Dielectric properties with heat-input condition of PZT thin films for ULSI's capacitor -1- A study on the improvement of leakage current of PZT thin films using a amorphous PZT layer

초고집적회로의 커패시터용 PZT박막의 입열 조건에 따른 유전특성 -1- 비정질 PZT를 사용한 PZT 박막의 누설전류 개선에 관한 연구

To improve the leakage current, we developed two step sputtering method where PZT thin film in first deposited at room temperature followed by 600.deg. C deposition. The method used an amorphous PZT layer deposited at room temperature to keep a stable interface during sputtering at high temperature. PZT thin films were deposited on Pt/Ti/SiO$_{2}$/Si substrate at room temperature and 600.deg. C sequentially. The effect of the layer deposited at room temperature was investigated with regard to I-V characteristics and P-E hysteresis loop. In the case of the sample with the layer deposited at room temperature, both leakage current and dielectric constant were decreased. The thicker the layer deposited at room temperature was, the lower dielectric constant was. However, leakage current was indepenent of the variation of the thickness ratio. The sample with 200$\AA$ of the layer deposited at room temperature showed the most promising results in both dielectric constant and leakage current.