A new cost-effective atomic layer deposition (ALD) technique, known as Proximity-Scan ALD (PS-ALD) was developed and its benefits were demonstrated by depositing Al2O3 and HfO2 thin films using TMA and TEMAHf, respectively, as precursors. The system is consisted of two separate injectors for precursors and reactants that are placed near a heated substrate at a proximity of less than 1 cm. The bell-shaped injector chamber separated but close to the substrate forms a local chamber, maintaining higher pressure compared to the rest of chamber. Therefore, a system configuration with a rotating substrate gives the typical sequential deposition process of ALD under a continuous source flow without the need for gas switching. As the pressure required for the deposition is achieved in a small local volume, the need for an expensive metal organic (MO) source is reduced by a factor of approximately 100 concerning the volume ratio of local to total chambers. Under an optimized deposition condition, the deposition rates of Al2O3 and HfO2 were 1.3 Å/cycle and 0.75 Å/cycle, respectively, with dielectric constants of 9.4 and 23. A relatively short cycle time (5~10 sec) due to the lack of the time-consuming "purging and pumping" process and the capability of multi-wafer processing of the proposed technology offer a very high through-put in addition to a lower cost.
MOCVD(Metal-Organic Chemical Vapor Dposition) TiN 박막을 다양한 온도와 압력에서 tetrakis-dimethyl-amino-titanium(TDMAT (Ti[N(CH3)2]4))의 자체 열분해와 NH3와의 반응을 사용하여 형성하였다. 비저항은 박막내의 불순물 함량에 의존하였는데 특히 XPS curve fitting 결과 주요 불순물인 탄소와 산소 같은 불순물들이 박막내에서 다양한 침입형화합물을 만들어 박막의 물리적, 전기적 특성에 영향을 준다는 것을 알았다. Metal-organic source만을 사용하여 TiN을 형성할 경우 지름이 0.5μm이고 aspect ratio가 3:1인 구멍에서 step coverage가 매우 우수하였으나 NH3를 흘림에 따라 step coverage가 감소하는 것이 SEM으로 확인되었는데 이는 각각의 활성화에너지와 관련된 것으로 보인다.