Placement method for liquid opening distance of single crystal furnace

Abstract

The invention relates to the technical field of monocrystalline silicon production, in particular to a placing method of a single crystal furnace liquid opening distance, which comprises the following steps of: 1, setting red dot capture, adding red dot capture through CCD (Charge Coupled Device) camera motion capture, and capturing the red dot on a bright and dark interface of an inverted image of the lower edge of a guide cylinder and a liquid level; step 2, camera debugging standardization is carried out; step 3, a crucible is controlled to move, so that the liquid opening distance range of the crucible is 25-35 mm; 4, the crucible is controlled to descend three times through the lifting piece, the distance between red dot capture and the lower edge position of the guide cylinder every time is calculated, then the average value of three times of descending is calculated, and the leading and discharging crucible position is adjusted on the basis of the average value. The liquid opening distance can be conveniently adjusted, the leading and discharging survival rate is increased, and the per unit yield is effectively increased.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal silicon production, and in particular to a method for placing a single crystal furnace liquid mouth distance. Background Art

[0002] The liquid mouth distance refers to the distance between the raw material liquid surface and the lower edge of the guide tube during the process of producing single crystal silicon using a single crystal furnace.

[0003] The accuracy of the liquid-to-mouth distance directly affects the growth of the crystal during the production of single crystal silicon, and thus directly affects the success of crystal pulling. The method for determining the liquid-to-mouth distance in the prior art is to locate the liquid-to-mouth distance by visually observing the furnace and adjusting the crucible position based on experience. The adjustment result fails to form a standard and has a large measurement error.

[0004] In the process of pulling single crystal silicon rods, the distance between the liquid nozzle and the rod is easily too large or too small, which reduces the survival rate of the rod. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for placing the distance between the liquid inlet and outlet of a single crystal furnace to solve the problem of reducing the survival rate of the lead-out.

[0006] Based on the above purpose, the present invention provides a method for placing a liquid mouth distance of a single crystal furnace, wherein the single crystal furnace comprises a furnace body, a furnace cover is arranged on the top of the furnace body, a crucible and a guide tube located above the crucible are arranged in the furnace body, a raw material liquid is contained in the crucible, and the upper surface of the raw material liquid is a liquid surface, a lifting member for adjusting the height of the crucible is arranged in the furnace body, and a CCD camera for observing the liquid surface in the crucible is arranged on the furnace cover; comprising:

[0007] Step 1: Set up red dot capture. Use CCD camera motion capture to add red dot capture. The red dot capture is on the reflection of the lower edge of the guide tube and the light and dark interface of the liquid surface. The red dot capture moves with the movement of the liquid surface.

[0008] Step 2: Camera debugging standardization:

[0009] Step 3: Control the movement of the crucible so that the liquid mouth distance of the crucible is within the range of 25-35mm;

[0010] Step 4: Control the crucible to descend three times by the lifting part, each time by 5mm, calculate the distance between the red dot capture and the lower edge of the guide tube each time, calculate the calculated value of the liquid mouth distance each time, and then calculate the average value of the three calculated values, display it on the CCD camera interface, and use it as a reference to adjust the crucible position.

[0011] Optionally, the camera debugging standardization includes:

[0012] Select the CCD camera auxiliary cross and enlarge the capture frame so that the CCD camera can capture the lower edge of the guide tube;

[0013] Adjust the position of the CCD camera so that the interface of the CCD camera is centered and symmetrical;

[0014] Insert the seed crystal into the composite center of the liquid surface aperture;

[0015] The furnace is in a state of temperature adjustment and the seed crystal is inserted into the liquid surface, and the introduction and capture tool is used for adjustment.

[0016] Optionally, in step three, the liquid mouth distance of the crucible is 30 mm.

[0017] Optionally, a water cooling screen is provided on the inner side of the guide tube.

[0018] Optionally, an isolation valve is provided on the furnace cover, a traction rope is provided above the isolation valve, a seed crystal is connected to the lower end of the traction rope, the seed crystal head is adjustably connected to the isolation valve through the traction rope, and the seed crystal passes through the isolation valve into the furnace body.

[0019] Beneficial effects of the present invention: The present invention provides a method for placing the liquid mouth distance of a single crystal furnace, which improves the survival rate of the lead-in and release and effectively increases the unit yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of the furnace body of the present invention;

[0022] Figure 2 It is a schematic diagram of red dot capture of the present invention;

[0023] Figure 3 It is a structural schematic diagram of the red dot capture position when the crucible is lowered three times according to the present invention.

[0024] In the figure: 1. furnace body; 2. furnace cover; 3. CCD camera; 4. crucible; 5. flow guide tube; 6. liquid surface; 7. red dot capture. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] like Figures 1 to 3 As shown, a method for placing a liquid mouth distance of a single crystal furnace is provided. The single crystal furnace comprises a furnace body 1, a furnace cover 2 is arranged on the top of the furnace body 1, a crucible 4 and a guide tube 5 located above the crucible 4 are arranged in the furnace body 1, a raw material liquid is contained in the crucible 4, and the upper surface of the raw material liquid is a liquid surface 6, a lifting member for adjusting the height of the crucible 4 is arranged in the furnace body 1, a CCD camera 3 for observing the liquid surface 6 in the crucible 4 is arranged on the furnace cover 2, the CCD camera 3 is connected to a controller, and the controller is connected to a display screen; comprising:

[0028] Step 1: Set the red dot capture 7. In the display screen on the furnace body 1, the red dot capture 7 is added through the motion capture of the CCD camera 3. The red dot capture 7 is at the light and dark interface between the reflection of the lower edge of the guide tube 5 and the liquid surface 6. The red dot capture 7 moves with the movement of the liquid surface 6.

[0029] Step 2: Camera debugging standardization:

[0030] Select the auxiliary cross of CCD camera 3, enlarge the capture frame, so that CCD camera 3 can capture the lower edge of guide tube 5. The diameter of the lower edge of guide tube 5 is confirmed by external measurement before installing the thermal field. The corresponding number of pixel blocks of CCD camera 3 is obtained according to the formula of number of pixels = number of centimeters × resolution / pixel density, and the diameter pixel value adjustment value 2330±1 is obtained;

[0031] Adjust the position of CCD camera 3 so that the interface of CCD camera 3 is centered and symmetrical;

[0032] Insert the seed crystal into the center of the compound circle of the 6 apertures on the liquid surface and fix it at the first grid below the intersection of the full-screen auxiliary lines;

[0033] When the furnace body 1 is in the state of temperature adjustment and the seed crystal is inserted into the liquid surface 6, the introduction and capture tool is used for adjustment, and adjustment is prohibited in other states;

[0034] Step 3: Control the movement of the crucible 4 so that the distance between the liquid mouth of the crucible 4 is in the range of 25-35 mm, preferably 30 mm, and place it at a visual distance without requiring an accurate position;

[0035] Step 4: The controller controls the crucible 4 to descend three times through the lifting part, each time by 5 mm, and calculates the distance between the red dot capture 7 and the lower edge of the guide tube 5 each time, calculates the calculated value of the liquid mouth distance each time, and then calculates the average value of the three calculated values, which is displayed on the CCD camera 3 interface, and is used as a reference to adjust the position of the lead-in crucible.

[0036] The present invention facilitates adjustment of the liquid mouth distance to a suitable position, improves the survival rate of the introduction and release, and effectively increases the yield per unit area. It does not require the installation of auxiliary devices such as reflectors, and does not have complicated adjustment actions. The liquid mouth distance measurement structure is simple, the measurement method is simple, and the liquid mouth distance adjustment is simple.

[0037] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. The present invention is not limited to the above-mentioned implementation modes, that is, it does not mean that the present invention must rely on the above-mentioned methods and structures to be implemented. Under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0038] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for placing a liquid mouth distance of a single crystal furnace, wherein the single crystal furnace comprises a furnace body, a furnace cover is arranged on the top of the furnace body, a crucible and a guide tube located above the crucible are arranged in the furnace body, a raw material liquid is contained in the crucible, and the upper surface of the raw material liquid is a liquid surface, a lifting member for adjusting the height of the crucible is arranged in the furnace body, and a CCD camera for observing the liquid surface in the crucible is arranged on the furnace cover; characterized in that: include: Step 1: Set up red dot capture. Use CCD camera motion capture to add red dot capture. The red dot capture is on the reflection of the lower edge of the guide tube and the light and dark interface of the liquid surface. The red dot capture moves with the movement of the liquid surface. Step 2: Camera debugging standardization: Step 3: Control the movement of the crucible so that the liquid mouth distance of the crucible is within the range of 25-35mm; Step 4: Control the crucible to descend three times by the lifting part, each time by 5mm, calculate the distance between the red dot capture and the lower edge of the guide tube each time, calculate the calculated value of the liquid mouth distance each time, and then calculate the average value of the three calculated values, display it on the CCD camera interface, and use it as a reference to adjust the crucible position.

2. The method for placing the distance between the single crystal furnace and the liquid mouth according to claim 1, characterized in that: The camera debugging standardization includes: Select the CCD camera auxiliary cross and enlarge the capture frame so that the CCD camera can capture the lower edge of the guide tube; Adjust the position of the CCD camera so that the interface of the CCD camera is centered and symmetrical; Insert the seed crystal into the composite center of the liquid surface aperture; The furnace is in a state of temperature adjustment and the seed crystal is inserted into the liquid surface, and the introduction and capture tool is used for adjustment.

3. The method for placing the distance between the single crystal furnace and the liquid mouth according to claim 1, characterized in that: In step 3, the liquid mouth distance of the crucible is 30 mm.

4. The method for placing the distance between the single crystal furnace and the liquid mouth according to claim 1, characterized in that: A water cooling screen is arranged inside the guide tube.

5. The method for placing the distance between the single crystal furnace and the liquid mouth according to claim 1, characterized in that: An isolation valve is arranged on the furnace cover, a traction rope is arranged above the isolation valve, a seed crystal is connected to the lower end of the traction rope, the seed crystal head is adjustably connected to the isolation valve through the traction rope, and the seed crystal passes through the isolation valve into the furnace body.

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