Characteristics of thin-film transistors based on silicon nitride passivation by excimer laser direct patterning

This study explored the removal of silicon nitride using KrF laser ablation technology with a high threshold fluence of 990 mJ/cm2. This technology was used for contact hole patterning to fabricate SiNx-passivation-based amorphous-silicon thin films in a transistor device. Compared to the photolithography process, laser direct patterning using KrF laser ablation technology can reduce the number of process steps by at least three. Experimental results showed that the mobility and threshold voltages of thin film transistors patterned using the laser process were 0.16 cm2/V-sec and 0.2 V, respectively. The device performance and the test results of gate voltage stress reliability demonstrated that laser direct patterning is a promising alternative to photolithography in the panel manufacturing of thin-film transistors for liquid crystal displays.

► KrF laser ablation technology is used to remove silicon nitride.
► A simple method for direct patterning contact-hole in thin-film-transistor device.
► Laser technology reduced processing by at least three steps.