A heat exchange device for a single crystal furnace is provided, including a heat exchanger on which an inner chamber for heat exchange defined in a shape of circular truncated cone is formed. A convex portion is defined by a chamber wall of the inner chamber for heat exchange partially projecting along a radial direction of the inner chamber for heat exchange, the convex portion extends along a direction of an axis of the inner chamber for heat exchange, and a minimum distance between an end away from the chamber wall of the inner chamber for heat exchange of the convex portion and the axis of the inner chamber for heat exchange is denoted as L, which is greater than or equal to a minimum radius of a cross section of the inner chamber for heat exchange.

A heat exchange device for a single crystal furnace is provided, including a heat exchanger on which an inner chamber for heat exchange defined in a shape of circular truncated cone is formed. A convex portion is defined by a chamber wall of the inner chamber for heat exchange partially projecting along a radial direction of the inner chamber for heat exchange, the convex portion extends along a direction of an axis of the inner chamber for heat exchange, and a minimum distance between an end away from the chamber wall of the inner chamber for heat exchange of the convex portion and the axis of the inner chamber for heat exchange is denoted as L, which is greater than or equal to a minimum radius of a cross section of the inner chamber for heat exchange.

A seeding method for crystal growth comprising: a first seeding step: rotating a crucible with a first rotation speed to grow the crystal to a first length; a second seeding step: gradually increasing the rotation speed of the crucible from the first rotation speed to a second rotation speed, and growing the crystal to a second length; a third seeding step: rotating the crucible with the second rotation speed to growing the crystal to a predicted length. By separating the seeding stage to three steps and gradually increasing the rotation speed in the second step of the crucible, the silicon melt convection is enhanced and the temperature at center of the silicon melt is kept to be not lower than the starting temperature of the seeding. Thereby, the removal of dislocation within the seed crystal can be increased, and the growth problems such as broken or polycrystallization can be prevented.

A seeding method for crystal growth comprising: a first seeding step: rotating a crucible with a first rotation speed to grow the crystal to a first length; a second seeding step: gradually increasing the rotation speed of the crucible from the first rotation speed to a second rotation speed, and growing the crystal to a second length; a third seeding step: rotating the crucible with the second rotation speed to growing the crystal to a predicted length. By separating the seeding stage to three steps and gradually increasing the rotation speed in the second step of the crucible, the silicon melt convection is enhanced and the temperature at center of the silicon melt is kept to be not lower than the starting temperature of the seeding. Thereby, the removal of dislocation within the seed crystal can be increased, and the growth problems such as broken or polycrystallization can be prevented.

A detection system includes a loadcell connected to a gear and motor of a crystal puller apparatus to measure force applied to the gear in a time domain. The data is analyzed though a Fourier transform to obtain data in the frequency domain. The frequency domain data includes an amplitude which corresponds to mechanical wear of the gear. The time domain data is compared against a threshold amplitude to determine if the gears have mechanical wear such that preventative maintenance can be performed on the motor.

A detection system includes a loadcell connected to a gear and motor of a crystal puller apparatus to measure force applied to the gear in a time domain. The data is analyzed though a Fourier transform to obtain data in the frequency domain. The frequency domain data includes an amplitude which corresponds to mechanical wear of the gear. The time domain data is compared against a threshold amplitude to determine if the gears have mechanical wear such that preventative maintenance can be performed on the motor.

Methods for producing monocrystalline silicon ingots by horizontal magnetic field Czochralski are disclosed. During growth of the neck and/or growth of at least a portion of the crown, a magnetic field is not applied to the neck and/or crown or a relatively weak magnetic field of 1500 gauss or less is applied. A horizontal magnetic field (e.g., greater than 1500 gauss) is applied during growth of the ingot main body.

Methods for producing monocrystalline silicon ingots by horizontal magnetic field Czochralski are disclosed. During growth of the neck and/or growth of at least a portion of the crown, a magnetic field is not applied to the neck and/or crown or a relatively weak magnetic field of 1500 gauss or less is applied. A horizontal magnetic field (e.g., greater than 1500 gauss) is applied during growth of the ingot main body.

Methods for producing monocrystalline silicon ingots by horizontal magnetic field Czochralski are disclosed. During growth of the neck and/or growth of at least a portion of the crown, a magnetic field is not applied to the neck and/or crown or a relatively weak magnetic field of 1500 gauss or less is applied. A horizontal magnetic field (e.g., greater than 1500 gauss) is applied during growth of the ingot main body.

Methods for producing monocrystalline silicon ingots by horizontal magnetic field Czochralski are disclosed. During growth of the neck and/or growth of at least a portion of the crown, a magnetic field is not applied to the neck and/or crown or a relatively weak magnetic field of 1500 gauss or less is applied. A horizontal magnetic field (e.g., greater than 1500 gauss) is applied during growth of the ingot main body.