Effect of RTA on TiN films as the barrier layer for Pt/BST/Pt capacitors prepared by RF magnetron Co-sputter technique at low substrate temperature

摘要

Effect of rapid-thermal-annealing on metallic barrier TiN against the interdiffusions of Ti and Si into BST in Pt/BST/Pt/TiN/Ti/Si capacitors has been studied.In the integration of BST capacitors,the thermal budget of the BST deposition would cause the inter-diffusions of Ti and Si from Ti adhesion layer and Si-plug respectively.This event would degrade the BST capacitors.To address this issue,rapid-thermal-annealed TiN barriers were used between the bottom electrode Pt and ahesion layer Ti.Optical RTA condition for TiN were found in this experiment.Excellent electrical characteristics of Pt/BST/Pt/TiN/Ti/Si capacitors,including high dielectric constant (epsilon_r=320),low leakage current (1.5X10~(-8)A/cm~2) under 0.1MV/cm,and life time longer than 10 year lifetime under 1.6MV/cm were obtained with Ar+O_2 mixed ambient at a low substrate temperature (300degC).