Owing to the constantly increasing requirements regarding modern cutting tools, the established wear protection coatings like TiN or TiCN, for example, are no longer in a position to cover all current areas of application for coated tools. Even the most advanced wear protection coatings come to their limits in applications like high-speed cutting or dry processing, for example. One of the principal reasons for the limited performance of these coatings is the high thermal and oxidative stress to which the coating is subjected in the aforementioned applications.

Through new bipolar pulse technology one is today in a position to deposit conducting and insulating coatings of almost any stoichiometry. Moreover, through extremely dense plasmas which now can be produced, also the deposition of crystalline high-temperature modifications is possible. This was enabled through the use of bipolar pulsed plasmas and a new kind of arrangement within the vacuum chamber, which guides the dense plasma to the substrate in a well directed manner (coating system CC800cirlce with R/9).

Highest plasma ionisation, optimum performance for insulating coatings, nanocomposites, perfect surfaces and optimised deposition rates are the result.

High power impulse magnetron sputtering (HIPIMS) is an emerging technology for the physical vapour deposition of coatings and substrate pretreatment. HIPIMS relies on a short duration (impulse) gas discharge reaching high peak power densities of 3000 Wcm^-2 at current density of 1-4 Acm^-2. Within the duration of each pulse the discharge develops from a gas-dominated to a metal-ion dominated state as the plasma density reaches peak values in the range of 10¹³cm^-3. A combination of gas and self-sputtering mechanisms are operational. HIPIMS plasmas contain significant proportions of singly and doubly charged metal ions whose relative densities are determined by the peak power of the discharge.

Applications of HIPIMS have been successful for substrate pretreatment to enhance adhesion whilst maintaining a macroparticle-free coating microstructure. The combination of the two factors has strongly improved the tribological and corrosion performance of conventional-magnetron sputtered CrN layers in comparison to glow discharge and arc discharge pretreatments. Functional layers deposited by HIPIMS have shown fully dense microstructures formed under deposition fluxes with high ion-to-neutral ratios.

Advanced hardware design is now available for the industrialisation of HIPIMS to cathode areas of >1000 cm².

Functional film metallization on polymer sheet becomes increasingly applied in emerging digital electronics and flexible packaging materials and devices. The prime issue in metallization on polymer substrate is the control of process temperature to avoid damage of temperature sensitive polymer materials. In addition the synthesis of compound films including oxides and nitrides of high temperature phase on polymer is often hard to be resolved in conventional magnetron sputtering process.

Pulsed magnetron sputtering process is a prospective way to overcome barriers in such thin film synthesis at low temperature. This paper discusses on the nucleation and growth behavior on a few polymer substrates at various plasma conditions by modulating pulse duty and frequency in pulsed magnetron sputtering. The surface temperature evolution is designed by theoretical modeling in terms of plasma parameters including particle flux and energy and compared with empirical data measured by in-situ monitoring of film surface temperature with specified IR measurement system at various pulsed power input conditions. The modulation of film microstructure and stress with temperature evolution is then achieved by control of plasma parameters with a variation of pulse conditions, which are illustrated with integrated diagnostics data measured by Langmuir probe, nano-second time resolved optical emission spectroscopy and laser absorption spectroscopy. Finally a couple of application of functional film synthesis on polymer by pulsed magnetron sputtering method is illustrated with theoretical process design and empirical results at low temperature range of 50 to 100°C.

Lead zirconate titanate (PZT) thin films are currently researched for memory applications, MEMS, sensors and transducers¹. Due to the growing interest in wearable computing, the need for industrial scale deposition of PZT has further increased. PZT can be grown by sol-gel, laser ablation, and CVD, but in particular PVD is a promising tool to produce PZT thin films with improved properties. Although much focus has been placed on the excitation mode², target design³, as well as post annealing conditions⁴, a real breakthrough in low-cost deposition processes for industry has not been achieved.

The goal of the present work is the development of multicrystalline PZT films deposited either on Si wafers or on optical fibers. Prior to PZT deposition, a top coat with the layer sequence Ti/Pt(111)/Ti was applied on the substrates. For the first time, a single metallic target with the composition (at%) Pb(55)Zr(22.5)Ti(22.5) was sputtered in an Ar/O₂ atmosphere using pulsed DC. The morphological, structural, chemical and mechanical properties of coated specimens deposited at different substrate temperatures and post-annealed either in a tubular oven or by rapid thermal annealing (RTA) at different temperatures were investigated. Emphasis was placed on the determination of the mechanical properties investigated by nanoindentation and nanoscratch techniques. Quantitative depth profiling for the determination of the chemical composition of PZT thin films was used for the first time with pulsed glow discharge optical emission spectroscopy (Pulsed-GDOES)

The method for PZT deposition on wafers was adapted for optical fiber coating and results are discussed.

¹ J. F. Scott et al., Science 246 (1989) 1400
² S. Yamauchi, et al.; Integrated Ferroelectrics 14 (1997) 159
³ T. Hata et al.; Vacuum 51 (1998) 665
⁴ C.V.R Vasant Kumar et al., J. Appl. Phys, 71 (1992) 864.