Embedded non–volatile memory study with surface potential based model

Coupling coefficients calculation is known to be a critical issue in embedded Non-Volatile Memory (eNVM) compact modeling. In this paper we have implemented the charge balance method within the Brew’s Charge Sheet Model equation, determining the floating gate potential of the cell and deriving the NVM coupling coefficients. The results have been compared with TCAD simulations and demonstrate that short channel effects, overlap capacitances and velocity saturation dominate over the intrinsic behavior of the cell in scaled devices. We have studied the transient behavior of the eNVM, reproducing the VTH shift due to charge injection and demonstrating the capability of our model to simulate the full electrical behavior of the device. Moreover we have included the charge balance equation in the VerilogA implementation of PSP MOSFET model and proved with SPICE simulations the suitability of our approach to compact modeling.

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