TWI815769B - Method and system for measuring the depth of damage layer on wafer surface - Google Patents

Abstract

The invention discloses a method and system for measuring the depth of the damage layer on the surface of a wafer; the method for measuring the depth of the damage layer on the surface of a wafer includes: dividing the surface of the wafer to be measured into a plurality of concentric circle to form multiple concentric ring areas; starting from the center to the edge of the wafer to be tested, use an etching solution of a set concentration for each concentric ring area and perform an etching operation according to the set etching time, so that Form a step with multiple step surfaces in the shape of a concentric ring on the surface of the wafer to be tested; perform damage detection on the multiple step surfaces in sequence until no damage is detected; when no damage is detected, based on all the The depth of the damaged layer on the surface of the wafer to be measured is determined by the height of the step corresponding to the step surface where damage is detected; the height of the step is calculated based on the etching rate and etching time of the etching solution.

Description

Method and system for measuring the depth of damage layer on wafer surface

The invention belongs to the technical field of wafer processing and manufacturing, and in particular refers to a method and system for measuring the depth of a damaged layer on a wafer surface.

In the manufacturing process from drawn single crystal silicon rods to wafers, multiple manufacturing processes such as tumbling, slicing, grinding, etching and polishing are required. During mechanical processing such as rolling, slicing or grinding, mechanical damage will inevitably be introduced on the wafer surface. These mechanical damages destroy the original single crystal layer on the wafer surface and seriously affect the quality of the wafer. Therefore, these mechanically damaged layers need to be removed during subsequent processing through techniques such as etching and polishing. When removing the mechanically damaged layer on the wafer surface, it is necessary to accurately measure the depth of the mechanically damaged layer, so as to set the specific removal amount involved in the removal operation accordingly.

The mechanical damage layer depth measurement technology in the related art is divided into direct measurement and indirect measurement. Direct measurement refers to directly observing the mechanical damage on the cross section of the wafer. However, because these mechanical damages are shallow, it is not easy to observe directly with a microscope. The wafer is usually cut off and then a scanning electron microscope (SEM) or transmission electron microscope is used. High-precision equipment such as Transmission Electron Microscope (TEM) can observe mechanical damage on the cross section, but the equipment cost of this method is high and the sample preparation is complicated.

The angle polishing method is an indirect measurement method commonly used in laboratories. In this method, the mechanically damaged layer is amplified by grinding and throwing the vertical mechanically damaged layer into a smooth bevel to match the measurement accuracy of the microscope. The ground and polished bevel is then etched to further magnify the mechanical damage and measured using a microscope, which is then geometrically converted to the actual damage depth.

However, the angle polishing method has higher requirements for sample processing and measurement. First of all, this method requires the wafer to be cracked to obtain samples before processing, and the etching of the samples after grinding and polishing requires the design of separate fixtures and tanks; furthermore, the samples need to be bonded to a bevel with a known angle, and then The bevel is bonded to the grinding and polishing disc. Two bondings result in poor stability. Moreover, new mechanical damage must be avoided when the sample is polished at an angle. It is best to grind and polish the bevel to a smooth surface. The smooth effect of the bevel directly affects the microscope. Resolution; finally, during slope measurement, the interface between the damaged layer and the non-damaged layer is determined by the naked eye, causing the measurement results to be greatly affected by the experience of the technician.

In view of this, the present invention hopes to provide a method and system for measuring the depth of the damage layer on the wafer surface; it can directly measure the depth of the damage layer on the wafer surface without inferring it through geometric relationships; at the same time, it can avoid the judgment error introduced by naked eye observation and improve Measurement accuracy.

The technical solution of the present invention is implemented as follows: First, the present invention provides a method for measuring the depth of the damage layer on the surface of a wafer. The steps include: measuring the surface of the wafer to be measured from the center to the edge of the wafer to be measured. Divide into multiple concentric circles to form multiple concentric ring areas; starting from the center to the edge of the wafer to be tested, use an etching solution with a set concentration for each concentric ring area and follow the set etching time. The etching operation forms steps with multiple step surfaces in the shape of concentric rings on the surface of the wafer to be tested; damage detection is performed on the multiple step surfaces in sequence until no damage is detected; when no damage is detected The depth of the damaged layer on the surface of the wafer to be tested is determined based on the height of the steps corresponding to all the detected damaged step surfaces; where the height of the step is calculated based on the etching rate and etching time of the etching solution.

In a second aspect, the present invention provides a system for measuring the depth of the damage layer on the surface of a wafer, which mainly includes: a dividing part configured to divide the surface of the wafer to be measured from the center to the edge of the wafer to be measured. Multiple concentric circles to form multiple concentric ring areas; the etching part, the etching part is configured to use an etching liquid of a set concentration for each concentric ring area from the center to the edge of the wafer to be tested. The etching operation is performed according to the set etching time, so that steps with multiple step surfaces and concentric rings are formed on the surface of the wafer to be tested; the detection part is configured to sequentially detect the multiple step surfaces. Perform damage detection until no damage is detected; the determination part is configured to determine the depth of the damage layer on the surface of the wafer to be tested based on the height of the steps corresponding to all the step surfaces where damage has been detected when no damage is detected. ; Among them, the height of the step is calculated based on the etching rate and etching time of the etching solution.

In a third aspect, the present invention provides a system for measuring the depth of the damage layer on a wafer surface, which mainly includes: a data processing device, a plurality of liquid pipelines and a detection device; wherein the data processing device is configured to: from the wafer to be tested From the center to the edge, the surface of the wafer to be tested is divided into multiple concentric circles to form multiple concentric ring areas; multiple liquid pipelines are used to circulate the etching liquid of the set concentration respectively to make the etching liquid of the set concentration The multiple concentric ring areas on the surface of the wafer to be tested are etched separately, so that steps with multiple step surfaces in the shape of concentric rings are formed on the surface of the wafer to be tested; the detection device is used to sequentially conduct multiple etching operations on the surface of the wafer to be tested. Damage detection is performed on each step surface until no damage is detected; the data processing device is also configured to: from the center to the edge of the wafer to be tested, control each concentric ring area to use an etching solution with a set concentration and Carry out the etching operation according to the set etching time; and, when no damage is detected, determine the depth of the damage layer on the surface of the wafer to be tested based on the height of the steps corresponding to all the step surfaces with detected damage; where, the step The height is calculated based on the etching rate and etching time of the etching solution.

The invention provides a method, system and computer storage medium for measuring the depth of the damage layer on the surface of a wafer. With the technical solution of the invention, the depth of the damage layer can be directly measured on the entire wafer, and the entire wafer can be divided into multiple The concentric ring area is then immersed in the etching solution and etched according to the set concentration and set etching time to generate multiple steps, so that the depth of the damage layer on the wafer surface can be obtained according to the height of the steps. In this method, since there is no need to split the wafer into samples, there is no problem of poor stability caused by two bondings when angularly polishing the samples, and there is no need to introduce new wafers on the bevel due to angle polishing. Damage affects the measurement results, thereby saving the production process, thereby reducing costs and improving the accuracy of measurement results.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Currently, the commonly used methods to measure the depth of the wafer damage layer include the angle polishing method, which requires splitting the wafer into small samples. The angle polishing method usually includes the following steps: splitting the wafer into multiple smaller-sized samples; bonding the samples to a bevel with a known angle using, for example, resin glue, and then bonding the bevel to the grinding and polishing disc; grinding the cross-section of the sample Polish to a slope of a known angle so that the damaged layer on the wafer surface can be exposed on the slope of a known angle; use a special fixture to hold the sample and put it into the etching solution for etching so that the damaged layer can be exposed on the slope of the known angle. The inclined surface of the known angle is further magnified and displayed; and the dividing line or interface of the bonded sample is observed using a microscope, and the cracks on the inclined surface of the known angle are measured based on the length of the cracks at the dividing line and the number and distribution of corrosion pits. the length of the damage, and the known angle between this length L and Calculate the sine value of to obtain the depth of the damaged layer, as shown in Figure 1. The depth H of the damaged layer is expressed as .

However, as can be seen from the above steps, this method requires splitting the wafer to obtain smaller samples, and during the specific implementation process, the size of the samples is usually less than 1cm × 1cm, making it difficult to operate during angle polishing; at the same time, When etching the polished sample, a separate fixture and tank need to be designed; the sample must be bonded to a bevel with a known angle, and the bevel must be bonded to the grinding and polishing disc again. The two bondings lead to stability. Poor; when angularly polishing the sample, it is necessary to avoid introducing new damage. It is best to grind the bevel to a smooth surface. The smooth effect of the bevel directly affects the microscope resolution; moreover, when measuring the bevel, the interface between the damaged layer and the non-damaged layer is determined by the naked eye. , which makes the measurement results greatly affected by the experience of the technician.

In order to solve the above problems, embodiments of the present invention are expected to provide a technical solution that decomposes the thickness of the damage layer on the wafer surface so as to directly measure the depth of the damage layer on the wafer surface. Specifically, refer to Figure 2, which shows an etching device 2 capable of implementing the technical solution of the embodiment of the present invention. The etching device 2 includes: a plurality of liquid pipelines 21 (21-A~21-F), respectively. Used to circulate the etching liquid with a set concentration to etch the surface of the wafer W in regions, so that steps with multiple step surfaces and concentric rings are formed on the surface of the wafer W; multiple liquid supply units 22 ( 22-A~22-F), used to supply the etching liquid of the set concentration to the corresponding liquid pipeline 21 respectively.

Based on the etching device 2 shown in Figure 2 above, see Figure 3, which shows a method for measuring the depth of the damage layer on the wafer surface provided by an embodiment of the present invention. The steps include: S301. From the center of the wafer to be measured To the edge direction, divide the surface of the wafer to be tested into multiple concentric circles to form multiple concentric ring areas; S302. Starting from the center of the wafer to be tested to the edge direction, use a set concentration for each concentric ring area. The etching solution is used and the etching operation is performed according to the set etching time, so that steps with multiple step surfaces and concentric rings are formed on the surface of the wafer to be tested; S303, damage the multiple step surfaces in sequence. Detect until no damage is detected; S304. When no damage is detected, determine the depth of the damage layer on the surface of the wafer to be tested based on the heights of the steps corresponding to all the step surfaces where damage has been detected; wherein, the height of the steps is based on The etching rate and etching time of the etching solution are calculated and obtained.

For the technical solution shown in Figure 3, in order to directly etch the damaged layer on the surface of the wafer W, in the embodiment of the present invention, the surface of the wafer W is divided into multiple concentric ring areas in advance, as shown in Figure 4 As shown, each liquid pipeline 21 corresponds to a corresponding concentric annular area. For example, the liquid pipeline 21-A corresponds to the smallest concentric annular area. During the specific implementation process, the etching liquid flows through multiple liquid pipelines 21 to match the The surface of wafer W is in contact. During the specific implementation process, for example, an etching liquid with a set concentration is passed from the liquid pipeline 21-A to the liquid pipeline 21-F, and the etching time t corresponding to each concentric circle area is from the liquid pipeline 21-A to the liquid pipeline 21-F. The liquid pipeline 21-F gradually increases; or the etching time t corresponding to each concentric circle area is equal, and the etching liquid concentration gradually increases from the liquid pipeline 21-A to the liquid pipeline 21-F. Based on this etching method, steps as shown in Figure 5 will be formed from the center to the edge of the surface of the wafer W. It can be understood that when no damage is detected, the height of the steps corresponding to all step surfaces with damage is counted. And calculate and obtain the height h of each step above based on the etching rate v of the etching solution and the etching time t, and finally obtain the depth of the surface damage layer of the wafer based on the height of all steps corresponding to all damaged step surfaces. H.

It can be understood that in the embodiment of the present invention, the depth H of the damage layer on the surface of the wafer W is related to the number of divided concentric ring areas (that is, the number of step surfaces) and the height of each step.

For the technical solution shown in Figure 3, the depth of the damaged layer can be measured directly on the entire wafer W. The entire wafer W is divided into multiple concentric ring areas and then immersed in the etching liquid. The etching liquid can pass through multiple Each liquid pipe 21 is in contact with the corresponding concentric annular area for etching. In this method, since there is no need to split the wafer into samples, there is no problem of poor stability caused by two bondings when angularly polishing the samples, and there is no need to introduce new wafers on the bevel due to angle polishing. Damage affects the measurement results, thereby saving the production process, thereby reducing costs and improving the accuracy of measurement results.

For the technical solution described in Figure 3, in some possible implementations, from the center to the edge of the wafer to be tested, an etching solution with a set concentration is used for each concentric ring area and according to the set etching time. The etching operation is performed for a long time to form steps with multiple step surfaces in the shape of concentric rings on the surface of the wafer to be tested, including: starting from the center of the wafer to be tested to the edge direction, for each concentric ring The etching operation is carried out in each area using the same concentration of etching solution and the etching time corresponding to each concentric ring area is gradually increasing, so that multiple step surfaces and concentric rings are formed on the surface of the wafer to be tested. shaped steps.

Specifically, the height h of each step can be calculated by the formula h=v×t. From the center to the edge of the wafer to be tested, when the etching time t of each concentric ring area increases arithmetic, the height h of each step is also equal. In this case, the depth H of the surface damage layer of the wafer can be directly calculated through the formula H=n×h, where n represents the total number of all step surfaces with detected damage.

On the other hand, from the center to the edge of the wafer to be tested, when the etching time t of each concentric ring area does not increase asymmetrically, the height h of each step is also unequal. In this case, the depth H of the surface damage layer of the wafer can be obtained by adding the step height h corresponding to all step surfaces where damage is detected.

For the technical solution described in Figure 3, in some possible implementations, from the center to the edge of the wafer to be tested, an etching solution with a set concentration is used for each concentric ring area and according to the set etching time. The etching operation is performed for a long time to form steps with multiple step surfaces in the shape of concentric rings on the surface of the wafer to be tested, including: starting from the center of the wafer to be tested to the edge direction, for each concentric ring The etching operation is carried out in each area with equal etching time and the concentration of the etching solution corresponding to each concentric ring area gradually increases, so that multiple step surfaces and concentric circles are formed on the surface of the wafer to be tested. Circular steps.

Specifically, from the center to the edge of the wafer to be tested, when the etching concentration of the etching solution corresponding to each concentric ring area increases arithmetic, the height h of each step is also equal. In this case, the depth H of the surface damage layer of the wafer can be directly calculated through the formula H=n×h, where n represents the total number of all step surfaces with detected damage.

On the other hand, from the center to the edge of the wafer to be tested, when the etching concentration of the etching solution corresponding to each concentric ring area does not increase arithmetic, the height h of each step is also unequal. of. In this case, the depth H of the surface damage layer of the wafer can be obtained by adding the step height h corresponding to all step surfaces where damage is detected.

For the technical solution described in Figure 3, in some possible implementations, damage detection is performed on multiple step surfaces in sequence until no damage is detected, including: roughness detection is performed on multiple step surfaces in sequence. When the roughness becomes constant, it indicates that no damage is detected.

Specifically, the detection of whether there is damage on the step surface can be achieved by detecting the roughness at each step surface. For this roughness detection process, after placing the wafer with the step surface on the test platform, as shown in Figure 6, the roughness detector, specifically the roughness probe 11 of the roughness detector, can be moved to detect the roughness. The roughness of a plurality of step surfaces of the wafer W carried on the carrying base 10 at a fixed position is detected sequentially.

Alternatively, the carrying base 10 for carrying the wafer W can also be moved, so that the roughness detector, specifically the roughness probe 11 of the roughness detector, in a fixed position detects a series of changes on the surface of the wafer 100 The roughness of the step surface is tested sequentially.

Figure 7 shows the detected step surface roughness value change curve. It can be understood that when there is no damage on the step surface and the roughness value tends to remain unchanged, that is, the curve in Figure 7 also changes from the curvature to approaching a horizontal straight line, it is judged that the etching has reached a perfect layer. , that is, no damage is detected.

For the technical solution described in Figure 3, in some possible implementations, damage detection is performed on multiple step surfaces in sequence until no damage is detected, including: performing X-ray diffraction detection on multiple step surfaces in sequence. When the detection No damage is detected until the half-width of the diffraction front becomes constant.

Specifically, the detection of whether there is damage on the step surface can be achieved by performing X-ray diffraction detection on each step surface. For the X-ray diffraction detection process, after placing the wafer W with the step surface on the test platform, as shown in Figure 8, the carrying base 10 for carrying the wafer W can be moved so that the X in the fixed position The ray diffractometer 12 sequentially performs X-ray diffraction detection on the plurality of step surfaces formed on the surface of the wafer W. As shown in Figure 8, X-rays are emitted from the X-ray diffractometer, diffracted at the step surface, and then received by the X-ray diffractometer.

Similarly, alternatively, the X-ray diffractometer 12 can also be moved to sequentially perform X-ray diffraction detection on multiple step surfaces of the wafer W carried on the carrying base 10 at a fixed position.

Figure 9 shows the change curve of the half-height width of the diffraction peak corresponding to the detected step surface. It can be understood that when there is no damage in the step surface, when the half-width of the diffraction peak tends to remain unchanged, and the curve in Figure 9 also changes from the curvature to approaching a horizontal straight line, it is judged that the etching has reached a perfect layer. , that is, no damage is detected.

In this method, for example, roughness detection or X-ray diffraction is used to detect each step surface to achieve a clear determination of the presence or absence of damage to the step surface, thus avoiding human judgment errors that may be introduced by naked eye observation.

Of course, in the embodiment of the present invention, detection methods in other related technologies can also be used to detect whether there is damage on the step surface, and the present invention is not limited to this.

For the technical solution described in Figure 3, in some possible implementations, the method for determining the etching rate includes: measuring the initial thickness of the sample wafer; immersing the sample wafer in an etching solution of a set concentration and etching for a specific time After growing, take it out; measure the remaining thickness of the etched sample wafer; calculate the etching rate corresponding to the set concentration of etching solution based on the difference between the initial thickness and the remaining thickness and a specific time period.

Specifically, for example, a whole wafer can be used as a test wafer. First, measure the initial thickness d ₀ of the test wafer, put it into an etching solution with a set concentration, etch it for a specific period of time t', and then take it out as a whole. Then the thickness at this time, that is, the remaining thickness, is measured as d ₁ . From this, the etching rate can be calculated according to v=(d ₁ -d ₀ )/t. For example, put the wafer into Bright etching solution which is composed of nitric acid, hydrofluoric acid, acetic acid and distilled water in a volume ratio of 4:1:2:3. After testing and calculation, the etching rate is 6um/ min. It is understandable that in embodiments of the present invention, etching solutions with different concentrations will be used, so the etching rates v corresponding to the above-mentioned etching solutions with different concentrations can be obtained in advance.

For the technical solution described in Figure 3, in some possible implementations, when no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the height of the steps corresponding to all step surfaces where damage has been detected, Including: when no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the product of the number of step surfaces with detected damage and the step height.

It can be understood that when the height h of each step is consistent, the depth H of the damage layer on the surface of the wafer to be tested can be determined based on the product of the number n of all step surfaces with detected damage and the step height h.

For the technical solution described in Figure 3, in some possible implementations, when no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the height of the steps corresponding to all step surfaces where damage has been detected, It includes: when no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the sum of the step heights corresponding to all step surfaces where damage has been detected.

It can be understood that when the height h of each step is inconsistent, the depth H of the damage layer on the surface of the wafer to be tested can be determined based on the sum of all step heights h corresponding to all step surfaces where damage has been detected.

Based on the same inventive concept of the foregoing technical solution, see Figure 10, which shows a system 100 for measuring the depth of the damage layer on the wafer surface provided by an embodiment of the present invention. The system 100 for measuring the depth of the damage layer on the wafer surface includes: a dividing part 101. The dividing part 101 is configured to divide the surface of the wafer to be tested into multiple concentric circles from the center to the edge of the wafer to form multiple concentric ring areas; the etching part 102, the etching part 102 is From the center to the edge of the wafer to be tested, the etching solution with a set concentration is used for each concentric ring area and the etching operation is performed according to the set etching time, so that the surface of the wafer to be tested is formed. A step with multiple step surfaces in the shape of concentric rings; the detection part 103 is configured to perform damage detection on the multiple step surfaces in sequence until no damage is detected; the determination part 104 is configured When no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the height of the steps corresponding to all the step surfaces where damage has been detected; where, the height of the step is based on the etching rate of the etching solution and the etching time. Obtained by long calculation.

It should be noted that, for specific implementation methods or implementation examples of the functions configured by each of the above components, please refer to the corresponding steps, implementation methods and examples of the foregoing technical solutions, and the embodiments of the present invention will not be described in detail here.

It can be understood that in this embodiment, "part" may be part of a circuit, part of a processor, part of a program or software, etc. Of course, it may also be a unit, or may be a module or non-modular.

In addition, each component in this embodiment can be integrated into one processing unit, or each unit can exist independently, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or software function modules.

If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially The part that contributes to the relevant technology or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions to enable a computer device (which can be a personal computer). Computer, server, or network equipment, etc.) or processor executes all or part of the steps of this embodiment. The aforementioned storage media include: USB disk, mobile hard disk, read only memory (ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk, etc. that can store program code. medium.

Therefore, this embodiment provides a computer storage medium. The computer storage medium stores a program for measuring the depth of the damage layer on the wafer surface. The program for measuring the depth of the damage layer on the wafer surface is executed by at least one processor to implement the measurement described in the above technical solution. Method steps for determining the depth of the damage layer on the wafer surface.

Based on the above-mentioned system 100 for measuring the depth of the damage layer on the wafer surface and the computer storage medium, see Figure 11, which shows the hardware structure of the system 100 for measuring the depth of the damage layer on the wafer surface, which may include: a data processing device 111, multiple A liquid pipeline 21 and a detection device 112; wherein, the data processing device 111 is configured to: from the center of the wafer W to be tested to the edge direction, divide the surface of the wafer W to be tested into a plurality of concentric circles to form a plurality of concentric circles. Ring area; the plurality of liquid pipes 21 are used to respectively circulate the etching liquid with a set concentration so that the etching liquid with the set concentration can perform etching operations on multiple concentric annular areas on the surface of the wafer W to be measured, so that in Steps with multiple step surfaces in the shape of concentric rings are formed on the surface of the wafer to be tested; the detection device 112 is used to perform damage detection on the multiple step surfaces in sequence until no damage is detected; the data processing device 111 also It is configured to: from the center to the edge of the wafer to be tested, control each concentric ring area to use the etching solution with a set concentration and perform the etching operation according to the set etching time; and, when no damage is detected The depth of the damaged layer on the surface of the wafer to be tested is determined based on the height of the steps corresponding to all the detected damaged step surfaces; where the height of the step is calculated based on the etching rate and etching time of the etching solution.

Specifically, the data processing device 111 can be a wireless device, a mobile or cellular phone (including a so-called smart phone), a personal digital assistant (Personal Digital Assistant, PDA), an audio-visual game console (including an audio-visual display, a mobile electronic Game devices, mobile video conferencing units), notebook computers, desktop computers, TV top boxes, tablet computers, e-book readers, settings or mobile media players, etc. The specific hardware structure can be shown in Figure 12 , including: communication interface 1201, memory 1202 and processor 1203; each component is coupled together through a system bus 1204. It can be understood that the system bus 1204 is used to implement connection and communication between these components. In addition to the data bus, the system bus 1204 also includes a power bus, a control bus, and a status signal bus. However, for clarity of illustration, the various buses are labeled system bus 1204 in FIG. 12 . Among them, the communication interface 1201 is used to receive and send signals in the process of sending and receiving information with other external network elements; the memory 1202 is used to store computer programs that can run on the processor 1203; the processor 1203, It is used to execute the functions and steps configured by each component in the data processing device 111 when running the computer program.

It can be understood that the memory 1202 in the embodiment of the present invention may be a volatile memory or a flash memory, or may include both volatile and flash memories. Among them, flash memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable rewritable read-only memory (Erasable PROM, EPROM) , Electronically erasable rewritable read-only memory (Electrically EPROM, EEPROM) or flash memory. Flash memory may be random access memory (RAM), which is used as an external high-speed cache. By way of illustration, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (Enhanced SDRAM, ESDRAM), Synchronous Linked Dynamic Random Access Memory (Synch Link DRAM, SLDRAM) and direct memory bus random access memory (Direct Rambus RAM, DRRAM). The memory 1202 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

The processor 1203 may be an integrated circuit chip with signal processing capabilities. During the implementation process, each step of the above method can be completed by instructions in the form of hardware integrated logic circuits or software in the processor 1203 . The above-mentioned processor 1203 can be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. Each method, step and logical block diagram disclosed in the embodiment of the present invention can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may be a processor in any related technology, etc. The steps of the method disclosed in conjunction with the embodiments of the present invention can be directly implemented by a hardware decoder, or executed by a combination of hardware and software modules in the decoder. The software module can be located in random access memory, flash memory, read-only memory, programmable read-only memory or electronically erasable rewritable read-only memory, temporary storage and other mature storage media in this field. The storage medium is located in the memory 1202. The processor 1203 reads the information in the memory 1202 and completes the steps of the above method in combination with its hardware.

It should be understood that the embodiments described in the present invention can be implemented using hardware, software, firmware, middleware, microprograms, or combinations thereof. For hardware implementation, the processing unit can be implemented in one or more Application Specific Integrated Circuits (ASIC), Digital Signal Processing (DSP), Digital Signal Processor (DSP Device, DSPD) , Programmable Logic Device (PLD), Field-Programmable Gate Array (FPGA), general-purpose processor, controller, microcontroller, microprocessor, used to execute this Invent other electronic units or combinations thereof with the described functions.

For software implementation, the technology described in the present invention can be implemented through modules (such as procedures, functions, etc.) that perform the functions described in the present invention. Software code can be stored in memory and executed by the processor. The memory can be implemented in the processor or external to the processor.

It should be noted that the technical solutions recorded in the embodiments of the present invention can be combined arbitrarily as long as there is no conflict.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field and having ordinary knowledge can easily think of changes or substitutions within the technical scope disclosed in the present invention. All are covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the patent application.

10: Carrying base 11: Roughness probe 12: X-ray diffractometer 100, W: Wafer 101: Division part 102: Etching part 103: Detection part 104: Determination part 111: Data processing device 112: Detection device 1201: Communication interface 1202: Memory 1203: Processor 1204: System bus 2: Etching device 21, 21-A~22-F: Liquid pipeline 22, 22-A~22-F: Liquid supply unit S301~S304: Step process h: height L: length H: depth n: quantity :angle

Figure 1 is a schematic diagram of the method for obtaining the depth of the damage layer on the wafer surface in the related art; Figure 2 is a schematic structural diagram of an etching device provided by an embodiment of the present invention; Figure 3 is a schematic flow chart of a method for measuring the depth of a damaged layer on a wafer surface provided by an embodiment of the present invention; Figure 4 is a schematic diagram of a wafer surface divided into multiple concentric circles according to an embodiment of the present invention; Figure 5 is a schematic diagram of multiple steps formed after etching a wafer according to an embodiment of the present invention; Figure 6 is a schematic diagram of the operation process of using roughness detection to detect damage to step surfaces according to an embodiment of the present invention; Figure 7 is a schematic diagram of the change curve of the step surface roughness value provided by the embodiment of the present invention; Figure 8 is a schematic diagram of the operation process of using X-ray diffraction detection to realize damage detection on step surfaces according to an embodiment of the present invention; Figure 9 is a schematic diagram of the change curve of the half-height width of the diffraction peak corresponding to the step surface provided by the embodiment of the present invention; Figure 10 is a schematic diagram of a system for measuring the depth of a damaged layer on a wafer surface provided by an embodiment of the present invention; Figure 11 is a schematic diagram of a system for measuring the depth of a damaged layer on a wafer surface provided by an embodiment of the present invention; Figure 12 is a schematic diagram of the hardware composition provided by an embodiment of the present invention.

S301~S304: step process

Claims (10)

A method for measuring the depth of damage layer on a wafer surface, the steps include: Divide the surface of the wafer to be tested into multiple concentric circles from the center to the edge of the wafer to be tested to form multiple concentric ring areas; Starting from the center to the edge of the wafer to be tested, use an etching solution with a set concentration for each concentric ring area and perform the etching operation according to the set etching time, so that on the surface of the wafer to be tested, Form steps with multiple step surfaces in the shape of concentric rings; Conduct damage detection on such step surfaces in sequence until no damage is detected; When no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the heights of the steps corresponding to all the step surfaces where damage has been detected; wherein, the height of the steps is determined according to the etching solution. The etching rate and etching time are calculated and obtained. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein from the center of the wafer to be measured to the edge direction, a set concentration of the etching liquid is used for each concentric ring area and according to the set The etching operation is performed for an etching time such that steps having the step surfaces and concentric annular shapes are formed on the surface of the wafer to be tested, including: Starting from the center to the edge of the wafer to be tested, an etching operation is performed on each concentric ring area using the same concentration of the etching solution and the etching time corresponding to each concentric ring area gradually increases. The steps having the step surfaces and concentric annular shapes are formed on the surface of the wafer to be tested. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein from the center of the wafer to be measured to the edge direction, a set concentration of the etching liquid is used for each concentric ring area and according to the set The etching operation is performed for an etching time such that steps having the step surfaces and concentric annular shapes are formed on the surface of the wafer to be tested, including: Starting from the center to the edge of the wafer to be tested, an etching operation is performed for each concentric ring area with an equal etching time and a gradually increasing concentration of the etching solution corresponding to each concentric ring area. , so that the steps having the step surfaces and concentric annular shapes are formed on the surface of the wafer to be tested. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein damage detection is performed on the stepped surfaces in sequence until no damage is detected, including: The roughness of these step surfaces is detected in sequence. When the detected roughness tends to remain unchanged, it means that no damage has been detected. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein damage detection is performed on the stepped surfaces in sequence until no damage is detected, including: X-ray diffraction detection is performed on these step surfaces in sequence. When the half-maximum width of the diffraction front is detected to be constant, it indicates that no damage has been detected. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein the method for determining the etching rate includes: Measure the initial thickness of the sample wafer; The sample wafer is immersed in the etching solution with a set concentration and etched for a specific period of time and then taken out; Measure the remaining thickness of the etched sample wafer; The etching rate corresponding to the etching liquid with a set concentration is calculated based on the difference between the initial thickness and the remaining thickness and a specific time period. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein when no damage is detected, the wafer to be tested is determined based on the height of the steps corresponding to all the step surfaces where the damage has been detected. The depth of the damage layer on the surface, including: When no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the product of the number of step surfaces with detected damage and the step height. The method for measuring the depth of the damage layer on the wafer surface as described in claim 1, wherein when no damage is detected, the wafer to be tested is determined based on the height of the steps corresponding to all the step surfaces where the damage has been detected. The depth of the damage layer on the surface, including: When no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the sum of the step heights corresponding to all the step surfaces where damage has been detected. A system for measuring the depth of the damage layer on the wafer surface, which mainly includes: A dividing part configured to divide the surface of the wafer to be tested into a plurality of concentric circles from the center to the edge of the wafer to be tested to form a plurality of concentric ring areas; The etching part is configured to use an etching liquid of a set concentration for each concentric ring area from the center to the edge of the wafer to be tested and perform the etching operation according to the set etching time. , so that steps with multiple step surfaces and concentric annular shapes are formed on the surface of the wafer to be tested; A detection part configured to perform damage detection on the step surfaces in sequence until no damage is detected; The determination part is configured to determine the depth of the damage layer on the surface of the wafer to be tested based on the heights of the steps corresponding to all the step surfaces where damage has been detected when no damage is detected; wherein, the The height of the step is calculated based on the etching rate and etching time of the etching solution. A system for measuring the depth of the damage layer on the surface of a wafer, which mainly includes: a data processing device, a plurality of liquid pipelines and a detection device; wherein, The data processing device is configured to: divide the surface of the wafer to be tested into a plurality of concentric circles from the center to the edge of the wafer to be tested to form a plurality of concentric ring areas; The liquid pipelines are used to respectively circulate the etching liquid of a set concentration so that the etching liquid of the set concentration can perform an etching operation on each concentric annular area on the surface of the wafer to be tested, so that the etching liquid is etched on the surface of the wafer to be tested. Concentric ring-shaped steps with multiple step surfaces are formed on the surface of the wafer; The detection device is used to detect damage to the step surfaces in sequence until no damage is detected; The data processing device is also configured to: From the center to the edge of the wafer to be tested, control each concentric ring area to use the etching solution with a set concentration and perform the etching operation according to the set etching time; And, when no damage is detected, the depth of the damage layer on the surface of the wafer to be tested is determined based on the heights of the steps corresponding to all the step surfaces where damage has been detected; wherein, the height of the steps is based on the height of the steps. The etching rate and etching time of the etching solution are calculated and obtained.

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