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impaginato corretto fullone_Layout 1 13/10/15 12.08 Pagina 31 Department of Engineering, ICT and Technologies for Energy and Transport Patent Title Title Method and apparatus for producing thin film on a Method and apparatus for producing thin film on a substrate via a pulsed-electron deposition process. substrate via a pulsed electron deposition process. Ref. CNR 9999 Ref. CNR 9999 Assignee(s): CNR CNR Institute: IMEM Main Inventor: Claudio Ferrari Countries: IT Priority date: 21/11/2008 Abstract Abstract The invention refers to a method for producing thin films on a substrate via a pulsed- electron deposition The invention refers to a method for producing thin films on a substrate via a pulsed electron deposition process comprises sending a pulsed- electron beam (3) onto a target material (5), set in the proximity of process comprises sending a pulsed electron beam (3) onto a target material (5), set in the proximity of a substrate (7), in such a way as to cause ablation of the target material and the consequent emission of a substrate (7), in such a way as to cause ablation of the target material and the consequent emission of vapour phase particles that deposit on the substrate to form a layer (8) or film; the discharge current of vapour phase particles that deposit on the substrate to form a layer (8) or film; the discharge current of the beam (3) is measured for controlling the parameters of the deposition process and optimizing, in the beam (3) is measured for controlling the parameters of the deposition process and optimizing, in particular, the rate of growth of the layer (8). The measurement of the discharge current is based upon particular, the rate of growth of the layer (8). The measurement of the discharge current is based upon the use of an induction coil (27), which does not affect the primary circuit (15) for beam discharge; in the use of an induction coil (27), which does not affect the primary circuit (15) for beam discharge; in particular, a coil (27) is used wound according to a particular geometry, referred to as "Rogowski coil". particular, a coil (27) is used wound according to a particular geometry, referred to as "Rogowski coil". Background Background The pulsed-electron deposition (PED) is a physical technique for producing thin layers of conductive and The pulsed electron deposition (PED) is a physical technique for producing thin layers of conductive and dielectric materials. Even though the general principles of the pulsed-electron deposition (PED) technique dielectric materials. Even though the general principles of the pulsed electron deposition (PED) technique are currently well known, the methods and equipment currently available for its technological and are currently well known, the methods and equipment currently available for its technological and industrial applications still present margins for improvement, above all in terms of control of the growth industrial applications still present margins for improvement, above all in terms of control of the growth parameters of the deposited layers and of efficiency and rate of deposition. parameters of the deposited layers and of efficiency and rate of deposition. Technology Technology The invention enable a complete and accurate control of the deposition process, enabling, in particular, The invention enable a complete and accurate control of the deposition process, enabling, in particular, setting of the parameters for optimizing and maximizing the rate of growth of the layers; at the same time setting of the parameters for optimizing and maximizing the rate of growth of the layers; at the same time it prevents a heating with decomposition of the target material and consequent change of the it prevents a heating with decomposition of the target material and consequent change of the stoichiometry of the deposited layer with respect to the target material. stoichiometry of the deposited layer with respect to the target material. Advantages and Applicatons Advantages and Applications The method developed does not affect the deposition process, allows to know the real-time e-beam current The method developed does not affect the deposition process, allows to know the real time e beam current and hence it controls all the variables associated with the process itself (rate control, area of deposition, and hence it controls all the variables associated with the process itself (rate control, area of deposition, energy of the evaporated, etc.). It can be useful in the field of material physics, especially in the material energy of the evaporated, etc.). It can be useful in the field of material physics, especially in the material science, in the case of growth techniques based on electron beams. science, in the case of growth techniques based on electron beams. Development stage Development stage The method and apparatus, applied in the field of solar cells, allows to obtain high efficiency devices. Their The method and apparatus, applied in the field of solar cells, allows to obtain high efficiency devices. Their application will allow the control of the growth parameters in pre-industrial machines. application will allow the control of the growth parameters in pre industrial machines. 31