阅读说明：本技术 一种利用全回料生长磷化铟单晶的工艺 (Process for growing indium phosphide single crystal by using full-returned material ) 是由 肖雨 李勇 于 2021-05-12 设计创作，主要内容包括：本发明公开了一种利用全回料生长磷化铟单晶的工艺,涉及晶体生长技术领域。本发明的一种利用全回料生长磷化铟单晶的工艺,所述工艺是将回料进行筛分、加工分段得到圆饼料、锥形料和边角料,然后根据原料种类选择相应的装料的方式进行装料,装料完成后,真空封管,进行长晶。本发明的一种利用全回料生长磷化铟单晶的工艺,在后续单晶生长工艺不变的情况下,使用全回料长晶,和现有的长晶工艺相比,成晶率有一定提升,同时减少了回料库存,大大的降低了生产成本。(The invention discloses a process for growing indium phosphide single crystals by using full-returned materials, and relates to the technical field of crystal growth. The invention relates to a process for growing indium phosphide single crystals by using full-return materials, which comprises the steps of screening the return materials, processing and segmenting to obtain round cake materials, conical materials and leftover materials, then selecting a corresponding charging mode according to the types of raw materials to charge, and after charging is finished, sealing a tube in vacuum to grow crystals. According to the process for growing the indium phosphide single crystal by using the full-recycled material, the full-recycled material is used for crystal growth under the condition that the subsequent single crystal growth process is not changed, compared with the existing crystal growth process, the crystal forming rate is improved to a certain extent, the recycled material inventory is reduced, and the production cost is greatly reduced.)

1. A process for growing indium phosphide single crystals by using full-return materials is characterized in that the process comprises the steps of screening the return materials, processing and segmenting to obtain round cake materials, conical materials and leftover materials, then selecting a corresponding charging mode according to the types of raw materials to charge, and after charging is finished, sealing a tube in vacuum to grow crystals.

2. The process for growing indium phosphide single crystals using the whole feed back material as claimed in claim 1, wherein the round cakes include thin round cakes and thick round cakes.

3. The process for growing indium phosphide single crystal by using full-return material as claimed in claim 2, wherein the screening and processing subsection of the return material is specifically operated as follows: screening the returned materials, selecting full materials, leftover materials and thin round cake materials, cutting a conical section and a straight cylinder section of the full materials, cutting one end, far away from the conical section, of the straight cylinder section by 1-2mm to obtain thick round cake materials, and cutting the conical materials to obtain frustum materials and small ends.

4. A process for growing an indium phosphide single crystal using a full-sized batch as defined in any one of claims 1 to 3, wherein the charging step is specifically operated as:

s1: two blind holes are formed in two symmetrical positions in the middle positions of a thick round cake material and a thin round cake material with the thickness exceeding 30mm, and dopants are filled in the two blind holes;

s2: putting seed crystals into a seed crystal cavity of the crucible and fixing the seed crystals by using a BN rod;

s3: putting the frustum material into a crucible, then putting red phosphorus and boron oxide into the crucible, and then putting thin round cake material or thick round cake material into the crucible;

or placing the small end into a crucible, then adding boron oxide and red phosphorus, then adding leftover materials, and finally adding thick round cake materials.

5. The process for growing indium phosphide single crystals by using the whole feed back material as claimed in claim 4, wherein the mass of the dopant is 0.01% of the mass of the corresponding thick round cake material or thin round cake material.

6. The process for growing indium phosphide single crystal by using the whole feed back material as claimed in claim 5, wherein the cleaning step comprises the working procedures of polishing cleaning, chemical cleaning, ultrasonic cleaning and dehydration before the charging.

7. The process for growing the indium phosphide single crystal by using the full-return material as claimed in claim 6, wherein the cleaning step specifically comprises:

polishing and cleaning: grinding PBN crucible fragments, adhesive tapes and edges and corners on the returned materials by using abrasive paper until the edges and corners are touched by fingers without scratching the hands, and then cleaning the materials by using deionized water;

chemical cleaning: soaking the cleaned returned material in acid solution for 10min, rinsing with deionized water, soaking in alkali mixed solution for 2h, taking out, and repeatedly rinsing with deionized water for 3 times;

ultrasonic cleaning: under the ultrasonic condition with the frequency of 40KHz, the materials after chemical cleaning are subjected to ultrasonic vibration cleaning for 0.5-1 h by using deionized water, then water is injected for overflowing for 1 minute, water is drained from the bottom, then the deionized water is filled again, and the ultrasonic vibration cleaning is repeated for 3 times;

and (3) dehydrating: and after the ultrasonic vibration washing is finished, washing the surfaces, gaps and holes of the returned materials by using deionized water, spraying UP-grade absolute ethyl alcohol for dehydration, and putting the materials into an ultra-clean workbench for air drying.

8. The process for growing the indium phosphide single crystal by using the full-return material as claimed in claim 7, wherein the acid solution is a mixed solution of nitric acid and deionized water, and the volume ratio of the nitric acid to the deionized water is 1: 5.

9. The process for growing the indium phosphide single crystal by using the full-return material as claimed in claim 8, wherein the alkali mixed solution is a mixed solution of ammonia water and hydrogen peroxide, and the volume ratio of the ammonia water to the hydrogen peroxide is 1: 3.

Technical Field

The invention relates to the technical field of crystal growth, in particular to a process for growing indium phosphide single crystals by using full-returned materials.

Background

Indium phosphide (InP) is one of the important group III-V compound semiconductor materials, a new generation of electronic functional materials following silicon, gallium arsenide. With the rapid development of current optical fiber communication and high-speed electronic devices and high-efficiency solar cells, a series of superior characteristics of InP are being developed, and have attracted more and more attention. The mainstream indium phosphide single crystal growth method at present is VGF (vertical gradient solidification) or VB (vertical Bridgman), which has the advantages that low-dislocation crystals can be stably grown, the method is suitable for large-scale production, the defects are obvious, the growth rate is slow, the crystal growth process is difficult to observe, the influence factors caused by external temperature fields, pressure, impurities and the like are large, the phosphorus dissociation pressure is 27.5MPa when the melting point temperature of indium phosphide is 1335 +/-7K, the single crystal forming rate is low under the conditions, generally only about 30 percent, and the rest 70 percent is left unused as single crystal return materials after processing.

In the existing indium phosphide single crystal preparation process, in order to utilize the returned materials, the returned materials and the polycrystalline materials are mixed according to the mass ratio within 1:5, which is equivalent to that each tube can only use 17% of the returned materials, so that the more the returned materials are accumulated, the idle waste of the cost is caused, the polycrystalline materials are too much consumed and not enough used, and the large-scale production is influenced. Therefore, if a full-return indium phosphide single crystal growth process can be designed, the problem of waste is solved, and the production cost can be greatly controlled.

Disclosure of Invention

In view of the above problems, the present invention aims to disclose a process for growing indium phosphide single crystals by using full-recycled materials, wherein the full-recycled materials are used for crystal growth under the condition that the subsequent single crystal growth process is not changed, and compared with the existing crystal growth process, the crystallization rate is improved to a certain extent, and meanwhile, the recycled material inventory is reduced, and the production cost is greatly reduced.

Specifically, the process for growing the indium phosphide single crystal by using the full-return material comprises the steps of screening the return material, processing and segmenting to obtain a cake material, a conical material and a leftover material, then selecting a corresponding charging mode according to the type of the raw material to charge, and after the charging is finished, sealing the tube in vacuum to grow the crystal.

Further, the cake material comprises thin cake material and thick cake material.

Further, the screening and processing subsection of the returned material specifically operates as follows: screening the returned materials, selecting full materials, leftover materials and thin round cake materials, cutting a conical section and a straight cylinder section of the full materials, cutting one end, far away from the conical section, of the straight cylinder section by 1-2mm to obtain thick round cake materials, and cutting the conical materials to obtain frustum materials and small ends.

Further, the charging step is specifically operated as:

s1: two blind holes are formed in two symmetrical positions in the middle positions of a thick round cake material and a thin round cake material with the thickness exceeding 30mm, and dopants are filled in the two blind holes;

s2: putting seed crystals into a seed crystal cavity of the crucible and fixing the seed crystals by using a BN rod;

s3: putting the frustum material into a crucible, then putting red phosphorus and boron oxide into the crucible, and then putting thin round cake material or thick round cake material into the crucible;

or placing the small end into a crucible, then adding boron oxide and red phosphorus, then adding leftover materials, and finally adding thick round cake materials.

Further, the mass of the dopant is 0.01% of the mass of the corresponding thick cake material or thin cake material.

Further, before loading, the cleaning step comprises the working procedures of polishing cleaning, chemical cleaning, ultrasonic cleaning and dehydration.

Further, the cleaning step specifically comprises:

polishing and cleaning: grinding PBN crucible fragments, adhesive tapes and edges and corners on the returned materials by using abrasive paper until the edges and corners are touched by fingers without scratching the hands, and then cleaning the materials by using deionized water;

chemical cleaning: soaking the cleaned returned material in acid solution for 10min, rinsing with deionized water, soaking in alkali mixed solution for 2h, taking out, and repeatedly rinsing with deionized water for 3 times;

ultrasonic cleaning: under the ultrasonic condition with the frequency of 40KHz, the materials after chemical cleaning are subjected to ultrasonic vibration cleaning for 0.5-1 h by using deionized water, then water is injected for overflowing for 1 minute, water is drained from the bottom, then the deionized water is filled again, and the ultrasonic vibration cleaning is repeated for 3 times;

and (3) dehydrating: and after the ultrasonic vibration washing is finished, washing the surfaces, gaps and holes of the returned materials by using deionized water, spraying UP-grade absolute ethyl alcohol for dehydration, and putting the materials into an ultra-clean workbench for air drying.

Further, the acid solution is a mixed solution of nitric acid and deionized water, and the volume ratio of the nitric acid to the deionized water is 1: 5.

Further, the alkali mixed solution is a mixed solution of ammonia water and hydrogen peroxide, and the volume ratio of the ammonia water to the hydrogen peroxide is 1: 3.

The invention has the beneficial effects that:

1. the invention discloses a process for growing indium phosphide single crystals by using full-recycled materials, which uses full-recycled materials to grow crystals under the condition that the subsequent single crystal growth process is not changed.

2. The process for growing the indium phosphide single crystal by using the full-return material can reduce the influence of impurities on the crystal growing process and improve the crystal forming rate by using the full-return material to grow the crystal, and in the crystal growing process, the melting point of the dopant is generally higher than that of indium phosphide, the dopant is generally diffused and doped by depending on the atmosphere, the amount of the dopant can not be well controlled when entering an indium phosphide melt, and the return material already contains part of the dopant, so that the doping amount can be properly reduced by using the full-return material, the electrical performance parameters of the indium phosphide crystal are improved, the quality is improved, and the cost is saved.

Drawings

FIG. 1 is a first schematic diagram of the positions of materials in a crucible after the materials are loaded in the embodiment;

FIG. 2 is a second schematic view of the positions of the materials in the crucible after the materials are loaded in the embodiment;

wherein, leftover materials 1, thin round cake materials 2, thick round cake materials 3, frustum materials 4, small heads 5, blind holes 6, a crucible 7, seed crystals 8, BN rods 9, red phosphorus 10 and boron oxide 11.

Detailed Description

The present invention will be described in detail with reference to specific examples below:

the invention relates to a process for growing indium phosphide single crystals by using full-return materials, which comprises the steps of screening the return materials, processing and segmenting to obtain round cake materials, conical materials and leftover materials, then selecting a corresponding charging mode according to the types of raw materials to charge, and after charging is finished, sealing a tube in vacuum to grow crystals. The method comprises the following specific steps:

examples

Sieving and processing subsection of feed back

Screening the returned materials to select a whole material, an leftover material 1 and a thin cake material 2, wherein the whole material is the returned material of a whole crystal bar without a single crystal, the leftover material 1 is the returned material of the crystal bar with a part growing into a single crystal, the residual returned material is the returned material without a fixed shape after processing, the thin cake material 2 is the returned material of the crystal bar with a part growing into a single crystal, the returned material with a cake shape is left after processing, a conical section and a straight section of the whole material are cut, one end of the straight section, which is far away from the conical section, is cut by 1-2mm to obtain a thick cake material 3, the conical material is cut to obtain a frustum material 4 and a small head 5, the diameter size of the bottom of the small head 5 is 5-10 mm, the thickness is 15-25 mm, the diameter size of the upper part is 25-35 mm, and impurities such as phosphorus or indium are rich and the like can be slowly solidified on the tail part of the crystal bar in the crystal growing process, so that the tail part of the straight section is cut, and the purity of the returned material is improved.

Cleaning of

Polishing and cleaning: PBN crucible piece, adhesive tape, edges and corners on the feed back are polished by abrasive paper, hands are not scratched when the edges and corners are touched by fingers, an oxide layer on the inner surface of the crucible is prevented from being scratched when the material is charged, then the material is washed clean by deionized water, and impurities and residues after polishing are washed away.

Chemical cleaning: soaking the cleaned recycled material in an acid solution prepared by mixing UP-grade nitric acid and deionized water according to the volume ratio of 1:5 for 10min, washing the recycled material with deionized water, soaking the recycled material in an alkali mixed solution prepared by uniformly mixing ammonia water and hydrogen peroxide according to the volume ratio of 1:3 for 2h, taking out the solution, repeatedly washing the solution for 3 times, and removing phosphorus, indium or oxides thereof on the surface of the indium phosphide recycled material through acid washing and alkali washing reactions to further improve the purity of the recycled material.

Ultrasonic cleaning: and (3) carrying out ultrasonic vibration washing on the material after chemical washing for 0.5-1 h by using deionized water under the ultrasonic condition with the frequency of 40KHz, then, flooding for 1min to remove impurities floating on the surface, draining water from the bottom, filling deionized water again, repeating the ultrasonic vibration washing for 3 times, and separating and discharging fine particle impurities on the surface, in gaps and in holes of the returned material.

And (3) dehydrating: and after the ultrasonic vibration washing is finished, washing the surfaces, gaps and holes of the returned materials by using deionized water, spraying UP-grade absolute ethyl alcohol for dehydration, putting the materials into an ultra-clean workbench for air drying, and controlling the moisture of the materials.

Charging

S1: two blind holes 6 are formed in symmetrical positions in the middle positions of the thick round cake 3 and the thin round cake 2 with the thickness exceeding 30mm, dopants are filled in the two blind holes 6, and the mass of the dopants is 0.01% of that of the corresponding thick round cake 3 or thin round cake 2.

S2: a seed crystal 8 is placed in the seed crystal chamber of the crucible 7 and fixed by a BN rod 9.

S4: putting the frustum material 4 into a crucible 7, then putting red phosphorus 10 and boron oxide 11, and then putting a thin round cake material 2 or a thick round cake material 3;

or the small head 5 is placed in the crucible 7, then the boron oxide 11 and the red phosphorus 10 are placed, then the leftover material 1 is placed, and finally the thick round cake material 3 is placed. The mass ratio of the total mass of the returned materials to the mass of the red phosphorus and the boron oxide is according to the conventional crystal growth proportion.

The PBN crucible 7 after charging is loaded into a quartz tube, a quartz cap is placed at the opening of the quartz tube, the quartz tube and the quartz cap are welded together by oxyhydrogen flame, the vacuum degree in the quartz tube is ensured, the welded quartz tube can be placed into a single crystal furnace, and single crystal growth is carried out according to a conventional mode.

The crystal bar prepared in the example is tested, and the crystal bar prepared by the existing method, namely, the returned material and the polycrystalline material are mixed according to the mass ratio of 1:5 to be used as raw materials for crystal growth, and the test results are shown in table 1 as comparison:

TABLE 1

As can be seen from the data in Table 1, the fully-recycled material crystal bar has the advantages of better carrier concentration uniformity, lower EPD (electrophoretic deposition) and certain improvement of the crystallization rate, and the fully-recycled material crystal growth process can not only fully utilize recycled materials, but also obtain crystal bars with better quality to a certain extent.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims. The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.