Reduction of the Cell-to-Cell Variability in Hf_1-xAl_xO_yBased RRAM Arrays by Using Program Algorithms

Abstract

In this letter, we propose an effective route to reduce the cell-to-cell variability in 1T-1R-based random access memories (RRAM) arrays by combining the excellent switching performance of Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sub> with an optimized incremental step pulse with verify algorithm for programming. The strongly reduced cell-to-cell variability improves the thermal and post-programming stability of the arrays, which is relevant for many applications of the RRAM technology. Finally, the retention study at 150 °C enables the prediction of the data storage capability.