A method of growing a semiconductor crystal

Abstract

The application discloses a semiconductor crystal growth method, wherein before semiconductor crystal growth, a seed crystal is subjected to defect detection to obtain defect data of a first surface, a defect dense area in the first surface is determined based on the defect data, after a structure member is grown in diameter to cover the defect dense area, semiconductor crystal growth is performed based on the first surface with the structure member grown in diameter, so that the influence of defects in the defect dense area on the quality of prepared semiconductor crystals can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor crystal growth process, and more particularly to a semiconductor crystal growth method. BACKGROUND

[0002] Single crystals can be grown in principle from the solid, liquid (melt or solution) or gas state. In practice, most artificial crystals are obtained from a melt or a solution that is supercooled or supersaturated to a certain extent. Crystal growth is the process of growing a single crystal from a liquid or gas state by using certain methods and techniques. Crystallization from a liquid state can be divided into two categories: melt growth and solution growth.

[0003] The growth method of semiconductor crystals mainly adopts melt growth method. The melt growth method mainly includes Czochralski method (also known as Cz method), Bridgman method, zone melting method, and flame fusion method (also known as Verneuil method).

[0004] When a semiconductor crystal is prepared based on the melt growth method, the growth of the semiconductor crystal is usually based on a seed crystal. However, the growth of the semiconductor crystal will inherit some defects on the surface of the seed crystal, thereby affecting the quality of the prepared semiconductor crystal. SUMMARY

[0005] Therefore, the present application provides a semiconductor crystal growth method, and the scheme is as follows:

[0006] A semiconductor crystal growth method comprises the following steps:

[0007] providing a seed crystal, wherein the seed crystal has a first surface, and the first surface is used for growing the semiconductor crystal;

[0008] obtaining defect data in the first surface;

[0009] determining a defect dense area in the first surface based on the defect data, wherein the distribution density of at least one defect in the defect dense area per unit area is greater than a corresponding set threshold value;

[0010] fixing a diameter expansion growth structure on the surface of the defect dense area;

[0011] growing the semiconductor crystal based on the first surface with the diameter expansion growth structure.

[0012] Preferably, in the semiconductor crystal growth method, the defects include at least one of screw dislocation, screw edge dislocation, basal plane dislocation and microtube.

[0013] The set threshold value corresponding to the screw dislocation is 300 / cm 2 ~ 10000 / cm 2 .

[0014] the set threshold value corresponding to the screw thread edge dislocation is 10000 / cm 2 ~ 20000 / cm 2 ;

[0015] the set threshold value corresponding to the basal plane dislocation is 2000 / cm 2 ~ 10000 / cm 2 ;

[0016] the set threshold value corresponding to the microtube is 5 / cm 2 ~ 5000 / cm 2 .

[0017] Preferably, in the method for growing a semiconductor crystal, the diameter-expanding growth structure is a circular cone, and the circular bottom surface of the circular cone completely covers the defect-dense region.

[0018] Preferably, in the method for growing a semiconductor crystal, the circular cone is a graphite circular cone.

[0019] Preferably, in the method for growing a semiconductor crystal, the defect-dense region is circular.

[0020] The center of the circular bottom surface and the center of the defect-dense region satisfy a coincidence condition, and the diameter of the circular bottom surface and the diameter of the defect-dense region have a preset difference, and the preset difference is in a range of 0.2 mm to 0.5 mm.

[0021] Preferably, in the method for growing a semiconductor crystal, the taper of the circular cone is not less than 1:1.

[0022] Preferably, in the method for growing a semiconductor crystal, the taper is not less than 1.5:1.

[0023] Preferably, in the method for growing a semiconductor crystal, the seed crystal is a wafer with a diameter of not less than 6 inches.

[0024] Preferably, in the method for growing a semiconductor crystal, the method for fixing the diameter-expanding growth structure on the surface of the defect-dense region comprises:

[0025] fixing the diameter-expanding growth structure on the surface of the defect-dense region by using a glue layer;

[0026] sintering in a sintering furnace to solidify the glue layer.

[0027] Preferably, in the method for growing a semiconductor crystal, the method further comprises:

[0028] The grown semiconductor crystal is cut, and the thickness of the cut-off portion is not less than the height of the diameter-expanding growth structure.

[0029] As can be seen from the above description, in the semiconductor crystal growth method provided by this application, before semiconductor crystal growth, defect detection is performed on the seed crystal to obtain defect data of the first surface. Based on the defect data, a defect-dense region in the first surface is determined. After the defect-dense region is covered by a diameter-expanding growth structure, semiconductor crystal growth is performed based on the first surface with the diameter-expanding growth structure. This can avoid the influence of defects in the defect-dense region on the quality of the prepared semiconductor crystal. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0032] Figure 1 A schematic flowchart of a semiconductor crystal growth method provided in an embodiment of this application;

[0033] Figure 2 This application provides a schematic diagram illustrating the principle of determining a densely defective region on the surface of a seed crystal.

[0034] Figure 3 for Figure 2 A magnified view of a portion of the seed crystal shown;

[0035] Figure 4 A top view of the seed crystal of the inherent diameter expansion growth structure;

[0036] Figure 5 A side view of the seed crystal of an inherent diameter-expanding growth structure;

[0037] Figure 6 A three-dimensional view of a diameter expansion growth structure provided in an embodiment of this application;

[0038] Figure 7FIG. 1 shows a side view of a diameter-expanding growth structure; Figure 6 FIG. 1 shows a side view of a diameter-expanding growth structure;

[0039] Figure 8 FIG. 1 shows a side view of a diameter-expanding growth structure; Figure 6 FIG. 1 shows a side view of a diameter-expanding growth structure;

[0040] Figure 9 FIG. 1 shows a side view of a diameter-expanding growth structure;

[0041] Figure 10 FIG. 1 shows a side view of a diameter-expanding growth structure. DETAILED DESCRIPTION

[0042] The embodiments in the present application will be described below in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0043] As described in the background, during the process of semiconductor crystal growth, defects of the adopted seed surface are inherited, thereby affecting the quality of the prepared semiconductor crystal.

[0044] Taking silicon carbide (SiC) material as an example, SiC belongs to the third generation of semiconductor materials, and has advantages of wide band gap, high thermal conductivity, high critical breakdown field strength, high electron saturation drift rate, etc., so it has great application prospects in the field of semiconductor manufacturing. Defects of SiC single crystal wafer mainly include microtubules, triangular defects, cavities and cracks, small-angle grain boundaries, dislocations and other defects.

[0045] At present, SiC industrial growth mainly adopts physical vapor transport (PVT) process. The growth conditions of PVT process are harsh, and the inheritance of microtubules and dislocations in the growth process leads to defects that cannot be reduced, so that the whole crystal has the same defects as the seed crystal. These defects limit the improvement of SiC device performance and further industrial application and development.

[0046] As can be known from the above description, the microtubule and dislocation defects on the seed crystal are inherited in the SiC crystal growth process, which will have adverse effects on the subsequent SiC device performance, so that the application of SiC devices is limited, and it is difficult to promote the use on a large scale, and the stability of the SiC device is also affected during use, so it is urgent to find a method to reduce the microtubule and dislocation density of the crystal; in addition, defects are prone to occur at the edge of the crystal during crystal diameter expansion growth, resulting in slow expansion speed, long iteration period of large-diameter seed crystal, and it is hoped to find an effective method to improve the expansion efficiency of the seed crystal.

[0047] Therefore, the technical scheme of the embodiments of the present application provides a semiconductor crystal growth method, which comprises:

[0048] providing a seed crystal, the seed crystal having a first surface, the first surface being used for growing the semiconductor crystal;

[0049] obtaining defect data of the first surface;

[0050] determining a defect dense area in the first surface based on the defect data; wherein in the defect dense area, the distribution density of at least one defect in a unit area is greater than a corresponding set threshold value;

[0051] fixing a diameter expansion growth structure on the surface of the defect dense area;

[0052] growing a semiconductor crystal based on the first surface with the diameter expansion growth structure.

[0053] As can be known from the above description, when the semiconductor crystal is prepared based on the growth method provided in the embodiments of the present application, the seed crystal is detected for defects before the semiconductor crystal growth, to obtain the defect data of the first surface, the defect dense area in the first surface is determined based on the defect data, and then the diameter expansion growth structure is used to cover the defect dense area, and then the semiconductor crystal is grown based on the first surface with the diameter expansion growth structure, so that the influence of the defects in the defect dense area on the quality of the prepared semiconductor crystal can be avoided.

[0054] It should be noted that in the embodiments of the present application, SiC is taken as an example to explain the problems in the field of semiconductor crystal growth and the semiconductor crystal growth method provided by the present application for solving the problems, and it is easy to know that the semiconductor crystal in the embodiments of the present application is not limited to SiC crystal, but can also be other semiconductor materials that need to use seed crystal for crystal growth, such as Si crystal, Ge crystal, InSb crystal and GaSb crystal, etc., and the material quality of the semiconductor crystal is not limited in the embodiments of the present application.

[0055] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0056] Reference Figures 1-5 as shown, Figure 1 A flowchart of a semiconductor crystal growth method provided by an embodiment of the present application is shown in FIG. 1. Figure 2 A schematic diagram of a principle of determining a defect dense region on a seed crystal surface provided by an embodiment of the present application is shown in FIG. 2. Figure 3 as shown, Figure 2 A partial enlarged view of the seed crystal shown in FIG. 3, Figure 4 A top view of the seed crystal of the inherent diameter-expanding growth structure, Figure 5 A side view of the seed crystal of the inherent diameter-expanding growth structure, the semiconductor crystal growth method comprising:

[0057] Step S11: providing a seed crystal 11, the seed crystal 11 having a first surface 12, the first surface 12 being used for growing a semiconductor crystal.

[0058] Step S12: obtaining defect data in the first surface 12. The defect data is the distribution density of surface defects or defects in the crystal.

[0059] Step S13: determining a defect dense region 13 in the first surface 12 based on the defect data.

[0060] In the defect dense region 13, the distribution density of at least one defect 14 per unit area is greater than a corresponding set threshold value.

[0061] Step S14: fixing a diameter-expanding growth structure 15 on the surface of the defect dense region 13.

[0062] Step S15: growing a semiconductor crystal based on the first surface 12 with the diameter-expanding growth structure 15.

[0063] The seed crystal with the diameter-expanding growth structure 15 fixed on the surface is loaded into a crucible with raw materials, and then is placed into a single crystal furnace. The semiconductor crystal is grown by using the same process as normal seed crystal growth. First, vacuum washing is performed, then preheating and N2 and Ar gas are introduced, a set low pressure state is maintained, and then crystal growth is performed by pulling. The semiconductor crystal grown based on the peripheral seed crystal of the diameter-expanding growth structure 15 is healed along the surface of the diameter-expanding growth structure 15 towards the top thereof in a diameter-expanding manner, and finally forms a complete semiconductor crystal.

[0064] In the semiconductor crystal growth method provided in the embodiments of the present application, before the semiconductor crystal growth, the defects 14 of the defect dense region 13 are shielded by the fixed diameter expansion growth structure 15, and in the crystal growth process, the crystal grows towards the diameter expansion growth structure 15 in a way that the crystal expands around the seed crystal 11 of the diameter expansion growth structure 15, and the top of the diameter expansion growth structure 15 is healed into a whole semiconductor crystal, which can effectively reduce the defect density of the semiconductor crystal and improve the quality of the semiconductor crystal.

[0065] Optionally, the defects 14 include at least one of a threading screw dislocation (TSD), a threading edge dislocation (TED), a basal plane dislocation (BPD) and a micropipe. The embodiments of the present application can effectively reduce the density of the micropipe and the dislocation in the semiconductor crystal. The dislocation can be at least one of the threading screw dislocation, the threading edge dislocation and the basal plane dislocation. When the defects 14 include the dislocation and the micropipe, the defect dense region 13 is a high-density micropipe and dislocation aggregation region, and the semiconductor crystal growth method provided in the embodiments of the present application can effectively reduce the dislocation and the micropipe in the prepared semiconductor crystal.

[0066] When the defects 14 include the threading screw dislocation, the set threshold value corresponding to the threading screw dislocation is 300 / cm 2 ~10000 / cm 2 When the defects 14 include the threading edge dislocation, the set threshold value corresponding to the threading edge dislocation is 10000 / cm 2 ~20000 / cm 2 When the defects 14 include the basal plane dislocation, the set threshold value corresponding to the basal plane dislocation is 2000 / cm 2 ~10000 / cm 2 When the defects 14 include the micropipe, the set threshold value corresponding to the micropipe is 5 / cm 2 ~5000 / cm 2 .

[0067] The set threshold value corresponding to the threading screw dislocation is set to 300 / cm 2 ~10000 / cm 2 , which can effectively reduce the distribution density of the threading screw dislocation in the prepared semiconductor crystal. The set threshold value corresponding to the threading edge dislocation is set to 10000 / cm 2 ~20000 / cm 2 , which can effectively reduce the distribution density of the threading edge dislocation in the prepared semiconductor crystal. The set threshold value corresponding to the basal plane dislocation is set to 2000 / cm 2 ~10000 / cm 2The distribution density of basal plane dislocations in the preparation of semiconductor crystals can be effectively reduced. The setting threshold corresponding to the microtubule is 5 / cm 2 ~ 5000 / cm 2 The distribution density of microtubules in the preparation of semiconductor crystals can be effectively reduced.

[0068] It should be noted that in the technical scheme of the embodiment of the application, the defects 14 are not limited to thread dislocations (TSD), thread edge dislocations (TED), basal plane dislocations (BPD) and microtubules, but can also include other types of defects, such as point defects, scratches and triangular defects. The setting threshold corresponding to different types of defects can be set according to the performance requirements of the semiconductor device to be prepared from the semiconductor crystal.

[0069] It should be noted that the setting threshold corresponding to different types of defects can be set according to the requirements, and is not limited to the numerical range provided in the embodiment of the application.

[0070] As shown in the reference Figures 6-8 , a three-dimensional view of the diameter expansion growth structure provided in the embodiment of the application is shown, Figure 6 , a side view of the diameter expansion growth structure shown in Figure 7 , a bottom view of the diameter expansion growth structure shown in Figure 6 , a side view of the diameter expansion growth structure shown in Figure 8 , a bottom view of the diameter expansion growth structure shown in Figure 6 The diameter expansion growth structure 15 shown in the bottom view is a circular cone, and the circular bottom of the circular cone completely covers the defect dense area.

[0071] When the semiconductor crystal is prepared based on the seed crystal 11 on which the diameter expansion growth structure 15 is fixed, during the growth of the semiconductor crystal, the semiconductor crystal grown from the defect-free or low-defect-density seed crystal at the periphery of the circular cone converges and grows towards the top end of the circular cone in a diameter expansion growth manner, and finally heals at the top of the circular cone, thereby forming a complete semiconductor crystal.

[0072] Optionally, the circular cone is a graphite circular cone. A graphite block with a purity greater than 99.99% can be selected to process a circular cone as the diameter expansion growth structure 15. Further, the purity of the graphite block is greater than 99.995%. The diameter expansion growth structure 15 is prepared from high-purity graphite, which can well adapt to SiC crystals during the preparation of SiC crystals, and high-quality SiC crystals can be prepared. The surface of the circular cone is polished to make it smooth and flat.

[0073] In combination with Figures 4-7As shown, the defect dense area 13 is circular; the center of the circular bottom surface of the conical body coincides with the center of the defect dense area 13, and the diameter of the circular bottom surface has a preset difference with the diameter of the defect dense area 13, and the preset difference is in the range of 0.2mm-0.5mm. Specifically, the defect dense area is a circle with a diameter of D1, and the diameter of the bottom circular surface of the graphite conical body is D2, and the value of D2-D1 is in the range of 0.2mm-0.5mm. In this way, the bottom circular surface of the graphite conical body can completely shield the defect dense area 13, so as to avoid the influence of the defects in the defect dense area 13 on the quality of the prepared semiconductor crystal.

[0074] It should be noted that in the embodiments of the present application, the shape of the defect dense area 13 is not limited to a circle, but can also be other planar shapes, such as a regular polygon structure, and the planar structure of the defect dense area 13 is not limited in the embodiments of the present application.

[0075] For the diameter expansion growth structure 15, the taper of the conical body is not less than 1:1, so as to facilitate the diameter expansion growth, and the semiconductor crystal grown from the seed crystal 11 around the conical body gradually grows towards the center of the conical body, and finally heals into a complete high-quality semiconductor crystal shielding the original high-defect area. Preferably, the taper is not less than 1.5:1.

[0076] In the embodiments of the present application, the seed crystal 11 is a wafer with a diameter of not less than 6 inches. Preferably, the seed crystal 11 is an 8-inch wafer.

[0077] In the semiconductor crystal growth method provided in the embodiments of the present application, the method for fixing the diameter expansion growth structure 15 on the surface of the defect dense area 13 can be as shown in Figure 9 .

[0078] Referring to Figure 9 , Figure 9 a method flow chart for fixing the diameter expansion growth structure on the surface of the defect dense area provided in the embodiments of the present application, the method comprises:

[0079] Step S21: fixing the diameter expansion growth structure on the surface of the defect dense area by using a glue layer.

[0080] Step S22: sintering in a sintering furnace to solidify the glue layer.

[0081] The glue layer can be epoxy resin or graphite glue, etc. After sintering treatment in the sintering furnace, the glue layer can be solidified to form a carbonized solidified layer, so that the diameter expansion growth structure 15 is fixed on the defect dense area 13 on the surface of the seed crystal 11.

[0082] In the embodiment of the present application, the glue layer is arranged not to exceed the coverage area of the diameter-expanding growth structure 15, that is, the glue layer does not overflow the bottom of the diameter-expanding growth structure 15, so as to avoid that the overflow glue layer affects the growth quality of the semiconductor crystal.

[0083] A sheet jig with a circular hole can be used to assist in coating the glue layer at the bottom of the cone. The circular hole of the sheet jig is arranged concentrically with the center of the circular bottom of the cone, so that the circular hole in the sheet jig defines the glue coating area. A glue layer is coated in the area defined by the circular hole of the sheet jig by a scraper, and the glue layer does not exceed the area of the circular bottom of the cone. After the cone with the glue layer coated at the bottom is placed in the defect-dense area 13, sintering is performed, so as to fix the cone and the defect-dense area 13.

[0084] Reference Figure 10 Figure 10 Another flowchart of a semiconductor crystal growth method provided in the embodiment of the present application is shown, which is based on the above-described embodiment, Figure 10 The semiconductor crystal growth method shown further includes:

[0085] Step S16: cutting the grown semiconductor crystal, and the thickness of the removed part is not less than the height of the diameter-expanding growth structure 15. After cutting, the semiconductor crystal above the diameter-expanding growth structure 15 is reserved.

[0086] It should be noted that in the embodiment of the present application, the semiconductor crystal is a single crystal.

[0087] The semiconductor crystal growth method provided in the embodiment of the present application can be used to prepare high-quality SiC crystals. In view of the problems that it is difficult to obtain a large-diameter SiC seed crystal, the iteration time is long, and it is difficult to reduce the micropipe and dislocation density, the present application provides an SiC single crystal growth method based on a PVT process. The prepared SiC crystal can be used to prepare a high-quality large-diameter SiC seed crystal.

[0088] The scheme of preparing an SiC single crystal by using the semiconductor crystal growth method provided in the embodiment of the present application will be further described in combination with specific process parameters.

[0089] Method one:

[0090] The single crystal furnace for growing the SiC crystal has a crucible, the bottom of the crucible is provided with SiC powder, the seed crystal 11 is fixed on the cover of the crucible, and the heat-insulating graphite felt is arranged above and below the crucible. The seed crystal 11 is a 160mm SiC seed crystal, and the micropipe defect-dense area 13 is determined by a tester scanner. For example, there is one micropipe defect-dense area 13 with a diameter of 8mm. The seed crystal is pre-processed as a normal seed crystal.

[0091] ​A high-purity graphite block is cut into a conical blank with a bottom diameter of 10 mm and a height of 11.3 mm, and then polished with fine sandpaper into a conical body with a bottom diameter of 8.3 mm and a height of 11 mm. The bottom of the graphite conical body is coated with epoxy resin glue and adhered to the SiC seed crystal, and the bottom of the conical body covers the above-mentioned microtube defect dense area 13, so that the microtube defect dense area 13 is completely covered, and then placed into a high-temperature furnace for sintering and solidification.

[0092] Subsequently, based on the SiC seed crystal 11 on which the graphite conical body is fixed on the surface, the SiC crystal is grown by using the PVT process. Specifically, the treated SiC seed crystal is loaded into the crucible loaded with raw materials, and then placed into a single crystal furnace. The same process as normal seed crystal growth is adopted, i.e., vacuum washing of the furnace is performed first, then preheating and N2 and Ar are introduced, a preset low pressure state is maintained, and then the crystal growth is pulled. The semiconductor crystal grows in the direction of the graphite conical body in a way of expanding the diameter based on the seed crystal around the graphite conical body, and finally heals at the top of the graphite conical body to become a complete SiC crystal.

[0093] After the growth is completed, the SiC crystal prepared by avoiding the graphite conical body is cut, the SiC crystal above the graphite conical body is reserved, and the optimized microtube distribution is measured. The SiC crystal prepared based on this method serves as a new 160 mm SiC seed crystal that is optimized, and the microtube density of the whole seed crystal is significantly reduced. A large single crystal with low microtube distribution density can be obtained by one-time growth, which greatly shortens the optimization iteration time of high-quality seed crystal.

[0094] Method two:

[0095] A 175 mm SiC seed crystal 11 is used to determine the microtube defect dense area 13 by testing the microtube distribution together. A microtube defect dense area 13 is determined at a position close to the edge of the seed crystal 11, with a diameter of 4 mm. The seed crystal is pre-treated according to normal seed crystal.

[0096] A high-purity graphite block is cut into a conical blank with a bottom diameter of 10 mm and a height of 11.3 mm, and then polished with fine sandpaper into a conical body with a bottom diameter of 8.3 mm and a height of 11 mm. The bottom of the graphite conical body is coated with epoxy resin glue and adhered to the SiC seed crystal, and the bottom of the conical body covers the above-mentioned microtube defect dense area 13, so that the microtube defect dense area 13 is completely covered, and then placed into a high-temperature furnace for sintering and solidification.

[0097] Subsequently, based on the SiC seed crystal 11 with the graphite cone fixed on the surface, the SiC crystal is grown by using the PVT process. Specifically, the treated SiC seed crystal is loaded into the crucible with raw materials, and then is placed into the single crystal furnace. The same process as the normal seed crystal growth is adopted. First, the furnace is vacuumed and washed. Then, N2 and Ar are introduced after preheating, and a preset low pressure state is maintained. Subsequently, the crystal growth is performed by lifting. The semiconductor crystal grows in the direction of the graphite cone in the way of expanding diameter based on the seed crystal around the graphite cone, and finally heals at the top of the graphite cone to become a complete SiC crystal.

[0098] After the growth is completed, the prepared SiC crystal is cut away from the graphite cone, the SiC crystal above the graphite cone is reserved, and the optimized microtubule distribution is measured. The SiC crystal prepared based on the method is used as a new 175 mm SiC seed crystal after optimization. The microtubule density of the whole seed crystal is significantly reduced, and a large single crystal with low microtubule distribution density can be obtained by one-time growth, which greatly shortens the iteration time of high-quality seed crystal optimization.

[0099] In the description of the present application, each embodiment is described in a progressive, or parallel, or a combination of progressive and parallel manner. Each embodiment focuses on the difference from other embodiments, and the same or similar parts of each embodiment can be referred to each other. The embodiments provided by the embodiments of the present application can be combined with each other without contradiction.

[0100] It should be noted that in the description of the present application, it should be understood that the description of the drawings and the embodiments is illustrative rather than limiting. The same reference numerals in the embodiments throughout the description indicate the same structure. In addition, for the purpose of understanding and ease of description, the thickness of some layers, films, panels, regions, etc. may be exaggerated in the drawings. It can be understood that when an element such as a layer, film, region or substrate is referred to as "on" another element, the element can be directly on the other element or there can be an intermediate element. In addition, "on" means positioning an element on another element or below another element, but essentially does not mean positioning on the upper side of another element according to the direction of gravity.

[0101] The terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there can be a component disposed therebetween.

[0102] It is also noted that the relational terms herein, such as first and second, and the like, are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a vesicle or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such vesicle or apparatus. An element proceeded by "comprises a... " does not, without more constraints, preclude the existence of additional identical elements in the vesicle or apparatus that comprises the recited element.

[0103] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of growing a semiconductor crystal, characterized by, The semiconductor crystal is a silicon carbide crystal, and the growth method comprises: providing a seed crystal, the seed crystal having a first surface for growing the semiconductor crystal; obtaining defect data in the first surface; based on the defect data, determining a defect dense area in the first surface; wherein in the defect dense area, the distribution density of at least one defect in unit area is greater than the corresponding set threshold value; fixing a diameter expansion growth structure on the surface of the defect dense area; based on the first surface with the diameter expansion growth structure, growing the semiconductor crystal; The defects include at least one of screw dislocations, screw edge dislocations, basal plane dislocations and microtubules. The set threshold value corresponding to the screw dislocation is 300 / cm 2 10000 / cm 2 ; The set threshold value corresponding to the threading dislocation is 10000 / cm 2 20000 / cm 2 ; The set threshold value corresponding to the basal plane dislocation is 2000 / cm 2 10000 / cm 2 ; The microtubules correspond to a set threshold of 5 per cm 2 ~5000 per cm 2 ; The diameter expansion growth structure is a cone, and the circular bottom surface of the cone completely covers the defect dense area.

2. The method of growing a semiconductor crystal according to claim 1, wherein The cone is a graphite cone.

3. The method of growing a semiconductor crystal according to claim 1, wherein The defect dense area is circular; The center of the circular bottom surface and the center of the defect dense area satisfy the coincidence condition, the diameter of the circular bottom surface and the diameter of the defect dense area have a preset difference, and the range of the preset difference is 0.2mm~0.5mm.

4. The method of growing a semiconductor crystal according to claim 1, wherein The taper of the cone is not less than 1:

1.

5. The method of growing a semiconductor crystal according to claim 4, wherein The taper is not less than 1.5:

1.

6. The method of growing a semiconductor crystal according to claim 1, wherein The seed crystal is a wafer not less than 6 inches.

7. The method of growing a semiconductor crystal according to claim 1, wherein The method for fixing the diameter expansion growth structure on the surface of the defect dense area comprises: using a glue layer to fix the diameter expansion growth structure on the surface of the defect dense area; sintering in a sintering furnace to solidify the glue layer.

8. The method of growing a semiconductor crystal according to any one of claims 1 to 7, wherein Further comprising: cutting the grown semiconductor crystal, and the thickness of the removed part is not less than the height of the diameter expansion growth structure.

Images