Epitaxial wafer production equipment, epitaxial wafer production method and device

Abstract

The present invention provides an epitaxial wafer production equipment, an epitaxial wafer production method and a device. The epitaxial wafer production equipment includes a reaction chamber and a gas input pipeline and an exhaust pipeline arranged in the reaction chamber, wherein the exhaust pipeline is used to exhaust the gas in the reaction chamber, and the gas input pipeline includes a main input pipeline and an auxiliary input pipeline, the main input pipeline and the auxiliary input pipeline are independently controlled, the main input pipeline is used to input doping gas and silicon source gas into the reaction chamber, and the auxiliary input pipeline is used to input doping gas into the reaction chamber. The present invention can improve the film forming effect and improve the uniformity of the resistivity of the epitaxial wafer by arranging an auxiliary input pipeline to input auxiliary doping gas during the film forming stage of the epitaxial wafer.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor technology, and in particular to an epitaxial wafer production equipment, an epitaxial wafer production method and a device. Background Art

[0002] Epitaxial wafers are generally obtained by growing an epitaxial film on a silicon wafer by chemical vapor deposition. In the epitaxial growth device, the silicon wafer is exposed to the reaction gas, and a layer of silicon single crystal film is deposited on the surface of the silicon wafer through a chemical vapor reaction. Thermal deformation of the substrate during the epitaxial process will introduce thermal stress. When the internal stress such as thermal stress is greater than the stress critical value of lattice slip in the epitaxial process, slip lines will be generated. The resistivity uniformity of the epitaxial layer is adjusted by controlling the heating power ratio of different areas of the epitaxial process, but temperature changes will affect the generation of slip. To prevent the generation of slip, the heating power ratio will be limited to a certain range, which makes it difficult to optimize the resistivity uniformity. Summary of the invention

[0003] The embodiments of the present invention provide an epitaxial wafer production device, an epitaxial wafer production method and an apparatus to solve the problem that the resistivity uniformity of the existing epitaxial wafer is difficult to optimize.

[0004] To solve the above problems, the present invention is achieved as follows:

[0005] In the first aspect, an embodiment of the present invention provides an epitaxial wafer production device, comprising a reaction chamber and a gas input pipeline and an exhaust pipeline arranged in the reaction chamber, wherein the exhaust pipeline is used to discharge the gas in the reaction chamber, the gas input pipeline comprises a main input pipeline and an auxiliary input pipeline, the main input pipeline and the auxiliary input pipeline are independently controlled, the main input pipeline is used to input doping gas and silicon source gas into the reaction chamber, and the auxiliary input pipeline is used to input doping gas into the reaction chamber.

[0006] In some embodiments, the main input pipeline includes a first main pipeline corresponding to the central area of ​​the reaction chamber and a second main pipeline corresponding to the edge area of ​​the reaction chamber.

[0007] The auxiliary input pipeline includes a first auxiliary pipeline corresponding to the central area of ​​the reaction chamber and / or a second auxiliary pipeline corresponding to the edge area of ​​the reaction chamber;

[0008] Wherein, the edge area surrounds the central area.

[0009] In a second aspect, an embodiment of the present invention further provides an epitaxial wafer production method, which is applied to the epitaxial wafer production equipment described in the first aspect, and the method comprises the following steps:

[0010] moving the single crystal silicon substrate into the reaction chamber;

[0011] In the first stage of the epitaxial process, the doping gas and the silicon source gas are introduced into the reaction chamber through the main input pipeline;

[0012] In the second stage of the epitaxial process, doping gas and silicon source gas are introduced into the reaction chamber through the main input pipeline, and doping gas is introduced into the reaction chamber through the auxiliary input pipeline.

[0013] In some embodiments, in the first stage of the epitaxial process, the method further comprises:

[0014] The heating power of the central area above the reaction chamber is controlled to be 65% to 75% of the total power of the upper heating module, and the heating power of the central area below the reaction chamber is controlled to be 15% to 20% of the total power of the lower heating module;

[0015] The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0016] In some embodiments, in the second stage of the epitaxial process, the method further comprises:

[0017] The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the central area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

[0018] In some embodiments, in the first stage of the epitaxial process, the method further comprises:

[0019] The heating power of the central area above the reaction chamber is controlled to be 80% to 87% of the total power of the upper heating module, and the heating power of the central area below the reaction chamber is controlled to be 18% to 23% of the total power of the lower heating module;

[0020] The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0021] In some embodiments, in the second stage of the epitaxial process, the method further comprises:

[0022] The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the edge area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

[0023] In some embodiments, after placing the single crystal silicon substrate in the reaction chamber, the method further comprises:

[0024] Purging the reaction chamber with hydrogen and heating the reaction chamber to a first temperature, wherein the first temperature is 800 to 900 degrees Celsius;

[0025] Inputting hydrogen into the reaction chamber and heating the reaction chamber to a second temperature, wherein the second temperature is 1100 to 1150 degrees Celsius, and the heating rate of the reaction chamber from the first temperature to the second temperature is 2 to 4 degrees Celsius per second;

[0026] An etching gas is input into the reaction chamber to etch the single crystal silicon substrate, and the temperature in the reaction chamber is controlled to be a third temperature, wherein the third temperature is 1100 to 1150 degrees Celsius and the third temperature is less than or equal to the second temperature.

[0027] In some embodiments, before the first stage of the epitaxial process, the method further comprises:

[0028] Doping gas is introduced into the main input pipeline and the auxiliary input pipeline to drive out other gases in the main input pipeline and the auxiliary input pipeline, wherein the connection ends of the main input pipeline, the auxiliary input pipeline and the reaction chamber are kept closed.

[0029] In a third aspect, an embodiment of the present invention further provides an epitaxial wafer production device, which is applied to the epitaxial wafer production equipment described in the first aspect, and the device includes:

[0030] A moving control module, used for moving the single crystal silicon substrate into the reaction chamber;

[0031] A first control module, used for introducing doping gas and silicon source gas into the reaction chamber through the main input pipeline in the first stage of the epitaxial process;

[0032] The second control module is used for introducing doping gas and silicon source gas into the reaction chamber through the main input pipeline and introducing doping gas into the reaction chamber through the auxiliary input pipeline in the second stage of the epitaxial process.

[0033] The present invention inputs auxiliary doping gas during the film forming stage of the epitaxial wafer by setting an auxiliary input pipeline, and combines the temperature control in the doping process. When the temperature of the central area of ​​the wafer decreases, the doping amount of the central area of ​​the wafer decreases, and the auxiliary doping gas can be input to the central area through the auxiliary input pipeline to increase the doping amount of the central area. When the temperature of the central area increases, the doping amount of the central area increases, and the auxiliary doping gas can be input to the edge area through the auxiliary input pipeline to increase the doping amount of the edge area. In this way, the doping effect in the production process of the epitaxial wafer can be regulated, which helps to control the uniformity of the resistivity of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0035] Figure 1 is a schematic structural diagram of an epitaxial wafer production device provided by an embodiment of the present invention;

[0036] Figure 2 It is another structural schematic diagram of an epitaxial wafer production device provided by an embodiment of the present invention;

[0037] Figure 3 is a flow chart of an epitaxial wafer production method provided by an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of wafer resistivity testing provided by an embodiment of the present invention;

[0039] Figure 5 It is a schematic diagram of wafer resistivity distribution in the first stage provided by the implementation of the present invention;

[0040] Figure 6 It is a schematic diagram of resistivity distribution of the 25th wafer provided in the implementation of the present invention;

[0041] Figure 7 This is a schematic diagram of resistivity distribution of the 50th wafer provided in the implementation of the present invention;

[0042] Figure 8 It is a schematic diagram of resistivity distribution of the 75th wafer provided in the implementation of the present invention;

[0043] Fig. 9 This is a schematic diagram of the resistivity distribution of the 100th wafer provided in the implementation of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The terms "first", "second" etc. in the embodiments of the present invention are used to distinguish similar objects, and need not be used to describe a specific order or sequential order. In addition, the terms "include" and "have" and any variation thereof are intended to cover non-exclusive inclusions, for example, the process, method, system, product or equipment comprising a series of steps or units need not be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or equipment. In addition, "and / or" is used in the present application to represent at least one of the connected objects, such as A and / or B and / or C, which represents 7 situations including single A, single B, single C, and A and B all exist, B and C all exist, A and C all exist, and A, B and C all exist.

[0046] An embodiment of the present invention provides an epitaxial wafer production device.

[0047] In some of the embodiments, the epitaxial wafer production equipment includes a reaction chamber and a gas input pipeline and an exhaust pipeline arranged in the reaction chamber.

[0048] More specifically, Figure 1 In some embodiments, the epitaxial wafer production equipment includes a first quartz bell jar 1 and a second quartz bell jar 2, which can be fixed by a fixing assembly 7, and a first liner 10A, a second liner 10B and an O-ring 11 are provided on the fixing assembly 7, and a sealable reaction chamber is formed between the first quartz bell jar 1 and the second quartz bell jar 2. A heating module 3 is provided above and below the reaction chamber, and illustratively, a halogen lamp or the like can be selected as the heating module.

[0049] like Figure 1 As shown, in this embodiment, an upper heating module is arranged above the outside of the reaction chamber, and the upper heating module includes a first heating module 301 for heating the central area above the reaction chamber and a second heating module 302 for heating the edge area below the reaction chamber; a lower heating module is arranged below the outside of the reaction chamber, and the lower heating module includes a third heating module 303 for heating the central area below the reaction chamber and a fourth heating module 304 for heating the edge area below the reaction chamber. One or more sensors 9 for detecting the temperature inside the reactant can also be arranged on the upper and lower sides outside the reaction chamber, and exemplary, they can be infrared sensors.

[0050] like Figure 2 As shown, a susceptor 8 for supporting a single crystal silicon substrate (wafer) 14 is disposed in the reaction chamber. In some embodiments, the susceptor 8 is supported by a support structure 5. During implementation, the single crystal silicon substrate is disposed on the susceptor 8, and then the single crystal silicon substrate is grown into a desired wafer through epitaxial growth.

[0051] like Figure 1 and Figure 2 As shown, the gas flows from the gas inlet 15 at the gas inlet cover 16 on one side of the process chamber through the surface of the single crystal silicon substrate (wafer) 14 supported on the base 8 for vapor phase growth, and the exhaust pipe 13 is used to exhaust the gas in the reaction chamber.

[0052] Please continue reading Figure 2 In this embodiment, the epitaxial wafer production equipment also includes a gas input pipeline arranged in the reaction chamber, wherein the gas input pipeline includes a main input pipeline 18 and an auxiliary input pipeline 17, and the main input pipeline 18 and the auxiliary input pipeline 17 are independently controlled.

[0053] The main input pipeline 18 is used to input doping gas and silicon source gas into the reaction chamber. In addition, the main input pipeline 18 can also be used to input other gases into the reaction chamber. The auxiliary input pipeline 17 is used to input doping gas into the reaction chamber.

[0054] In some embodiments, the main input pipeline 18 includes a first main pipeline corresponding to the central area of ​​the reaction chamber and a second main pipeline corresponding to the edge area of ​​the reaction chamber.

[0055] The auxiliary input pipeline 17 includes a first auxiliary pipeline corresponding to the central area of ​​the reaction chamber and / or a second auxiliary pipeline corresponding to the edge area of ​​the reaction chamber.

[0056] In this embodiment, the edge region in the reaction chamber refers to the region surrounding the central region.

[0057] An embodiment of the present invention further provides an epitaxial wafer production method, which is applied to the epitaxial wafer production equipment described in the first aspect.

[0058] like Figure 3 As shown, in one embodiment, the method includes the following steps:

[0059] Step 301: Move the single crystal silicon substrate into the reaction chamber.

[0060] In this embodiment, a single crystal silicon substrate is first placed in a reaction chamber of an epitaxial system, specifically, placed on a base, and the base can be made of materials such as SiC.

[0061] In practice, the single crystal silicon substrate generally has <100> Crystal orientation and <110> For the two types of crystal orientations, the single crystal silicon substrate can be manufactured by referring to the relevant technology. For example, in general, the single crystal silicon substrate can be manufactured by the steps of crystal growth (pulling silicon crystal rods from polycrystalline silicon materials), forming (slicing and grinding), polishing (double-sided polishing) and cleaning (removing surface particles, metal ions and organic matter).

[0062] In some embodiments, after moving the single crystal silicon substrate into the reaction chamber, the method further comprises:

[0063] Purging the reaction chamber with hydrogen and heating the reaction chamber to a first temperature, wherein the first temperature is 800 to 900 degrees Celsius;

[0064] Inputting hydrogen into the reaction chamber and heating the reaction chamber to a second temperature, wherein the second temperature is 1100 to 1150 degrees Celsius, and the heating rate of the reaction chamber from the first temperature to the second temperature is 2 to 4 degrees Celsius per second;

[0065] An etching gas is input into the reaction chamber to etch the single crystal silicon substrate, and the temperature in the reaction chamber is controlled to be a third temperature, wherein the third temperature is 1100 to 1150 degrees Celsius and the third temperature is less than or equal to the second temperature.

[0066] In this embodiment, the first temperature can be different values ​​such as 820 degrees Celsius, 830 degrees Celsius, 840 degrees Celsius, 850 degrees Celsius, 860 degrees Celsius, 870 degrees Celsius, 890 degrees Celsius, 900 degrees Celsius, etc. While heating, the reaction chamber is purged with hydrogen to remove nitrogen that enters the reaction chamber during the process of loading the single crystal silicon substrate into the reaction chamber.

[0067] After a certain period of purging, hydrogen is introduced into the reaction chamber and nitrogen is removed. Next, the reaction chamber is closed and the reaction chamber is continuously heated, so that the temperature in the reaction chamber is increased to a second temperature to remove the residue on the surface of the single crystal silicon substrate. During implementation, the power of the upper lamp module center and the lower lamp module center of the heating assembly can be increased to increase the temperature of the reaction chamber.

[0068] In one embodiment, the heating rate is 2 to 4 degrees Celsius per second, and for example, it can be 2.2 degrees Celsius per second, 2.3 degrees Celsius per second, 3.6 degrees Celsius per second, 3.8 degrees Celsius per second, and 3.9 degrees Celsius per second. More specifically, it can be 2.5 to 3.5 degrees Celsius per second, and for example, it can be 2.5 degrees Celsius per second, 2.7 degrees Celsius per second, 2.9 degrees Celsius per second, 3 degrees Celsius per second, and 3.5 degrees Celsius per second.

[0069] The third temperature is 1100 to 1150 degrees Celsius, and illustratively can be 1110 degrees Celsius, 1120 degrees Celsius, 1130 degrees Celsius, 1140 degrees Celsius, and 1150 degrees Celsius, which helps to quickly heat up to efficiently remove residual oxides and organic matter on the surface of the single crystal silicon substrate under high temperature and hydrogen atmosphere.

[0070] Next, the single crystal silicon substrate is etched. For example, hydrogen chloride (HCl) can be selected as the etching gas. In one embodiment, the flow direction of the etching gas is controlled to be 1.5 to 2.5 slm. For example, it can be 1.6 slm, 1.7 slm, 1.8 slm, 1.9 slm, 2 slm, 2.2 slm, 2.3 slm, 2.4 slm, preferably 2 slm. Wherein slm is a flow unit, which means the volume value in cubic centimeters per minute under the conditions of 1 atmosphere and 25 degrees Celsius. The delivery time can be 10s-30s. After the etching gas is input, the reaction chamber is closed. In this process, the chamber temperature can be 1110 degrees Celsius, 1120 degrees Celsius, 1130 degrees Celsius, 1140 degrees Celsius, 1150 degrees Celsius, preferably 1125 degrees Celsius, which helps to remove the attachments and damage layers on the surface of the single crystal silicon substrate, and can also adjust the flatness of the silicon wafer.

[0071] In some embodiments, the method further comprises:

[0072] Doping gas is introduced into the main input pipeline and the auxiliary input pipeline to drive out other gases in the main input pipeline and the auxiliary input pipeline, wherein the connection ends of the main input pipeline, the auxiliary input pipeline and the reaction chamber are kept closed.

[0073] In the hydrogen baking step, the doping gas is introduced through the auxiliary input pipeline. In this step, the doping gas does not enter the chamber, but is only used to purge the residual gas in the auxiliary input pipeline. At the same time, it can ensure that the gas pressure is stable before entering the reaction chamber.

[0074] In the two steps of hydrogen baking and etching gas etching, silicon source gas and doping gas are introduced through the main input pipeline. In this step, the silicon source gas and doping gas do not enter the chamber, but are only used to purge the residual gas in the pipeline. At the same time, the gas pressure can be guaranteed to be stable before entering the reaction chamber.

[0075] It should be understood that the doping gas is generally B2H6 and the silicon source gas is generally SiHCl3.

[0076] Next comes the epitaxial film formation stage.

[0077] Step 302: In the first stage of the epitaxial process, inputting doping gas and silicon source gas into the reaction chamber through the main input pipeline;

[0078] Step 303: In the second stage of the epitaxial process, doping gas and silicon source gas are input into the reaction chamber through the main input pipeline, and doping gas is input into the reaction chamber through the auxiliary input pipeline.

[0079] Different from the prior art, in this embodiment, the epitaxial film forming process includes a first stage and a second stage which are performed sequentially.

[0080] In the first stage, silicon source gas and doping gas are introduced into the reaction chamber through the main input pipeline. In the second stage, doping gas and silicon source gas are input into the reaction chamber through the main input pipeline, and doping gas is input into the reaction chamber through the auxiliary input pipeline, thereby depositing a film on the surface of the silicon wafer.

[0081] The technical solution of this embodiment is to improve the uniformity of the resistivity of the manufactured wafer. Figure 4 As shown in one embodiment, the resistivity values ​​of 9 points on the silicon wafer are tested for calculation. P1 is the central point, P2, P3, P4, and P5 are 4 points at R / 2, and P6, P7, P8, and P9 are 4 points at the edge. 5mm is the width of the edge removal, that is, the outermost point of the silicon wafer is 5mm away from the edge of the silicon wafer. The maximum resistivity value of the 9 points is recorded as R_max, and the minimum is recorded as R_min, then

[0082]

[0083] In the technical solution of this embodiment, in the first stage, the numerical value of the resistivity is not considered, and only the curve distribution needs to be adjusted. In the second stage, the resistivity uniformity can be further adjusted to an ideal range.

[0084] In some embodiments, in the first stage of the epitaxial process, the method further comprises:

[0085] The ratio of the heating power in the central area and the heating power in the edge area of ​​the reaction chamber is controlled to be 65:17 to 75:17, and the gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0086] In the second stage of the epitaxial process, the method further comprises:

[0087] The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the central area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

[0088] The heating power of the central area above the reaction chamber is controlled to be 65% to 75% of the total power of the upper heating module, and the heating power of the central area below the reaction chamber is controlled to be 15% to 20% of the total power of the lower heating module. In this embodiment, it can be recorded as 65-75:15-20.

[0089] It should be understood that, in this embodiment, the total heating power of the upper heating module is certain. In this embodiment, the upper heating module can be understood as heating the central area and edge area of ​​the reaction chamber from above, that is, the total power of the upper heating module is equal to the sum of the heating power of the central area and the heating power of the edge area.

[0090] In this embodiment, the heating power of the central area above the reaction chamber is controlled to be 65% to 75% of the total power of the upper heating module, that is, the heating power of the edge area above the reaction chamber is 35% to 25% of the total power of the upper heating module.

[0091] Furthermore, the heating power of the central area above the reaction chamber can be 66%, 67%, 68%, 69%, 70%, 71%, 72%, 75%, preferably 70% of the total power of the upper heating module, and the heating power of the edge area above the reaction chamber is adjusted accordingly.

[0092] Similarly, the heating power of the central area below the reaction chamber is 15% to 20% of the total power of the lower heating module, that is, the heating power of the edge area below the reaction chamber is 80% to 85% of the total power of the lower heating module.

[0093] Furthermore, the heating power of the central area below the reaction chamber can be 15%, 16%, 17%, 18%, 19%, 20%, preferably 17% of the total power of the lower heating module, and the heating power of the edge area below the reaction chamber is adjusted accordingly.

[0094] That is to say, in this embodiment, the preferred solution is that above the reaction chamber, the heating power of the central area is 70% of the total power of the upper heating module, and below the reaction chamber, the heating power of the central area is 17% of the total power of the lower heating module, which is recorded as 70:17 in this embodiment.

[0095] The gas flow rate of the main input pipeline can be 280 sccm, 285 sccm, 290 sccm, 295 sccm, 300 sccm, preferably 290 sccm.

[0096] In the existing process, the heating power of the central area of ​​the upper heating module is usually 78% of the total power of the upper heating module, and the heating power of the central area of ​​the lower heating module is usually 19% of the total power of the lower heating module. Therefore, in this embodiment, the ratio of the heating power in the central area to the heating power in the edge area in the first stage is relatively low. Therefore, the center temperature will become lower than the edge, resulting in a decrease in the resistivity of the center part, and the closer to the center part, the greater the impact.

[0097] By this principle, the resistivity distribution can be adjusted as follows: Figure 5As shown in the curve, the resistivity of the central area is adjusted to the same level as a whole. Next, in the second stage, doping gas is introduced through the auxiliary input pipeline to start further adjustment. In the current case, the central part has a higher resistivity and less doping. Therefore, the resistivity is adjusted by introducing doping gas through the auxiliary input pipeline in the central area.

[0098] Figure 5 In the figure, the horizontal axis represents the distance from the center of the wafer, the coordinate 0 represents the position of the center axis of the wafer, the positive and negative represent the two sides of the center axis of the wafer, and the vertical axis is the resistivity.

[0099] Next, the gas flow rate of the main input pipeline is reduced, and for example, it can be 220sccm, 230sccm, 240sccm, 250sccm, 260sccm, 270sccm, preferably 230-260sccm. At the same time, the doping gas is introduced into the central area through the auxiliary input pipeline, and its gas flow rate can be 20-50sccm, for example, it can be 20sccm, 30sccm, 40sccm or 50sccm. In this way, the resistivity of the central area can be reduced to the same level as the edge, greatly improving the uniformity of the resistivity.

[0100] In some embodiments, in the first stage of the epitaxial process, the method further comprises:

[0101] The ratio of the heating power in the central area and the heating power in the edge area of ​​the reaction chamber is controlled to be 80:20.5 to 87:20.5, and the gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0102] In some embodiments, in the second stage of the epitaxial process, the method further comprises:

[0103] The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the edge area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

[0104] In this embodiment, the resistivity of the central area is first adjusted to be lower than that of the edge.

[0105] During implementation, first adjust the heating power to 80-87:18-23.

[0106] Further, the heating power of the central area above the reaction chamber can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, preferably 84%, of the total power of the upper heating module, and the heating power of the edge area above the reaction chamber is adjusted accordingly. The heating power of the central area below the reaction chamber can be 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, etc., of the total power of the lower heating module, preferably 20.5%, and the heating power of the edge area above the reaction chamber is adjusted accordingly.

[0107] That is to say, the heating power is preferably 84:20.5.

[0108] Next, further adjustment is started by introducing doping gas through the auxiliary input pipeline in the second stage. In the case described here, the central part has a lower resistivity and a higher doping. Therefore, the resistivity is adjusted by introducing doping gas through the auxiliary input pipeline in the edge area.

[0109] Next, the gas flow rate of the main input pipeline is reduced, and for example, it can be 220sccm, 230sccm, 240sccm, 250sccm, 260sccm, 270sccm, preferably 230-260sccm. At the same time, the doping gas is introduced into the edge area through the auxiliary input pipeline, and its gas flow rate can be 20-50sccm, for example, it can be 20sccm, 30sccm, 40sccm or 50sccm. In this way, the resistivity of the edge area can be reduced to the same level as the central area, greatly improving the uniformity of the resistivity.

[0110] In some embodiments, the chamber is purged with hydrogen after film deposition to discharge the gas remaining in the reaction chamber. At the same time, this step cools the reaction chamber and the wafer after film formation, and unloads the wafer out of the reaction chamber. In this way, the production of the epitaxial wafer is completed.

[0111]

[0112] Please refer to Table 1 above, and Figures 6 to 9 The above table shows the test results of the resistivity of the wafer obtained by the existing method and the generation method in the embodiment of the present application. Figures 6 to 9 The 25th, 50th, 75th and 100th wafers manufactured by the method of an embodiment of the present invention were selected for resistivity testing. In the figure, the horizontal axis represents the distance from the center of the wafer, the coordinate 0 represents the position of the central axis of the wafer, the positive and negative represent the two sides of the central axis of the wafer, and the vertical axis is the resistivity.

[0113] From the table Figures 6 to 9 It can be seen from the data in that the technical solution of this embodiment can significantly improve the uniformity of the resistivity of the wafer.

[0114] An embodiment of the present invention further provides an epitaxial wafer production device, which is applied to the epitaxial wafer production equipment described in the first aspect.

[0115] In one embodiment, the apparatus comprises:

[0116] A moving control module, used for moving the single crystal silicon substrate into the reaction chamber;

[0117] A first control module, used for inputting doping gas and silicon source gas into the reaction chamber through the main input pipeline in the first stage of the epitaxial process;

[0118] The second control module is used to input doping gas and silicon source gas into the reaction chamber through the main input pipeline and input doping gas into the reaction chamber through the auxiliary input pipeline in the second stage of the epitaxial process.

[0119] In some embodiments, the first control module is used to control the heating power of the central area above the reaction chamber to be 65% to 75% of the total power of the upper heating module, and to control the heating power of the central area below the reaction chamber to be 15% to 20% of the total power of the lower heating module in the first stage of the epitaxial process;

[0120] The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0121] In some embodiments, the second control module is used to control the gas flow rate of the main input pipeline to 220 to 270 sccm and control the auxiliary input pipeline to introduce doping gas into the central area of ​​the reaction chamber with a gas flow rate of 20 to 50 sccm in the second stage of the epitaxial process.

[0122] In some embodiments, the first control module is used to control the heating power of the central area above the reaction chamber to be 80% to 87% of the total power of the upper heating module, and to control the heating power of the central area below the reaction chamber to be 18% to 23% of the total power of the lower heating module in the first stage of the epitaxial process;

[0123] The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

[0124] In some embodiments, the second control module is used to control the gas flow rate of the main input pipeline to 220 to 270 sccm and control the auxiliary input pipeline to introduce doping gas into the edge area of ​​the reaction chamber with a gas flow rate of 20 to 50 sccm in the second stage of the epitaxial process.

[0125] In some embodiments, it also includes:

[0126] a purge control module, configured to purge the reaction chamber with hydrogen and heat the reaction chamber to a first temperature, wherein the first temperature is 800 to 900 degrees Celsius;

[0127] a baking control module, configured to input hydrogen into the reaction chamber and heat the reaction chamber to a second temperature, wherein the second temperature is 1100 to 1150 degrees Celsius, and a heating rate of heating the reaction chamber from the first temperature to the second temperature is 2 to 4 degrees Celsius per second;

[0128] An etching control module is used to input etching gas into the reaction chamber to etch the single crystal silicon substrate, and control the temperature in the reaction chamber to a third temperature, wherein the third temperature is 1100 to 1150 degrees Celsius and the third temperature is less than or equal to the second temperature.

[0129] In some embodiments, a gas input control module is further included, which is used to introduce doping gas into the main input pipeline and the auxiliary input pipeline to drive out other gases in the main input pipeline and the auxiliary input pipeline, wherein the connecting ends of the main input pipeline, the auxiliary input pipeline and the reaction chamber are kept closed.

[0130] The above is a preferred implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for producing an epitaxial wafer, characterized in that: Applicable to epitaxial wafer production equipment, the epitaxial wafer production equipment includes a reaction chamber and a gas input pipeline and an exhaust pipeline arranged in the reaction chamber, wherein the exhaust pipeline is used to exhaust the gas in the reaction chamber, the gas input pipeline includes a main input pipeline and an auxiliary input pipeline, the main input pipeline and the auxiliary input pipeline are independently controlled, the main input pipeline is used to input doping gas and silicon source gas into the reaction chamber, the auxiliary input pipeline is used to input doping gas into the reaction chamber, the main input pipeline includes a first main pipeline corresponding to the central area of ​​the reaction chamber and a second main pipeline corresponding to the edge area of ​​the reaction chamber; the auxiliary input pipeline includes a first auxiliary pipeline corresponding to the central area of ​​the reaction chamber and / or a second auxiliary pipeline corresponding to the edge area of ​​the reaction chamber; wherein the edge area surrounds the central area; The method comprises the following steps: moving the single crystal silicon substrate into the reaction chamber; In the first stage of the epitaxial process, the doping gas and the silicon source gas are introduced into the reaction chamber through the main input pipeline; In the second stage of the epitaxial process, doping gas and silicon source gas are introduced into the reaction chamber through the main input pipeline, and doping gas is introduced into the reaction chamber through the auxiliary input pipeline; In the first stage of the epitaxial process, only the resistivity curve distribution needs to be adjusted, and in the second stage of the epitaxial process, the resistivity uniformity is adjusted to an ideal range.

2. The method according to claim 1, characterized in that In the first stage of the epitaxial process, the method further comprises: The heating power of the central area above the reaction chamber is controlled to be 65% to 75% of the total power of the upper heating module, and the heating power of the central area below the reaction chamber is controlled to be 15% to 20% of the total power of the lower heating module; The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

3. The method according to claim 2, characterized in that In the second stage of the epitaxial process, the method further comprises: The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the central area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

4. The method according to claim 1, characterized in that In the first stage of the epitaxial process, the method further comprises: The heating power of the central area above the reaction chamber is controlled to be 80% to 87% of the total power of the upper heating module, and the heating power of the central area below the reaction chamber is controlled to be 18% to 23% of the total power of the lower heating module; The gas flow rate of the main input pipeline is controlled to be 280 to 300 sccm.

5. The method according to claim 2, characterized in that In the second stage of the epitaxial process, the method further comprises: The gas flow rate of the main input pipeline is controlled to be 220 to 270 sccm, and the auxiliary input pipeline is controlled to introduce doping gas into the edge area of ​​the reaction chamber, and the gas flow rate is 20 to 50 sccm.

6. The method according to claim 1, characterized in that After the single crystal silicon substrate is disposed in the reaction chamber, the method further comprises: Purging the reaction chamber with hydrogen and heating the reaction chamber to a first temperature, wherein the first temperature is 800 to 900 degrees Celsius; Inputting hydrogen into the reaction chamber and heating the reaction chamber to a second temperature, wherein the second temperature is 1100 to 1150 degrees Celsius, and the heating rate of the reaction chamber from the first temperature to the second temperature is 2 to 4 degrees Celsius per second; An etching gas is input into the reaction chamber to etch the single crystal silicon substrate, and the temperature in the reaction chamber is controlled to be a third temperature, wherein the third temperature is 1100 to 1150 degrees Celsius and the third temperature is less than or equal to the second temperature.

7. The method according to claim 6, characterized in that Prior to the first stage of the epitaxial process, the method further comprises: Doping gas is introduced into the main input pipeline and the auxiliary input pipeline to drive out other gases in the main input pipeline and the auxiliary input pipeline, wherein the connection ends of the main input pipeline, the auxiliary input pipeline and the reaction chamber are kept closed.

8. An epitaxial wafer production device, characterized in that: Applicable to epitaxial wafer production equipment, the epitaxial wafer production equipment includes a reaction chamber and a gas input pipeline and an exhaust pipeline arranged in the reaction chamber, wherein the exhaust pipeline is used to exhaust the gas in the reaction chamber, the gas input pipeline includes a main input pipeline and an auxiliary input pipeline, the main input pipeline and the auxiliary input pipeline are independently controlled, the main input pipeline is used to input doping gas and silicon source gas into the reaction chamber, the auxiliary input pipeline is used to input doping gas into the reaction chamber, the main input pipeline includes a first main pipeline corresponding to the central area of ​​the reaction chamber and a second main pipeline corresponding to the edge area of ​​the reaction chamber; the auxiliary input pipeline includes a first auxiliary pipeline corresponding to the central area of ​​the reaction chamber and / or a second auxiliary pipeline corresponding to the edge area of ​​the reaction chamber; wherein the edge area surrounds the central area; The device comprises: A moving control module, used for moving the single crystal silicon substrate into the reaction chamber; A first control module, used for introducing doping gas and silicon source gas into the reaction chamber through the main input pipeline in the first stage of the epitaxial process; a second control module, configured to introduce doping gas and silicon source gas into the reaction chamber through the main input pipeline and introduce doping gas into the reaction chamber through the auxiliary input pipeline in the second stage of the epitaxial process; In the first stage of the epitaxial process, only the resistivity curve distribution needs to be adjusted, and in the second stage of the epitaxial process, the resistivity uniformity is adjusted to an ideal range.

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