A measurement system includes a target object at least partially visible through an opening in a crystal puller. The crystal puller has a silicon melt in a crucible and a reflector defining a central passage through which a crystal is pulled. A detector array captures light through the opening. The detector array is directed to a surface of the silicon melt in the crystal puller and to the target object, and a laser selectively transmits a coherent light beam through the opening to the target object to produce a reflection of the target object on the surface of the silicon melt. An optical modulator pulses the coherent light beams of the laser into discrete coherent light beams having a period, and a lock-in amplifier is connected to the detector array to filter discrete coherent light having the period from captured light.

A convection pattern estimation method of a silicon melt includes: applying a horizontal magnetic field of 0.2 tesla or more to a silicon melt in a rotating quartz crucible with use of a pair of magnetic bodies disposed across the quartz crucible; before a seed crystal is dipped into the silicon melt to which the horizontal magnetic field is applied; measuring temperatures at a first and second measurement points positioned on a first imaginary line that passes through a center of a surface of the silicon melt and is not in parallel with a central magnetic field line of the horizontal magnetic field as viewed vertically from above; and estimating a direction of a convection flow in a plane in the silicon melt orthogonal to the direction in which the horizontal magnetic field is applied on a basis of the measured temperatures of the first and second measurement points.

A convection pattern estimation method of a silicon melt includes: applying a horizontal magnetic field of 0.2 tesla or more to a silicon melt in a rotating quartz crucible with use of a pair of magnetic bodies disposed across the quartz crucible; before a seed crystal is dipped into the silicon melt to which the horizontal magnetic field is applied; measuring temperatures at a first and second measurement points positioned on a first imaginary line that passes through a center of a surface of the silicon melt and is not in parallel with a central magnetic field line of the horizontal magnetic field as viewed vertically from above; and estimating a direction of a convection flow in a plane in the silicon melt orthogonal to the direction in which the horizontal magnetic field is applied on a basis of the measured temperatures of the first and second measurement points.

The method involves a substrate 21 near which reagents 25 are provided. Pump (26) and Raman (27) photons make it possible to create a stimulated Raman emission during the synthesis (29) of the material. The Raman emission can be Stokes or anti-Stokes. In one embodiment of the invention, the zone where the synthesis (29) occurs is in an optical cavity and Raman photons (27) emitted by the Raman emission are reoriented toward the zone where the synthesis (29) occurs. In another embodiment of the invention, the zone where the synthesis (29) occurs is not in an optical cavity, and a stream of Raman photons (27) is created in an outside optical cavity before being sent toward the zone where the synthesis (29) occurs. The synthesis (29) preferably involves a CVD method or solidification by the Czochralski method.

The method involves a substrate 21 near which reagents 25 are provided. Pump (26) and Raman (27) photons make it possible to create a stimulated Raman emission during the synthesis (29) of the material. The Raman emission can be Stokes or anti-Stokes. In one embodiment of the invention, the zone where the synthesis (29) occurs is in an optical cavity and Raman photons (27) emitted by the Raman emission are reoriented toward the zone where the synthesis (29) occurs. In another embodiment of the invention, the zone where the synthesis (29) occurs is not in an optical cavity, and a stream of Raman photons (27) is created in an outside optical cavity before being sent toward the zone where the synthesis (29) occurs. The synthesis (29) preferably involves a CVD method or solidification by the Czochralski method.

This invention provides method, device, system, and computer storage medium for crystal growth control of a shouldering process. The method comprises: presetting a setting value of a crystal diameter variation at different stages of a shouldering process and a setting value of a crystal growth process parameter at different stages of the shouldering process; obtaining crystal diameters at different stages of the shouldering process and calculating a measured crystal diameter variation; comparing the measured crystal diameter variation with the setting value of the crystal diameter variation to obtain a difference as an input variable of PID algorithm; calculating an adjustment value of a crystal growth process parameter by PID algorithm as an output variable of PID algorithm; adding the adjustment value of the crystal growth process parameter and the setting value of the crystal growth process parameter to obtain a process parameter of an actual crystal growth process. The method, device, system, and computer storage medium control the crystal diameter variation during the shouldering process by PID algorithm to overcome an influence of small changes in the thermal field to the shouldering process, ensure the crystal diameter variation is consistent, and improve the repeatability of the shouldering process and the stability of the process.

This invention provides method, device, system, and computer storage medium for crystal growth control of a shouldering process. The method comprises: presetting setting values of a crystal diameter variation, and a shouldering length variation at different stages of a shouldering process and a crystal growth process parameter at different stages of the shouldering process; obtaining crystal diameters at different stages of the shouldering process and calculating a measured crystal diameter variation; obtaining shouldering lengths at different stages of the shouldering process and calculating a measured shouldering length variation; comparing a ratio of the measured crystal diameter variation and the measured shouldering length variation with a ratio of the setting values of the crystal diameter variation and the shouldering length variation to obtain a difference as an input variable of PID algorithm; calculating an adjustment value of a crystal growth process parameter by PID algorithm as an output variable of PID algorithm; adding the adjustment value of the crystal growth process parameter and the setting value of the crystal growth process parameter to obtain a process parameter of an actual crystal growth process. The method, device and system and computer storage medium control the crystal diameter variation during the shouldering process by PID algorithm to overcome an influence of small changes in the thermal field to the shouldering process, ensure the changing value of the crystal diameter is consistent, and improve the repeatability of the shouldering process and the stability of the process.

This invention provides method, device, system, and computer storage medium for crystal growth control of a shouldering process. The method comprises: presetting setting values of a crystal diameter variation, and a shouldering length variation at different stages of a shouldering process and a crystal growth process parameter at different stages of the shouldering process; obtaining crystal diameters at different stages of the shouldering process and calculating a measured crystal diameter variation; obtaining shouldering lengths at different stages of the shouldering process and calculating a measured shouldering length variation; comparing a ratio of the measured crystal diameter variation and the measured shouldering length variation with a ratio of the setting values of the crystal diameter variation and the shouldering length variation to obtain a difference as an input variable of PID algorithm; calculating an adjustment value of a crystal growth process parameter by PID algorithm as an output variable of PID algorithm; adding the adjustment value of the crystal growth process parameter and the setting value of the crystal growth process parameter to obtain a process parameter of an actual crystal growth process. The method, device and system and computer storage medium control the crystal diameter variation during the shouldering process by PID algorithm to overcome an influence of small changes in the thermal field to the shouldering process, ensure the changing value of the crystal diameter is consistent, and improve the repeatability of the shouldering process and the stability of the process.

A method for measuring distance between lower end surface of heat shielding member and surface of raw material melt, the method including providing the member being located above the melt, when a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the melt in a crucible, the method including: forming a through-hole in the member; measuring distance between the member and the melt surface, and observing position of mirror image of the through-hole with fixed point observation apparatus, the mirror image being reflected on the melt surface; then measuring a moving distance of the mirror image, and calculating distance between the member and the melt surface from a measured value and the moving distance of the mirror image, during the pulling of the crystal. The distance between the member and the melt can be precisely measured by the method.

A method for measuring distance between lower end surface of heat shielding member and surface of raw material melt, the method including providing the member being located above the melt, when a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the melt in a crucible, the method including: forming a through-hole in the member; measuring distance between the member and the melt surface, and observing position of mirror image of the through-hole with fixed point observation apparatus, the mirror image being reflected on the melt surface; then measuring a moving distance of the mirror image, and calculating distance between the member and the melt surface from a measured value and the moving distance of the mirror image, during the pulling of the crystal. The distance between the member and the melt can be precisely measured by the method.