Method of manufacturing a semiconductor device capable of reducing contact resistance

摘要

The present invention relates to a method of manufacturing a semiconductor device, which is capable of effectively removing a WO3 film generated on a tungsten silicide during contact hole etch that opens a gate electrode including the tungsten silicide as its top film by selectively etching a interlayer insulating film. The WO3 film is removed by a washing process using an alkaline solution such as TMAH(tetra-methyl-ammonium-hydroxide) or NH4OH solution. The effective removal of the WO3 film reduces the contact resistance between a conductive material layer to be formed in the contact hole by a later process and the gate electrode, thereby improving the operative characteristics of the semiconductor device. TMAH solution used in the washing process has a high selectivity of WO3 film relative to a thermal oxide film or a BPSG film that is generally used as the interlayer insulating film. Thus, the present invention is capable of minimizing the damage of the side parts of the interlayer insulating film during the washing process after contact etching.