Optimization of driving current and crosstalk effect in epitaxial diode array for phase change memory application

Abstract

In this paper, aiming at the consistency of driving current and the reliability of crosstalk current, we propose two methods to optimize the performance of the dual-trench epitaxial diode array for phase change memory (PCM), as well as the optimization calculation model. By inserting pickup and using the new bias scheme, we can improve the consistency of the diode arrays and reduce the impact of crosstalk current on the idle storage cell, respectively. The test results show that all the diodes in arrays, including 4F2 in 40 nm process node, can provide a driving current of more than 900 μA at 2.7 V, after inserting pickups. With the new bias scheme, the maximum of the crosstalk ratio in the 12F2 diode array can be reduced to less than 2%, which is proved has no effect on the idle PCM cell. Moreover, the optimization model is the basis of design and fabrication to improve the performance of the diode access PCM chip.