The study of the impurity in HK film

摘要

As CMOS size scaling down, HKMG was introduced into CMOS manufacture process to replace Poly-SiON scheme earlier at 45nm node. In many HK materials, HfO2 was finally chosen for its good thermal stability, non-reacting with silicon, no water absorption. Both ALD and MOCVD could be used for HfO2 deposition. From film quality, ALD was the better choice for its film quality, since ALD as self-limited process was not very sensitive to the process parameters like flow, temperature or pressure. Though considered relative stable, HK film properties, especially film impurity should be carefully studies for its dominating influence to device performance. From SIMS analysis, Cl in HK film will reduce when adding water pulse time or raising temperature of the water tank, and H will increase. While the content of Hf and O will keep stable.