizes 2) Assuming kprime = 1/2*unCox, the unCox printed by Cadence is orders of magnitude from the value extracted.
Thank you in advance for your input and comments!
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