| Summary: | 碩士 === 國立中興大學 === 電機工程學系 === 87 === The main purpose of this thesis is to investigate the influence of the chemical mechanical polishing process on the fluorine-doped silicon dioxide (SiOF). Since the polarized Si-F bonding of SiOF film is a low resistance material to moisture, it would cause a poor dielectric stability and higher leakage current. During CMP process, aqueous slurry and film surface hydrolysis reactions make SiOF film easily attacked by moisture and cause a serious degradation of SiOF film. In this study, N2O and NH3 plasma treatment was employed as post CMP process to inhibit the moisture uptake. After N2O plasma treatment, oxygen content in SiOF film has been increased. After NH3 plasma treatment, a nitride passivation formed on the surface of SiOF film has been observed. In the “thermal desorption atmospheric pressure ionization mass spectrometer” (TDS-APIMS) analysis, shows most of moisture molecules absorbed on the surface and penetrated into bulk film could be driven out from surface at the temperature up to 400℃. We find that post CMP N2O and NH3 plasma treatments are quite efficient for overcoming moisture attack of SiOF film.
Both N2O and NH3 plasma treatments can reduce dielectric constants and leakage current for the film after CMP process. NH3 plasma treated film reveals a worse surface roughness. N2O plasma treated film shows a better behavior on leakage current.
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