There is the crucible of the growing silicon carbide single crystal of many growth chamber
Technical field
The invention belongs to crystal technique field, be specifically related to one and transport technology based on physical vaporThe crucible structure of growing silicon carbide single crystal.
Background technology
Carborundum (SiC) is a kind of compound semiconductor, has the performance of a lot of excellences, its thermal conductivityHeight, reaches 5.0W/cm (higher than any known metal), is therefore suitable for very much high temperature, large meritRate field of electronic devices. In addition, carborundum also has high chemical stability and Radiation hardness, withThe Lattice Matching degree of GaN also higher, be the desirable backing material of manufacturing high brightness GaN light emitting diode.Carborundum is universally acknowledged third generation semi-conducting material.
The synthetically grown technology of carborundum crystals has had the history of more than 100 year so far. It the earliest canTo trace back to 1891, Edward's Gyorgy Gurics Ah and Sen (EdwardGoodrichAcheson)(1856~1931), in the time improving diamond abrasive preparation method, have been used carbon and alumina silicate as formerMaterial, has obtained a large amount of SiC first. This method is still applied to making SiC abrasive material so far. J.A.Le Li (J.A.Lely) has obtained the measured SiC crystal of crystalline with nineteen fifty-five in graphite crucible(U.S. Patent No. 2845364). 1978, the people such as Yu.M. thyrode (Yu.M.Tairo)In the method for strangling jasmine (Lely), improve, use seed crystal auxiliary to obtain bulk SiC mono-Brilliant (" crystal growth magazine " (J.CrystalGrowth) 52,209~212,1978; " crystalline substanceBulk-growth magazine " (J.CrystalGrowth) 52,146~150,1981). Thyrode (Tairo)This method using Deng people is called as improved Le Lifa, and this method is still being widely used so far,At present to transport (PVT) technology be exactly to strangle jasmine based on improved to the physical vapor of growing high-quality SiC crystalMethod.
Use the straight wall crucible of conventional design when grow silicon carbide crystals, to be subject in Medium frequency induction growth furnaceBe limited to crucible design and insulation construction, in common each growth cycle, can only obtain 1 silicon carbide whiskerIngot, and be limited to the growing method of carborundum crystal ingot, the length of each crystal ingot can only reach at most 30~40mm. This intrinsic problem of silicon carbide monocrystal growth has increased growth of silicon carbide cost greatly, makesThe holding at high price of silicon carbide wafer, limited large within the scope of whole market of silicon carbide waferArea spreads out, and has limited greatly the extensive utilization of carborundum crystals. Can say carborundum crystalsGrowth cost is the key factor that determines carborundum prospect.
Summary of the invention
The object of the invention is to overcome the defect of prior art, provide a kind of and transport skill based on physical vaporThe crucible design of art, multiple carborundum crystal ingots of can simultaneously growing.
On the one hand, the invention provides a kind of earthenware that transports technology growth single-crystal silicon carbide based on physical vaporCrucible, wherein, described crucible is many growth chamber structure.
In an embodiment of the invention, described crucible has and independently expects chamber and growth chamberSplit type multi-segment structure. Preferably, in described split type multi-segment structure, between each section, pass through screw threadOr bench port connects.
In an embodiment of the invention, described crucible has 3~5 independently growth chamber. ExcellentSelection of land, the diameter of described growth chamber is 50mm~80mm.
In an embodiment of the invention, the height of described growth chamber exceedes described crucible total height20%, and described material chamber height is not less than 50% of described crucible total height.
In an embodiment of the invention, processing raw material as high-purity, high-compactness of described crucibleGraphite, its total impurities content is less than 100ppm, and density is greater than 1.8g/cm3, the porosity is less than 15%.
In crucible design of the present invention, have multiple independently growth chamber, these growth chamber share phaseSame material chamber, described growth chamber and material chamber are preferably separately independently.
In crucible design of the present invention, crucible material chamber and growth chamber are two-part separate structure, thisBetween two parts (section), connect by screw thread or bench port.
Crucible of the present invention is cylinder, external diameter 150~250mm, total height 200~300mm.
The growth chamber of crucible of the present invention is many growth chamber structure independently, 3~5 of growth chamber quantity,Growth chamber internal diameter 50~80mm, growth chamber height 30~80mm.
In crucible design of the present invention, material chamber internal diameter is that 130~230mm, material chamber height are not less than50% of crucible total height.
In crucible design of the present invention, the height of upper chamber's (growth chamber section) exceedes described crucible height overall20% of degree.
In crucible design of the present invention, raw material for crucible uses the graphite block of high-purity, high-compactnessBody is processed. High-purity refers to that total impurities content is less than 100ppm, and high-compactness refers to that density is greater than1.8g/cm3, the porosity is less than 15%.
Crucible of the present invention is made and is used high precision machine tool to carry out, and the machining accuracy error of crucible is littleIn 0.1mm.
Crucible design of the present invention can be for 2 inches of growth diameters or above carborundum listCrystal. Many growth chamber designs can make growth in same growth cycle obtain multiple crystal, effectively fallThe growth cost of low carborundum crystals, raising growth efficiency.
Brief description of the drawings
The crucible that Fig. 1 uses for conventional PVT technology growth SiC monocrystalline.
Wherein, 1: induction coil; 2: sidewall of crucible; 3: growth raw material; 4: seed crystal support.
Fig. 2 is the schematic diagram of crucible in one embodiment of the present invention.
Wherein, 1: crucible growth chamber section; 2: crucible material chamber; 3: growth chamber 1; 4: growth chamber 2;5: growth chamber 3; 6: growth chamber; 7: seed crystal support.
Detailed description of the invention
The present invention will be described in detail for the embodiment providing hereinafter with reference to the present invention. The present invention canTo embody with multiple different form, not should be understood to be limited to the embodiment that this provides. JustJust contrary, it is in order to make scope of the present invention pass to the technology of this area completely that these embodiment are providedPersonnel.
Embodiment 1
The crucible that Fig. 1 uses for existing conventional PVT technology growth SiC monocrystalline. Wherein crucible material chamberSidewall of crucible thickness equate.
Adopt the crucible design shown in Fig. 2 to carry out the growth of PVT crystal. It is (raw that this crucible is divided into upper chamberLong chamber section) and lower chambers (material chamber). Upper and lower two chambers of crucible (, two sections) external diameter is equal,For 150mm. Described crucible has 3 independently growth chamber, and each growth chamber internal diameter is 53mm, materialChamber internal diameter is 130mm. Crucible top cover and bottom thickness are 5mm, and the seed crystal frame thickness that seed crystal is installed is5mm. Crucible total height is 200mm, and wherein the height of growth chamber section is 50mm, and material chamber height is 150Mm. Two parts are threaded connection.
Load the 6H-SiC powder of 500 microns of particle diameters in the material chamber of crucible shown in Fig. 2. At the bottom of controlling crucible2400 DEG C of observed temperatures of lid, 2280 DEG C of top cover observed temperatures, growth furnace internal pressure 30 are held in the palm (Torr),It is that 53mm, length are 20mm that growth 80 as a child can obtain 3 diameters in 3 growth chamber6H-SiC crystal ingot. Clear and coherent after material chamber surplus stock takes out, without recrystallization phenomenon. After crystal ingot section test5 rocking curve halfwidths are 20 second of arc ± 5 second of arcs, and microchannel density is less than 5/cm2。