Etching of organic low dielectric constant film in 100MHz capacitively coupled H2/N2 gases plasmas

摘要

Organic low dielectric constant (low-k) film etching was carried out by 100MHz capacitivelycoupled plasmas (CCP) employing H2/N2 gases in order to investigate the correlation between theetching characteristics of organic low-k film and H and N radicals. The absolute densities of H andN radicals were evaluated by the vacuum ultraviolet absorption spectroscopy (VUVAS) withoutinterrupting the etching process. It was found that the etch rate and etched profile could becontrolled with an internal plasma parameter of the ratio of the H and N radical densities in 100MHzCCP. The optimal conditions for the vertical profile and high etch rate were determined by the ratioof the H and N radical densities on the condition of a constant substrate temperature.