METHOD AND DEVICE FOR SYNCHRONOUS GROWTH OF SILICON CARBIDE CRYSTALS IN MULTIPLE CRUCIBLES Russian patent published in 2024 - IPC C30B29/36 C30B23/00 

FIELD: chemical industry; semiconductor technology.

SUBSTANCE: device for synchronous growth of silicon carbide crystals in a plurality of crucibles contains chamber (1) and an insulating layer block located near its internal walls, inside of which a plurality of heating components are located at intervals, representing first (13), second (14), and third (15) heaters, as a result of which it is divided into many independent growth cavities (2), containing an independent growth block with graphite crucible (3) and seed crystal tray (4). Each graphite crucible (3) is connected to a drive unit intended for its movement, containing lifting (5) and rotating (6) mechanisms. Lifting mechanism (5) contains hollow lifting rod (7), connected to the bottom of graphite crucible (3) in a sliding manner, and lifting motor (8). Rotary mechanism (6) contains stepper motor (11) attached inside hollow lifting rod (7) and rotary rod (12) coaxial and fixedly connected to both the output shaft of stepper motor (11) and the bottom of graphite crucible (3). At preheating stage S1, graphite crucible (3), a drive unit, and initial silicon carbide are installed in chamber (1), air tightness of chamber (1) is checked, it is evacuated to an internal pressure of 0.1-5 Pa, and additionally evacuated to 10^-5 - 10^-2 Pa, power of the heating components is increased to establish a temperature of 500-700°C, chamber (1) is filled with mixed gas containing nitrogen/hydrogen and inert gas, pressure is controlled to maintain it in the range of 10,000-70,000 Pa after reaching the temperature of more than 1500°C, and then power of the heating components is increased further to achieve the temperature of the graphite crucible (3) of 2000°C. At crystallization stage S2, the power ratio of the heating components is adjusted so that the temperature at the bottom of graphite crucible (3) is 10-100°C higher than the temperature in its upper part, its position is adjusted through the drive unit so that the temperature of the initial silicon carbide in graphite crucible (3) is 15-80°C above the temperature of the seed crystal, and pressure inside chamber (1) is reduced to 50-2500 Pa. At final processing stage S3, pressure inside chamber (1) is maintained in the range from 2500-10,000 Pa, power of the heating components is reduced in such a way as to reduce the temperature difference between the bottom of graphite crucible (3) and its upper part and set it within 20°C, and, in addition, power of the heating components is slowly reduced until zero power is established.

EFFECT: increased yield of usable large crystals due to elimination of their cracking caused by internal stress.

19 cl, 1 tbl, 5 dwg, 6 ex