Title :
New approaches to improve the endurance of TiN/HfO/sub 2//TiN capacitor during the back-end process for 70nm DRAM device
Author :
Jae Hyoung Choi ; Jeong-Hee Chung ; Se-Hoon Oh ; Jeong Sik Choi ; Cha-Young Yoo ; Sung-Tae Kim ; U-In Chung ; Joo-Tae Moon
Author_Institution :
Semicond. R&D Div., Samsung Electron. Co., Ltd., Gyeonggi-Do, South Korea
Abstract :
We have successfully developed a MIM capacitor process technology with a HfO/sub 2/ single layer deposited by ALD (atomic layer deposition), where a Hf(NEtMe)4 and CVD-TiN cylinder-type storage-node were used as a Hf liquid source and bottom electrode for 90 nm-scale DRAMs. Our experimental results indicated that NH/sub 3/-plasma treatment on HfO/sub 2/ film promoted crystallization below 400/spl deg/C as well as the formation of a HfO/sub x/N/sub y/ layer on the surface of the HfO/sub 2/ film. With this treatment, it was possible to solve the degradation problem of the leakage current depending on deposition method of the top electrode, and a stable leakage current without degradation was obtained up to 550/spl deg/C. As a result, a TiN/HfO/sub 2//TiN (TIT) capacitor with 1.4 /spl mu/m-height storage node was successfully demonstrated with stable leakage current of 1fA/cell at +1.2 V and high cell capacitance of 40 fF after metal-2 integration.
Keywords :
DRAM chips; MIM devices; ammonia; atomic layer deposition; capacitors; crystallisation; hafnium compounds; leakage currents; plasma materials processing; titanium compounds; 1.2 V; 1.4 micron; 40 fF; 400 degC; 550 degC; 70 nm; 90 nm; ALD; DRAM device back-end process; Hf liquid source; Hf(NEtMe)4; HfON-HfO/sub 2/; MIM capacitor process technology; NH/sub 3/; TIT capacitor; TiN; TiN-HfO/sub 2/; ammonia-plasma treatment; atomic layer deposition; bottom electrode; cell capacitance; crystallization; cylinder-type storage-node; leakage current degradation problem; metal-2 integration; Atomic layer deposition; Capacitance; Crystallization; Degradation; Electrodes; Hafnium oxide; Leakage current; MIM capacitors; Surface treatment; Tin;
Conference_Titel :
Electron Devices Meeting, 2003. IEDM '03 Technical Digest. IEEE International
Conference_Location :
Washington, DC, USA
Print_ISBN :
0-7803-7872-5
DOI :
10.1109/IEDM.2003.1269367
