RU2000127356A - METHOD OF CONTROL OF DIAMETER OF SILICON SINGLE CRYSTAL GROWN FROM MELTING - Google Patents

Claims (5)

1. The method of controlling the diameter of a single crystal of silicon grown from a melt, including the regulation of temperature and speed parameters of the growing process using an automatic diameter control system incorporating an optical sensor with a sensitive element, which records the change in the direction of radiation from the meniscus of a melt column in a subcrystal during the growth of the single crystal, and the determination of the moment of reaching the cylindrical part of the grown single crystal, I distinguish The fact that the optical axis of the sensor is positioned obliquely to the plane passing through the axis of the grown single crystal, the moment of reaching the cylindrical part of the grown single crystal is determined depending on the optical sensor position of the meniscus of the melt column in the subcrystal region of the previously grown reference single crystal when measured at its cylindrical part, and additionally establish the initial position of the level of the melt grown monok istalla by combining radiation from the meniscus of the melt column in a region podkristalnoy seed single crystal grown with a fixed scale on the measuring optical radiation sensor position from the meniscus of the melt column of a seed for growing single crystal on said comparison.  2. The method according to p. 1, characterized in that the initial position of the level of the melt set by moving the crucible. 3. The method according to p. 1 or 2, characterized in that the angle of the specified inclination of the optical axis of the sensor is 5-20 ^o .  4. Method according to any one of claims. 1-3, characterized in that when growing a monocrystal of silicon with a diameter equal to the diameter of a previously grown reference single crystal, the moment of reaching the cylindrical part is carried out by combining radiation from the meniscus of the melt column of the single crystal grown with the position of radiation from the meniscus of the single crystal of the reference crystal melted corresponding to the moment of exit on its cylindrical part. 5. A method according to any one of claims. 1-3, characterized in that when growing a single crystal of silicon with a diameter different from the diameter of the pre-grown single crystal comparison, the moment of access to the cylindrical part is determined by the formula:

where Y ₃ - the desired position of the radiation from the meniscus of the melt column of the grown single crystal on the measuring scale of the optical sensor, corresponding to the moment of reaching the specified diameter of its cylindrical part, mm;
U _with - fixed on the measuring scale of the optical sensor position of the radiation from the meniscus of the melt column of a single crystal of comparison, corresponding to the time of its exit to its cylindrical part, mm;
At _about - fixed on the measuring scale of the optical sensor position of the radiation of the meniscus of the melt column seed, corresponding to the initial level of the melt, mm;
D ₃ - the specified diameter of the cylindrical part of the grown single crystal, mm;
D _c - the actual diameter of the cylindrical part of the single crystal comparison, mm.