Localised insulation layer removal in integrated circuit - uses simultaneous ablation and metal deposition by thermal decomposition by UV laser in irradiated area

摘要

UV transparent insulator layers (21), pref. SiO2, are removed in a localised area, pref. 2x2 to 15x15 micron2, of a semiconductor device in a vacuum chamber by irradiation with a UV laser. Inside the chamber, a gas mixt. is used consisting of a carrier gas and a gaseous metal cpd., pref. a metal carbonyl, esp. W-hexacarbonyl, pref. at a pressure of 0.1-5 mbar, capable of forming a metal film. A pulsed ArF laser with a wavelength of 193 nm is pref. used with an energy of pref. 0.5-20 micro-joules and pulse frequency of 20-100 Hz. USE/ADVANTAGE - The method allows a localised area of a circuit to be exposed even though UV transport insulation layers are used. The method is used in the analysis of IC's to allow testing or other analysis in a small area. The process does not cause harmful side reactions and does not degrade the equipment inside the chamber as currently used etch processes.