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local layout effects

Local layout effects (LLEs) or Layout-dependent effects (LDEs) are envrionmental effects that negatively impact the electrical characteristics of a semiconductor device due to its physical layout and proximity to other features on an integrated circuit.

Overview

The physical environment (i.e., layout) in which a semiconductor device resides in can vary its characteristics. For example, a transistor that is placed close to the edge of a well will exhibit threshold voltage shift due to ion scattering back out of photoresist during ion implantation. All the various device effects are collectivity called Local layout effects (LLEs).

Effects

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See also