METHOD OF CONTROLLING CROSS-SECTIONAL AREA OF CRYSTAL WHEN GROWING SAID CRYSTAL BY PULLING FROM MELT Russian patent published in 2015 - IPC C30B15/28 

FIELD: chemistry.

SUBSTANCE: invention relates to automation in the chemical and semiconductor industry. The cross-sectional area of a crystal is controlled when growing said crystal by pulling from a melt using a pulling mechanism with a controlled drive in growth apparatus having a sensor of the weight of the crystal or a crucible with a melt. In order to measure the cross-sectional area of the growing crystal, uniform motion transferred by the pulling mechanism to the seed holder is modulated with continuous or pulsed stepped measurement back-and-forth displacements. The values of the displacements of the seed holder and the values of the selected modulated responses of the weight sensor are then recorded. The cross-sectional area of the growing crystal $${\overline{S}}_{kpn}$$ is calculated at a given number of points. The average value of the cross-sectional area $${\overline{S}}_{kp}$$ is found and compared with a given cross-sectional area. The necessary change of temperature of the heater is generated based on a signal of mismatch between the measured cross-sectional area and the required value.

EFFECT: high quality of the grown crystal.

7 dwg