TW201625822A - Method for manufacturing mono-like silicon - Google Patents

Abstract

A method for manufacturing mono-like silicon is described, which includes the following steps. Various crucibles are disposed within a furnace body. One monocrystal seed crystal is disposed in each crucible. A silicon material is disposed on the monocrystal seed crystal in each crucible. A crystal growth step is performed to form a mono-like silicon ingot in each crucible using the silicon material and the monocrystal seed crystal.

Description

Method for preparing single crystal

The present invention relates to a method for producing a coffin, and more particularly to a method for preparing a mono-like silicon.

The monocrystalline growth technique is a semi-melting technique. In the single crystal growth technique, a single crystal is first laid in the crucible as a crystal seed of the long crystal, and then the crucible is laid on the single crystal. Next, the coffin in the crucible is heated in a crystal growth furnace to melt the coffins. During the heating of the coffin, the coffin is melted from top to bottom by means of temperature control, and the melting of the coffin is controlled to be higher than the position of the single crystal seed. When the coffin is melted to the position of the single crystal seed crystal, the crystal growth furnace is switched to the crystal growth mode, and at this time, the growth of the twin crystal grows along the single crystal seed crystal to obtain a single crystal crystal crucible. However, since the single crystal germanium grown in such a manner is not obtained by Czochralski crystal growth technology, it is not defect-free, and is generally called a single crystal.

One of the reasons why the single crystal cannot be effectively mass-produced is that the quality of the crystal is difficult to control. The main reason for the poor control of crystal quality is that, limited by the size of the single crystal seed crystal, it is necessary to lay a plurality of single crystal seeds in the crucible to substantially cover the entire bottom surface of the crucible, and the grain boundary between the seed crystal and the seed crystal. Easy to form defects in the process of crystal growth The initial region or the induced region of the twin crystal. As a result, the quality of the grown crystal is deteriorated, or the crystal orientation of the single crystal cannot be maintained. Among them, the induced zone of twin crystals occurs in the case of serious defects, and the growth of twins may grow polycrystals, resulting in the presence of both single crystals and polycrystals in the crystal grains.

Another reason why a single crystal cannot be effectively mass-produced is that since the cost of the single crystal process is high and the cost of the crystal process is high, it is necessary to consider the ratio and quality of the single crystal which can be obtained in the casting process. In addition, the seed crystal thickness required for large-sized wafers is relatively large, which also increases the process cost.

Therefore, an object of the present invention is to provide a method for preparing a single crystal in which a plurality of crucibles are disposed in a furnace body of the same crystal growth furnace, and a single crystal seed crystal is disposed in each crucible, so that It achieves the purpose of amorphous interface in the case of crystal growth, and can reduce defects of crystal crucible.

Another object of the present invention is to provide a method for preparing a single crystal, which can provide a heater between adjacent crucibles, so that the thermal field in each crucible can be effectively controlled during the crystal growth process, and thus Accurate control of the solid-liquid interface of the crystal.

It is still another object of the present invention to provide a method for producing a single crystal which can be provided with a high thermal conductivity element below the bottom central portion of each crucible, or can be additionally disposed below the bottom outer edge region of the crucible. The heat conduction coefficient element, thereby more effectively controlling the thermal field in each crucible, and more accurately controlling the solid-liquid interface of the crystal growth, so that the solid-liquid interface is convex and the outer side is low, so that the outer side of the solid-liquid interface is Is the tensile stress, which in turn reduces the crystal Defects in the interface. In addition, since the solid-liquid interface can be effectively controlled, it is advantageous to reduce the degree of over-melt and avoid partial melting of the single crystal seed, especially the outer edge region.

A further object of the present invention is to provide a method for preparing a single crystal in which each crucible is rectangular, so that the wafer can be more efficiently utilized when the wafer is diced.

In accordance with the above object of the present invention, a method of producing a single crystal-like method comprising the following steps is proposed. Set a few squats in the furnace. A single crystal seed crystal is placed in each crucible. The crucible is placed on the single crystal seed crystal in each crucible. A crystal growth step is performed to form a single crystal crystal enthalpy by using the tantalum in each crucible and the single crystal seed crystal.

According to an embodiment of the present invention, the length and the width of the bottom surface of each of the cymbals are respectively 10 mm to 100 mm longer than the length and the width of the bottom surface of the single crystal seed crystal.

According to another embodiment of the present invention, the bottom surface of each of the crucibles is substantially the same size as the bottom surface of the single crystal seed crystal.

According to still another embodiment of the present invention, the single crystal seed crystals have the same crystal orientation.

According to still another embodiment of the present invention, the above crystal orientation is a [100] crystal orientation.

According to still another embodiment of the present invention, each of the above shapes is rectangular.

According to still another embodiment of the present invention, before the performing the crystal growth step, the method for preparing the single crystal-like method further comprises: setting a plurality of heaters respectively Between adjacent turns, wherein the growth step is performed, the heater is heated by these heaters.

According to still another embodiment of the present invention, before the crystal growth step, the method for preparing the single crystal-like method further comprises disposing a high thermal conductivity coefficient element below a central portion of the bottom of each crucible.

According to still another embodiment of the present invention, before the crystal growth step, the method for preparing the single crystal-like method further comprises: providing a high thermal conductivity coefficient element under the bottom central portion of each crucible, and a bottom outer edge of each crucible A low heat transfer coefficient element is placed below the area.

100‧‧‧ steps

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

200‧‧‧坩埚

202‧‧‧ furnace body

204‧‧‧Reaction room

206‧‧‧ bottom

208‧‧‧ side wall

210‧‧‧Changjing Space

212‧‧‧Single crystal seeds

214‧‧‧ bottom

216‧‧‧ bottom

218‧‧‧矽

220‧‧‧ class single crystal

222‧‧‧ liquid 矽

224‧‧‧ solid-liquid interface

226‧‧‧High thermal conductivity element

228‧‧‧Central area

230‧‧‧Outer area

232‧‧‧Low thermal conductivity component

234‧‧‧heater

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; FIG. 2A is a schematic cross-sectional view showing a device for growing a single crystal according to an embodiment of the present invention; FIG. 2B is a growth class according to an embodiment of the present invention. FIG. 2C is a schematic view showing a growth of a single crystal according to an embodiment of the present invention; FIG. 3 is a schematic view showing another embodiment of the present invention. A schematic cross-sectional view of a device for growing a single crystal; FIG. 4 is a schematic cross-sectional view showing a device for growing a single crystal according to still another embodiment of the present invention; FIG. 5A is a view showing a device for growing a single crystal according to still another embodiment of the present invention. FIG. 5B is a schematic top view showing a device for growing a single crystal according to still another embodiment of the present invention.

In view of the conventional growth type single crystal, since the crystal grain boundary exists between the single crystal seed crystal and the seed crystal, the quality of the grown crystal is deteriorated, and even the crystal lattice cannot maintain the crystal orientation of the single crystal, and the process control is performed. Not easy to wait for questions. Therefore, the present invention proposes a method for preparing a single crystal in which a plurality of crucibles are disposed in the same crystal growth furnace body, and a single crystal seed crystal is disposed in each crucible, thereby achieving a crystal-free interface. The utility model can effectively reduce the defects of the single crystal crystal enthalpy and greatly improve the quality of the crystal enamel. In addition, the preparation method of the present invention can further provide a heater between the adjacent two turns, and/or a high heat conduction coefficient element and a low heat conduction coefficient element respectively in the central region and the outer edge region of the bottom of each crucible. It can effectively control the thermal field in each crucible and improve the control of the solid-liquid interface during the growth process. Therefore, in addition to improving the quality of the crystal, it can reduce the degree of over-melting.

Referring to FIG. 1 , FIG. 2A and FIG. 2B , FIG. 1 is a flow chart showing a method for preparing a single crystal according to an embodiment of the present invention, and FIG. 2A and FIG. 2B are respectively diagrams according to the present invention. A schematic cross-sectional view and a top view of a device for growing a single crystal according to an embodiment. In this implementation In the method, when preparing a single crystal, step 100 may be first performed to provide a plurality of crucibles 200, and the crucibles 200 are all disposed in the reaction chamber 204 in the furnace body 202 of the same crystal growth furnace, as shown in FIG. 2A. . These crucibles 200 can be arranged in the reaction chamber 204 in a manner adjacent to each other. Each crucible 200 includes a bottom portion 206 and a side wall 208, wherein the side wall 208 is disposed on the bottom portion 206 along the edge of the bottom portion 206, and the bottom portion 206 and the side wall 208 define a crystal growth space 210. In some examples, as shown in Figure 2B, each of the crucibles 200 is rectangular in shape. The rectangular crucible design can make the grown single crystal crystal crucible into a rectangular parallelepiped, so that when the wafer is diced, more wafers can be cut out, so that the single crystal crystal germanium can obtain better utilization efficiency, but this The rectangular ridge is only a description of the preferred embodiment, and the 坩埚 shape is not limited to a rectangle.

Next, step 102 can be performed to place a single crystal seed 212 in the crystal growth space 210 of each crucible 200. In each crucible 200, a single crystal seed crystal 212 is placed on the bottom surface 214 of the crucible 200. In some examples, the bottom surface 214 of each crucible 200 is larger than the bottom surface 216 of the single crystal seed crystal 212. For example, the length and width of the bottom surface 214 of each crucible 200 are 10 mm to 100 mm longer than the bottom surface 216 of the single crystal seed crystal 212 located thereon, that is, each of the bottom surfaces 216 of each single crystal seed crystal 212. One side is separated from the adjacent side of the bottom surface 214 of the crucible 200 by about 5 mm to 50 mm. In some particular examples, the bottom surface 214 of each crucible 200 is substantially the same size as the bottom surface 216 of the single crystal seed crystal 212 located thereon. Moreover, in some examples, the single crystal seed crystals 212 placed in the crucibles 200 have different crystal orientations; or, the crystal orientations of the single crystal seed crystals 212 are not completely the same, that is, the crystal orientation of some single crystal seed crystals 212. Same as other single crystal seeds 212 The crystal orientation is different. In some specific examples, all single crystal seed crystals 212 have the same crystal orientation, such as [100] crystal orientation.

After the setting of the single crystal seed crystal 212 is completed, step 104 may be performed to provide a tantalum 218 on the single crystal seed crystal 212 in each crucible 200. These dips 218 can be, for example, a block. Next, a step 106 of crystal growth may be performed to melt the tantalum 218 in each crucible 200 by heating. During the step 106 of the crystal growth, the tantalum 218 is melted from top to bottom by controlling the distribution of the thermal field within the reaction chamber 204 of the furnace body 202. Also, the melting height of the tantalum 218 in each crucible 200 is controlled at the upper surface of the single crystal seed crystal 212 to avoid melting all or part of the single crystal seed crystal 212.

Please refer to FIG. 2A and FIG. 2C simultaneously, wherein FIG. 2C is a schematic view showing a growth of a single crystal according to an embodiment of the present invention. When the tantalum 218 in each crucible 200 has melted to a position at the upper surface of the single crystal seed crystal 212, the operating conditions of the reaction chamber 204 of the furnace body 202 can be switched to the crystal growth mode. At this time, the twin crystal grows along the crystal lattice of the single crystal seed crystal 212 in the crystal growth space 210 of the crucible 200 to obtain a single crystal-like crystal germanium. In the process of the crystal growth, the solid-like single crystal 220 starts to grow upward from the single crystal seed crystal 212, and thus the liquid helium 222 is above the solid crystal such as the single crystal 220, and there is a Solid-liquid interface 224. In the present embodiment, during the growth of the crystal, the solid-liquid interface 224 can be controlled to have a central convexity and a low outer side. With such interface control, the tensile stress can be generated in the central region and the compressive stress is generated on the outer side, so that if there is a lattice defect, such a stress distribution causes these lattice defects to be formed on the outer side of the single crystal-like 220. When the single crystal-like crystal germanium is completed, the portion on the outer side of the single crystal-like crystal crucible is usually cut off, and thus it can be formed in the class The defects on the outer side of the crystal 220 are collectively removed. Therefore, defects of the finished single crystal 220 can be reduced, and the quality of the single crystal 220 can be greatly improved.

Please refer to FIG. 1 and FIG. 3 simultaneously. FIG. 3 is a schematic cross-sectional view showing a device for growing a single crystal according to another embodiment of the present invention. In the present embodiment, a high thermal conductivity coefficient element 226 may be disposed below the central region 228 of the bottom portion 206 of each crucible 200 prior to the step 106 of growing crystals. These high thermal conductivity elements 226 can cause the mash melt above the central region 228 of the bottom 206 of the crucible 200 to condense faster during the growth of the single crystal 220, thereby facilitating the solid interface 224 The center is convex and the outer side is concave. Therefore, such a device design is advantageous for controlling the solid-liquid interface 224, and can effectively reduce lattice defects, thereby improving the quality of the finished single crystal 220.

Please refer to FIG. 1 and FIG. 4 simultaneously. FIG. 4 is a schematic cross-sectional view showing a device for growing a single crystal according to still another embodiment of the present invention. In the present embodiment, a high thermal conductivity coefficient element 226 and an outer edge region 230 of the bottom portion 206 of each crucible 200 may be disposed below the central region 228 of the bottom portion 206 of each crucible 200 prior to the step 108 of growing crystals. A low heat transfer coefficient element 232 is disposed below. In some examples, as shown in FIG. 4, the low thermal conductivity elements 232 of the crucibles can be integrated into a structural layer, and the high thermal conductivity component 226 can be embedded in the structural layer of the low thermal conductivity component 232. During the crystal growth of the single crystal-like 220, these high thermal conductivity elements 226 can cause the bismuth melt above the central region 228 of the bottom 206 of the crucible 200 to condense and grow faster, and these low thermal conductivity elements 232 can be used for 坩埚200. The bottom of the bottom 206 is outside the edge area 230 The condensed growth is slower than the center, whereby it is more advantageous to control the state in which the solid-liquid interface 224 is convex in the center and low in the outside. Therefore, such a device design is more conducive to controlling the solid-liquid interface 224, and can more effectively reduce lattice defects, thereby further contributing to the improvement of the quality of the single crystal-like 220 finished product.

Referring to FIG. 1 , FIG. 5A and FIG. 5B , FIG. 5A and FIG. 5B are respectively a schematic cross-sectional view and a top view of a device for growing a single crystal according to still another embodiment of the present invention. In the present embodiment, heater 234 may be additionally disposed between any two adjacent turns 200 before proceeding with step 108 of the growth. Since the crucibles 200 are arranged adjacent to one another and these heaters 234 are respectively disposed between adjacent turns 200, these heaters 234 are respectively located on the sides of each crucible 200, that is, beside the side walls 208 of each crucible 200. In some examples, as shown in Figure 5A, these heaters 234 are graphite rods. As shown in FIG. 5B, these heaters 234 can be arranged between adjacent turns 200, respectively. Alternatively, these heaters 234 can surround each of the turns 200, respectively. After the heater 234 is set, the heaters 234 can be used to heat the crucible 200 from the side of each crucible 200 during the growth of the single crystal 220, thereby assisting in controlling the solid-liquid interface 224 during the growth process. In order to reduce the lattice defects of the single crystal-like 220, and thereby achieve the effect of improving the quality of the single crystal 220 finished product.

It is obvious from the above embodiments that one of the advantages of the present invention is that a method for preparing a single crystal according to the present invention is to provide a plurality of crucibles in a furnace body of the same crystal growth furnace, and to provide a single crystal seed crystal in each crucible. Therefore, the crystal-free interface can be achieved in the case of crystal growth, and the defects of the crystal crucible can be reduced.

It can be seen from the above embodiments that another advantage of the present invention is that a method for preparing a single crystal according to the present invention can provide a heater between adjacent crucibles, thereby effectively controlling the inside of each crucible during the crystal growth process. The thermal field, in turn, can more accurately control the solid-liquid interface of the crystal growth.

According to the above embodiments, another advantage of the present invention is that a method for preparing a single crystal according to the present invention can provide a high thermal conductivity coefficient element under the central portion of the bottom of each crucible, or can be additionally placed outside the bottom of the crucible. A low heat conduction coefficient element is disposed under the edge region, thereby more effectively controlling the thermal field in each crucible, and more accurately controlling the solid-liquid interface of the crystal growth, so that the solid-liquid interface is convex and the outer side is low, so that The outer side of the solid-liquid interface is tensile stress, which can reduce the defects of the crystal interface. Since the solid-liquid interface can be effectively controlled, it is advantageous to reduce the degree of over-melting and to avoid the single-crystal seed in the local region being melted.

It can be seen from the above embodiments that another advantage of the present invention is that in the preparation method of the single crystal of the present invention, each crucible can be rectangular, so that the wafer can be used more efficiently when the wafer is cut. .

While the present invention has been described above by way of example, it is not intended to be construed as a limitation of the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧ steps

102‧‧‧Steps

104‧‧‧Steps

106‧‧‧Steps

Claims (9)

A method for preparing a single crystal, comprising: setting a plurality of crucibles in a furnace; providing a single crystal seed in each of the plurality of crucibles; and disposing a crucible in the plurality of crucibles Seeding; and performing a crystal growth step to form a single crystal crystal enthalpy with the single crystal seed using each of the plurality of bismuth materials. The method for preparing a single crystal according to the first aspect of the invention, wherein the length and the width of the bottom surface of each of the plurality of crucibles are respectively 10 mm to 100 mm longer than the length of the bottom surface of the single crystal seed crystal. The method for preparing a single crystal according to the first aspect of the invention, wherein the bottom surface of each of the plurality of crucibles is substantially the same size as the bottom surface of the single crystal seed crystal. The method for preparing a single crystal according to claim 1, wherein the plurality of single crystal seeds have the same crystal orientation. A method for producing a single crystal according to the fourth aspect of the patent application, wherein the crystal orientation is a [100] crystal orientation. The method for preparing a single crystal according to claim 1, wherein each of the plurality of crucibles has a rectangular shape. The method for preparing a single crystal according to the first aspect of the patent application, before performing the crystal growth step, further comprising: setting a plurality of heaters respectively located between the adjacent plurality of crucibles, wherein the crystal growth step comprises The plurality of heaters are heated by the plurality of heaters. For the preparation method of the single crystal according to the first aspect of the patent application, before the crystal growth step, a high heat conduction coefficient element is further disposed under the central portion of the bottom of each of the plurality of crucibles. The method for preparing a single crystal according to the first aspect of the patent application, before performing the crystal growth step, further comprising: disposing a high heat conduction coefficient element under the bottom central portion of each of the plurality of crucibles; A low heat conduction coefficient element is disposed below the bottom outer edge region of the plurality of turns.