Patent ID: 8399351

Claim:
A method of manufacturing a semiconductor device, the method including a process for filling a hole formed in a dielectric film in the semiconductor device with tungsten, said process comprising: initially depositing tungsten in the hole by supplying tungsten hexafluoride (WF6) gas and hydrogen gas under chemical vapor deposition conditions producing a reaction rate and a deposition rate such that the deposition rate is equal to the reaction rate, a void being disposed in the tungsten deposited in the hole; halting the supply of hydrogen gas and continuing to supply tungsten hexafluoride gas to etch an upper part of the tungsten deposited in the hole, the etching creating an opening leading to the void in the deposited tungsten; depositing additional tungsten in the hole by again supplying the tungsten hexafluoride gas and the hydrogen gas under the chemical vapor deposition conditions producing a reaction rate and a deposition rate such that the deposition rate is equal to the reaction rate, the additional tungsten substantially filling the void and the opening; wherein in halting the supply of hydrogen gas and continuing to supply tungsten hexafluoride gas, a rate of the supply of tungsten hexafluoride gas is reduced to less than that when initially depositing tungsten in the hole by supplying tungsten hexafluoride gas and hydrogen gas; wherein depositing additional tungsten in the hole also includes depositing the additional tungsten on the dielectric film, the method further comprising: halting the supply of hydrogen gas and continuing to supply tungsten hexafluoride gas to etch the additional tungsten deposited on the dielectric film; and depositing further tungsten on the dielectric film by supplying the tungsten hexafluoride gas and the hydrogen gas under chemical vapor deposition conditions producing a supply rate and a deposition rate such that the deposition rate is equal to the supply rate.