A semiconductor integrated circuit of the present invention comprises a hard macro and a plurality of wirings connected to the hard macro. The oxygen content in the tungsten electrodes is not more than 15 ppm, while the amount of the encapsulated halogen lies in the range of 1107 to 1102 molmm3. Reaction products generated during polishing interact with the aqueous phase complexing agent to form water soluble metallic complexes, the water soluble metallic complexes diffuse to an organicwater interface where they release complexing agent molecules in the aqueous phase and generate metal ions which interact with the organic phase complexing agent to form organometallic complexes. The contact resistance between the porous silicon region and the front contact is between about 10 ohms and 100 ohms.