基于ALD Al_2O_3新型反熔丝器件的可靠性研究

Study on Reliability of A New Anti-fuse Device Based on ALD Al_2O_3

金属-绝缘体-金属(Metal-Insulator-Metal,MIM)反熔丝器件常被用于现场可编程逻辑阵列(Field Programmable Gate Array,FPGA)的互联结构单元.本文使用高介电常数材料Al_2O_3作为介质层,使用原子层沉积(Atomic Layer Deposition,ALD)技术,制备了高可靠性,高性能的MIM反熔丝单元.该反熔丝单元关态电阻超过1TΩ,同时开态电阻非常低,满足正态分布,集中在22Ω左右,波动幅度很小,标准差仅为3.7Ω,因此Al_2O_3反熔丝器件具有很高的开关比.本文研究了该器件编程前后两种状态的特性及时变击穿特性(Time Dependent Dielectric Breakdown,TDDB).研究结果表明,在2V工作电压下,未编程的反熔丝单元的预测寿命为1591年,同时,当读电流在0～20mA时,编程后的反熔丝保持稳定.这说明该反熔丝单元在低阻态和高阻态都具有非常高的可靠性.

Metal-Insulator-Metal (MIM)antifuse has always been used in Field Programmable Gate Array (FPGA) interconnection structure unit.A High-performance and High-reliability Metal-Insulator-Metal antifuse was fabricated with high KAl2O3 deposited by Atomic Layer Deposition (ALD)as the dielectric.The anti-fuse units offstate resistance exceeds 1TΩ,and the on-state resistance is very low,which satisfies the normal distribution,the on-resistance value is concentrated around 22Ω,and the standard deviation is only 3.7Ω,so it has high on/off ratio. In this paper,the Time Dependent DielectricBreakdown (TDDB)of the structure is studied.The results show that the predicted lifetime of the unprogrammed anti-fuse cell is 1591 years at 2V operating voltage.At the same time, when the read current is 0~20mA,the programmed anti-fuse remains stable.This shows that the antifuse has a very high reliability in both low-impedance and high-impedance states.