CN114606569A - Preparation process of P-type low-dislocation germanium single crystal - Google Patents
Preparation process of P-type low-dislocation germanium single crystal Download PDFInfo
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- C30B15/00—Single-crystal growth by pulling from a melt, e.g. Czochralski method
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Abstract
The invention belongs to the technical field of single crystal growth, and discloses a preparation process of a P-type low-dislocation germanium single crystal, which specifically comprises the following steps: the process comprises the following steps of raw material acid method corrosion, neck thinning, shouldering, shoulder rotating, equal-diameter growth, ending annealing and cooling, wherein the process keeps constant temperature in the shouldering stage, linearly reduces the crystal growth speed in two stages, and comprises the following first stage: reducing the growth speed from 2.0-2.5 mm/min to 0.5-1.0 mm/min within 3-3.5 h; and a second stage: within 5-5.5 h, the growth speed is reduced from 0.5-1.0 mm/min to 0.2-0.25 mm/min. The invention improves the shouldering process on the basis of the prior CZ process, can grow the P-type germanium single crystal with low dislocation density, and lays a solid foundation for realizing the solar-grade P-type germanium single crystal with zero dislocation and low defect in the future.
Description
Technical Field
The invention belongs to the technical field of single crystal growth, and particularly relates to a preparation process of a P-type low-dislocation germanium single crystal.
Background
Germanium single crystal is mainly used as a raw material of a semiconductor originally, and since the cheaper silicon single crystal replaces the germanium single crystal from the later stage of the 70 th 20 th century, but since the electron mobility of germanium and the frequency of a germanium device are higher than those of silicon and the strength of the germanium device is better than that of the silicon, the germanium material has a dominant position in the fields of high frequency, far infrared and aviation and aerospace. In addition, the application of germanium in military thermal imaging instruments, night vision instruments and radiation detectors is also developing rapidly. With the development of modern science and technology, germanium is increasingly widely applied to optical fibers, solar cells, fluorescent powder, medicines, catalysts and the like. With the exploration of various countries in the space field, the market demand of solar-grade germanium single crystals is increased rapidly, and the solar-grade germanium single crystals have excellent photoelectric efficiency and high-concentration carriers, so that the solar-grade germanium single crystals replace silicon single crystals and become substrate materials of solar power generation panels of space transmitters.
The space solar cell manufactured on the P-type germanium single crystal substrate slice has higher efficiency and better comprehensive performance, the P-type germanium single crystal becomes a main substrate material of a space high-efficiency high-power multi-section solar cell, the yield of the P-type low-dislocation germanium substrate slice in China is low at present, the P-type low-dislocation germanium substrate slice mainly depends on import, and the P-type low-dislocation germanium substrate slice becomes a bottleneck of space power supply development.
Chinese patent No. CN200710099557.5 discloses a process and apparatus for growing low dislocation germanium single crystal by crucible lowering czochralski method, which solves the contradiction between necking and dislocation multiplication, and the large size (more than 4 inches) low dislocation germanium single crystal can not be successfully grown, and the surface oxide scum can not be effectively controlled, so the dislocation density is high.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to provide a preparation process of a P-type low-dislocation germanium single crystal, which improves a shouldering process on the basis of the original CZ process, has short growth period and low cost investment and can realize batch production.
In order to realize the purpose of the invention, the specific technical scheme is as follows:
a preparation process of a P-type low-dislocation germanium single crystal comprises the following steps:
(1) putting a germanium ingot into a graphite crucible, melting the germanium ingot into a melt at a high temperature, and inserting a seed crystal into the surface of the melt for fusion welding;
(2) a step of leading a narrow neck, wherein crystals are led out of the seed crystal, the crystal conversion rate of the crystals is adjusted to be 5.0-8.0 r/min, the crucible conversion rate of the crucible is adjusted to be 2.0-5.0 r/min, the growth speed of the crystals is 2.0-2.5 mm/min, and the length of the narrow neck is 250-300 mm; (ii) a
(3) The shouldering stage, keeping the temperature constant, linearly reducing the crystal growth speed in two stages, wherein the first stage is as follows: reducing the growth speed from 2.0-2.5 mm/min to 0.5-1.0 mm/min within 3-3.5 h; the second stage is as follows: reducing the growth speed from 0.5-1.0 mm/min to 0.2-0.25 mm/min within 5-5.5 h;
(4) in the shoulder turning stage, the growth speed of the crystal is kept to be 0.2-0.25 mm/min, and the shoulder turning effect is achieved through linear temperature rise;
(5) in the stage of constant diameter, after the target diameter of the single crystal is reached, setting the pulling speed to be 0.20-0.25 mm/min through growing different size specifications;
(6) in the ending stage, when the single crystal grows to the target length in an equal diameter mode, ending, gradually reducing the diameter of the single crystal, finally separating a cone from a germanium melt, and starting annealing;
(7) and a cooling stage, namely cooling to room temperature after annealing is finished, and taking out the germanium single crystal to finish crystal growth.
Further, before the germanium ingot is melted in the step (1), hydrogen fluoride and hydrogen peroxide are adopted to carry out acid corrosion pretreatment on the germanium ingot.
Further, in the step (1), before inserting the seed crystal into the surface of the melt for welding, keeping the temperature in the furnace at 920-940 ℃, and keeping the seed crystal at a constant temperature of 50-70 mm above the melt for not less than 20min before contacting the seed crystal with the germanium melt.
And furthermore, in the shouldering stage in the step (3), the included angle between the shouldering angle and the horizontal direction is 50-70 degrees.
And further, in the shoulder rotating stage in the step (4), the heating rate is controlled to be 1-1.5 ℃/h, and when the shoulder rotating program is started, the crucible lifting rate is set to be 0.015-0.02 mm/min.
And (3) in the equal-diameter stage of the step (5), after the shoulder is turned, starting the equal-diameter growth program when the length of the manual equal-diameter is about 20-50 mm after the crystal reaches the target diameter.
Further, in the step (6), in the final annealing stage, the growth speed of the crystal is kept unchanged in the separation process of the germanium single crystal and the melt, and the temperature rise rate is controlled to be 1-1.5 ℃/min.
Further, in the step (6), the step of ending annealing specifically includes: and within 8-10 h, the pulling speed of the crystal is increased to 0.3-0.5 mm/min.
And (3) further, in the cooling stage in the step (7), cooling is carried out at a linear speed of 0.2-0.3 ℃/min.
Further, the target diameter of the single crystal is 100-150 mm, and the target length of the single crystal is 750-1000 mm.
Further, in the processes of the step (1) to the step (7), the low pressure and protective gas atmosphere are maintained; preferably, the low pressure is 2800-3200 Pa; preferably the protective gas is nitrogen or an inert gas.
Compared with the prior art, the invention has the beneficial effects that:
(1) the preparation process of the P-type low-dislocation germanium single crystal improves the shouldering process on the basis of the original CZ process, grows the P-type germanium single crystal with low dislocation density, fills the blank of the domestic P-type low-dislocation germanium single crystal, realizes the crossing of the domestic CZ method germanium single crystal growth process from high dislocation to low dislocation, and lays a solid foundation for realizing the solar-grade P-type germanium single crystal with zero dislocation and low defect in the future.
(2) The preparation process of the P-type low-dislocation germanium single crystal has the advantages of short growth period, low cost investment, realization of batch production and contribution to high profit and return of industrial output.
Drawings
FIG. 1 is a flow chart of the growth process of the P-type low dislocation germanium single crystal of the invention.
FIG. 2 shows a low dislocation germanium single crystal as discharged in example 1.
Fig. 3 shows the dislocation verification results of the head (H) and tail (T) of the low dislocation germanium single crystal obtained in example 1.
Fig. 4 shows the dislocation verification results of the head (H) and tail (T) of the low dislocation germanium single crystal in example 2.
Fig. 5 is a dislocation verification result of the shouldering process in comparative example 1.
Detailed Description
In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
Example 1
The embodiment discloses a growth process of a 4-inch P-type low-dislocation germanium single crystal, which is a flow chart of the growth process disclosed by the invention and specifically comprises the following steps of:
(1) taking zone-melting germanium ingots as a raw material, performing acid corrosion on the zone-melting germanium ingots by adopting a mixed solution of hydrogen fluoride and hydrogen peroxide, wherein the ratio of hydrogen fluoride to hydrogen peroxide to deionized water is 1:1:6, putting the corroded germanium ingots into a graphite crucible, melting the germanium ingots at a high temperature to obtain a melt, vacuumizing the graphite crucible to below 10Pa, and introducing nitrogen to maintain the furnace at a low pressure of about 3000Pa and keep a nitrogen atmosphere;
then cooling to 920 ℃, slowly placing the seed crystal above the liquid level of the germanium melt by about 50mm, keeping the constant temperature for at least 20min, and inserting the seed crystal into the surface of the melt for fusion;
(2) and a step of narrowing the neck, wherein a crystal is led out of the seed crystal, when the contact depth of the seed crystal and the germanium melt is about 3mm, an aperture to be grown appears, the temperature is manually reduced by about 7 ℃, the growth speed of the crystal is gradually and manually fed until the difference between the led-out crystal and the seed crystal is almost the same, then the temperature is kept constant, the diameter is controlled by gradually increasing the growth speed of the crystal, specifically, the pulling speed of the crystal is adjusted to be 2.5mm/min, the crystal of the crystal is adjusted to be 5.03r/min, the crucible of the crucible is adjusted to be 2.03r/min, so that the growth speed of the crystal is maintained at 2.0mm/min until the length of the neck reaches 250mm, and the diameter of the neck is about 4 mm.
(3) The shouldering stage, keeping the temperature constant, linearly reducing the crystal growth speed in two stages, wherein the first stage is as follows: within 3h, the growth speed is reduced from 2.0mm/min to 0.5 mm/min; the second stage is as follows: within 5, reducing the growth speed from 0.5mm/min to 0.2 mm/min; the angle between the shouldering angle and the horizontal direction is controlled to be 70 degrees in the two shouldering processes.
(4) A shoulder turning stage, wherein the shoulder putting process of the two stages is carried out, the shoulder turning stage is started, the growth speed of the crystal is kept at 0.2mm/min, the shoulder turning effect is achieved by linear temperature rise, and the temperature rise rate is controlled at 1 ℃/h; meanwhile, when the shoulder rotating program is started, the crucible lifting rate is given to be 0.02 mm/min;
(5) in the isometric stage, after the shoulder is turned, after the crystal reaches the target diameter, when the length of the crystal is manually isometric by about 20-50 mm, starting an isometric growth program, adopting an YPIR-QT type infrared diameter control instrument, aiming the visual aiming device at the outermost ring of the crystal growth surface by measuring the infrared radiation energy change of a special wave band of a visual field based on the infrared radiation principle, and converting a stable electric signal into a temperature control signal to ensure that the crystal uniformly grows;
(6) and in the ending stage, when the single crystal grows to the target length of 750mm in an equal diameter mode, ending, gradually reducing the diameter of the single crystal, finally separating the conical shape from the germanium melt, controlling the temperature rise rate at 1.5 ℃/min in the ending stage, and stopping crucible rising in the ending stage. Then, opening annealing: within 8-10 h, the pulling speed of the crystal is increased to 0.3 mm/min;
(7) and in the cooling stage, after annealing is finished, cooling at a linear speed of 0.2 ℃/min, taking out the ingot after the ingot is cooled to room temperature, and finishing crystal growth to obtain the P-type germanium crystal bar.
Fig. 2 shows that the P-type germanium ingot taken out from the furnace in step (7) of this embodiment has a length of 750mm, four edges on the surface of the ingot are uniform and symmetrical, and no super-cooling line or crystal transformation occurs on the surface of the ingot, and fig. 3 shows that the P-type germanium ingot has the same diameter at the beginning and the end of the ingot, and it can be seen from the figure that the dislocations appearing at the head (H) and the tail (T) of the ingot are very low and almost close to zero dislocation.
Example 2
The embodiment discloses a 6-inch P-type low-dislocation germanium single crystal growth process, which is a growth process flow chart shown in fig. 1 and specifically comprises the following steps:
(1) taking zone-melting germanium ingots as a raw material, performing acid corrosion on the zone-melting germanium ingots by adopting a mixed solution of hydrogen fluoride and hydrogen peroxide, wherein the ratio of hydrogen fluoride to hydrogen peroxide to deionized water is 1:1:6, putting the corroded germanium ingots into a graphite crucible, melting the germanium ingots at a high temperature to obtain a melt, vacuumizing the graphite crucible to below 10Pa, and introducing nitrogen to maintain the furnace at a low pressure of about 3000Pa and keep a nitrogen atmosphere;
then cooling to 920 ℃, slowly placing the seed crystal 50mm above the liquid level of the germanium melt, keeping the temperature for at least 20min, inserting the seed crystal into the surface of the melt and welding;
(2) and a step of narrowing the neck, wherein a crystal is led out of the seed crystal, when the contact depth of the seed crystal and the germanium melt is about 3mm, an aperture to be grown appears, the temperature is manually reduced by about 7 ℃, the growth speed of the crystal is gradually and manually fed until the difference between the led-out crystal and the seed crystal is almost the same, then the temperature is kept constant, the diameter is controlled by gradually increasing the growth speed of the crystal, specifically, the pulling speed of the crystal is adjusted to be 2.5mm/min, the crystal of the crystal is adjusted to be 5.0r/min, the crucible of the crucible is adjusted to be 2.0r/min, the growth speed of the crystal is maintained at 2.0mm/min until the length of the neck reaches 250mm, and the diameter of the neck is about 4 mm.
(3) The shouldering stage, keeping the temperature constant, linearly reducing the crystal growth speed in two stages, wherein the first stage is as follows: reducing the growth speed from 2.0mm/min to 1.0mm/min within 6 h; the second stage is as follows: reducing the growth speed from 1.0mm/min to 0.2mm/min within 6 h; the angle between the shouldering angle and the horizontal direction is controlled to be 70 degrees in the two shouldering processes.
(4) A shoulder turning stage, wherein the shoulder putting process of the two stages is carried out, the shoulder turning stage is started, the growth speed of the crystal is kept at 0.2mm/min, the shoulder turning effect is achieved by linear temperature rise, and the temperature rise rate is controlled at 1 ℃/h; meanwhile, when the shoulder rotating program is started, the crucible lifting rate is given to be 0.015 mm/min;
(5) in the isometric stage, after the shoulder is turned, after the crystal reaches the target diameter, when the length of the crystal is manually isometric by about 20-50 mm, starting an isometric growth program, adopting an YPIR-QT type infrared diameter control instrument, aiming the visual aiming device at the outermost ring of the crystal growth surface by measuring the infrared radiation energy change of a special wave band of a visual field based on the infrared radiation principle, and converting a stable electric signal into a temperature control signal to ensure that the crystal uniformly grows;
(6) and in the ending stage, when the single crystal grows to the target length of 600mm in an equal diameter manner, starting an ending procedure, gradually reducing the diameter of the single crystal, finally separating a cone from the germanium melt, controlling the temperature rise rate at 1.5 ℃/min in the ending stage, and stopping crucible lifting in the ending stage. Then, opening annealing: within 8h, the pulling speed of the crystal is increased to 0.3 mm/min;
(7) and in the cooling stage, after annealing is finished, cooling at a linear speed of 0.2 ℃/min, taking out the ingot after the ingot is cooled to room temperature, and finishing crystal growth to obtain the P-type germanium crystal bar.
In the case of 6-inch P-type low-dislocation germanium single crystal, 100 kg of the material is fed, the length of the obtained P-type germanium crystal bar reaches 600mm, four edges on the surface of the crystal bar are uniform and symmetrical, and the phenomenon of supercooling or crystal transformation does not occur on the surface of the crystal. Fig. 4 shows the dislocation results of the starting equal diameter and ending position of the P-type germanium ingot, and it can be seen that the dislocations presented at the head (H) and tail (T) of the crystal are very low and almost close to zero dislocation.
Comparative example 1
The comparative example discloses a 4-inch germanium single crystal growth process, which specifically comprises the following steps:
(1) taking zone-melting germanium ingots as a raw material, performing acid corrosion on the zone-melting germanium ingots by adopting a mixed solution of hydrogen fluoride and hydrogen peroxide, wherein the ratio of hydrogen fluoride to hydrogen peroxide to deionized water is 1:1:6, putting the corroded germanium ingots into a graphite crucible, melting the germanium ingots at a high temperature to obtain a melt, vacuumizing the graphite crucible to below 10Pa, and introducing nitrogen to maintain the furnace at a low pressure of about 3000Pa and a nitrogen atmosphere; cooling to 920 ℃, slowly placing the seed crystal above the liquid level of the germanium melt by about 50mm, and keeping the constant temperature for at least 20 min; inserting a seed crystal into the surface of the melt for fusion;
(2) and (2) a step of drawing a thin neck, wherein when the contact depth of the seed crystal and the germanium melt is about 3mm, a stop to be grown appears, the temperature is manually reduced by about 7 ℃, the growth speed of the crystal is gradually and manually fed until the difference between the drawn crystal and the seed crystal is almost the same, then the temperature is kept constant, the diameter is controlled by gradually increasing the growth speed of the crystal, specifically, the pulling speed of the crystal is adjusted to be 2.0-2.5 mm/min, the crystal of the crystal is adjusted to be 5.0-8.0 r/min, the crucible of the crucible is adjusted to be 2.0-5.0 r/min, so that the growth speed of the crystal is maintained at 2.0-2.5 mm/min until the length of the thin neck reaches 250-300 mm, and the diameter of the thin neck is about 3-5 mm.
(3) In the shouldering stage, a traditional automatic shouldering process is adopted in the shouldering process, the crystal growth speed at the beginning of shouldering is the crystal growth speed at the equal diameter, the shouldering process is not divided, the shouldering angle has no special requirement, the shouldering effect is realized by cooling, and the average cooling rate is 0.3-0.5 ℃/h;
(4) in the shoulder turning stage, the growth speed of the crystal is kept at 0.25mm/min, the shoulder turning effect is achieved by linear temperature rise, and the temperature rise rate is controlled at 1.5 ℃/h;
(5) in the isometric stage, after the shoulder is turned and the crystal growth length is about 50mm, an YPIR-QT type infrared diameter control instrument is adopted, based on the infrared radiation principle, the visual aiming device is aligned to the outermost ring of the crystal growth surface by measuring the infrared radiation energy change of a special wave band of a view field, and a stable electric signal is converted into a temperature control signal to ensure that the crystal grows uniformly.
(6) And in the ending stage, when the single crystal grows to the target length of 800mm in an equal diameter mode, ending, gradually reducing the diameter of the single crystal, finally separating the conical shape from the germanium melt, controlling the temperature rise rate at 1.5 ℃/min in the ending stage, and stopping crucible rising in the ending stage. Then, opening annealing, and increasing the pulling speed of the crystal to 0.3mm/min within 8-10 h.
(7) And in the cooling stage, after annealing is finished, cooling at a linear speed of 0.3 ℃/min, taking out the ingot after the ingot is cooled to room temperature, and finishing crystal growth to obtain the germanium crystal bar.
Fig. 5 shows the dislocation results of the shouldering process in comparative example 1, and it is apparent that dislocations are present and dislocation lines are present throughout the crystal growth plane.
The main difference between this comparative example and examples 1 and 2 is the (4) shouldering stage. In the embodiment 1, the shouldering process is realized by reducing the crystal growth speed in the shouldering process, the temperature is kept unchanged in the whole process, the dislocation density of the crystal growth is effectively reduced, and the stable growth of the crystal is ensured by the constant temperature. In the comparative example 1, the conventional cooling shouldering process is adopted, and the phenomenon of crystallization or devitrification is easily caused in the shouldering process due to the changed temperature, so that the crystal growth period is prolonged.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. A preparation process of a P-type low-dislocation germanium single crystal is characterized by comprising the following steps:
(1) putting a germanium ingot into a crucible, melting the germanium ingot into a melt at a high temperature, and inserting a seed crystal into the surface of the melt for fusion welding;
(2) a step of leading a narrow neck, wherein crystals are led out of the seed crystal, the crystal conversion rate of the crystals is adjusted to be 5.0-8.0 r/min, the crucible conversion rate of the crucible is adjusted to be 2.0-5.0 r/min, the growth speed of the crystals is 2.0-2.5 mm/min, and the length of the narrow neck is 250-300 mm;
(3) the shouldering stage, keeping the temperature constant, linearly reducing the crystal growth speed in two stages, namely: reducing the growth speed from 2.0-2.5 mm/min to 0.5-1.0 mm/min within 3-3.5 h; and a second stage: reducing the growth speed from 0.5-1.0 mm/min to 0.2-0.25 mm/min within 5-5.5 h;
(4) in the shoulder turning stage, the growth speed of the crystal is kept to be 0.2-0.25 mm/min, and the shoulder turning effect is achieved through linear temperature rise;
(5) in the equal diameter stage, when the diameter of the crystal is equal to the target diameter, an equal diameter growth program is started;
(6) in the ending stage, when the single crystal grows to the target length in an equal diameter mode, ending procedures are started, the diameter of the single crystal is gradually reduced, finally, the conical shape is separated from the germanium melt, and annealing is started;
(7) and a cooling stage, after annealing is completed, cooling, and taking out the germanium single crystal to complete crystal growth.
2. The process for preparing the P-type low dislocation germanium single crystal according to claim 1, wherein in step (1), before the germanium ingot is melted, the germanium ingot is subjected to acidic etching pretreatment by using hydrogen fluoride and hydrogen peroxide.
3. The preparation process of the P-type low-dislocation germanium single crystal as claimed in claim 1, wherein in the step (1), before the seed crystal is inserted into the surface of the melt for fusion welding, the temperature in the furnace is kept at 920-940 ℃, the seed crystal is 50-70 mm above the melt before contacting with the germanium melt, and the constant temperature is kept for not less than 20 min.
4. The process for preparing the P-type low dislocation germanium single crystal according to claim 1, wherein in the shouldering stage in the step (3), the included angle between the shouldering angle and the horizontal direction is 50-70 degrees.
5. The preparation process of the P-type low-dislocation germanium single crystal according to claim 1, wherein in the shoulder rotating stage in the step (4), the temperature rise rate is controlled to be 1-1.5 ℃/h, and when a shoulder rotating program is started, the crucible rise rate is set to be 0.015-0.02 mm/min.
6. The process for preparing the P-type low-dislocation germanium single crystal according to claim 1, wherein in the step (6) of final annealing, the crystal growth speed is kept unchanged in the separation process of the germanium single crystal and the melt, and the temperature rise rate is controlled to be 1-1.5 ℃/min.
7. The process for preparing the P-type low dislocation germanium single crystal according to claim 1 or 6, wherein the step (6) is a final annealing stage, and the annealing process is specifically as follows: and within 8-10 h, increasing the pulling speed of the crystal to 0.3-0.5 mm/min.
8. The process for preparing the P-type low dislocation germanium single crystal according to claim 1, wherein in the cooling stage of the step (7), the temperature is reduced at a linear speed of 0.2-0.3 ℃/min.
9. The process for preparing a P-type low dislocation germanium single crystal according to claim 1, wherein the target diameter of the single crystal is 100 to 150mm and the target length of the single crystal is 750 to 1000 mm.
10. The process for preparing the P-type low-dislocation germanium single crystal according to any one of claims 1 to 9, wherein the steps (1) to (7) are carried out while maintaining a low-pressure protective gas atmosphere; preferably, the low pressure is 2800 to 3200 Pa; preferably the protective gas is nitrogen or an inert gas.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US20090293804A1 (en) * | 2008-06-03 | 2009-12-03 | Hiroaki Taguchi | Method of shoulder formation in growing silicon single crystals |
| CN103938270A (en) * | 2014-04-09 | 2014-07-23 | 云南北方驰宏光电有限公司 | Growth method of gallium heavily doped low-dislocation germanium single crystal |
| CN109112625A (en) * | 2018-09-28 | 2019-01-01 | 宁晋晶兴电子材料有限公司 | A kind of monocrystalline silicon speed change shouldering technique |
| CN111101195A (en) * | 2018-10-29 | 2020-05-05 | 上海新昇半导体科技有限公司 | Crystal growth method of monocrystalline silicon crystal bar |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090293804A1 (en) * | 2008-06-03 | 2009-12-03 | Hiroaki Taguchi | Method of shoulder formation in growing silicon single crystals |
| CN103938270A (en) * | 2014-04-09 | 2014-07-23 | 云南北方驰宏光电有限公司 | Growth method of gallium heavily doped low-dislocation germanium single crystal |
| CN109112625A (en) * | 2018-09-28 | 2019-01-01 | 宁晋晶兴电子材料有限公司 | A kind of monocrystalline silicon speed change shouldering technique |
| CN111101195A (en) * | 2018-10-29 | 2020-05-05 | 上海新昇半导体科技有限公司 | Crystal growth method of monocrystalline silicon crystal bar |
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