A novel direct-write glass metallization based on laser induced plasma assisted ablation (LIPAA) was investigated. Laser is passed through a glass substrate and irradiated onto a metal target placed beneath the substrate. By tuning laser fluence above target ablation threshold, target ablation and plasma generation occur. The plasma flies towards the glass at a high speed and deposits metal materials onto glass backside surface. Metal films were fabricated and their sheet resistances were measured by a four-point probe. It was found that sheet resistances of the metal films vary with processing parameters. Experimental results reveal that low resistivity metal film (< 0.3 Ω/∠) can be obtained at an optimal laser scanning speed and pulse repetition rate. When target-to-substrate distance increases, film resistance also increases. Optimal design of overlap schemes among metal tracks provides a lower film resistance. Meanwhile, thin film and bulk metal targets were used to study their difference on film resistance. It was discovered that deposition using thin film target is more efficient. Laser annealing technique was also applied to activate the deposited metal materials to get higher quality glass surface metallization.
NiTi Shape Memory Alloy (SMA) is with great potential for actuation in microsystems. It is particularly suitable for medical applications due to its excellent biocompatibility. In MEMS, local annealing of SMA is required in the process of fabrication. In this paper, local annealing of Ni52Ti48 SMA with excimer laser is proposed for the first time. The Ni52Ti48 thin film in a thickness of 5 μm was deposited on Si (100) wafer by sputtering at room temperature. After that, the thin film was annealed by excimer laser (248nm KrF laser) for the first time. Field-Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) were used to characterize the surface profile of the deposited film after laser annealing. The phase transformation was measured by Differential Scanning Calorimeter (DSC) test. It is concluded that NiTi film sputtering on Si(100) substrate at room temperature possesses phase transformation after local laser annealing but with cracks.