Method, device and equipment for detecting oxidation aperture of wafer

Abstract

The present invention discloses a method, device, and apparatus for detecting the diameter of an oxidation pore of a wafer. The detection method comprises: obtaining a mapping relationship between the diameter of a reference oxidation pore of a reference wafer and the resistance value of a reference step where the reference oxidation pore is located; the material of the reference wafer is the same as that of the wafer to be tested; obtaining an electrical signal of the step to be tested of the wafer to be tested; the step to be tested includes an oxidation pore to be tested; the electrical signal includes a current signal and a voltage signal; and determining the diameter of the oxidation pore to be tested in the step to be tested based on the mapping relationship and the electrical signal of the step to be tested. The above technical solution improves the accuracy of the detection result. The diameter of the oxidation pore to be tested can be determined only by the electrical signal of the step to be tested and the mapping relationship. The detection method is simple and fast, and whether the oxidation pore to be tested is qualified can be known in advance before shipment, thereby avoiding the high risk of shipping defective products.

Description

Technical Field

[0001] The present invention relates to the field of wafer oxidation technology, and in particular to a method, device and equipment for detecting oxidation apertures of a wafer. Background Art

[0002] The oxidation process of vertical-cavity surface-emitting lasers (VCSELs) is a critical step in chip manufacturing. However, the measurement of the oxidation aperture is subject to significant constraints. The diameter of a typical oxidation aperture is less than 10 μm, and the oxidation process is relatively short. Any poor process control can lead to failure of the entire process, resulting in scrap.

[0003] Currently, oxidation pore size monitoring typically uses an infrared CCD microscope to measure optical effects. However, when the optical effect contrast is poor, there will be large errors in the oxidation pore size measurement results, increasing the risk of shipping defective products.

[0004] Therefore, proposing a method to accurately detect the oxidation pore size is crucial for the entire oxidation process to chip manufacturing. Summary of the Invention

[0005] The present invention provides a method, device and equipment for detecting the oxidation aperture of a wafer, so as to solve the problem of large errors in the measurement results of the oxidation aperture.

[0006] According to one aspect of the present invention, a method for detecting oxidation apertures of a wafer is provided, wherein the wafer includes a plurality of VCSEL laser setting areas, the VCSEL laser setting areas include steps, the steps include an oxide layer, and the oxide layer includes oxidation apertures;

[0007] The detection method comprises:

[0008] Obtaining a mapping relationship between a diameter of a reference oxidation hole of a reference wafer and a resistance value of a reference step where the reference oxidation hole is located; the material of the reference wafer is the same as that of the wafer to be tested;

[0009] Acquiring an electrical signal of a step to be measured of the wafer to be measured; the step to be measured includes an oxidation hole to be measured; the electrical signal includes a current signal and a voltage signal;

[0010] The diameter of the oxidation pore to be measured in the step to be measured is determined according to the mapping relationship and the electrical signal of the step to be measured.

[0011] Optionally, the VCSEL laser setting area further includes a first electrode and a second electrode; the first electrode is at least partially located on a side of the step away from the oxidation hole;

[0012] The projection of the first electrode on the plane where the oxide layer is located overlaps with the projection of the step on the plane where the oxide layer is located.

[0013] Optionally, the reference wafer includes reference steps of different sizes, and the reference oxidation holes provided in the reference steps of different sizes have different diameters;

[0014] Obtaining a mapping relationship between a diameter of a reference oxidation hole of a reference wafer and a resistance value of a reference step where the reference oxidation hole is located includes:

[0015] Acquiring an electrical signal of each reference step of the reference wafer and a diameter of a reference oxidation hole in each reference step;

[0016] determining the resistance value of each reference step in a one-to-one correspondence according to the electrical signal of each reference step;

[0017] According to the corresponding relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located, a mapping relationship between the diameter of the reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located is determined.

[0018] Optionally, the reference wafer includes a plurality of evenly distributed reference monitoring areas; each of the reference monitoring areas includes reference steps of different sizes, and the size distribution of the reference steps in different reference monitoring areas is the same;

[0019] Acquiring an electrical signal of each reference step of the reference wafer and a diameter of a reference oxidation hole in each reference step includes:

[0020] The electrical signal of each reference step in each reference monitoring area and the diameter of the reference oxidation hole of each reference step in each reference monitoring area are respectively obtained.

[0021] Optionally, determining a mapping relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located according to a correspondence between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located includes:

[0022] Determining an average diameter of the reference oxidation pores in the reference steps of the same size according to the diameters of the reference oxidation pores;

[0023] Determining an average resistance value of each reference step of the same size according to the resistance value of the reference step where each reference oxidation hole is located;

[0024] According to the correspondence between the average diameter of the reference oxidation holes in the reference steps of each size and the average resistance value of the reference steps of each size, a mapping relationship between the diameter of the reference oxidation holes and the resistance value of the reference steps where the reference oxidation holes are located is determined.

[0025] Optionally, determining the diameter of the oxidation pore to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured includes:

[0026] Obtaining a resistance value of the step to be measured according to the electrical signal of the step to be measured;

[0027] According to the mapping relationship, the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured is determined, and the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured is determined as the diameter of the oxidation hole to be measured in the step to be measured.

[0028] Optionally, the wafer to be tested includes a plurality of evenly distributed monitoring areas to be tested; each monitoring area to be tested includes a plurality of steps to be tested;

[0029] Acquiring an electrical signal of each step to be tested of the wafer to be tested, comprising:

[0030] The electrical signal of each step to be tested in each monitoring area to be tested is obtained respectively.

[0031] Optionally, also include:

[0032] Obtaining the total number of the steps to be tested and the number of unqualified oxidation holes to be tested that are not within a preset diameter range in all the monitoring areas to be tested;

[0033] Determining the unqualified ratio of the oxidation pores to be tested according to the total number of the steps to be tested and the unqualified number;

[0034] Determining whether the unqualified ratio is greater than or equal to a preset unqualified threshold;

[0035] If so, it is determined that the wafer to be tested is an unqualified wafer.

[0036] According to another aspect of the present invention, a device for detecting the oxidation aperture of a wafer is provided, wherein the wafer is used to prepare a VCSEL laser, and the detection device comprises:

[0037] A mapping relationship acquisition module is used to obtain a mapping relationship between the diameter of a reference oxidation hole of a reference wafer and the resistance value of a reference step where the reference oxidation hole is located; the material of the reference wafer is the same as that of the wafer to be tested;

[0038] An electrical signal acquisition module, configured to acquire electrical signals of each step to be tested of the wafer to be tested; the step to be tested includes an oxidation hole to be tested; the electrical signals include current signals and voltage signals;

[0039] The diameter determination module is used to determine the diameter of the oxidation hole to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

[0040] According to another aspect of the present invention, there is provided a device for detecting the oxidation aperture of a wafer, wherein the wafer is used to prepare a VCSEL laser, and the device comprises:

[0041] at least one processor; and

[0042] a memory communicatively connected to the at least one processor; wherein,

[0043] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for detecting the oxidation aperture of the wafer described in any embodiment of the present invention.

[0044] The technical solution of the embodiment of the present invention can determine the mapping relationship between the diameter of the oxidation hole to be measured and the resistance value of the reference step where the oxidation hole to be measured is located by obtaining the mapping relationship between the diameter of the reference oxidation hole of a reference wafer made of the same material as the wafer to be measured and the resistance value of the reference step where the oxidation hole to be measured is located, thereby improving the accuracy of the detection result; the resistance value of the step to be measured can be determined by obtaining the electrical signal of the step to be measured of the wafer to be measured, and then the diameter of the oxidation hole to be measured in the step to be measured can be determined through the mapping relationship and the resistance value of the step to be measured. The diameter of the oxidation hole to be measured can be determined only through the electrical signal of the step to be measured and the mapping relationship. The detection method is simple and fast, and whether the oxidation hole to be measured is qualified can be known in advance before shipment, thereby avoiding the high risk of shipping defective products.

[0045] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1This is a flow chart of a method for detecting oxidation pore diameter of a wafer provided in the first embodiment of the present invention;

[0048] Figure 2 A schematic diagram of a cross-sectional structure of a reference wafer provided in an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of a top view of a reference wafer provided in an embodiment of the present invention;

[0050] Figure 4 A schematic diagram of a mapping relationship between a diameter D1 of a reference oxidation hole and a resistance value R1 of a reference step where the reference oxidation hole is located, provided in an embodiment of the present invention;

[0051] Figure 5 A flow chart of a method for detecting oxidation aperture of a wafer provided in the second embodiment of the present invention;

[0052] Figure 6 This is a flow chart of a method for detecting oxidation aperture of a wafer provided in the third embodiment of the present invention;

[0053] Figure 7 A schematic diagram of a top view of another reference wafer provided in an embodiment of the present invention;

[0054] Figure 8 This is a flow chart of a method for detecting oxidation pore diameter of a wafer provided in a fourth embodiment of the present invention;

[0055] Figure 9 A schematic structural diagram of a device for detecting oxidation aperture of a wafer provided in a fifth embodiment of the present invention;

[0056] Figure 10 This is a schematic structural diagram of a device for detecting oxidation aperture of a wafer provided in Example 6 of the present invention. DETAILED DESCRIPTION

[0057] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0059] Example 1

[0060] Figure 1 The flowchart of a method for detecting the oxidation aperture of a wafer provided in the first embodiment of the present invention is applicable to the case when preparing the oxidation aperture of a VCSEL laser. The wafer includes multiple VCSEL laser setting areas, the VCSEL laser setting areas include steps, the steps include an oxide layer, and the oxide layer includes oxidation apertures. The detection method can be performed by a detection device for the oxidation aperture of a wafer. The detection device for the oxidation aperture of a wafer can be implemented in the form of hardware and / or software. The detection device for the oxidation aperture of a wafer can be configured in a detection device for the oxidation aperture of a wafer. Figure 1 As shown, the method includes:

[0061] S1001. Obtain a mapping relationship between the diameter of a reference oxidation hole of a reference wafer and the resistance value of a reference step where the reference oxidation hole is located.

[0062] The material of the reference wafer is the same as that of the wafer to be tested, and they are manufactured using the same process. For example, the reference wafer and the wafer to be tested can be manufactured using the same material and the same epitaxial process.

[0063] For example, Figure 2 A schematic cross-sectional structure diagram of a reference wafer provided in an embodiment of the present invention, Figure 3 A schematic diagram of a top view of a reference wafer provided in an embodiment of the present invention, combined with reference Figure 2 and Figure 3 , the reference wafer 01 includes a substrate 02 , on which a plurality of VCSEL laser setting areas are provided, and only one VCSEL laser setting area is shown in the figure as an example.

[0064] The VCSEL laser setting area includes a first Bragg reflector 041, a second Bragg reflector 042, an active layer 05, an oxide layer 061, a reference oxide hole 062, a passivation layer 07, and a reference step 08. When the oxidation depth of the oxide layer 061 is determined, the diameter D1 of the reference oxide hole 062 is related to the size L1 of the reference step 08. At the same oxidation depth, the smaller the size L1 of the reference step 08, the smaller the diameter D1 of the reference oxide hole 062. When the size L1 of the reference step 08 is small to a certain extent, the diameter D1 of the reference oxide hole 062 is equal to 0 (not shown in the figure). It should be noted that Figure 2 and Figure 3 Only a partial structural diagram of the reference wafer is shown, and only a reference step setting area is shown. The reference wafer 01 may include multiple reference step setting areas.

[0065] In an alternative embodiment, continue to refer to Figure 2 The VCSEL laser arrangement area further includes a first electrode 031, a second electrode 032, and an ohmic metal 033. The first electrode 031 is at least partially located on a side of the reference step 08 away from the reference oxidation hole 062. The first electrode 031 can be electrically connected to the first Bragg reflector 041 via the ohmic metal 033. The projection of the first electrode 031 on the plane where the reference oxide layer 061 is located overlaps with the projection of the reference step 08 on the plane where the reference oxide layer 061 is located. That is, the first electrode 031 may only cover a portion of the surface of the reference step 08 (at least a portion of the surface of the reference step 08 away from the reference oxidation hole 062 is not covered by the first electrode 031). Alternatively, the first electrode 031 may completely cover the surface of the reference step 08 away from the reference oxidation hole 062 (not shown in the figure), which is not limited in this embodiment of the present invention.

[0066] It will be understood that the figure only exemplarily shows that the first electrode 031 and the second electrode 032 are located on opposite sides of the reference oxide layer 061. The first electrode 031 and the second electrode 032 may also be located on the same side of the reference oxide layer 061 (not shown in the figure), and this embodiment of the present invention does not limit this.

[0067] Carriers can be transferred from the first electrode 031 to the second electrode 032 through the reference oxidation hole 062 in the middle of the oxide layer 061, or from the second electrode 032 to the first electrode 031 through the reference oxidation hole 062 in the middle of the oxide layer 061. The diameter D1 of the reference oxidation hole 062 directly affects the transfer of carriers, and thus affects the resistance value R1 of the reference step 08 where the reference oxidation hole 062 is located. The smaller the diameter D1 of the reference oxidation hole 062, the greater the resistance value R1 of the reference step 08 where the reference oxidation hole 062 is located; the larger the diameter D1 of the reference oxidation hole 062, the smaller the resistance value R1 of the reference step 08 where the reference oxidation hole 062 is located. The corresponding relationship between the diameter D1 of the reference oxidation hole 062 and the resistance value R1 of the reference step 08 where the reference oxidation hole 062 is located is the mapping relationship between the diameter D1 of the reference oxidation hole 062 and the resistance value R1 of the reference step 08 where the reference oxidation hole 062 is located, as shown in FIG. Figure 4 shown.

[0068] It is understandable that Figure 2 and Figure 3 The structure of a reference wafer is shown for illustrative purposes only. In addition, the reference wafer may also have other structures, which are not specifically limited in the embodiments of the present invention.

[0069] S1002 : Acquire an electrical signal of a step to be tested of the wafer to be tested.

[0070] The structures of the wafer to be tested and the reference wafer are similar and will not be described in detail. The wafer to be tested may include multiple steps to be tested, and each step to be tested includes an oxidation hole to be tested. The electrical signal includes a current signal and a voltage signal.

[0071] Exemplarily, a voltage signal of a certain potential is applied to the first electrode and the second electrode of the step to be measured, and a current signal flowing through the step to be measured is obtained.

[0072] S1003 : Determine the diameter of the oxidation hole to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

[0073] For example, the resistance value of the step to be measured can be determined by the voltage signals and current signals of the first electrode and the second electrode of the step to be measured, and the diameter of the oxidation aperture to be measured in the step to be measured can be inferred based on the mapping relationship between the resistance value of the step to be measured and the diameter of the reference oxidation aperture 062 and the resistance value of the reference step 08 where the reference oxidation aperture 062 is located.

[0074] In an optional embodiment, the detection method can be performed before 100% testing of the entire wafer to be tested, which can avoid finding that the oxidation holes of the test steps in the test wafer are unqualified after 100% testing of the entire wafer, thereby wasting labor time and costs.

[0075] In an embodiment of the present invention, by obtaining a mapping relationship between the diameter of a reference oxidation hole of a reference wafer made of the same material as the wafer to be tested and the resistance value of a reference step where the reference oxidation hole is located, the mapping relationship between the diameter of the oxidation hole to be tested and the resistance value of the step to be tested where the oxidation hole to be tested is located can be determined, thereby improving the accuracy of the detection result; by obtaining an electrical signal of the step to be tested of the wafer to be tested, the resistance value of the step to be tested can be determined, and then the diameter of the oxidation hole to be tested in the step to be tested can be determined through the mapping relationship and the resistance value of the step to be tested. The diameter of the oxidation hole to be tested can be determined only through the electrical signal of the step to be tested and the mapping relationship. The detection method is simple and fast, and whether the oxidation hole to be tested is qualified can be known in advance before shipment, thereby avoiding the high risk of shipping defective products.

[0076] Example 2

[0077] Figure 5 This is a flow chart of a method for detecting the oxidation aperture of a wafer provided in the second embodiment of the present invention. Compared with the above embodiment, this embodiment specifically describes how to determine the mapping relationship between the diameter of the reference oxidation aperture and the resistance value of the reference step where the reference oxidation aperture is located. Figure 5 As shown, the method includes:

[0078] S2001 , acquiring an electrical signal of each reference step of a reference wafer and a diameter of a reference oxidation hole in each reference step.

[0079] S2002 : Determine the resistance value of each reference step in a one-to-one correspondence according to the electrical signal of each reference step.

[0080] S2003 , determining a mapping relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located according to the corresponding relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located.

[0081] S2004 , obtaining an electrical signal of the step to be tested of the wafer to be tested.

[0082] S2005 : Determine the diameter of the oxidation pore to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

[0083] Exemplarily, the reference wafer includes reference steps of different sizes, the oxide layer of the same reference wafer is oxidized in the same oxidation process, and the oxidation depth of the oxide layer at each reference step in the same reference wafer is basically the same. Therefore, the diameters of the reference oxidation holes set in reference steps of different sizes are different.

[0084] By detecting the voltage signals and current signals of reference steps of different sizes in the reference wafer, the resistance values of the reference steps of different sizes can be determined, that is, the resistance values of the reference steps where reference oxide holes of different diameters are located can be determined; by physically cutting the steps to be measured on the reference wafer, the diameters of each reference oxide hole can be obtained, and based on the diameters of each reference oxide hole and the resistance values of the reference steps where each oxide hole is located, the correspondence between the diameters of reference oxide holes of different diameters and the resistance values of the reference steps where the reference oxide holes of different diameters are located can be obtained, so that the corresponding mapping relationship can be determined.

[0085] In an embodiment of the present invention, reference steps of different sizes and oxide holes of different diameters can be obtained by using the same reference wafer. By obtaining the electrical signal of each reference step and the diameter of the reference oxide hole in each reference step, the mapping relationship between the diameter of the reference oxide hole and the resistance value of the reference step where the reference oxide hole is located can be determined. The mapping relationship between the diameter of the reference oxide hole and the resistance value of the reference step where the reference oxide hole is located can be determined using only one reference wafer. The method is simple, fast, and low-cost.

[0086] Example 3

[0087] Figure 6 This is a flow chart of a method for detecting the oxidation aperture diameter of a wafer provided in the third embodiment of the present invention. Compared with the above embodiments, this embodiment takes into account the influence of reference steps of the same size at different positions on the mapping relationship when determining the mapping relationship between the diameter of the reference oxidation aperture and the resistance value of the reference step where the reference oxidation aperture is located. Figure 6 As shown, the method includes:

[0088] S3001 , respectively acquiring the electrical signal of each reference step in each reference monitoring area and the diameter of the reference oxidation hole of each reference step in each reference monitoring area.

[0089] S3002 : Determine the resistance value of each reference step in a one-to-one correspondence according to the electrical signal of each reference step.

[0090] S3003 : Determine a mapping relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located according to the corresponding relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located.

[0091] S3004. Determine the average diameter of the reference oxidation holes in each reference step of the same size based on the diameter of each reference oxidation hole.

[0092] S3005 , determining an average resistance value of each reference step of the same size based on the resistance value of each reference step where each reference oxidation hole is located.

[0093] S3006 , determining a mapping relationship between the diameter of the reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located based on the correspondence between the average diameter of the reference oxidation hole in the reference steps of each size and the average resistance value of the reference steps of each size.

[0094] S3007 , obtaining an electrical signal of the step to be tested of the wafer to be tested.

[0095] S3008 : Determine the diameter of the oxidation hole to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

[0096] For example, Figure 7 A schematic diagram of a top view structure of another reference wafer provided in an embodiment of the present invention is shown as follows: Figure 7 As shown, reference wafer 01 includes multiple evenly distributed reference monitoring regions 100 at various locations on reference wafer 01. Due to manufacturing process influences, the mapping relationship between the diameter of the reference oxide holes at different locations on reference wafer 01 and the resistance value of the reference step where the reference oxide holes are located may vary slightly. Each reference monitoring region 100 includes reference steps 08 of different sizes, and the size distribution of reference steps 08 within different reference monitoring regions 100 is the same.

[0097] By detecting the voltage and current signals of reference steps of different sizes within the reference monitoring region 100 at various locations, the resistance values of the reference steps of different sizes within the reference monitoring region 100 at various locations can be determined. Furthermore, the diameters of the reference oxidation holes of the reference steps of different sizes within the reference monitoring region 100 at various locations can be obtained by physical cutting. By averaging the resistance values of reference steps of the same size within the reference monitoring region 100 at various locations, the average resistance value of the reference steps of the same size can be obtained. By averaging the diameters of the reference oxidation holes of the reference steps of the same size within the reference monitoring region 100 at various locations, the average diameter of the oxidation holes of the reference steps of the same size can be obtained. The mapping relationship between the diameters of the reference oxidation holes of different diameters and the resistance values of the reference steps containing the reference oxidation holes of different diameters can be obtained from the average resistance values of the reference steps of different sizes and the average diameters of the oxidation holes of the reference steps of different sizes.

[0098] In an embodiment of the present invention, a mapping relationship between the diameter of a reference oxidation hole and the resistance value of a reference step where the reference oxidation hole is located is determined based on the correspondence between the average diameter of the reference oxidation hole in reference steps of various sizes and the average resistance value of the reference steps of various sizes. This can avoid the problem of wafer uniformity caused by the manufacturing process, which may lead to distortion of the mapping relationship.

[0099] In an optional embodiment, in addition to averaging the resistance values of reference steps of the same size and the diameters of reference oxidation holes in the reference monitoring area 100 at each position, other methods can be used to avoid the problem of wafer uniformity caused by the manufacturing process. For example, the distribution of the monitoring area to be tested can be the same as that of the reference monitoring area, and the mapping relationship corresponding to the reference monitoring area 100 at each position can be determined based on the resistance values of the reference steps and the diameters of the reference oxidation holes in the reference monitoring area 100 at each position; the electrical signals of each step to be tested in the monitoring area to be tested at a certain position are obtained to determine the resistance values of each step to be tested in the monitoring area to be tested at that position, and the diameters of each oxidation holes to be tested in the monitoring area to be tested at that position are determined based on these resistance values and the mapping relationship corresponding to the reference monitoring area 100 at that position.

[0100] In an optional embodiment, it is also possible to average only the resistance values of the reference steps of the same size and the diameters of the reference oxidation holes in the reference monitoring areas 100 at similar positions, and then determine the mapping relationship corresponding to the reference monitoring areas 100 at these similar positions based on the average resistance values of the reference steps of the same size and the average diameters of the reference oxidation holes in the reference monitoring areas 100 at similar positions; obtain the electrical signals of each step to be measured in the monitoring area to be measured at the similar position, determine the resistance value of each step to be measured in the monitoring area to be measured at the similar position, and determine the diameter of each oxidation hole to be measured in the monitoring area to be measured at the similar position based on these resistance values and the mapping relationship corresponding to the reference monitoring areas 100 at the similar positions. Wherein, similar positions refer to multiple reference monitoring areas or monitoring areas to be measured that are the same distance from the edge or center of the wafer.

[0101] Example 4

[0102] Figure 8 This is a flow chart of a method for detecting oxidation aperture of a wafer provided by the fourth embodiment of the present invention. Compared with the above embodiments, this embodiment adds the content of how to determine unqualified wafers. Figure 8 As shown, the method includes:

[0103] S4001. Obtain a mapping relationship between the diameter of a reference oxidation hole of a reference wafer and the resistance value of a reference step where the reference oxidation hole is located.

[0104] S4002 , respectively obtain the electrical signal of each step to be tested in each monitoring area to be tested.

[0105] S4003 : Obtain the resistance value of the step to be measured according to the electrical signal of the step to be measured.

[0106] S4004 , determining the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured according to the mapping relationship, and determining the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured as the diameter of the oxidation hole to be measured in the step to be measured.

[0107] S4005: Obtain the total number of steps to be tested and the number of unqualified oxidation holes to be tested that are not within a preset diameter range in all monitored areas to be tested;

[0108] S4006. Determine the unqualified ratio of the oxidation holes to be tested based on the total number of the steps to be tested and the number of unqualified steps.

[0109] S4007: Determine whether the unqualified ratio is greater than or equal to a preset unqualified threshold. If so, execute S4008.

[0110] S4008. Determine whether the wafer to be tested is an unqualified wafer.

[0111] For example, the resistance value of each step to be measured in the monitoring area to be measured at each location can be determined based on the voltage signal and current signal of each step to be measured in the monitoring area to be measured at each location. Based on the mapping relationship between the resistance value of the step to be measured, the diameter of the reference oxidation pore, and the resistance value of the reference step where the reference oxidation pore is located, the diameter of the reference oxidation pore in the reference step can be determined when the resistance value of the reference step is the resistance value of the step to be measured. Under the same resistance value, the diameter of the reference oxidation pore is the diameter of the oxidation pore to be measured in the step to be measured. In an optional embodiment, based on the corresponding relationship between the diameter of the reference oxidation pore and the resistance value of the reference step where the reference oxidation pore is located, a mapping relationship curve can be obtained by fitting. In this fitting curve, the diameter corresponding to the resistance value of the step to be measured is the diameter of the oxidation pore to be measured in the step to be measured.

[0112] In an exemplary embodiment, when the diameter of the oxidation pore to be tested is within the range of 6 μm to 8 μm, the oxidation pore to be tested is qualified. When the diameter of the oxidation pore to be tested is less than 6 μm or greater than -8 μm, the oxidation pore to be tested is unqualified. The unqualified ratio of the oxidation pores to be tested in the wafer to be tested can be determined by the number of all oxidation pores to be tested in the wafer to be tested (i.e., the total number of steps to be tested in all monitoring areas to be tested) and the number of unqualified oxidation pores among them. Assuming a preset unqualified threshold of 70%, when the unqualified ratio is greater than or equal to 70%, the wafer to be tested is determined to be unqualified.

[0113] It should be noted that the number of all oxidation holes to be tested in the wafer to be tested does not refer to the number of all oxidation holes in the wafer to be tested, but only refers to the number of oxidation holes that need to be detected.

[0114] In an optional embodiment, it is also possible to determine whether the unqualified proportion of the oxide holes to be tested is greater than or equal to a preset adjustment threshold and less than a preset unqualified threshold; if so, the unqualified oxide holes to be tested can be repaired and removed without directly determining that the wafer to be tested is unqualified.

[0115] In an embodiment of the present invention, by obtaining the total number of steps to be tested in all monitored areas to be tested and the number of unqualified oxidation holes to be tested that are not within a preset diameter range, the unqualified ratio of the oxidation holes to be tested is determined, and the unqualified ratio is compared with a preset unqualified threshold value, unqualified wafers to be tested can be quickly detected, thereby improving detection efficiency and reducing detection costs.

[0116] Example 5

[0117] Figure 9 This is a schematic diagram of the structure of a device for detecting oxidation aperture of a wafer provided in the fifth embodiment of the present invention. Figure 9 As shown, the device includes:

[0118] A mapping relationship acquisition module 610 is used to acquire a mapping relationship between the diameter of a reference oxidation hole of a reference wafer and the resistance value of a reference step where the reference oxidation hole is located; the material of the reference wafer is the same as that of the wafer to be tested;

[0119] The electrical signal acquisition module 620 is used to acquire electrical signals of each step to be tested of the wafer to be tested; the step to be tested includes an oxidation hole to be tested; the electrical signals include current signals and voltage signals;

[0120] The diameter determination module 630 is configured to determine the diameter of the oxidation hole to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

[0121] In an embodiment of the present invention, by setting a mapping relationship acquisition module, the mapping relationship between the diameter of the oxidation hole to be tested of the step to be tested and the resistance value of the step to be tested where the oxidation hole to be tested is located can be determined, thereby improving the accuracy of the detection result; by setting an electrical signal acquisition module, the electrical signal of the step to be tested of the wafer to be tested can be obtained to determine the resistance value of the step to be tested; through the diameter determination module, the diameter of the oxidation hole to be tested can be determined only by the electrical signal of the step to be tested and the mapping relationship. The detection method is simple and fast, and whether the oxidation hole to be tested is qualified can be known in advance before shipment, thereby avoiding the high risk of shipping defective products.

[0122] An apparatus for detecting oxidation aperture of a wafer provided by an embodiment of the present invention can execute a method for detecting oxidation aperture of a wafer provided by any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0123] Example 6

[0124] Figure 10A schematic structural diagram of a device for detecting the oxidation aperture of a wafer provided in Example 6 of the present invention, wherein the device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0125] like Figure 10 As shown, the detection device 20 includes at least one processor 21, and a memory connected to the at least one processor 21, such as a read-only memory (ROM) 22, a random access memory (RAM) 23, etc., wherein the memory stores a computer program that can be executed by the at least one processor, and the processor 21 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 22 or the computer program loaded from the storage unit 28 into the random access memory (RAM) 23. Various programs and data required for the operation of the detection device 20 can also be stored in the RAM 23. The processor 21, ROM 22 and RAM 23 are connected to each other via a bus 24. An input / output (I / O) interface 25 is also connected to the bus 24.

[0126] Multiple components in the detection device 20 are connected to the I / O interface 25, including: an input unit 26, such as a keyboard, a mouse, etc.; an output unit 27, such as various types of displays, speakers, etc.; a storage unit 28, such as a magnetic disk, an optical disk, etc.; and a communication unit 29, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 29 allows the detection device 20 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0127] The processor 21 may be any general-purpose and / or specialized processing component with processing and computing capabilities. Examples of the processor 21 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The processor 21 executes the various methods and processes described above, such as the method for detecting oxidation apertures of wafers.

[0128] In some embodiments, method XXX can be implemented as a computer program that is tangibly contained in a computer-readable storage medium, such as storage unit 28. In some embodiments, part or all of the computer program can be loaded and / or installed on the detection device 20 via ROM 22 and / or communication unit 29. When the computer program is loaded into RAM 23 and executed by processor 21, one or more steps of method XXX described above can be performed. Alternatively, in other embodiments, processor 21 can be configured to perform the method for detecting the oxidation aperture of the wafer in any other appropriate manner (e.g., by means of firmware).

[0129] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0130] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0131] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0132] To provide interaction with a user, the systems and techniques described herein can be implemented on a detection device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the detection device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0133] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0134] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0135] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0136] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for detecting oxidation pore size of a wafer, characterized in that: The wafer includes a plurality of VCSEL laser setting areas, each of which includes a step, a first electrode, and a second electrode; the step includes an oxide layer, and the oxide layer includes an oxide hole; the first electrode is at least partially located on a side of the step away from the oxide hole; wherein a projection of the first electrode on a plane where the oxide layer is located overlaps with a projection of the step on the plane where the oxide layer is located; The detection method comprises: Obtaining a mapping relationship between a diameter of a reference oxidation hole of a reference wafer and a resistance value of a reference step where the reference oxidation hole is located; the material of the reference wafer is the same as that of the wafer to be tested; Acquiring an electrical signal of a step to be measured of the wafer to be measured; the step to be measured includes an oxidation hole to be measured; the electrical signal includes a current signal and a voltage signal; The diameter of the oxidation pore to be measured in the step to be measured is determined according to the mapping relationship and the electrical signal of the step to be measured.

2. The method for detecting oxidation pore size of a wafer according to claim 1, wherein: The reference wafer includes reference steps of different sizes, and the reference oxidation holes provided in the reference steps of different sizes have different diameters; Obtaining a mapping relationship between a diameter of a reference oxidation hole of a reference wafer and a resistance value of a reference step where the reference oxidation hole is located includes: Acquiring an electrical signal of each reference step of the reference wafer and a diameter of a reference oxidation hole in each reference step; determining the resistance value of each reference step in a one-to-one correspondence according to the electrical signal of each reference step; According to the corresponding relationship between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located, a mapping relationship between the diameter of the reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located is determined.

3. The method for detecting oxidation pore size of a wafer according to claim 2, wherein: The reference wafer includes a plurality of uniformly distributed reference monitoring areas; each of the reference monitoring areas includes reference steps of different sizes, and the size distribution of the reference steps in different reference monitoring areas is the same; Acquiring an electrical signal of each reference step of the reference wafer and a diameter of a reference oxidation hole in each reference step includes: The electrical signal of each reference step in each reference monitoring area and the diameter of the reference oxidation hole of each reference step in each reference monitoring area are respectively obtained.

4. The method for detecting oxidation pore size of a wafer according to claim 3, wherein: Determining, based on the correspondence between the diameter of each reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located, a mapping relationship between the diameter of the reference oxidation hole and the resistance value of the reference step where the reference oxidation hole is located, includes: Determining an average diameter of the reference oxidation pores in the reference steps of the same size according to the diameters of the reference oxidation pores; Determining an average resistance value of each reference step of the same size according to the resistance value of the reference step where each reference oxidation hole is located; According to the correspondence between the average diameter of the reference oxidation holes in the reference steps of each size and the average resistance value of the reference steps of each size, a mapping relationship between the diameter of the reference oxidation holes and the resistance value of the reference steps where the reference oxidation holes are located is determined.

5. The method for detecting oxidation pore size of a wafer according to claim 1, wherein: Determining the diameter of the oxidation pore to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured, comprising: Obtaining a resistance value of the step to be measured according to the electrical signal of the step to be measured; According to the mapping relationship, the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured is determined, and the diameter of the reference oxidation hole corresponding to the resistance value of the step to be measured is determined as the diameter of the oxidation hole to be measured in the step to be measured.

6. The method for detecting oxidation pore diameter of a wafer according to claim 5, wherein: The wafer to be tested includes a plurality of monitoring areas to be tested that are evenly distributed; each monitoring area to be tested includes a plurality of steps to be tested; Acquiring an electrical signal of each step to be tested of the wafer to be tested, comprising: The electrical signal of each step to be tested in each monitoring area to be tested is obtained respectively.

7. The method for detecting oxidation pore diameter of a wafer according to claim 6, wherein: Also includes: Obtaining the total number of the steps to be tested and the number of unqualified oxidation holes to be tested that are not within a preset diameter range in all the monitoring areas to be tested; Determining the unqualified ratio of the oxidation pores to be tested according to the total number of the steps to be tested and the unqualified number; Determining whether the unqualified ratio is greater than or equal to a preset unqualified threshold; If so, it is determined that the wafer to be tested is an unqualified wafer.

8. A device for detecting oxidation pore diameter of a wafer, characterized in that: The wafer is used to prepare a VCSEL laser; the wafer includes a plurality of VCSEL laser setting areas, the VCSEL laser setting areas including steps, a first electrode, and a second electrode; the steps include an oxide layer, and the oxide layer includes an oxide hole; the first electrode is at least partially located on a side of the step away from the oxide hole; wherein a projection of the first electrode on a plane where the oxide layer is located overlaps with a projection of the step on the plane where the oxide layer is located; The detection device comprises: A mapping relationship acquisition module is used to obtain a mapping relationship between the diameter of a reference oxidation hole of a reference wafer and the resistance value of a reference step where the reference oxidation hole is located; the material of the reference wafer is the same as that of the wafer to be tested; An electrical signal acquisition module is used to acquire electrical signals of each step to be tested of the wafer to be tested; the step to be tested includes an oxidation hole to be tested; the electrical signals include current signals and voltage signals; The diameter determination module is used to determine the diameter of the oxidation hole to be measured in the step to be measured according to the mapping relationship and the electrical signal of the step to be measured.

9. A device for detecting oxidation pore diameter of a wafer, characterized in that: The wafer is used to prepare a VCSEL laser, and the detection equipment includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor. The computer program is executed by the at least one processor so that the at least one processor can perform the method for detecting oxidation pore size of a wafer according to any one of claims 1 to 7.

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