| 학회 | 한국재료학회 |
| 학술대회 | 2013년 봄 (05/23 ~ 05/24, 여수 엠블호텔(THE MVL)) |
| 권호 | 19권 1호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | TiO2 and Al-doped TiO2 films grown by atomic layer deposition for next generation DRAM capacitor |
| 초록 | As the density of the dynamic random access memories (DRAM) increases ＞ 1giga bit, the fabrication of capacitors having enough cell capacitance to meet the refresh requirement becomes very difficult because of the extremely small feature sizes (＜＜ 100 nm). Therefore, many researchers have focused on the development of metal-insulator-metal capacitors with high-k dielectrics for achieving large cell capacitance. In this study, the author reports TiO2 and Al-doped TiO2 films grown by ALD for application to next-generation DRAM capacitors. The TiO2 films on Ru electrode at 250 oC show higher dielectric constant (＞80) due to the formation of rutile structure. The k value is much higher than the value (~ 40) of anatase structured TiO2 films which are usually formed by normal depositing methods (ALD, CVD, sputtering, and etc). The formation of rutile TiO2 with high k value is due to the structural compatibility between the in-situ formed RuO2 at the interface during the ALD of TiO2 films using O3 and rutile TiO2. Although the rutile-structured TiO2 films fabricated on the Ru electrode show a k value high enough to be employed in future DRAMs, the leakage current level is unacceptably high for DRAM capacitor with sub-50 nm due to the small conduction band offset of TiO2 films. Therefore, Al ions as an acceptor are incorporated into the TiO2 films for compensating for the n-type carrier of the films. It is found that the leakage properties of the films are remarkably improved by the doping of Al ions into the films due to an increase in Schottky barrier height. |
| 저자 | 김성근 |
| 소속 | 한국과학기술(연) |
| 키워드 | ALD; capacitor; TiO2 |
