NOVELTY - The method for improving quality of wafer, comprises heating the wafer in a tempering-step using a heat source by means of relative movement of the wafer to the heat source in layer-wise manner under formation of a temperature gradient, where the maximum temperature in the wafer is below the melting point of silicon. The impurities in the wafer are transported within areas, which have a higher temperature and are arranged in the area of impurity region. The impurity regions are grain boundaries or twin boundaries.    USE - Method for improving quality of wafer useful for producing crystalline silicon solar cells, silicon thin-film solar cells, sensors, actuators, silicon-based light emitting diodes, flat panel displays and optical filters and in silicon on insulator technology (all claimed).    ADVANTAGE - The method ensures improving the quality of wafer with improved diffusion ability.    DETAILED DESCRIPTION - The method for improving quality of wafer, comprises heating the wafer in a tempering-step using a heat source by means of relative movement of the wafer to the heat source in layer-wise manner under formation of a temperature gradient, where the maximum temperature in the wafer is below the melting point of silicon. The impurities in the wafer are transported within areas, which have a higher temperature and are arranged in the area of impurity region. The impurity regions are grain boundaries or twin boundaries. The wafer is guided on the heat source, which is bound stationary. Electron beam heater, laser beam source, graphite strip heater, halogen lamp heater, graphite strip heater, infrared emitter and/or ultraviolet heater is used as the heat source. The heat sources are arranged sequentially or next to one another. The temperature in the heating region is 500-800 degrees C. The impurities are copper, nickel, iron and chromium. In addition, a high temperature step such as a phosphorus getting step or a phosphorus diffusion step is carried out. The high-temperature step is carried out before the temperature step, where various temperature gradients exist through two heat sources. The high temperature step is carried out at 700-1000 degrees C.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of a processing of solar cell (Drawing includes non-English language text).