Papers by Author: A. Pankiew

Abstract: Titanium nitride (TiN) film has been widely used as a diffusion barrier layer for VLSI contact metallization because TiN is an excellent barrier against inter-diffusion between Al and Si substrate or silicide. In this work, we studied the properties of TiN films deposited by DC magnetron sputtering with varying N2:Ar flow rate ratio in order to optimize growth conditions and film properties provided for Al diffusion barrier purpose. The TiN films were deposited at the constant pressure level and sputtering time. The crystalline orientation, composition and electrical properties of deposited TiN films were characterized by XRD, AES-depth profile and Four Point Probe measurement, respectively. The XRD results show that the deposited TiN film has two preferred orientations of TiN(111) and TiN(200) planes. The highest intensity of the TiN(111) plane was obtained when the N2:Ar flow rate ratio was 3:1. The electrical resistivity was increased when the N2:Ar flow rate ratio was decreased. The minimum electrical resistivity is 127.8 μΩ-cm when the N2:Ar flow rate ratio is 3:1.

Abstract: In this report, we present sputtered zinc oxide (ZnO) thin films grown with different argon (Ar) and oxygen (O2) gas-timing sequence. Metallic zinc (Zn) with 5N-purity was used as a sputtering target, while Ar and O2 of 6N-purity were used as the bombard and reactive gases, respectively. The crystalline orientation, surface morphology, chemical composition, optical and electrical properties of deposited ZnO thin films were determined by XRD,AFM and UV-VIS measurement, respectively. The XRD result implied that deposition ZnO thin films at different O2 gas-timing control corresponded to the (002) plane of hexagonal ZnO structure at 2Ө = 34.4◦. Furthermore, when the reactive time of O2 was increased, the transmittance of ZnO thin films exhibited the energy gap increase from ~2.95 to ~3.18 eV, whereas the surface roughness was found to decrease. Finally, ZnO thin films were oxidized after the deposition.

Abstract: Two different viscous coating materials, which are Polydimethylsiloxane (PDMS) mixed with 10%wt of Dicumylperoxide (DCP), and Semifluorinate Silane (SFS), were applied to silicon micro-asperity. The cosine’s Young and viscosity of those coating materials are -0.3584,-0.3496 and 3.176x10-3, 1.339 x10-3 Pas, respectively. The rough surfaces with nine asperity shapes were studied. The results shown that, pillar shape has an effect on water contact angle (WCA): Stripe asperity cannot make the average WCA greater than 150. When consider the pillar asperity, the WCA falls between 152 and 157, which exhibits a superhydrophobic surface property. However, actual WCA of the micro-asperity coated with PDMS+10%wt of DCP is lower than that coated with SFS around 1 to 7. High viscous material makes the asperity size bigger than the design and decreases the WCA: the low viscous material is more suitable for coating on the asperities.