Method, device and readable storage medium for controlling growth of light emitting diode epitaxial wafer

Abstract

The application discloses a growth control method and device of a light emitting diode epitaxial wafer and a readable storage medium, relates to the technical field of semiconductors, and comprises the following steps: acquiring wavelength information and warping information of the epitaxial wafer output in each furnace cycle; calculating first correlation information of a graphite disc in each furnace cycle; calculating mean wavelength information of the epitaxial wafer output in each furnace cycle; calculating second correlation information of the graphite disc; calculating mean warping information of the epitaxial wafer output in each furnace cycle; calculating warping compensation temperature of the epitaxial wafer output in each furnace cycle according to preset target warping information, the mean warping information, the first correlation information and the second correlation information; calculating a wavelength difference value of the epitaxial wafer in the graphite disc according to the mean wavelength information and preset target wavelength information; calculating temperature adjustment information according to the wavelength difference value, the second correlation information, the warping compensation temperature and a preset adjustment factor; and adjusting preset temperature information of the graphite disc according to the temperature adjustment information. By adopting the application, the wavelength yield of products can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a growth control method, device and readable storage medium of light emitting diode epitaxial wafer. BACKGROUND

[0002] In the MOCVD (Metal-organic Chemical Vapor Deposition) equipment, high-purity graphite disc is usually used as the heat conduction medium of the epitaxial substrate and the heating system.

[0003] The graphite disc is made of high-purity graphite and plated with a SiC coating on the surface, which is used to place the substrate for growing LED (Light Emitting Diode) epitaxial wafer. In the reaction chamber of the MOCVD equipment, since the graphite disc has good stability at high temperature, the temperature of the surface of the graphite disc is usually detected by the RT probe as the reference temperature in the reaction chamber, and the heating system is used to control the temperature of the reaction chamber, so that the temperature of the substrate reaches the synthesis temperature of each chemical film in the epitaxial wafer. For the wavelength of the epitaxial wafer output, the set temperature of the current furnace is usually adjusted by referring to the set temperature and output wavelength of the last furnace of the graphite disc, so that the output wavelength is closer to the target wavelength, and the wavelength yield is improved.

[0004] In addition, due to the initial warping of the sapphire (AL2O3) substrate and the thermal stress warping of the substrate material (temperature gradient exists between the upper and lower interfaces), the situation of partial concave / convex may occur during epitaxial growth, especially when growing the light emitting layer, the uneven heating of the epitaxial wafer will cause the uneven output wavelength of the single epitaxial wafer, which affects the wavelength yield of the epitaxial wafer. At present, the industry usually adjusts the stress between the substrate and the epitaxial layer to adjust the warping of the epitaxial wafer.

[0005] However, the adjustment of the warping will simultaneously affect the wavelength change of the epitaxial wafer, and in the conventional epitaxial wafer wavelength adjustment, the temperature and the warping are adjusted separately, and the influence of the warping on the wavelength of the epitaxial wafer is ignored, so that the warping after adjustment is hit, but the output wavelength of the epitaxial wafer deviates from the target, which affects the wavelength yield. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a growth control method, device and readable storage medium of light emitting diode epitaxial wafer, which can improve the influence of warping on the wavelength of epitaxial wafer, make the output wavelength more close to the target wavelength, and improve the wavelength yield of the product.

[0007] In order to solve the above technical problems, the application provides a growth control method of a light emitting diode epitaxial wafer, comprising: acquiring wavelength information and warping information of the epitaxial wafer output per furnace time; calculating first correlation information of a graphite disc in each furnace time according to the wavelength information and the warping information, wherein the first correlation information is used to represent the relationship between the wavelength information and the warping information of the epitaxial wafer in the graphite disc; calculating mean wavelength information of the epitaxial wafer output per furnace time according to the wavelength information; calculating second correlation information of the graphite disc according to the mean wavelength information of the epitaxial wafer output by different furnace times corresponding to the graphite disc and preset temperature information, wherein the second correlation information is used to represent the relationship between the mean wavelength information and the preset temperature information of the epitaxial wafer in the graphite disc; calculating mean warping information of the epitaxial wafer output per furnace time according to the warping information; calculating warping compensation temperature of the epitaxial wafer output per furnace time according to preset target warping information, the mean warping information, the first correlation information and the second correlation information; calculating a wavelength difference value of the epitaxial wafer in the graphite disc according to the mean wavelength information and preset target wavelength information; calculating temperature adjustment information according to the wavelength difference value, the second correlation information, the warping compensation temperature and a preset adjustment factor; and adjusting preset temperature information of the graphite disc according to the temperature adjustment information.

[0008] As an improvement of the above scheme, the step of calculating the first correlation information of the graphite disc in each furnace time according to the wavelength information and the warping information comprises: calculating the first correlation information of the graphite disc in each furnace time according to the formula ; wherein, is the first correlation information of the graphite disc in a target furnace time, is the wavelength information of one epitaxial wafer in the target furnace time, is the wavelength information of another epitaxial wafer in the target furnace time, is the warping information of one epitaxial wafer in the target furnace time, is the warping information of another epitaxial wafer in the target furnace time.

[0009] As an improvement of the above scheme, the step of calculating the second correlation information of the graphite disc according to the mean wavelength information of the epitaxial wafer output by different furnace times corresponding to the graphite disc and preset temperature information comprises: calculating the second correlation information of the graphite disc according to the formula ; wherein, is the second correlation information of a target graphite disc, is the mean wavelength information of the epitaxial wafer output by a current furnace time corresponding to the target graphite disc, is the mean wavelength information of the epitaxial wafer output by a previous furnace time corresponding to the target graphite disc, is preset temperature information of the current furnace time corresponding to the target graphite disc, is preset temperature information of the previous furnace time corresponding to the target graphite disc.

[0010] As an improvement of the above-mentioned scheme, the step of calculating the warpage compensation temperature of the epitaxial wafer produced in each furnace cycle according to the preset target warpage information, the mean warpage information, the first correlation information and the second correlation information comprises: calculating the warpage compensation temperature of the epitaxial wafer produced in each furnace cycle according to the formula ; wherein, is the warpage compensation temperature of the epitaxial wafer produced in the target furnace cycle, is the mean warpage information of the epitaxial wafer produced in the target furnace cycle, is the preset target warpage information of the epitaxial wafer produced in the target furnace cycle, is the first correlation information of the graphite disc in the target furnace cycle, is the second correlation information of the graphite disc in the target furnace cycle.

[0011] As an improvement of the above-mentioned scheme, the step of calculating the temperature adjustment information according to the wavelength difference value, the second correlation information, the warpage compensation temperature and the preset adjustment factor comprises: calculating the temperature adjustment information according to the formula ; wherein, is the temperature adjustment information, is the wavelength difference value of the epitaxial wafer in the target graphite disc, is the second correlation information of the target graphite disc, is the warpage compensation temperature of the epitaxial wafer in the target graphite disc, is the adjustment factor of the target graphite disc.

[0012] As an improvement of the above-mentioned scheme, when the absolute value of the warpage compensation temperature is less than or equal to a preset first reference temperature, the value range of the adjustment factor is [0.5, 1]; when the absolute value of the warpage compensation temperature is greater than the first reference temperature and less than or equal to a preset second reference temperature, the value range of the adjustment factor is (0, 0.5); when the absolute value of the warpage compensation temperature is greater than the preset second reference temperature, the value of the adjustment factor is 0.

[0013] As an improvement of the above-mentioned scheme, the warpage information is the difference value between the wavelength mean value of the central region of the epitaxial wafer and the wavelength mean value of the edge region of the epitaxial wafer.

[0014] As an improvement of the above-mentioned scheme, the step of calculating the warpage information comprises: dividing the epitaxial wafer into a plurality of point sets, each point set corresponding to an independent reference coordinate and a reference wavelength; calculating the wavelength mean value of the central region of the epitaxial wafer according to the reference wavelengths of the point sets in the central region of the epitaxial wafer; calculating the wavelength mean value of the edge region of the epitaxial wafer according to the reference wavelengths of the point sets in the edge region of the epitaxial wafer; calculating the difference value between the wavelength mean value of the central region of the epitaxial wafer and the wavelength mean value of the edge region of the epitaxial wafer, and taking the difference value as the warpage information of the epitaxial wafer.

[0015] Correspondingly, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the growth control method of the epitaxial wafer of light emitting diode when executing the computer program.

[0016] Correspondingly, the present application further provides a computer readable storage medium, which stores a computer program, wherein the computer program is executed by a processor to implement the steps of the growth control method of the epitaxial wafer of light emitting diode.

[0017] The present application has the following beneficial effects:

[0018] (1) The present application can avoid the influence of warping on the wavelength of the epitaxial wafer, so that the output wavelength tends to the target wavelength, and the wavelength yield of the product is improved.

[0019] (2) The present application can make the heating temperature of the epitaxial wafer more accurate by warping compensation temperature, so as to effectively improve the wavelength hit rate of the next furnace.

[0020] (3) The present application can reduce the influence of the abnormal large or small compensation temperature caused by the serious abnormal warping on the output wavelength by adding an adjustment factor. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is an embodiment flowchart of the growth control method of the epitaxial wafer of light emitting diode of the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings. It is hereby declared that the up, down, left, right, front, back, inner and outer directions appearing or about to appear in the present application are based on the drawings of the present application, and are not specific limitations of the present application.

[0023] Referring to Figure 1 , Figure 1 shows an embodiment flowchart of the growth control method of the epitaxial wafer of light emitting diode of the present application, which comprises:

[0024] S101, obtaining the wavelength information and warping information of the epitaxial wafer output by each furnace;

[0025] After measuring y (y>=1) epitaxial wafers output by each furnace, the wavelength information and warping information of each epitaxial wafer can be obtained respectively.

[0026] It should be noted that the warping information is the difference between the average wavelength of the center region and the average wavelength of the edge region of the epitaxial wafer. Wherein, the greater the warping information, the more convex the epitaxial wafer is; on the contrary, the smaller the warping information, the more concave the epitaxial wafer is. Correspondingly, the calculation steps of the warping information include:

[0027] (1) dividing the epitaxial wafer into a plurality of point sets, each point set corresponding to an independent reference coordinate and a reference wavelength;

[0028] For example, each epitaxial wafer is divided into N point sets, each point set containing a specific reference coordinate and an independent reference wavelength.

[0029] (2) calculating the average wavelength of the center region according to the reference wavelength of each point set in the center region of the epitaxial wafer;

[0030] For example, the center region of the epitaxial wafer includes point set nx1 and point set nx2, wherein the reference wavelength of point set nx1 is WDx1, and the reference wavelength of point set nx2 is WDx2, then the average wavelength of the center region of the epitaxial wafer can be obtained as: WDx=(WDx1+WDx2) / 2.

[0031] (3) calculating the average wavelength of the edge region according to the reference wavelength of each point set in the edge region of the epitaxial wafer;

[0032] For example, the edge region of the epitaxial wafer includes point set ny1 and point set ny2, wherein the reference wavelength of point set ny1 is WDy1, and the reference wavelength of point set ny2 is WDy2, then the average wavelength of the edge region of the epitaxial wafer can be obtained as: WDy=(WDy1+WDy2) / 2.

[0033] (4) calculating the difference between the average wavelength of the center region and the average wavelength of the edge region of the epitaxial wafer, and taking the difference as the warping information of the epitaxial wafer.

[0034] For example, by comparing the average wavelength WDx of the center region and the average wavelength WDy of the edge region of each epitaxial wafer, the warping information of each epitaxial wafer can be obtained as: B=WDx-WDy.

[0035] S102, calculating the first correlation information of the graphite disc in each furnace according to the wavelength information and the warping information;

[0036] It should be noted that the first correlation information is used to represent the relationship between the wavelength information and the warping information of the epitaxial wafer in the graphite disc;

[0037] Specifically, the first correlation information of the graphite disc in each furnace can be calculated according to the following formula:

[0038]

[0039] Wherein:

[0040] the first correlation information of the graphite tray in the target furnace;

[0041] the wavelength information of an epitaxial wafer in the target furnace;

[0042] the wavelength information of another epitaxial wafer in the target furnace;

[0043] the warping information of an epitaxial wafer in the target furnace;

[0044] the warping information of another epitaxial wafer in the target furnace.

[0045] For example, the wavelength information and the warping information of the first epitaxial wafer in the same furnace can be taken respectively and the wavelength information and the warping information of the second epitaxial wafer can be taken respectively and to calculate the first correlation information .

[0046] As can be seen from the above, the first correlation information is the ratio of the change amount of the wavelength information of the epitaxial wafer in the graphite tray to the change amount of the warping information, i.e. the wavelength-warping slope.

[0047] S103, calculating the average wavelength information of the epitaxial wafer produced in each furnace according to the wavelength information;

[0048] For example, after measuring y (y>=1) epitaxial wafers produced in each furnace, the wavelength information of each epitaxial wafer can be obtained respectively; then, the average of the wavelength information of the y epitaxial wafers is calculated, and the average wavelength information of the epitaxial wafer is obtained.

[0049] S104, calculating the second correlation information of the graphite tray according to the average wavelength information of the epitaxial wafer produced in different furnaces corresponding to the graphite tray and the preset temperature information;

[0050] It should be noted that the second correlation information is used to represent the relationship between the average wavelength information of the epitaxial wafer in the graphite tray and the preset temperature information;

[0051] Specifically, the second correlation information of the graphite tray can be calculated according to the following formula:

[0052]

[0053] Wherein:

[0054] the second correlation information of the target graphite tray;

[0055] the average wavelength information of the epitaxial wafer produced in the last furnace corresponding to the target graphite disc;

[0056] the average wavelength information of the epitaxial wafer produced in the last furnace corresponding to the target graphite disc;

[0057] the preset temperature information of the current furnace corresponding to the target graphite disc;

[0058] the preset temperature information of the last furnace corresponding to the target graphite disc.

[0059] As can be seen, the second correlation information is the ratio of the average wavelength information change of the epitaxial wafer in the graphite disc to the preset temperature information change, i.e. the wavelength-temperature slope.

[0060] S105, calculating the average warp information of the epitaxial wafer produced in each furnace according to the warp information;

[0061] For example, after measuring y (y>=1) epitaxial wafers produced in each furnace, the warp information of each epitaxial wafer can be obtained respectively; then, the average warp information of the y epitaxial wafers is calculated, i.e. the average warp information of the epitaxial wafer is obtained.

[0062] S106, calculating the warp compensation temperature of the epitaxial wafer produced in each furnace according to the preset target warp information, the average warp information, the first correlation information and the second correlation information;

[0063] Specifically, the warp compensation temperature of the epitaxial wafer produced in each furnace can be calculated according to the following formula:

[0064]

[0065] Wherein:

[0066] the warp compensation temperature of the epitaxial wafer produced in the target furnace, the warp compensation temperature may be negative;

[0067] the average warp information of the epitaxial wafer produced in the target furnace;

[0068] the preset target warp information of the epitaxial wafer produced in the target furnace;

[0069] the first correlation information of the graphite disc in the target furnace;

[0070] the second correlation information of the graphite disc in the target furnace.

[0071] That is, the average warping information of the epitaxial wafer produced according to the same graphite disc , target warping information , first correlation information and second correlation information , the warping compensation temperature of the graphite disc is obtained .

[0072] Different from the prior art, the first correlation information and the second correlation information are introduced at the same time, the warping of the epitaxial wafer is compensated according to the influence of the warping on the wavelength while considering the influence of temperature on the wavelength, the influence of the warping of the epitaxial wafer on the wavelength can be effectively avoided, the output wavelength of the next furnace cycle tends to be the target wavelength, and the wavelength yield is improved.

[0073] S107, calculating the wavelength difference value of the epitaxial wafer in the graphite disc according to the average wavelength information and the preset target wavelength information;

[0074] For example, the wavelength difference value DX of the epitaxial wafer in each graphite disc can be obtained by comparing the average wavelength information of the epitaxial wafer with the target wavelength information, and DX>=0.

[0075] S108, calculating the temperature adjustment information according to the wavelength difference value, the second correlation information, the warping compensation temperature and the preset adjustment factor;

[0076] Specifically, the temperature adjustment information can be calculated according to the following formula:

[0077]

[0078] Wherein:

[0079] is the temperature adjustment information;

[0080] is the wavelength difference value of the epitaxial wafer in the target graphite disc;

[0081] is the second correlation information of the target graphite disc;

[0082] is the warping compensation temperature of the epitaxial wafer in the target graphite disc;

[0083] is the adjustment factor of the target graphite disc, and .

[0084] It should be noted that by adding the adjustment factor, the influence of the abnormally large or small compensation temperature caused by the serious abnormal warping on the output wavelength can be reduced. Further, when calculating the temperature adjustment information of different graphite discs, the following condition is met:

[0085] (1) when , , and ∈[0.5, 1];

[0086] That is, when the absolute value of the warpage compensation temperature is less than or equal to a preset first reference temperature, the value range of the adjustment factor is [0.5, 1]; in the embodiment, the first reference temperature is 1℃.

[0087] (2) when , , and ∈(0, 0.5);

[0088] That is, when the absolute value of the warpage compensation temperature is greater than the first reference temperature and less than or equal to a preset second reference temperature, the value range of the adjustment factor is (0, 0.5); in the embodiment, the first reference temperature is 1℃ and the second reference temperature is 3℃.

[0089] (3) when , , and K=0.

[0090] That is, when the absolute value of the warpage compensation temperature is greater than the preset second reference temperature, the value of the adjustment factor is 0; in the embodiment, the second reference temperature is 3℃.

[0091] S109, adjusting preset temperature information of the graphite disc according to the temperature adjustment information.

[0092] Therefore, the growth control method of the light emitting diode epitaxial wafer can adjust the temperature of the next furnace according to the output wavelength, and calculate the warpage compensation temperature according to the output warpage adjustment range, and the implementation of the present application has the following beneficial effects:

[0093] (1) The influence of warpage on the wavelength of the epitaxial wafer can be avoided, so that the output wavelength tends to be closer to the target wavelength, and the wavelength yield of the product is improved;

[0094] (2) The heating temperature of the epitaxial wafer is more accurate through the warpage compensation temperature, and the wavelength hit rate of the next furnace is effectively improved;

[0095] (3) By adding the adjustment factor, the influence of the abnormally large or small compensation temperature caused by the serious abnormal warpage on the output wavelength can be reduced.

[0096] Correspondingly, the present application also discloses a computer device comprising a memory and a processor, the memory stores a computer program, wherein the processor implements the steps of the growth control method of the light emitting diode epitaxial wafer when executing the computer program.

[0097] In addition, the application further discloses a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the steps of the growth control method of the LED epitaxial wafer.

[0098] The above is the preferred embodiment of the application, and it should be pointed out that, for those skilled in the art, without departing from the principles of the application, a number of improvements and refinements can be made, and these improvements and refinements are also considered to be within the protection scope of the application.

Claims

1. A method for controlling the growth of a light-emitting diode epitaxial wafer, characterized in that, The method comprises the following steps: acquiring wavelength information and warping information of epitaxial wafers produced in each batch, the warping information being a difference between a wavelength mean value of a central region of the epitaxial wafer and a wavelength mean value of an edge region of the epitaxial wafer; According to the wavelength information and the warping information, first correlation information of the graphite disc in each furnace cycle is calculated, and the first correlation information is used to represent the relationship between the wavelength information and the warping information of the epitaxial wafer in the graphite disc. Specifically, the first correlation information of the graphite disc in each furnace cycle is calculated according to the formula , wherein, is the first correlation information of the graphite disc in the target furnace cycle, is the wavelength information of one epitaxial wafer in the target furnace cycle, is the wavelength information of another epitaxial wafer in the target furnace cycle, is the warping information of one epitaxial wafer in the target furnace cycle, is the warping information of another epitaxial wafer in the target furnace cycle. calculating mean wavelength information of the epitaxial wafers produced in each batch according to the wavelength information; The second correlation information of the graphite disc is calculated according to the mean wavelength information of the epitaxial wafer corresponding to different furnace outputs of the graphite disc and preset temperature information, and the second correlation information is used to represent the relationship between the mean wavelength information of the epitaxial wafer in the graphite disc and the preset temperature information. Specifically, the second correlation information of the graphite disc is calculated according to the formula , wherein, is the second correlation information of the target graphite disc, is the mean wavelength information of the epitaxial wafer corresponding to the current furnace output of the target graphite disc, is the mean wavelength information of the epitaxial wafer corresponding to the last furnace output of the target graphite disc, is the preset temperature information of the current furnace corresponding to the target graphite disc, is the preset temperature information of the last furnace corresponding to the target graphite disc. calculating mean warping information of the epitaxial wafers produced in each batch according to the warping information; According to the preset target warping information, the mean warping information, the first correlation information and the second correlation information, a warping compensation temperature of the epitaxial wafer produced in each furnace cycle is calculated; specifically, the warping compensation temperature of the epitaxial wafer produced in each furnace cycle is calculated according to the formula , wherein, is the warping compensation temperature of the epitaxial wafer produced in the target furnace cycle, is the mean warping information of the epitaxial wafer produced in the target furnace cycle, is the preset target warping information of the epitaxial wafer produced in the target furnace cycle. calculating a wavelength difference of the epitaxial wafers in the graphite disc according to the mean wavelength information and preset target wavelength information; calculating temperature adjustment information according to the wavelength difference, second correlation information, warping compensation temperature and a preset adjustment factor; adjusting preset temperature information of the graphite disc according to the temperature adjustment information.

2. The growth control method of a light emitting diode epitaxial wafer according to claim 1, wherein The step of calculating the temperature adjustment information according to the wavelength difference, second correlation information, warping compensation temperature and a preset adjustment factor comprises: The temperature adjustment information is calculated according to the formula ; wherein, is temperature adjustment information, is a wavelength difference value of the epitaxial wafer in the target graphite disc, is second correlation information of the target graphite disc, is a warpage compensation temperature of the epitaxial wafer in the target graphite disc, is an adjustment factor of the target graphite disc.

3. The growth control method of light emitting diode epitaxial wafers according to claim 2, characterized in that, when the absolute value of the warping compensation temperature is less than or equal to a preset first reference temperature, the value range of the adjustment factor is [0.5, 1]; when the absolute value of the warping compensation temperature is greater than the first reference temperature and less than or equal to a preset second reference temperature, the value range of the adjustment factor is (0, 0.5); when the absolute value of the warping compensation temperature is greater than the preset second reference temperature, the value of the adjustment factor is 0.

4. The growth control method of a light emitting diode epitaxial wafer according to claim 1, wherein The step of calculating the warping information comprises: dividing the epitaxial wafer into a plurality of point sets, each point set corresponding to an independent reference coordinate and a reference wavelength; calculating the wavelength mean value of the central region according to the reference wavelengths of the point sets in the central region of the epitaxial wafer; calculating the wavelength mean value of the edge region according to the reference wavelengths of the point sets in the edge region of the epitaxial wafer; calculating the difference between the wavelength mean value of the central region and the wavelength mean value of the edge region of the epitaxial wafer, and taking the difference as the warping information of the epitaxial wafer. 5.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-4 when the computer program is executed by the processor. The processor executes the computer program to implement the steps of the growth control method of light emitting diode epitaxial wafers according to any one of claims 1 to 4.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the growth control method of light emitting diode epitaxial wafers according to any one of claims 1 to 4.

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