| 摘要 |
PURPOSE:To easily prevent the short circuit of the wiring of a high melting point metallic gate by a method wherein a high melting point metal remaining at a base stepwise difference is removed with good controllability after processing of a film of said high melting point metal used for a gate electrode. CONSTITUTION:An SiO2 film 102 and an SiO2 film 103 are formed on a P type Si substrate 101, and a W film 104 is formed on this insulation film; then, the gate electrode pattern of an MOS type FET is formed out of a photo resist 105. The gate electrode 106 is formed by 100% over dry etching of the W film 104 with the photo resist 105 as a mask. At this time, a W film etching remnant 107 is produced at the stepwise difference of the boundary between an active region and an element isolation region. The surface of the gate electrode 106 and the etching remnant 107 are changed into W oxides 108 and 109 respectively by oxidizing the W for 60min in 500 deg.C O2 gas, and then N type impurity layers of source and drain 100 and 111 are formed by As ion implantation from the surface of the Si substrate 101. The W oxides 109 and 108 are removed in a solution of ammonium acetate heated to 60 deg.C. |
