Taper Angle of Silicon Nitride Thin Film Control by Laser Direct Pattern for Transistors Fabrication

Silicon nitride (SiNx), an important material used as a dielectric layer and passivation layer in thin film transistor liquid crystal display (TFT LCD) was patterned by a non-lithographic process. SiNx was deposited by plasma enhanced chemical vapor deposition (PECVD) on glass substrate. Laser photoablation can effectively pattern 5 µm diameter with 200 nm depth hole in SiNx thin films with laser photoablation. The threshold remove fluence is 1350 mJ/cm2 with 1 laser irradiation shot. The contact-hole taper angle as a function of the laser irradiation shot number. The taper angle increased with increasing the laser irradiation shot number. The contact-hole taper angle etched profile was successfully controlled by vary the laser irradiation shot number.