Sheludko V. Influence of laser processing on structure and properties of Ni3B-, BaB6-LaB6- and SnO2-Sb-based composite thick films

The work is devoted to the study of the effect of laser processing on structural and electrophysical characteristics of thick films for microelectronics. Thick films (TF) composition on the base of borides Ni3B, BaB6, LaB6, solid solutions (Ba, La)В6, (Sn, Sb)O2 and glass СЦ3-55 and С279-2 were adopted as the objects for investigation. Basic thermalphysic and optical characteristics of these compositions are calculated and determined experimentally, and calculations of the temperature fields in TF at laser processing are also carrried out. The morphology, phase contrast as well as surface structure in the secondary and back-scattered electrons are studied by the methods of AFM and SEM at the different modes of laser processing and energies intervals at which the minimum roughness of Ni3B-based TF is observed, are defined and the curves of concentration distribution of conducting phase elements on the surface and in depth are obtained. The recommendations on laser processing of TF in the energies intervals promoting roughness' decreasing are obtained. It has practical interest when producing variable resistors. The laser processing of all kinds of TF with pulse irradiation of nanosecond duration is established to result in decreasing of thickness of resistive layer and crushing of conducting phase particles. The line of TF stability to the repeated influence of nanosecond duration pulses is determined: LaВ6 > (Ba, La)B6 > BaВ6 > (Sn, Sb)O2 > Ni3B. The laser irradiation by nano- and microsecond duration pulses promotes TF work in optimal performance (the value of parameter alfa~1). Gage factor g for TF in study is investigated. The influence of nanosecond duration pulses is shown to raise the g value for (Sn, Sb)O2-based TF ~by 35 % at a good repeatability. This mode is recommended for practical application.