High Power Impulse Magnetron Sputtering (HiPIMS) is the most promising innovation in physical vapor deposition technology. It helps to improve magnetron sputtering because it permits to deposit high quality and ultra-dense coatings with highly controlled microstructure and residual stress. An increased adhesion, in particular for complex-shaped surfaces, and a decreased deposition temperature are further advantages. In HiPIMS, high power is applied to the magnetron target in unipolar pulses at low duty cycle and low repetition frequency while keeping the average power about 2 orders of magnitude lower than the peak power. In this way it is possible to achieve a peak plasma density (electron density) higher than 1o1019 m-3 resulting in a highly ionized sputtered flux while maintaining the average power to values similar to those used in DC. The high degree of ionization of the sputtered species (typically ranging from 4.5% for C up to 70% for Cu) leads to a better control of the growing film. Indeed the use of a substrate bias allows to accelerate and guide the depositing material improving the adatom mobility. In the literature there are numerous studies about the physics of the process, but a little attention is paid to the features of the equipment design. This presentation deals with the peculiarities of the HiPIMS system which was designed and built at the CNR - IENI of Padova. In particular, an HiPIMS commercial generator is used. It can provide a peak power up to 2 MW, an average power up to 10 kW, a voltage peak up to 2 kV, a peak current up to 1 kA. The pulsing frequency is in the range 1÷500 Hz. In the present configuration it is connected to a 4 inches single cathode. The sample holder system has been designed to have the greatest flexibility to meet the requirements of the IENI lab various groups. It is positioned in front of the HiPIMS cathode. It can be moved to change the target - substrate distance (TSD) from 50 to 200 mm. It can rotate (up to 20 rpm) continuously or in a reciprocating motion. It permits to accommodate a set of halogen lamps to heat the substrate up to 800°C, even in an oxygen atmosphere. The carousel is coupled to a bias generator (Vmax = 1200 V) with a powerful arc management. It is indispensable for the substrate pre-treatment or etching too. An high voltage probe and a current probe are connected to a 2-channel oscilloscope to control the instant deposition power and to ensure a stable operation. The power signal is used as a feedback. An automatic system for the pressure control has been realized: we have the possibility to adjust the gas flows and/or the pumping speed. Some coatings obtained by HiPIMS are compared with similar films deposited by traditional DC and RF Magnetron Sputtering.
HiPMS DEPOSITION SYSTEM: IMPORTANCE OF THE EQUIPMENT DESIGN
Francesco Montagner;Silvia Maria Deambrosis;Enrico Miorin;Valentina Zin;Monica Fabrizio
2013
Abstract
High Power Impulse Magnetron Sputtering (HiPIMS) is the most promising innovation in physical vapor deposition technology. It helps to improve magnetron sputtering because it permits to deposit high quality and ultra-dense coatings with highly controlled microstructure and residual stress. An increased adhesion, in particular for complex-shaped surfaces, and a decreased deposition temperature are further advantages. In HiPIMS, high power is applied to the magnetron target in unipolar pulses at low duty cycle and low repetition frequency while keeping the average power about 2 orders of magnitude lower than the peak power. In this way it is possible to achieve a peak plasma density (electron density) higher than 1o1019 m-3 resulting in a highly ionized sputtered flux while maintaining the average power to values similar to those used in DC. The high degree of ionization of the sputtered species (typically ranging from 4.5% for C up to 70% for Cu) leads to a better control of the growing film. Indeed the use of a substrate bias allows to accelerate and guide the depositing material improving the adatom mobility. In the literature there are numerous studies about the physics of the process, but a little attention is paid to the features of the equipment design. This presentation deals with the peculiarities of the HiPIMS system which was designed and built at the CNR - IENI of Padova. In particular, an HiPIMS commercial generator is used. It can provide a peak power up to 2 MW, an average power up to 10 kW, a voltage peak up to 2 kV, a peak current up to 1 kA. The pulsing frequency is in the range 1÷500 Hz. In the present configuration it is connected to a 4 inches single cathode. The sample holder system has been designed to have the greatest flexibility to meet the requirements of the IENI lab various groups. It is positioned in front of the HiPIMS cathode. It can be moved to change the target - substrate distance (TSD) from 50 to 200 mm. It can rotate (up to 20 rpm) continuously or in a reciprocating motion. It permits to accommodate a set of halogen lamps to heat the substrate up to 800°C, even in an oxygen atmosphere. The carousel is coupled to a bias generator (Vmax = 1200 V) with a powerful arc management. It is indispensable for the substrate pre-treatment or etching too. An high voltage probe and a current probe are connected to a 2-channel oscilloscope to control the instant deposition power and to ensure a stable operation. The power signal is used as a feedback. An automatic system for the pressure control has been realized: we have the possibility to adjust the gas flows and/or the pumping speed. Some coatings obtained by HiPIMS are compared with similar films deposited by traditional DC and RF Magnetron Sputtering.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
