31 results about "Crystal rotation" patented technology

The invention provides a crystal pulling method for improving light boron-doped crystal BMD and a silicon single crystal rod, and belongs to the technical field of silicon single crystal pulling, crystal rod pulling is carried out in a predetermined thermal field to change the temperature gradient in the thermal field and increase the interval length of the BMD nucleation temperature, and in the crystal pulling process, the BMD nucleation temperature is increased. According to the present invention, the crystal rotation, the crucible rotation and the pulling speed are adjusted so as to improve the concentration and the distribution uniformity of the interstitial oxygen and the vacancy in the crystal bar, such that the concentration and the distribution uniformity of the interstitial oxygen and the vacancy in the crystal bar are pre-improved so as to provide sufficient raw materials for BMD nucleation, and then the temperature gradient in the thermal field is changed so as to increase the interval length of the BMD nucleation temperature, interstitial oxygen and vacancies are promoted to generate BMD, and then the BMD defect density in the light boron-doped crystal is remarkably improved through the synergistic effect of a preset thermal field, crystal transition, crucible transition and the pulling speed.

According to the invention, heavy arsenic doping 1t is reduced; 111gt, 111gt; the invention relates to a crystal pulling method based on crystal orientation monocrystalline silicon section defect density and a monocrystalline silicon rod, and belongs to the technical field of monocrystalline silicon pulling. In the equal-diameter process, the liquid opening distance is constant, the pulling speed of the crystal bar is gradually reduced according to the length of the crystal bar, and the ratio (CR / SR) of crystal rotation / pot rotation is adjusted, so that heat conduction is uniformly transmitted in the radial direction of the crystal bar by controlling the growth rate of crystals, the temperature gradient of a solid-liquid interface and precipitation of oxides, and the heat conduction efficiency is improved. And in the crystal growth process, point defects such as interstitial atoms and vacancies have more opportunities to diffuse outwards, so that the generation of the point defects and impurity decorations is inhibited, the defect density of the section of the single crystal silicon rod is reduced, and the quality of the heavily arsenic-doped crystal rod is improved.

The application discloses a single crystal growth ending method and system based on convex solid-liquid interface control and belongs to the technical field of semiconductor material preparation. The method is applied to the ending stage of Czochralski method single crystal silicon growth, the heating power, the pulling speed, the crystal rotation state and the crystal lifting state are cooperatively controlled, the solid-liquid interface is adjusted from a concave surface to a plane and a convex shape towards the melt in four steps, and the rapid ending is completed under the stable convex interface; the matching system comprises a single crystal furnace body and a heating power and a pulling parameter control module, and further comprises a state monitoring and central control module, so that the accurate cooperation and automatic control of process parameters are realized. The application fundamentally eliminates the generation conditions of dislocation back extension and hidden cracks, reduces the occurrence rate, shortens the ending time, has strong process controllability, can be upgraded on the existing equipment, and has a good industrialization and popularization prospect.

The invention provides a crystal face orientation method, a crystal face orientation device and crystal processing equipment. The crystal face orientation method comprises the following steps: adjusting the crystal face orientation device to enable an included angle between a signal transmitting direction and a signal receiving direction to be equal to a diffraction angle when a predetermined same-family crystal face in a crystal to be detected meets Bragg diffraction; establishing a space rectangular coordinate system, taking a predetermined reflection point as an original point, enabling an X axis to be parallel to a rotation axis of the crystal to be measured, enabling a signal emission direction to be parallel to an XOY plane, and enabling an included angle between the signal emission direction and the X axis to be equal to a Bragg angle theta B of a predetermined family crystal plane; the to-be-detected crystal is driven to rotate around a crystal rotation axis, a diffraction signal is received through a receiver and a rotation angle stroke S is recorded during the period, the crystal rotation axis is parallel to the X axis and is perpendicular to the reference axis, and the rotation angle stroke is a rotation angle of the to-be-detected crystal from an initial state to a peak value of the diffraction signal; and determining an end face crystal orientation deflection angle alpha, an end face crystal orientation positioning angle omega and an end face crystal orientation inclination direction angle phi according to the at least three groups of corner strokes S.

The invention discloses a method for processing a transparent melt based on a machine vision image and controlling crystal growth in real time. The method comprises the following steps: acquiring a video image of a crystal and a melt interface in a crystal growth process in real time through image acquisition equipment; preprocessing the acquired image and extracting effective features; based on a double-threshold segmentation image, determining an accurate identification range and identification accuracy, and in combination with a polar coordinate sector density analysis method, identifying the lower edge boundary of the crystal and calculating the radius of the crystal; recursive least square harmonic wave trapping is adopted to remove periodic interference signals caused by crystal rotation, and a balance diameter sequence reflecting the actual growth trend is obtained; according to the change of the balance diameter sequence along with time, calculating a diameter slope as a crystal growth rate prediction value; based on the growth rate and the crystal radius, a diameter-slope-power relation model is established, and real-time closed-loop regulation and control of the heating power are achieved; according to the invention, a function relationship is established between the crystal diameter change trend and the power correction, automatic correction of the temperature deviation is realized through a sine smooth power regulation function, and a closed-loop system of visual detection-trend analysis-power feedback is formed.

This invention relates to monocrystalline silicon, its manufacturing method, and silicon wafers. The invention provides a method for manufacturing monocrystalline silicon with low oxygen concentration and high uniformity in the in-plane distribution of oxygen concentration and resistivity, as well as a silicon wafer. A method for manufacturing monocrystalline silicon based on the MCZ method, in which monocrystalline silicon (3) is pulled from molten silicon (2) in a quartz crucible (11) while applying a hook-shaped magnetic field, wherein the crystal rotation speed during the pulling process is 17 rpm or more and 19 rpm or less. The oxygen concentration of the monocrystalline silicon (3) pulled in this way is 1 × 10⁻⁶. 17 atoms / cm 3 Above and 8×10 17 atoms / cm 3 The following values ​​are provided: ROG in the crystal section orthogonal to the crystal growth direction is less than 15%, and RRG in the crystal section is less than 5%.

The embodiment of the invention discloses a monocrystalline silicon growth furnace and a control method thereof, and relates to the technical field of monocrystalline silicon production. The method comprises the following steps: acquiring expected production parameters and actual production parameters of a monocrystalline silicon growth furnace under preset control parameters to obtain a production parameter characteristic matrix, the expected production parameters and the actual production parameters comprise temperature field data, air pressure data, crystal pulling speed, crystal rotation rate and crucible rotation rate in the monocrystalline silicon growth furnace; calculating an error coupling degree and a fluctuation coupling degree based on the production parameter characteristic matrix to obtain control parameter disturbance analysis data; calculating control parameter compensation data according to the production parameter characteristic matrix and the control parameter disturbance analysis data; and correcting and optimizing the control parameters of the monocrystalline silicon growth furnace based on the control parameter compensation data to obtain target control parameters. Through the method, the control precision of the monocrystalline silicon growth furnace can be improved, and the quality and efficiency of monocrystalline silicon production are further improved.

The utility model provides a top dividing structure, which relates to the technical field of crystal revolving door glass and comprises a top plate, an adjusting piece and revolving door top glass. The whole top plate is cylindrical, and the top plate is fixedly connected to a ceiling. The adjusting piece is arranged at the bottom of the top plate; the revolving door top glass is arranged below the top plate, and the revolving door top glass is a circle formed by four pieces of glass. The problems that when an existing top partition structure is used, time and labor are wasted due to the fact that the existing top partition structure is mostly divided into two pieces of glass to be installed, damage is prone to occurring, the whole piece of glass needs to be replaced when the glass is broken, and then using is not convenient are solved.

A preparation method of large-size ultra-low-oxygen monocrystalline silicon relates to the technical field of ultra-low-oxygen monocrystalline silicon drawing, and comprises a material melting process, after material melting is completed, a CUSP hook-shaped magnetic field is opened, the crystal rotation direction and the crucible rotation direction are controlled to be the same, ultra-low-oxygen monocrystalline silicon drawing is carried out, after material melting is completed and before ultra-low-oxygen monocrystalline silicon drawing is carried out, the CUSP hook-shaped magnetic field is closed, and the ultra-low-oxygen monocrystalline silicon drawing is carried out. And controlling the direction of crystal rotation to be opposite to the direction of crucible rotation, and drawing at least one transition crystal bar, so that the oxygen content in the monocrystalline silicon can be reduced, and the ultralow-oxygen monocrystalline silicon can be obtained.

The application provides a finishing process for reducing crack dislocation of a single crystal silicon rod, which comprises the following steps: S1: instantaneously increasing a heating power, instantaneously reducing a pulling speed to a first pulling speed, reducing the first pulling speed to a second pulling speed at a first acceleration, keeping a crystal rotation and a crucible rotation unchanged as an equal-diameter section crystal rotation and crucible rotation, and keeping a first crystal rotation and a first crucible rotation unchanged, and gradually reducing a single crystal diameter; S2: increasing the second pulling speed to a third pulling speed at a second acceleration, increasing the first crystal rotation and the first crucible rotation to a second crystal rotation and a second crucible rotation at a third acceleration, and continuing to reduce the single crystal diameter; and S3: increasing the third pulling speed to a fourth pulling speed at the second acceleration, increasing the second crystal rotation and the second crucible rotation to a third crystal rotation and a third crucible rotation at a fourth acceleration, and ending the finishing process. The application has the beneficial effects of effectively reducing the broken edge of the single crystal, shortening the finishing time, effectively controlling the dislocation and crack of the single crystal, and improving the qualified rate of the single crystal product.

The utility model relates to the technical field of crystal processing equipment, in particular to a crystal multi-surface synchronous polishing and rotating device, which comprises a processing table for crystal polishing, a rotating servo motor is embedded in the center of the top surface of the processing table, and a side lifting cylinder and a back lifting cylinder are respectively mounted on one side surface and the back surface of the processing table. A basic platform for crystal polishing is provided through the arranged machining table, the rotating servo motor is installed in the center of the top face of the machining table, and a rotating shaft of the rotating servo motor is connected with the rotating disc and the replaceable lower clamping disc and used for driving a crystal to rotate; the side lifting cylinder and the back lifting cylinder are mounted on the side surface and the back surface of the machining table, and the polishing pushing cylinder at the top of a piston rod can push the polishing motor and the polishing head to perform polishing operation to realize multi-surface polishing; the stand column is installed on one side of the top of the machining table, a crystal clamping air cylinder and an upper clamping disc at the end of a top transverse frame of the stand column can clamp crystals, and stability of the crystals in the polishing process is guaranteed.

The invention provides a method for drawing a plurality of 6-inch heavily doped crystal bars by using a 24-inch thermal field, and relates to the technical field of small-size monocrystalline silicon crystal bar drawing, and the method comprises the following steps: firstly, in an MCZ process based on the 24-inch thermal field, presetting the pulling speed of crystal bars with different equal-diameter lengths, the rotating speed of crystals and the rotating speed of a crucible in an equal-diameter process; wherein the set value of the pulling speed of the crystal bars is 0.68-1.3 mm / min, the set value of the rotating speed of the crystals is 12-16 rpm, the set value of the rotating speed of the crucible is 0.5-4 rpm, and then in the isometric crystal pulling process, the multiple crystal bars are pulled according to the preset pulling speed of the crystal bars with different isometric lengths, the rotating speed of the crystals and the rotating speed of the crucible; in the MCZ process, complex heat convection in a thermal field is inhibited and the doping uniformity is good through cooperation of a strong magnetic field, a low pulling speed and a specific crystal rotating speed to crucible rotating speed ratio, so that the resistivity consistency of the head and the tail of a drawn crystal bar is good, and the fluctuation range is small.

The application discloses a kind of high-efficiency low-attenuation antimony-doped N-type monocrystalline silicon rod and preparation method thereof, belongs to monocrystalline silicon rod manufacturing technical field, its preparation method is as follows: polycrystalline silicon material is layered in quartz crucible according to bottom layer, middle layer, top layer order layering charge, antimony source is uniformly mixed in middle layer silicon material;After vacuumizing to single crystal furnace, fill in argon as protective atmosphere, make polycrystalline silicon material and antimony source completely melt by subsection heating, and form stable melt;Seed crystal is added to melt, then after seeding, shoulder is released and enters constant diameter growth stage, and the pulling speed is dynamically adjusted and the crystal rotation speed is matched with the crucible rotation speed;After constant diameter growth to target length, start to finish, after in-situ annealing treatment, cool, and obtain.The application is based on Czochralski method by doping high-purity antimony source in system, and dynamically controls constant diameter growth process parameters, which can eliminate the light-induced attenuation hidden danger of N-type monocrystalline silicon, significantly improve the resistivity uniformity, and realize the balance of low dislocation density and high crystal yield.

The invention relates to the technical field of semiconductors, and provides a method for improving a crystal growth ending slip line and a computer program product. The method comprises the following steps: providing crystals after equal-diameter growth; setting ending process parameters, to be specific, setting the ending temperature to increase in a stepped manner along with the gradual increase of the ending length, setting the ending pulling speed to increase gradually along with the increase of the ending length, and matching the setting of the ending pulling speed with the setting of the ending temperature; setting the ending crucible to linearly increase along with the increase of the ending length, and setting the ending initial crystal transition of the ending crystal to be the same as the equal-diameter growth end-stage crystal transition; and executing an ending process according to the ending process parameters to obtain the non-slip crystal with the conical tail. According to the method, proper ending process parameters are set after equal-diameter growth is completed, so that the crystals can be ended to form a non-slip conical tail, and finally, a high-quality silicon single crystal rod grows.

Monocrystalline silicon with a controllable oxygen content, a silicon wafer with a controllable oxygen content, and a monocrystalline silicon growth method and system. The method comprises: during a growth process of monocrystalline silicon, acquiring an actual heating duration of a quartz crucible; on the basis of a difference range in which the difference between the actual heating duration and a target heating duration is located, determining a control parameter set and configuration parameter values thereof, wherein the control parameter set comprises a crystal rotation speed and / or a crucible rotation speed, and different difference ranges correspond to different control parameter sets; and on the basis of the configuration parameter values of the control parameter set, automatically configuring corresponding control parameters, such that an oxygen content deviation between the oxygen content of the monocrystalline silicon and a target oxygen content is -10% to 10%.

The invention belongs to the technical field of doping agent synthesis, and particularly relates to a preparation method and a doping process of an efficient doping agent for monocrystalline silicon, diffusion of the doping agent in the whole preparation process of the monocrystalline silicon is improved by selecting a diffusion accelerant, the surface chemical performance of the doping agent is improved through surface activation treatment, and the doping performance of the doping agent is improved. Meanwhile, anions of the surface active agent can react with oxygen in the monocrystalline silicon to reduce the oxygen content in the monocrystalline silicon, and when the doping agent is prepared, a material which diffuses quickly is selected according to different diffusion speeds of the material, so that holes can be provided for a material which diffuses slowly in time, and the distribution of the doping agent in the monocrystalline silicon is improved; in the doping process, the condition of doping diffusion efficiency is considered, and the distribution of the whole doping agent is more uniform by changing the crystal rotation and crucible rotation rates in the single crystal equipment, so that the electrical properties of the single crystal silicon are ensured.

The invention discloses a birefringence and polarization beam splitting ratio measurement system and method based on crystal rotation, and relates to the technical field of optical characteristic measurement, and the system comprises a birefringence measurement module, a polarization beam splitting ratio measurement module and a data processing module. The birefringence measurement module comprises a sodium lamp, a collimator tube, a crystal rotation objective table, a first birefringence crystal, a first rotatable polarizing film and a spectrometer telescope which are arranged along a first light path. The polarization beam splitting ratio measuring module comprises a laser, a second birefringent crystal and a second rotatable polaroid which are arranged along a second light path, and the output end of the polarization beam splitting ratio measuring module is connected with a light screen with a scale and a photoelectric sensor in parallel. And the data processing module is respectively connected with the angle encoder, the double-vernier dial and the oscilloscope. The birefringence and polarization beam splitting ratio measuring device can realize synchronous and accurate measurement of birefringence and polarization beam splitting ratio parameters, and has the advantages of reducing measurement cost, improving data consistency, and being compact in structure and convenient to operate.

To perform establishment by a finite element method using a macroscopic yield function capable of expressing a Bauschinger effect.SOLUTION: Provided is a finite element method using a constitutive expression in which a macroscopic stress is decomposed into components of a shear stress of a slip system by a Taylor factor to obtain a strain rate. In the crystal plasticity, since the Bauschinger effect was exhibited even without rotating the crystal, it was confirmed that the Bauschinger effect was exhibited by the back stress. Therefore, the Taylor factor is set to a constant. This is a program of a finite element method accompanied by a macroscopic constitutive expression obtained by improving a constitutive expression of crystal plasticity. The finite element method is composed of a constitutive expression, a yield function, and an expression representing plastic strain. This corresponds to the heart of the finite element method.SELECTED DRAWING: None

The application discloses a method for preparing ultra-high resistivity silicon substrate by a Czochralski method, and the process flow of the method is as follows: preparing a silicon single crystal by the Czochralski method, rolling and grinding the single crystal rod, multi-wire cutting, edge chamfering, double-side grinding, chemical etching, heat treatment and chemical mechanical polishing; wherein, in the process of preparing the silicon single crystal by the Czochralski method, a horizontal superconducting magnetic field is used in the single crystal growth process, the magnetic field strength is 1000-5000 Gauss, meanwhile, specific crystal rotation speed and crucible rotation speed are matched, the crystal rotation speed is 1-12 rpm, and the crucible rotation speed is 0.1-2 rpm; the heat treatment process is POLY+LTO thin film growth or high-temperature annealing. The method is suitable for preparing P-type silicon substrate with a diameter of 8 inches or above, a resistivity of 3000 ohm*cm or above and oxygen content of 5 ppma or below. The prepared single crystal has an oxygen content of less than 5 ppma, a resistivity of more than 3000 ohm*cm after annealing, an oxygen content uniformity of less than 10%, and a resistivity uniformity of less than 5%.

The present application relates to the technical field of crystal processing, and discloses a large-size crystal crystal direction product forming and processing device, which comprises a slicing assembly, a direction assembly and a rotating assembly, wherein the slicing assembly comprises a mounting frame, an emery wire arranged in front of the mounting frame, a guide rail arranged in the mounting frame, a sliding block arranged on the guide rail, a telescopic cylinder connected with the sliding block and a lifting piece arranged on the sliding block; the direction assembly is provided with two and is fixedly arranged on the mounting frame in horizontal and vertical directions; and the rotating assembly is arranged; the large-size crystal crystal direction product forming and processing device can perform XY bidirectional X-ray testing on the crystal, the X-ray direction instrument is driven by a motor, the incident angle can be adjusted on the arc-shaped frame, the crystal direction detection is facilitated, the crystal direction angle deviation value is determined, the crystal pitch angle is adjusted by the lifting piece; the crystal is fixed by a second motor control clamping hand, the angle of the crystal rotation is simultaneously regulated, the cutting is performed by the emery wire after the testing is completed.

The present disclosure relates to a method and device for detecting dislocation of a crystal line, a storage medium and an electronic device, and belongs to the field of single crystal silicon production. The method comprises: during the production of a single crystal silicon rod by the Czochralski method, obtaining a single crystal silicon rod production image in a preset measurement area at a shoulder stage according to a preset shooting period; and determining whether the crystal line of the single crystal silicon rod is broken according to the single crystal silicon rod production image and the crystal rotation rule of the single crystal silicon rod. By setting a camera and shooting an image of the single crystal silicon rod at the shoulder stage according to a preset shooting period, and according to the image and the rotation rule of the single crystal silicon rod, it can be determined whether the crystal line of the single crystal silicon rod is broken, without manual investigation, thereby reducing labor costs.

The embodiment of the invention relates to the field of photovoltaic technology, and provides a single crystal silicon rod and a preparation method thereof, a silicon wafer and a solar cell, so as to improve the radial and axial uniformity of the resistance of the single crystal rod and further improve the efficiency of the solar cell. The preparation method of the silicon single crystal rod comprises an equal-diameter growth process which is sequentially divided into a first stage, a second stage, a third stage and a fourth stage according to the change trend of the pulling speed; the equal-diameter growth process comprises the following steps: gradually increasing the pulling speed from an initial pulling speed to a first pulling speed and gradually increasing the crystal rotation from an initial crystal rotation to a first crystal rotation in a first stage on the basis of a positive correlation relationship between the pulling speed and the crystal rotation; in the second stage, the pulling speed is kept at the first pulling speed, and crystal transition is kept to be first crystal transition; in the third stage, the pulling speed is gradually decreased from the first pulling speed to the second pulling speed, and the crystal transition is gradually decreased from the first crystal transition to the second crystal transition; and in the fourth stage, the pulling speed is kept at the second pulling speed, and the crystal transition is kept to be second crystal transition.

A method for producing a single crystal from silicon in a crystal-pulling apparatus comprising the following steps: (a) melting polycrystalline silicon to a melt; (b) contacting a seed crystal with the surface of the melt; (c) pulling the seed crystal to a thin neck of a diameter; (d) expanding the diameter of the thin neck to a target diameter; (e) pulling a substantially cylindrical subsection of the single crystal to said target diameter, wherein geometric parameters are measured as a function of the crystal length and stored as a numerical sequence together with at least one feature from the pulling process from a list of features including pulling speed and crystal rotation; (f) terminating the pulling of the substantially cylindrical subsection; (g) separating the single crystal from the melt and removing the single crystal from the crystal-pulling apparatus;(h) cutting the substantially cylindrical section into substantially cylindrical rod pieces at fixed rod positions, characterized in that a zero position is defined at an axial position on the single crystal, the diameter of the single crystal is measured along its length in relation to the zero position and the values ​​obtained are correlated with the series of geometric parameters, so that features from the drawing process are obtained relative to the zero position which serve to define the rod positions.

The application provides a method for drawing multiple 6-inch heavy-doped crystal rods by using a 24-inch hot field, relates to the technical field of small-size single crystal silicon rod drawing, and first sets the crystal rod drawing speed, the crystal rotation speed and the crucible rotation speed of different isodiametric lengths in the preset isodiametric process in the MCZ process of the 24-inch hot field; wherein, the crystal rod drawing speed setting value is 0.68mm / min-1.3mm / min, the crystal rotation speed setting value is 12rpm-16rpm, and the crucible rotation speed setting value is 0.5rpm-4rpm; then, multiple crystal rods are drawn according to the preset crystal rod drawing speed, the crystal rotation speed and the crucible rotation speed of different isodiametric lengths in the isodiametric crystal drawing process; in the MCZ process, the complex thermal convection in the hot field is inhibited through the cooperation of the'strong magnetic field, low drawing speed, specific crystal rotation speed and crucible rotation speed ratio', the doping uniformity is good, and then the head and tail resistivity consistency of the drawn crystal rods is good and the fluctuation range is small.

The application discloses a birefringence and polarization beam splitting ratio measuring system and method based on crystal rotation, relates to the technical field of optical characteristic measurement, and comprises a birefringence measuring module, a polarization beam splitting ratio measuring module and a data processing module. The birefringence measuring module comprises a sodium lamp, a collimator tube, a crystal rotation stage, a first birefringent crystal, a first rotatable polarizer and a spectrometer telescope arranged along a first light path. The polarization beam splitting ratio measuring module comprises a laser, a second birefringent crystal and a second rotatable polarizer arranged along a second light path, and the output ends of the laser, the second birefringent crystal and the second rotatable polarizer are connected in parallel with a light screen with a scale and a photoelectric sensor. The data processing module is connected with an angle encoder, a double cursor scale and an oscilloscope respectively. The application can realize synchronous and accurate measurement of birefringence and polarization beam splitting ratio parameters, has the advantages of low measurement cost, improved data consistency, compact structure and convenient operation.

Provided is a method for producing a single crystal silicon, which is a single crystal for a 200-mm-diameter wafer, has a straight tube diameter of 201 mm or more and 230 mm or less, has a resistivity of 0.8 mΩcm or more and 1.2 mΩcm or less in the straight tube start portion, and is produced by pulling a single crystal silicon (10) from a silicon melt (9) containing red phosphorus as a dopant by a pulling method and growing the single crystal silicon (10), wherein the crystal rotation speed of the single crystal silicon (10) is controlled to be 17 rpm or more and 40 rpm or less for at least a part of a shoulder forming process of the single crystal silicon (10).

The invention belongs to the technical field of semiconductor preparation, and particularly relates to a crystal rotating method in a semiconductor preparation process, which is characterized in that a rotating motor, a guide bearing and a fixing piece are integrated into a rotating structure with a large-size central hole, and the rotating structure is mounted in a cavity. After the crystal growth base is arranged in the central hole and rotates synchronously with the output shaft of the motor, the chamber is sealed by a corrugated pipe. And starting a motor to drive the crystal to rotate, and performing growth monitoring through the central hole. According to the method, the rotating structure has the large-view monitoring capability in a limited space, stable rotation under high load is realized through the synergistic effect of the bearing and the fixing piece, the rotation radial deviation is accurately controlled within + / -0.02 mm, and the uniformity and quality of crystal growth are effectively guaranteed.

The invention discloses a rotatable human body model display device, and belongs to the field of medical equipment, the display device comprises a base, a protective frame plate fixedly arranged at the upper end of the base, a crystal arranged in the protective frame plate, and a human body model body fixedly arranged in the crystal; a driving structure for driving the crystal to rotate is arranged in the base; the driving structure comprises a rotating shaft which is inserted into the top of the base and is fixedly connected with the lower end of the crystal, a sleeve which is rotatably arranged in the base and is connected with the lower end of the rotating shaft, a spring shaft which is rotatably arranged in the sleeve and is connected with the sleeve, and a locking piece which is arranged on the base and is connected with the rotating shaft; and a driving piece is arranged in the base. A mechanical structure transmission mode is adopted, the rotating action can be achieved only by rotating the spring shaft and unlocking the locking piece, and operation is easy and convenient. By rotating the crystal and the internal human body model body, the structure and the function of the human body can be displayed in all directions, and the teaching or displaying effect is improved.

The invention discloses czochralski silicon and a preparation method thereof. The preparation method of the czochralski silicon comprises the following steps: 1) melting materials; 2) seeding: immersing the seed crystal into a silicon liquid, and stretching the silicon liquid to grow into a neck crystal; 3) shouldering: stretching and growing the neck crystal into a shouldered crystal; 4) shoulder rotation: stretching and growing the shouldered crystal until the diameter of the crystal is equal-diameter growth diameter to obtain a shoulder rotation crystal; 5) performing equal-diameter growth: performing equal-diameter growth on the shouldered crystal under the condition that the first crystal rotation speed is 2-6 rpm greater than the first crucible rotation speed to obtain a middle equal-diameter crystal; performing equal-diameter growth on the intermediate equal-diameter crystal under the condition that the second crystal rotation speed is 1-5 rpm lower than the second crucible rotation speed to obtain an equal-diameter growth crystal bar; and 6) ending: ending the equal-diameter growth crystal bar at a second crystal rotation speed to obtain the czochralski silicon. The uniformity of the transverse resistance of the czochralski silicon prepared by the method is relatively good.