Production manner and converse T die high melting point metal gate null of high melting point metal gate

摘要

A method of manufacturing a MOS transistor having an inverted T-type refractory metal gate is provided.The gate produced by the present invention comprises a main CVD tungsten layer 14a and a lower sputter tungsten layer 16A extending outwardly from the bottom of the CVD portion so that the cross section of the gate is inverted "t". Using Cl2 / O2 plasma etching to etch the CVD tungsten layer, chemical etching is used to etch the sputtered tungsten layer forming the gate electrode. For Cl2 / O2 reactive ion etching, sputtered tungsten is hard to be etched than CVD tungsten. The sputtered tungsten layer acts as a shield and prevents the lower oxide layer 10 from ion damage during the manufacturing process.