METHOD FOR AUTOMATIC FEEDBACK CONTROL OF PROCESS OF GROWING MONOCRYSTALS BY KYROPOULOS METHOD Russian patent published in 2015 - IPC C30B17/00 C30B15/28 C30B29/20 

FIELD: chemistry.

SUBSTANCE: method includes dynamic measurement of the weight of the crystal being grown and automatic control of heater power, calculating the time derivative of the measured weight, calculating its mismatch with the reference value of the weight derivative set according to a time function based on experimentally obtained data, or mass transfer models of the growth process, the input data of which are the linear crystallisation rate, the shape of the crystallisation front, geometric dimensions of the crucible, the mass of the crucible charge, the diameter of the seed crystal, the density of the crystal and the melt, the surface tension of the melt, the crystal growth angle, and the output data are the shape of the crystal being grown and the corresponding reference value; generating the main channel control signal of heater power using a controller with a dead zone, and additional channel control of the drawing rate is carried out under the condition that the mismatch of a predetermined threshold value is exceeded.

EFFECT: improved quality of the monocrystal and higher output of non-defective articles.

3 cl, 6 dwg