서강대학교

초록/요약

The reliability of a storage capacitor is an important issue to increase the density of dynamic random access memory (DRAM). Recently, high-k materials, such as ZrO2, have been used to maximize the cell capacitance. However, high-k materials have serious problems such as low bandgap energy which decreases with respect to the increase of k and high defect density. Moreover, it is known that the higher k-value, the lower the bonding strength of the high-k material. Thus, storage capacitors using high-k materials have high leakage current characteristics which cause reduce data retention time and low lifetime which guarantees the reliability of the storage capacitor. Unfortunately, the difficulty of reliability analysis gradually increases due to the complex structure of the state-of-the-art DRAM storage capacitors and the properties of high-k materials. Therefore, in this paper, we propose the full 3-D TCAD-based reliability simulation platform for DRAM storage capacitors. Through this simulation platform, it is possible to perform preemptive prediction for DRAM storage capacitors considering material and structural characteristics, thereby obtaining time and economic benefits.