In this work we show the viability of laser scribing as a tool for selective patterning of CuInSe... more In this work we show the viability of laser scribing as a tool for selective patterning of CuInSe2(CIS)/Molybdenum(Mo)/Soda Lime Silica (SLS) thin film structures. The dependence of scribing quality on the basic process parameters is investigated by optical microscopy, talystep, SEM and microprobe analysis. Two different configurations are used for Mo-patterning: the frontal scribing whereby the laser beam interacts first with the air/Mo interface and the back scribing with the laser beam passing through the glass slide and interacting with the SLS/Mo interface. Back scribing can result in a high quality patterning, with no droplets or swelling, but only the Mo layer is removed and the SLS is left untouched. The Mo removal is due to a laser induced stress detachement. Using the frontal scribing, is also possible to obtain good quality scribing where evaporation is the main mechanism for Mo removal. To obtain good quality scribing, it is necessary to gain accurate control of the focus position and of laser beam characteristics. When a laser with a poor gaussian profile was used, high swelling and large droplets were always present. Optimum scribing parameters for both CIS/SLS and Mo proved to be roughly equivalent. Consequently, selective scribing of an individual layer was not possible using Q-switched operation. Using cw laser power output the relatively low melting and evaporation temperatures, low thermal diffusivity, optical reflection and high absorption coefficient of the CIS layer allow for local heating and consequent evaporation of the CIS whilst leaving the Mo layer unaffected. Scribing are performed on CIS/Mo/SLS layers and the resulting selective removal of the CIS layer is shown.
In this work we show the viability of laser scribing as a tool for selective patterning of CuInSe... more In this work we show the viability of laser scribing as a tool for selective patterning of CuInSe2(CIS)/Molybdenum(Mo)/Soda Lime Silica (SLS) thin film structures. The dependence of scribing quality on the basic process parameters is investigated by optical microscopy, talystep, SEM and microprobe analysis. Two different configurations are used for Mo-patterning: the frontal scribing whereby the laser beam interacts first with the air/Mo interface and the back scribing with the laser beam passing through the glass slide and interacting with the SLS/Mo interface. Back scribing can result in a high quality patterning, with no droplets or swelling, but only the Mo layer is removed and the SLS is left untouched. The Mo removal is due to a laser induced stress detachement. Using the frontal scribing, is also possible to obtain good quality scribing where evaporation is the main mechanism for Mo removal. To obtain good quality scribing, it is necessary to gain accurate control of the focus position and of laser beam characteristics. When a laser with a poor gaussian profile was used, high swelling and large droplets were always present. Optimum scribing parameters for both CIS/SLS and Mo proved to be roughly equivalent. Consequently, selective scribing of an individual layer was not possible using Q-switched operation. Using cw laser power output the relatively low melting and evaporation temperatures, low thermal diffusivity, optical reflection and high absorption coefficient of the CIS layer allow for local heating and consequent evaporation of the CIS whilst leaving the Mo layer unaffected. Scribing are performed on CIS/Mo/SLS layers and the resulting selective removal of the CIS layer is shown.
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Papers by Enrico Salza