Electronic Transport across the Grain Boundary of Poly-Si Channel in 3D NAND Flash Memory: A Theoretical Perspective

By first-principles calculations, we study how grain boundaries can quantitatively impact the electronic transport properties of poly-Si, which serves as transport channel in 3D NAND flash memory. We propose a double-ended nanodevice model of poly-Si to analyze four typical types of grain boundaries. It is shown that all the grain boundaries have negative impacts on electronic transport. In particular, the thickness of defective grain boundaries has the most prominent impact, indicating that reducing grain boundary thickness is important for improving the electronic transport properties of polv-Si.