Study on the effect of electron beam curing on low-K porous organosilicate glass (OSG) material

The effect of electron beam (e-beam) curing on an ultra low dielectric constant material, porous organosilicate glass (OSG) is investigated. In conventional IC integration processes, photoresist (P. R.) stripping with O ₂ plasma and wet chemical stripper is an inevitable step. However, dielectric degradation often occurs when low-k dielectrics undergo the PR stripping processing. This limits the application of incorporating low-k material into semiconductor fabrication. In order to overcome the integration issue, e-beam direct curing process was proposed in this study. In this technology, the dielectric regions irradiated by e-beam will be cross-linked, forming the desired patterns. Meanwhile, the regions without e-beam illumination are dissolvable in a mingled solvent of 2.38 wt.% terra-methyl ammonium hydroxide (TMAH) and methanol with the ratio of 1:8. In this work, the possible doses of e-beam exposed porous OSG are decided by Fourier transform infrared spectroscopy, n&k 1200 analyzer and electrical analyses. The experimental results expressed that the minimum dosage to cure porous OSG film is 6 μC/cm², which is similar to commercial e-beam resist. Additionally, a scanning electron microscope ±S.E.M.) image of homemade pattern was made to estimate the process practicability.