| Title |
Effect of Pressure increase on the Deposition of Tungsten by CVD |
| Authors |
윤호철(H . C . Yoon); 이정중(J . J . Lee); 금동화(D . W . Kum) |
| Abstract |
CVD blanket tungsten films have been formed by the hydrogen reduction of WF_6 in a high pressure regime (10∼20 torr) at temperatures of 300∼400℃. The effects of pressure and reaction temperature on the deposition rate and the characteristics of the films were investigated. The deposition rate of tungsten increased with the total pressure in the reactor at pressures below 40 torr, while it decreased when the total pressure exceeded 40 torr. The deposition rate also showed a maximum value at 360℃ regardless of the pressure. Films with a good step coverage have been also formed at 40 torr and 360℃. It was found that the deposition mechanism changes with pressure and temperature : at low pressures and low temperatures, surface reaction determines the overall reaction rate, while at high pressures(＞40 torr) and high temperature(＞360℃), the deposition is controlled by the transportation of reactive gas molecules. |