A control method and system for processing gallium oxide LDMOSFET devices

Abstract

The invention relates to the technical field of processing control, and specifically discloses a control method and system for processing a gallium oxide LDMOSFET device, comprising: step one: detecting an epitaxial layer in an epitaxial growth stage to obtain detection data; step two: calculating and obtaining a detection coefficient based on the detection data; step three: evaluating the thickness of the epitaxial layer based on the detection coefficient, judging whether the thickness of the epitaxial layer is qualified, and generating a thickness evaluation signal; step four: analyzing whether temperature fluctuations have an impact on the growth of the epitaxial layer based on a thickness unqualified signal, and generating an impact evaluation signal; step five: limiting the temperature fluctuation range of a subsequent epitaxial growth stage based on a temperature impact signal. The invention can dynamically adjust the temperature fluctuation range in the epitaxial growth stage, effectively suppress the adverse impact of temperature fluctuations on the uniformity of the thickness of the epitaxial layer, thereby improving the quality of the epitaxial layer and the process stability.

Description

Technical Field

[0001] The present invention relates to the technical field of processing control, and in particular to a control method and system for processing a gallium oxide LDMOSFET device. Background Art

[0002] As a typical representative of ultra-wide bandgap semiconductors, gallium oxide has obvious advantages in the development of future power devices due to its excellent breakdown field strength, bandgap width, and electron saturation mobility.

[0003] However, in the prior art, when inspecting the epitaxial layer during the processing of gallium oxide, it is not possible to obtain the thickness coefficient and the uniformity coefficient based on the thickness of the epitaxial layer to determine the quality of the epitaxial layer. It is also not possible to calculate the temperature control value based on the influence of temperature fluctuations on the thickness of the epitaxial layer growth and limit the temperature fluctuation range, thereby improving the quality of the epitaxial layer and the process stability. Summary of the invention

[0004] The object of the present invention is to provide a control method and system for processing gallium oxide LDMOSFET devices to solve the technical problems in the above background.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] In a first aspect, the present invention provides a control method for processing a gallium oxide LDMOSFET device, comprising: an epitaxial growth stage and a photolithography and etching stage, and evaluating and detecting the epitaxial layer in the epitaxial growth stage, wherein the specific method comprises the following steps:

[0007] Step 1: Detect the epitaxial layer in the epitaxial growth stage and obtain detection data;

[0008] Among them, the test data include: thickness coefficient and uniformity coefficient;

[0009] Step 2: Based on the detection data, calculate and obtain the detection coefficient;

[0010] Step 3: Based on the detection coefficient, evaluate the thickness of the epitaxial layer, determine whether the thickness of the epitaxial layer is qualified, and generate a thickness evaluation signal;

[0011] The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal;

[0012] Step 4: Based on the thickness failure signal, analyze whether the temperature fluctuation has an impact on the growth of the epitaxial layer, and generate an impact assessment signal;

[0013] The impact assessment signals include: temperature impact signal and temperature no impact signal;

[0014] Step 5: Based on the temperature influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited.

[0015] As a further solution of the present invention: the method for acquiring the detection data is:

[0016] Dividing the surface of the epitaxial layer into a plurality of sub-regions to obtain a plurality of epitaxial layer surface sub-regions, and obtaining a thickness sub-region average value of each epitaxial layer surface sub-region;

[0017] Based on the thickness sub-region average values ​​of the surface sub-regions of each epitaxial layer, the thickness coefficient and uniformity coefficient of the epitaxial layer are calculated respectively.

[0018] As a further solution of the present invention: the process of dividing the epitaxial layer surface into a plurality of epitaxial layer surface sub-areas is:

[0019] Obtaining the thickness of each position point of the epitaxial layer, extracting the maximum and minimum values ​​of the thickness therein, and obtaining the maximum and minimum values ​​of the thickness;

[0020] Based on the maximum thickness value and the minimum thickness value, a total thickness range is obtained, and the total thickness range is equally divided into a number of thickness sub-ranges;

[0021] Based on the thickness sub-range, the epitaxial layer surface is divided into a plurality of epitaxial layer surface sub-regions, wherein the specific method of dividing the epitaxial layer surface sub-regions is as follows: adjacent positions of the epitaxial layer and positions with thicknesses in the same thickness sub-range are divided into the same epitaxial layer surface sub-region.

[0022] As a further solution of the present invention: the method for obtaining the thickness coefficient is:

[0023] Based on a single epitaxial layer surface sub-region, obtaining the number of position points of the epitaxial layer surface sub-region, and marking it as the sub-region position point number;

[0024] Calculate the ratio of the number of sub-region position points of the epitaxial layer surface sub-region to the total number of position points to obtain the sub-region ratio of the epitaxial layer surface sub-region;

[0025] The sub-region thickness average of the epitaxial layer surface sub-region is multiplied by the sub-region ratio to obtain the sub-region thickness ratio;

[0026] The sub-region thickness ratios of all epitaxial layer surface sub-regions are summed up to obtain a total average thickness of the epitaxial layer;

[0027] The difference between the total mean thickness and the total mean standard thickness is calculated to obtain the total thickness deviation value, and then the ratio of the total thickness deviation value to the total mean standard thickness is calculated to obtain the thickness coefficient.

[0028] As a further solution of the present invention: the method for obtaining the uniformity coefficient of the epitaxial layer is:

[0029] Based on the thickness sub-region mean values ​​of the surface sub-regions of each epitaxial layer, the region quantity difference ratio and the thickness variance ratio are calculated; the region quantity difference ratio and the thickness variance ratio are summed to obtain the uniformity coefficient of the epitaxial layer;

[0030] Among them, the method for obtaining the difference ratio of the number of districts is:

[0031] Calculate the difference between the total number of epitaxial layer surface sub-regions and the total number of thickness sub-ranges to obtain a region number difference, calculate the ratio of the region number difference to the total number of thickness sub-ranges to obtain a region number difference ratio;

[0032] The thickness variance ratio is obtained as follows:

[0033] Based on the sub-region thickness proportion values ​​of each epitaxial layer surface sub-region, the variance value of all sub-region thickness proportion values ​​is calculated to obtain the thickness variance value, and the thickness variance value is ratio-calculated with the thickness variance threshold to obtain the thickness variance ratio.

[0034] As a further solution of the present invention: the process of obtaining the detection coefficient is:

[0035] Obtain the thickness coefficient and uniformity coefficient of the epitaxial layer through the formula: , the detection coefficient JC is calculated, where a1 and a2 are preset proportional factors, and both are greater than 0, HD is the thickness coefficient, and JY is the uniformity coefficient.

[0036] As a further solution of the present invention: the method for generating the thickness assessment signal is:

[0037] Comparing and analyzing the detection coefficient with the detection coefficient threshold, thereby generating a thickness assessment signal;

[0038] If the detection coefficient is less than the detection coefficient threshold, a thickness qualified signal is generated;

[0039] If the detection coefficient is greater than or equal to the detection coefficient threshold, a thickness failure signal is generated.

[0040] As a further solution of the present invention: the method for generating the impact assessment signal is:

[0041] Based on the thickness failure signal, the temperature value of the epitaxial growth stage is obtained in real time, and the temperature abnormality period is obtained;

[0042] Based on the analysis of the change of uniformity coefficient during the abnormal temperature period, the change value of uniformity coefficient is calculated;

[0043] At the same time, the abnormal period fluctuation value of the temperature abnormal period is obtained; the abnormal period fluctuation value and the uniformity coefficient change value are calculated by ratio, and the abnormal impact value of the temperature abnormal period is obtained;

[0044] Calculate the variance of the abnormal impact values ​​of all abnormal temperature periods to obtain the impact coefficient;

[0045] Preset the impact coefficient threshold, and compare and analyze the impact coefficient with the impact coefficient threshold;

[0046] If the influence coefficient is less than the influence coefficient threshold, a temperature influence signal is generated;

[0047] If the influence coefficient ≥ the influence coefficient threshold, a temperature no influence signal is generated.

[0048] As a further solution of the present invention: the specific method for limiting the temperature fluctuation range of the subsequent epitaxial growth stage is:

[0049] Based on the temperature influence signal, the maximum temperature and minimum temperature of this epitaxial growth stage from the start time to the current time are extracted to obtain the current temperature fluctuation range [WS, WM], where WS represents the minimum temperature and WM represents the maximum temperature;

[0050] At the same time, the uniformity coefficient of the current state is obtained, marked as the uniform current coefficient, the difference between the uniform current coefficient and the uniform coefficient threshold is calculated, and the absolute value is taken to obtain the uniform control value;

[0051] By formula: , calculate and obtain the temperature control value WT, where YC represents the abnormal impact value and JT represents the uniform control value. It is expressed as the target cycle duration;

[0052] Based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is controlled to obtain the temperature fluctuation range after control [TWS, TWM], where TWS represents the minimum value of the temperature fluctuation after control, and TWM represents the maximum value of the temperature fluctuation after control.

[0053] In a second aspect, the present invention provides a control system for processing a gallium oxide LDMOSFET device, the system comprising:

[0054] Data acquisition module: detect the epitaxial layer in the epitaxial growth stage and obtain detection data;

[0055] Among them, the test data include: thickness coefficient and uniformity coefficient;

[0056] Data processing module: based on the detection data, calculate and obtain the detection coefficient;

[0057] Data evaluation module: Based on the detection coefficient, the thickness of the epitaxial layer is evaluated to determine whether the thickness of the epitaxial layer is qualified, and a thickness evaluation signal is generated;

[0058] The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal;

[0059] Impact analysis module: analyzes whether the temperature fluctuation has an impact on the growth of the epitaxial layer and generates an impact assessment signal;

[0060] The impact assessment signals include: temperature impact signal and temperature no impact signal;

[0061] Control module: Based on the temperature influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited.

[0062] Beneficial effects of the present invention:

[0063] (1) The present invention obtains the thickness data of each position point of the epitaxial layer through a scanning device, and then divides the surface of the epitaxial layer into multiple sub-regions, and calculates the thickness mean of each sub-region; based on these mean values, the thickness coefficient of the epitaxial layer is calculated to quantify the degree of deviation between the actual thickness and the preset standard thickness; at the same time, by comparing the difference between the number of sub-regions and the number of thickness sub-ranges, and calculating the variance of the thickness data of the sub-regions, a uniformity coefficient reflecting the uniformity of the thickness distribution is obtained; then, using a preset formula, the thickness coefficient and the uniformity coefficient are weighted and summed to obtain a detection coefficient that comprehensively reflects the quality of the epitaxial layer; the detection coefficient The number not only considers the accuracy of the thickness, but also takes into account the uniformity of the thickness, providing a comprehensive quantitative index for the quality evaluation of the epitaxial layer; finally, according to the comparison result between the detection coefficient and the preset threshold, it is judged whether the thickness of the epitaxial layer is qualified, and a corresponding evaluation signal is generated; if the detection coefficient is lower than the threshold, it indicates that the thickness of the epitaxial layer meets the standard and is evenly distributed, and a qualified signal is generated; otherwise, an unqualified signal is generated, indicating that further adjustment or inspection is required; the embodiment of the present invention can not only accurately measure and evaluate the thickness and uniformity of the epitaxial layer, but also timely discover potential problems, providing strong support for the semiconductor manufacturing process;

[0064] (2) When the present invention detects that the thickness of the epitaxial layer is unqualified, the temperature data of the epitaxial growth stage is tracked in real time to identify and determine the temperature abnormality period; by comparing the change of the uniformity coefficient before and after the abnormal period, the uniformity coefficient change value is calculated to quantify the direct impact of temperature fluctuation on thickness uniformity; at the same time, the sum of the fluctuation characteristic ratios of each period in the abnormal period is calculated to obtain the abnormal period fluctuation value, which reflects the overall intensity of the temperature fluctuation; further, the uniformity coefficient change value is compared with the abnormal period fluctuation value to obtain the abnormal impact value, which evaluates the relative significance of the impact of temperature fluctuation on uniformity; then, all temperatures are compared. The variance analysis of the abnormal impact value of the abnormal period is performed to extract the impact coefficient. This comprehensive indicator comprehensively reflects the overall impact of temperature fluctuation on the uniformity of epitaxial layer thickness. Finally, by presetting the impact coefficient threshold, the impact coefficient is compared with it, and a temperature impact signal or a temperature no impact signal is intelligently generated. If the impact coefficient is lower than the threshold, it indicates that temperature fluctuation is an important factor causing thickness unevenness; if it is higher than or equal to the threshold, it indicates that temperature fluctuation has little impact on uniformity. The embodiment of the present invention provides strong data support and decision-making basis for process optimization, which helps to achieve a more stable and efficient semiconductor manufacturing process.

[0065] (3) Based on the temperature influence signal, the present invention first extracts the temperature fluctuation range [WS, WM] of the current epitaxial growth stage, namely the maximum temperature WM and the minimum temperature WS; at the same time, the uniformity coefficient (uniform current coefficient) in the current state is evaluated and compared with the uniformity coefficient threshold, and the uniform control value JT is obtained by difference calculation and taking the absolute value; then, the abnormal influence value YC, the uniform control value JT and the target cycle duration are used to calculate the uniform control value JT. , the temperature control value WT is calculated by a specific formula; this value reflects the temperature range that needs to be adjusted to reduce the impact of temperature fluctuations on uniformity; based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is finely controlled to calculate the temperature fluctuation range after control [TWS, TWM]; wherein TWS is the minimum value of the temperature fluctuation after control, obtained by adding WS and WT; TWM is the maximum value of the temperature fluctuation after control, obtained by subtracting WM from WT; through the above technical solution, the embodiment of the present invention can dynamically adjust the temperature fluctuation range in the epitaxial growth stage, effectively suppress the adverse effects of temperature fluctuations on the uniformity of the thickness of the epitaxial layer, thereby improving the quality of the epitaxial layer and the process stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will be further described below in conjunction with the accompanying drawings.

[0067] Figure 1 is a flowchart of Embodiment 2 of the present invention;

[0068] Figure 2is a flowchart of Embodiment 3 of the present invention;

[0069] Figure 3 is a flowchart of Embodiment 4 of the present invention;

[0070] Figure 4 It is a system block diagram of embodiment 5 of the present invention. DETAILED DESCRIPTION

[0071] 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 only 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. Embodiment 1:

[0072] A method for controlling the processing of a gallium oxide LDMOSFET device according to an embodiment of the present invention comprises the following steps:

[0073] Epitaxial growth stage:

[0074] An epitaxial layer is grown on top of a semi-insulating or high-purity diamond insulating layer by sputtering deposition, the epitaxial layer comprising: p-type doped gallium oxide;

[0075] Lithography and etching phase (multiple iterations):

[0076] First barrier layer and N-channel region formation:

[0077] Depositing a first barrier layer on the epitaxial layer for protection and positioning for subsequent processing;

[0078] Forming a first through hole in the N-channel region by photolithography and etching techniques, and performing N-type ion implantation to form the N-channel region;

[0079] The second barrier layer and source region are formed:

[0080] A second barrier layer is formed, and the source region position is defined by photolithography and etching techniques, and N-type doping is performed to form the source region;

[0081] Third barrier layer and source and drain metallization:

[0082] Depositing a third barrier layer, photolithography and etching to define contact holes for source and drain electrodes;

[0083] A nickel-copper alloy metal is deposited on the contact hole to form metal contacts of the source and drain;

[0084] Fourth barrier layer and high-K dielectric insulating layer:

[0085] Depositing a fourth barrier layer, photolithography and etching to form a deposition area of ​​a high-K dielectric (such as hafnium dioxide) for gate insulation;

[0086] Depositing hafnium dioxide in the deposition area to improve gate control capability and reduce leakage current;

[0087] Fifth barrier layer and gate metallization:

[0088] Depositing a fifth barrier layer and defining the position of the gate by photolithography and etching techniques;

[0089] Aluminum (Al) is deposited at the gate position as gate metal;

[0090] The sixth barrier layer and diamond insulation layer are restored:

[0091] A sixth barrier layer is deposited and photolithographically etched to restore the diamond insulating layer above the N-channel region. Embodiment 2:

[0092] Based on Example 1, please refer to Figure 1 As shown, a control method for processing a gallium oxide LDMOSFET device according to an embodiment of the present invention further includes evaluating and detecting the epitaxial layer in the epitaxial growth stage, and the specific method is the following steps:

[0093] Step 1: Detect the epitaxial layer in the epitaxial growth stage and obtain detection data;

[0094] Among them, the test data include: thickness coefficient and uniformity coefficient;

[0095] It should be explained that epitaxial growth is the basis for forming high-quality device structures; the thickness of the epitaxial layer directly determines the electrical performance and reliability of the device; if the epitaxial layer grows unevenly, it will seriously affect the key parameters of the device such as on-resistance, breakdown voltage, threshold voltage, and thus affect the overall performance of the device;

[0096] In some embodiments, the epitaxial layer surface is divided into a plurality of sub-regions to obtain a plurality of epitaxial layer surface sub-regions, and a thickness sub-region average value of each epitaxial layer surface sub-region is obtained;

[0097] Based on the thickness sub-region average values ​​of each epitaxial layer surface sub-region, the thickness coefficient and uniformity coefficient of the epitaxial layer are calculated respectively;

[0098] In a first exemplary embodiment, the process of dividing the epitaxial layer surface into a plurality of epitaxial layer surface sub-regions is as follows:

[0099] Using echo technology, the thickness of each position point of the epitaxial layer is obtained, and the maximum and minimum values ​​of the thickness are extracted to obtain the maximum and minimum values ​​of the thickness;

[0100] Based on the maximum thickness value and the minimum thickness value, the total thickness range is obtained, and the total thickness range is equally divided into a number of thickness sub-ranges (the number of thickness sub-ranges is determined by a person skilled in the art according to experimental requirements, which is an empirical value, and the number may be 10 or 20);

[0101] Based on the thickness sub-range, the epitaxial layer surface is divided into a plurality of epitaxial layer surface sub-regions, wherein the specific method of dividing the epitaxial layer surface sub-regions is: adjacent position points of the epitaxial layer and position points with thicknesses in the same thickness sub-range are divided into the same epitaxial layer surface sub-region; it should be explained that, since the position points of the same epitaxial layer surface sub-region are all continuous, it will result in the appearance that the thicknesses of the plurality of epitaxial layer surface sub-regions are in the same thickness sub-range, that is, the total number of the thickness sub-ranges is less than or equal to the total number of the epitaxial layer surface sub-regions;

[0102] It should be explained that the method for obtaining the thickness of each position point of the epitaxial layer is:

[0103] Scanning the surface of the epitaxial layer using a scanning device (the scanning device includes but is not limited to: a handheld ultrasonic thickness gauge, an ultrasonic scanning microscope, and an automated robotic arm equipped with an ultrasonic probe) to obtain the thickness of each position point on the surface of the epitaxial layer;

[0104] In a second exemplary embodiment, the process of obtaining the thickness sub-area mean is as follows:

[0105] Based on a single epitaxial layer surface sub-region, calculating the average thickness of all position points in the epitaxial layer surface sub-region to obtain the thickness sub-region average of the epitaxial layer surface sub-region;

[0106] In a third exemplary embodiment, the thickness coefficient is obtained by:

[0107] Based on a single epitaxial layer surface sub-region, obtaining the number of position points of the epitaxial layer surface sub-region, and marking it as the sub-region position point number;

[0108] Calculate the ratio of the number of sub-region position points of the epitaxial layer surface sub-region to the total number of position points (the total number of position points is the total number of all position points on the epitaxial layer surface) to obtain the sub-region ratio of the epitaxial layer surface sub-region;

[0109] The sub-region thickness average of the epitaxial layer surface sub-region is multiplied by the sub-region ratio to obtain the sub-region thickness ratio;

[0110] The sub-region thickness ratios of all epitaxial layer surface sub-regions are summed up to obtain a total average thickness of the epitaxial layer;

[0111] The total mean value of thickness is calculated by difference with the total mean value of standard thickness to obtain the total deviation value of thickness, and then the total deviation value of thickness is calculated by ratio with the total mean value of standard thickness to obtain the thickness coefficient;

[0112] It should be explained that the total mean value of the standard thickness is: the thickness of the epitaxial layer preset by the process during the epitaxial growth stage;

[0113] In a fourth exemplary embodiment, a method for obtaining the uniformity coefficient of the epitaxial layer is:

[0114] Based on the thickness sub-region mean values ​​of the surface sub-regions of each epitaxial layer, the region quantity difference ratio and the thickness variance ratio are calculated; the region quantity difference ratio and the thickness variance ratio are summed to obtain the uniformity coefficient of the epitaxial layer;

[0115] Furthermore, the method for obtaining the difference ratio of the number of zones is as follows:

[0116] Calculate the difference between the total number of epitaxial layer surface sub-regions (the total number of epitaxial layer surface sub-regions is the total number of epitaxial layer surface sub-regions) and the total number of thickness sub-ranges (the total number of epitaxial layer thickness sub-ranges) to obtain the region number difference, calculate the ratio of the region number difference to the total number of thickness sub-ranges to obtain the region number difference ratio (the region number difference ratio reflects: the difference between the number of epitaxial layer surface sub-regions and the number of thickness sub-ranges. If the total number of epitaxial layer surface sub-regions is much larger than the total number of thickness sub-ranges, it means that the division of epitaxial layer surface sub-regions is uneven, which indirectly reflects the discreteness of epitaxial layer thickness distribution; the larger the value, the more uneven the thickness distribution; the smaller the value, the relatively uniform the thickness distribution);

[0117] Furthermore, the thickness variance ratio is obtained as follows:

[0118] Based on the sub-region thickness proportion values ​​of each epitaxial layer surface sub-region, the variance values ​​of all sub-region thickness proportion values ​​are calculated to obtain the thickness variance value, and the thickness variance value is calculated by ratio with the thickness variance threshold to obtain the thickness variance ratio (the thickness variance ratio reflects: the degree of discreteness of the epitaxial layer thickness data; the larger the value of the thickness variance ratio, the greater the thickness difference between the epitaxial layer surface sub-regions, that is, the more discrete the data; conversely, the smaller the value of the thickness variance ratio, the more concentrated the data);

[0119] Step 2: Based on the detection data, calculate and obtain the detection coefficient;

[0120] In some embodiments, the thickness coefficient and uniformity coefficient of the epitaxial layer are obtained by the formula: , calculate and obtain the detection coefficient JC, where a1 and a2 are preset proportional factors, both greater than 0, HD is the thickness coefficient, and JY is the uniformity coefficient;

[0121] Step 3: Based on the detection coefficient, evaluate the thickness of the epitaxial layer, determine whether the thickness of the epitaxial layer is qualified, and generate a thickness evaluation signal;

[0122] The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal;

[0123] In some embodiments, the detection coefficient is compared with a detection coefficient threshold value to generate a thickness assessment signal;

[0124] If the detection coefficient is less than the detection coefficient threshold, it means that the thickness of the epitaxial layer is slightly different from the preset thickness of the process and the thickness of the epitaxial layer is uniform, and a thickness qualified signal is generated;

[0125] If the detection coefficient is ≥ the detection coefficient threshold, it means that the thickness of the epitaxial layer is greatly different from the preset thickness of the process or the thickness of the epitaxial layer is uneven, and a thickness failure signal is generated;

[0126] The technical solution of the embodiment of the present invention is mainly as follows: the thickness data of each position point of the epitaxial layer is obtained by a scanning device, and then the surface of the epitaxial layer is divided into multiple sub-regions, and the thickness mean of each sub-region is calculated; based on these mean values, the thickness coefficient of the epitaxial layer is calculated to quantify the degree of deviation between the actual thickness and the preset standard thickness; at the same time, the uniformity coefficient reflecting the uniformity of the thickness distribution is obtained by comparing the difference between the number of sub-regions and the number of thickness sub-ranges, and calculating the variance of the thickness data of the sub-regions; then, the thickness coefficient and the uniformity coefficient are weighted and summed using a preset formula to obtain a detection system that comprehensively reflects the quality of the epitaxial layer. number; the detection coefficient not only takes into account the accuracy of the thickness, but also takes into account the uniformity of the thickness, providing a comprehensive quantitative indicator for the quality evaluation of the epitaxial layer; finally, based on the comparison result between the detection coefficient and the preset threshold, it is judged whether the thickness of the epitaxial layer is qualified, and a corresponding evaluation signal is generated; if the detection coefficient is lower than the threshold, it indicates that the thickness of the epitaxial layer meets the standard and is evenly distributed, and a qualified signal is generated; otherwise, an unqualified signal is generated, indicating that further adjustment or inspection is required; the embodiment of the present invention can not only accurately measure and evaluate the thickness and uniformity of the epitaxial layer, but also promptly discover potential problems, providing strong support for the semiconductor manufacturing process. Embodiment 3:

[0127] Based on Example 1 and Example 2, please refer to Figure 2 As shown, the control method for processing a gallium oxide LDMOSFET device according to an embodiment of the present invention further includes the following steps:

[0128] Step 4: Based on the thickness failure signal, analyze whether the temperature fluctuation has an impact on the growth of the epitaxial layer, and generate an impact assessment signal;

[0129] The impact assessment signals include: temperature impact signal and temperature no impact signal;

[0130] In some embodiments, based on the thickness failure signal, the temperature value of the epitaxial growth stage is obtained in real time to obtain the temperature abnormality period;

[0131] Based on the analysis of the change of the uniformity coefficient during the temperature anomaly period, the uniformity coefficient change value is calculated (the uniformity coefficient change value is obtained by performing difference calculation on the uniformity coefficient at the end time and the uniformity coefficient at the start time to obtain the uniformity coefficient change value; wherein, the uniformity coefficient at the end time is the uniformity coefficient at the end time point of the temperature anomaly period, and the uniformity coefficient at the start time is the uniformity coefficient at the start time point of the temperature anomaly period, and the methods for obtaining the uniformity coefficient at the end time and the uniformity coefficient at the start time are the same as the methods for obtaining the uniformity coefficient of the epitaxial layer mentioned above, which will not be repeated here);

[0132] At the same time, the abnormal period fluctuation value of the temperature abnormal period is obtained; the abnormal period fluctuation value and the uniformity coefficient change value are calculated by ratio, and the abnormal impact value of the temperature abnormal period is obtained;

[0133] Calculate the variance of the abnormal impact values ​​of all abnormal temperature periods to obtain the impact coefficient;

[0134] Preset the impact coefficient threshold, and compare and analyze the impact coefficient with the impact coefficient threshold;

[0135] If the influence coefficient is less than the influence coefficient threshold, it means that the temperature fluctuation has a greater impact on the uniformity of the epitaxial layer thickness, and a temperature influence signal is generated;

[0136] If the influence coefficient is ≥ the influence coefficient threshold, it means that the temperature fluctuation has little influence on the uniformity of the epitaxial layer thickness, and a temperature-independent signal is generated;

[0137] In a first exemplary embodiment, the process of obtaining the abnormal temperature period is as follows:

[0138] Based on the thickness failure signal, the temperature value of the epitaxial growth stage is obtained in real time, and based on a two-dimensional coordinate system with time as the X-axis and temperature as the Y-axis, a temperature fluctuation curve is drawn. At the same time, a straight line with the Y-axis value as the standard temperature value is drawn in the two-dimensional coordinate system to obtain a standard temperature straight line; the area of ​​the enclosed area between the temperature fluctuation curve and the standard temperature straight line within a target period (the target period includes but is not limited to: 1 minute, 10 minutes) is obtained, and a fluctuation characterization value is output. The fluctuation characterization value is calculated by ratio with the fluctuation characterization threshold to obtain a fluctuation characterization ratio; a fluctuation characterization ratio threshold is preset, and the fluctuation characterization ratio is compared and analyzed with the fluctuation characterization ratio threshold;

[0139] If the fluctuation characteristic ratio is less than the fluctuation characteristic ratio threshold, it means that the temperature fluctuation in the target period is small, a normal temperature signal is generated, and the corresponding target period is marked as a normal period;

[0140] If the fluctuation characterization ratio ≥ the fluctuation characterization ratio threshold, it means that the temperature fluctuation in the target period is large, and a temperature anomaly signal is generated, and the corresponding target period is marked as an abnormal period;

[0141] Based on the temperature abnormality signal, obtain the temperature abnormality period (the temperature abnormality period is: the sum of continuous abnormal cycles);

[0142] It should be explained that the standard temperature value is: the temperature value required for the growth of the epitaxial layer set in advance by the process during the epitaxial growth stage;

[0143] In a second exemplary embodiment, the process of obtaining the abnormal period fluctuation value is as follows:

[0144] Obtaining the fluctuation characterization ratios of all abnormal periods in the abnormal temperature period, and summing up the fluctuation characterization ratios of all abnormal periods in the abnormal temperature period to obtain the fluctuation value of the abnormal period;

[0145] The technical solution of the embodiment of the present invention is mainly as follows: when it is detected that the thickness of the epitaxial layer is unqualified, the temperature data of the epitaxial growth stage is tracked in real time, and the temperature abnormality period is identified and determined; by comparing the change of the uniformity coefficient before and after the abnormal period, the uniformity coefficient change value is calculated to quantify the direct impact of temperature fluctuation on thickness uniformity; at the same time, the sum of the fluctuation characteristic ratios of each period in the abnormal period is calculated to obtain the abnormal period fluctuation value, which reflects the overall intensity of the temperature fluctuation; further, the uniformity coefficient change value is calculated with the abnormal period fluctuation value to obtain the abnormal impact value, which evaluates the relative significance of the impact of temperature fluctuation on uniformity; then, The variance analysis is performed on the abnormal impact values ​​of all temperature abnormality periods to extract the impact coefficient. This comprehensive indicator comprehensively reflects the overall impact of temperature fluctuations on the uniformity of epitaxial layer thickness. Finally, by presetting the impact coefficient threshold, the impact coefficient is compared with it, and a temperature impact signal or a temperature no impact signal is intelligently generated. If the impact coefficient is lower than the threshold, it indicates that temperature fluctuation is an important factor causing thickness unevenness. If it is higher than or equal to the threshold, it indicates that temperature fluctuation has little effect on uniformity. The embodiment of the present invention provides strong data support and decision-making basis for process optimization, which helps to achieve a more stable and efficient semiconductor manufacturing process. Embodiment 4:

[0146] Based on Example 1, Example 2 and Example 3, please refer to Figure 3 As shown, the control method for processing a gallium oxide LDMOSFET device according to an embodiment of the present invention further includes the following steps:

[0147] Step 5: Based on the temperature-influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited;

[0148] In some embodiments, based on the temperature influence signal, the maximum temperature and the minimum temperature of the epitaxial growth stage from the start time to the current time are extracted to obtain the current temperature fluctuation range [WS, WM], where WS represents the minimum temperature and WM represents the maximum temperature;

[0149] At the same time, the uniformity coefficient of the current state is obtained, marked as the uniform current coefficient, the difference between the uniform current coefficient and the uniform coefficient threshold is calculated, and the absolute value is taken to obtain the uniform control value;

[0150] By formula: , calculate and obtain the temperature control value WT, where YC represents the abnormal impact value and JT represents the uniform control value. It is expressed as the target cycle duration;

[0151] Based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is controlled to obtain the temperature fluctuation range after control [TWS, TWM], where TWS represents the minimum value of the temperature fluctuation after control, and TWM represents the maximum value of the temperature fluctuation after control;

[0152] Specifically, the method for obtaining the minimum value of temperature fluctuation after regulation is:

[0153] The minimum temperature fluctuation value TWS after regulation is calculated by the formula: TWS=WS+WT;

[0154] The method for obtaining the maximum value of temperature fluctuation after regulation is:

[0155] The maximum temperature fluctuation TWM after regulation is calculated by the formula: TWM=WM-WT;

[0156] The technical solution of the embodiment of the present invention is mainly as follows: based on the temperature influence signal, firstly, the temperature fluctuation range [WS, WM] of the current epitaxial growth stage is extracted, that is, the maximum temperature WM and the minimum temperature WS; at the same time, the uniformity coefficient (uniform current coefficient) in the current state is evaluated, and it is compared with the uniformity coefficient threshold, and the uniform control value JT is obtained by difference calculation and taking the absolute value; then, the abnormal influence value YC, the uniform control value JT and the target cycle duration are used. , the temperature control value WT is calculated by a specific formula; this value reflects the temperature range that needs to be adjusted to reduce the impact of temperature fluctuations on uniformity; based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is finely controlled to calculate the temperature fluctuation range after control [TWS, TWM]; wherein TWS is the minimum value of the temperature fluctuation after control, obtained by adding WS and WT; TWM is the maximum value of the temperature fluctuation after control, obtained by subtracting WM from WT; through the above technical solution, the embodiment of the present invention can dynamically adjust the temperature fluctuation range in the epitaxial growth stage, effectively suppress the adverse effects of temperature fluctuations on the uniformity of the thickness of the epitaxial layer, thereby improving the quality of the epitaxial layer and the process stability. Embodiment 5:

[0157] Based on Example 1, Example 2, Example 3 and Example 4, please refer to Figure 4 As shown, a control system for processing a gallium oxide LDMOSFET device according to an embodiment of the present invention includes:

[0158] Data acquisition module: detect the epitaxial layer in the epitaxial growth stage and obtain detection data;

[0159] Among them, the test data include: thickness coefficient and uniformity coefficient;

[0160] Data processing module: based on the detection data, calculate and obtain the detection coefficient;

[0161] Data evaluation module: Based on the detection coefficient, the thickness of the epitaxial layer is evaluated to determine whether the thickness of the epitaxial layer is qualified, and a thickness evaluation signal is generated;

[0162] The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal;

[0163] Impact analysis module: analyzes whether the temperature fluctuation has an impact on the growth of the epitaxial layer and generates an impact assessment signal;

[0164] The impact assessment signals include: temperature impact signal and temperature no impact signal;

[0165] Control module: Based on the temperature influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited.

[0166] The above thresholds are set for the convenience of comparison. The thresholds depend on the amount of sample data and the number of bases set by technicians in this field for each set of sample data.

[0167] The above formulas are obtained by collecting a large amount of data and performing software simulation to select a formula close to the actual value. The factors in the formula are set by technicians in this field according to actual conditions; for example: Formula ; A technician in this field collects multiple groups of test data and sets corresponding test coefficients for each group of test data; substitutes the set test coefficients and the collected test data into the formula, any two formulas constitute a binary linear equation system, and the calculated factors are screened and averaged to obtain The values ​​of are 3.47 and 2.23 respectively;

[0168] The size of the factor is to quantify each parameter to obtain a specific value for subsequent comparison. The size of the factor depends on the amount of test data and the preliminary setting of the corresponding detection coefficient for each set of test data by technical personnel in this field; as long as it does not affect the proportional relationship between the parameter and the quantized value, such as the detection coefficient is proportional to the value of the uniformity coefficient.

[0169] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A control method for processing a gallium oxide LDMOSFET device, characterized in that: The method comprises the following steps: an epitaxial growth stage and a photolithography and etching stage, and evaluating and detecting the epitaxial layer in the epitaxial growth stage. The specific method comprises the following steps: Step 1: Detect the epitaxial layer in the epitaxial growth stage and obtain detection data; Among them, the test data include: thickness coefficient and uniformity coefficient; Step 2: Based on the detection data, calculate and obtain the detection coefficient; Step 3: Based on the detection coefficient, evaluate the thickness of the epitaxial layer, determine whether the thickness of the epitaxial layer is qualified, and generate a thickness evaluation signal; The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal; Step 4: Based on the thickness failure signal, analyze whether the temperature fluctuation has an impact on the growth of the epitaxial layer, and generate an impact assessment signal; The impact assessment signals include: temperature impact signal and temperature no impact signal; Step 5: Based on the temperature-influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited; The process of obtaining the detection coefficient is as follows: Obtain the thickness coefficient and uniformity coefficient of the epitaxial layer through the formula: , calculate and obtain the detection coefficient JC, where a1 and a2 are preset proportional factors, both greater than 0, HD is the thickness coefficient, and JY is the uniformity coefficient; The method for generating the thickness evaluation signal is: Comparing and analyzing the detection coefficient with the detection coefficient threshold, thereby generating a thickness assessment signal; If the detection coefficient is less than the detection coefficient threshold, a thickness qualified signal is generated; If the detection coefficient ≥ the detection coefficient threshold, a thickness failure signal is generated; The method for generating the impact assessment signal is: Based on the thickness failure signal, the temperature value of the epitaxial growth stage is obtained in real time, and the temperature abnormality period is obtained; Based on the analysis of the change of uniformity coefficient during the abnormal temperature period, the change value of uniformity coefficient is calculated; At the same time, the abnormal period fluctuation value of the temperature abnormal period is obtained; the abnormal period fluctuation value and the uniformity coefficient change value are calculated by ratio, and the abnormal impact value of the temperature abnormal period is obtained; Calculate the variance of the abnormal impact values ​​of all abnormal temperature periods to obtain the impact coefficient; Preset the impact coefficient threshold, and compare and analyze the impact coefficient with the impact coefficient threshold; If the influence coefficient is less than the influence coefficient threshold, a temperature influence signal is generated; If the influence coefficient ≥ the influence coefficient threshold, a temperature no influence signal is generated; The specific method for limiting the temperature fluctuation range in the subsequent epitaxial growth stage is: Based on the temperature influence signal, the maximum temperature and minimum temperature of this epitaxial growth stage from the start time to the current time are extracted to obtain the current temperature fluctuation range [WS, WM], where WS represents the minimum temperature and WM represents the maximum temperature; At the same time, the uniformity coefficient of the current state is obtained, marked as the uniform current coefficient, the difference between the uniform current coefficient and the uniform coefficient threshold is calculated, and the absolute value is taken to obtain the uniform control value; By formula: , calculate and obtain the temperature control value WT, where YC represents the abnormal impact value and JT represents the uniform control value. It is expressed as the target cycle duration; Based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is controlled to obtain the temperature fluctuation range after control [TWS, TWM], where TWS represents the minimum value of the temperature fluctuation after control, and TWM represents the maximum value of the temperature fluctuation after control.

2. The method for controlling the processing of a gallium oxide LDMOSFET device according to claim 1, characterized in that: The method for acquiring the detection data is: Dividing the surface of the epitaxial layer into a plurality of sub-regions to obtain a plurality of epitaxial layer surface sub-regions, and obtaining a thickness sub-region average value of each epitaxial layer surface sub-region; Based on the thickness sub-region average values ​​of the surface sub-regions of each epitaxial layer, the thickness coefficient and uniformity coefficient of the epitaxial layer are calculated respectively.

3. The control method for processing a gallium oxide LDMOSFET device according to claim 2, characterized in that: The process of dividing the epitaxial layer surface into a plurality of epitaxial layer surface sub-areas is as follows: Obtaining the thickness of each position point of the epitaxial layer, extracting the maximum and minimum values ​​of the thickness therein, and obtaining the maximum and minimum values ​​of the thickness; Based on the maximum thickness value and the minimum thickness value, a total thickness range is obtained, and the total thickness range is equally divided into a number of thickness sub-ranges; Based on the thickness sub-range, the epitaxial layer surface is divided into a plurality of epitaxial layer surface sub-regions, wherein the specific method of dividing the epitaxial layer surface sub-regions is as follows: adjacent positions of the epitaxial layer and positions with thicknesses in the same thickness sub-range are divided into the same epitaxial layer surface sub-region.

4. The method for controlling the processing of a gallium oxide LDMOSFET device according to claim 3, characterized in that: The method for obtaining the thickness coefficient is: Based on a single epitaxial layer surface sub-region, obtaining the number of position points of the epitaxial layer surface sub-region, and marking it as the sub-region position point number; Calculate the ratio of the number of sub-region position points of the epitaxial layer surface sub-region to the total number of position points to obtain the sub-region ratio of the epitaxial layer surface sub-region; The sub-region thickness average of the epitaxial layer surface sub-region is multiplied by the sub-region ratio to obtain the sub-region thickness ratio; The sub-region thickness ratios of all epitaxial layer surface sub-regions are summed up to obtain a total average thickness of the epitaxial layer; The difference between the total mean thickness and the total mean standard thickness is calculated to obtain the total thickness deviation value, and then the ratio of the total thickness deviation value to the total mean standard thickness is calculated to obtain the thickness coefficient.

5. The method for controlling the processing of a gallium oxide LDMOSFET device according to claim 1, characterized in that: The method for obtaining the uniformity coefficient of the epitaxial layer is: Based on the thickness sub-region mean values ​​of the surface sub-regions of each epitaxial layer, the region quantity difference ratio and the thickness variance ratio are calculated; the region quantity difference ratio and the thickness variance ratio are summed to obtain the uniformity coefficient of the epitaxial layer; Among them, the method for obtaining the difference ratio of the number of districts is: Calculate the difference between the total number of epitaxial layer surface sub-regions and the total number of thickness sub-ranges to obtain a region number difference, calculate the ratio of the region number difference to the total number of thickness sub-ranges to obtain a region number difference ratio; The thickness variance ratio is obtained as follows: Based on the sub-region thickness proportion values ​​of each epitaxial layer surface sub-region, the variance value of all sub-region thickness proportion values ​​is calculated to obtain the thickness variance value, and the thickness variance value is ratio-calculated with the thickness variance threshold to obtain the thickness variance ratio.

6. A control system for processing gallium oxide LDMOSFET devices, characterized in that: The system is used to execute the method described in any one of claims 1 to 5, and the system comprises: Data acquisition module: detect the epitaxial layer in the epitaxial growth stage and obtain detection data; Among them, the test data include: thickness coefficient and uniformity coefficient; Data processing module: based on the detection data, calculate and obtain the detection coefficient; Data evaluation module: Based on the detection coefficient, the thickness of the epitaxial layer is evaluated to determine whether the thickness of the epitaxial layer is qualified, and a thickness evaluation signal is generated; The thickness evaluation signal includes: a thickness qualified signal and a thickness unqualified signal; Impact analysis module: analyzes whether the temperature fluctuation has an impact on the growth of the epitaxial layer and generates an impact assessment signal; The impact assessment signals include: temperature impact signal and temperature no impact signal; Control module: Based on the temperature-influencing signal, the temperature fluctuation range of the subsequent epitaxial growth stage is limited; The process of obtaining the detection coefficient is as follows: Obtain the thickness coefficient and uniformity coefficient of the epitaxial layer through the formula: , calculate and obtain the detection coefficient JC, where a1 and a2 are preset proportional factors, both greater than 0, HD is the thickness coefficient, and JY is the uniformity coefficient; The method for generating the thickness evaluation signal is: Comparing and analyzing the detection coefficient with the detection coefficient threshold, thereby generating a thickness assessment signal; If the detection coefficient is less than the detection coefficient threshold, a thickness qualified signal is generated; If the detection coefficient ≥ the detection coefficient threshold, a thickness failure signal is generated; The method for generating the impact assessment signal is: Based on the thickness failure signal, the temperature value of the epitaxial growth stage is obtained in real time, and the temperature abnormality period is obtained; Based on the analysis of the change of uniformity coefficient during the abnormal temperature period, the change value of uniformity coefficient is calculated; At the same time, the abnormal period fluctuation value of the temperature abnormal period is obtained; the abnormal period fluctuation value and the uniformity coefficient change value are calculated by ratio, and the abnormal impact value of the temperature abnormal period is obtained; Calculate the variance of the abnormal impact values ​​of all abnormal temperature periods to obtain the impact coefficient; Preset the impact coefficient threshold, and compare and analyze the impact coefficient with the impact coefficient threshold; If the influence coefficient is less than the influence coefficient threshold, a temperature influence signal is generated; If the influence coefficient ≥ the influence coefficient threshold, a temperature no influence signal is generated; The specific method for limiting the temperature fluctuation range in the subsequent epitaxial growth stage is: Based on the temperature influence signal, the maximum temperature and minimum temperature of this epitaxial growth stage from the start time to the current time are extracted to obtain the current temperature fluctuation range [WS, WM], where WS represents the minimum temperature and WM represents the maximum temperature; At the same time, the uniformity coefficient of the current state is obtained, marked as the uniform current coefficient, the difference between the uniform current coefficient and the uniform coefficient threshold is calculated, and the absolute value is taken to obtain the uniform control value; By formula: , calculate and obtain the temperature control value WT, where YC represents the abnormal impact value and JT represents the uniform control value. It is expressed as the target cycle duration; Based on the temperature control value WT, the current temperature fluctuation range [WS, WM] is controlled to obtain the temperature fluctuation range after control [TWS, TWM], where TWS represents the minimum value of the temperature fluctuation after control, and TWM represents the maximum value of the temperature fluctuation after control.

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