Ion implantation dose monitoring method, computer equipment, storage medium and product

Abstract

The invention relates to the technical field of ion implantation processing, and discloses an ion implantation dose monitoring method, computer equipment, a storage medium and a product, and the method comprises the steps: carrying out the ion implantation processing of a semiconductor wafer; determining a first reflectivity of the semiconductor wafer after ion implantation processing; and monitoring the ion implantation dose based on the first reflectivity. According to the invention, the ion implantation dose and the stability thereof are monitored through the reflectivity of the surface of the semiconductor wafer, so that the situation that the dose and the stability of doped ions cannot be reflected by measuring the square resistance due to stripping of the wafer surface after high-temperature activation after certain ions (such as hydrogen ions, helium ions and the like) are doped can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of ion implantation processing, and in particular to a method for monitoring ion implantation dosage, computer equipment, storage medium and product. Background Art

[0002] In the manufacturing process of Silicon on Insulator (SOI) wafer SmartCut technology, hydrogen ion implantation is involved so that the wafer can be split in the subsequent process. During the hydrogen ion implantation process, if the hydrogen ion implantation dose is unstable, the wafer may not be split or the split may be abnormal, which may lead to the scrapping of SOI wafer.

[0003] At present, common N-type implanted ions such as arsenic ions (AS+) or phosphorus ions (P+) can be implanted using wafer control based on specific ion implantation conditions, and then undergo rapid thermal treatment to measure the stability of the ion implantation dose by measuring the block resistance. However, when testing the hydrogen ion implantation dose and its stability in the above manner, the high temperature environment required to measure the block resistance can easily cause the hydrogen ions to form hydrogen (H2) at the implantation layer interface, resulting in peeling of the wafer surface and even fragmentation. Summary of the invention

[0004] In view of this, the present invention provides a method for monitoring ion implantation dose, a computer device, a storage medium and a product to solve the problem that it is difficult to effectively monitor the hydrogen ion implantation process dose and its stability in the wafer by measuring the resistance of the block after heat treatment.

[0005] In a first aspect, the present invention provides a method for monitoring an ion implantation dose, the method comprising: performing an ion implantation process on a semiconductor wafer; determining a first reflectivity of the semiconductor wafer after the ion implantation process; and monitoring the ion implantation dose based on the first reflectivity.

[0006] The method for monitoring ion implantation dose provided in this embodiment determines a first reflectivity after ion implantation is performed on a semiconductor wafer, and then monitors the ion implantation dose based on the first reflectivity. This can avoid a high-temperature heat treatment environment, thereby effectively monitoring the ion implantation dose and its stability, and reducing product risks caused by unstable ion implantation dose.

[0007] In an optional implementation, monitoring the ion implantation dose based on the first reflectivity includes: monitoring whether the ion implantation dose is stable based on the first reflectivity.

[0008] In an optional embodiment, based on the first reflectivity, monitoring whether the ion implantation dose is stable includes: determining the first reflectivity variation range based on a first corresponding relationship and a first preset reflectivity, wherein the first corresponding relationship is used to characterize the sensitivity of the first reflectivity to the ion implantation dose; if the first reflectivity is within the first reflectivity variation range, the ion implantation dose is stable.

[0009] In this embodiment, the first reflectivity variation range is determined based on the first corresponding relationship and the first preset reflectivity, and then whether the ion implantation dose is stable is determined based on whether the first reflectivity is within the first reflectivity variation range, which can improve the accuracy of the judgment.

[0010] In an optional embodiment, before monitoring whether the ion implantation dose is stable based on the first reflectivity, the method further includes: fitting and determining a first corresponding relationship based on reflectivities corresponding to the semiconductor wafer under a plurality of different ion implantation doses.

[0011] In an optional embodiment, before performing ion implantation on the semiconductor wafer, the method also includes: determining a second reflectivity of the semiconductor wafer before the ion implantation; based on the first reflectivity, monitoring whether the ion implantation dose is stable, including: determining a relative reflectivity based on the first reflectivity and the second reflectivity; and determining whether the ion implantation dose is stable based on the relative reflectivity.

[0012] In this embodiment, ion implantation is performed after the second reflectivity is determined, and then the relative reflectivity is determined based on the first reflectivity and the second reflectivity. Based on the relative reflectivity, whether the ion implantation dose is stable is determined by statistical process control, which can reduce interference from external factors such as the test environment and test instruments, and further improve the accuracy of determining whether the ion implantation dose is stable.

[0013] In an optional embodiment, determining whether the ion implantation dose is stable is based on the relative reflectivity, including: determining the relative reflectivity variation range based on a second corresponding relationship and a second preset reflectivity, wherein the second corresponding relationship is used to characterize the sensitivity of the relative reflectivity to the ion implantation dose; if the relative reflectivity is within the relative reflectivity variation range, the ion implantation dose is stable.

[0014] In an optional embodiment, the ion implantation dose is monitored based on the first reflectivity, including: determining whether the ion implantation dose is within a target dose fluctuation range based on the first reflectivity; and stopping ion implantation processing on the semiconductor wafer when the ion implantation dose is within the target dose fluctuation range.

[0015] In an optional implementation, the semiconductor wafer is a P-type substrate doped wafer or an N-type substrate doped wafer.

[0016] In an optional embodiment, the ion types of the ion implantation process include hydrogen ions, helium ions, argon ions, xenon ions, etc.

[0017] In a second aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0018] In a third aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to cause a computer to execute the method of the first aspect or any corresponding embodiment thereof.

[0019] In a fourth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a schematic flow chart of a method for monitoring ion implantation dose according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram of a two-dimensional map of 49-point absolute reflectivity measured according to an embodiment of the present invention;

[0023] Figure 3 is a flow chart of another method for monitoring ion implantation dose according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of a path of light on a semiconductor wafer according to an embodiment of the present invention;

[0025] Figure 5 is a schematic diagram of a first corresponding relationship at a wavelength of 633 nm according to an embodiment of the present invention;

[0026] Figure 6 is a schematic diagram of a first corresponding relationship at a wavelength of 248 nm according to an embodiment of the present invention;

[0027] Figure 7is a schematic diagram of a first corresponding relationship at a wavelength of 193 nm according to an embodiment of the present invention;

[0028] Figure 8 is a flow chart of another method for monitoring ion implantation dose according to an embodiment of the present invention;

[0029] Fig. 9 is a structural block diagram of an ion implantation dose monitoring device according to an embodiment of the present invention;

[0030] Fig.10 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] Silicon on Insulator (SOI) adds a buried oxide layer (BOX) between the top silicon and the substrate. This structure electrically isolates the top silicon and the substrate, which can reduce the parasitic capacitance between transistors, reduce the delay in signal transmission, and increase the operating speed of the circuit. It also reduces the leakage current from the substrate to the top silicon device and reduces the power consumption of the circuit.

[0033] At present, SOI wafers can be manufactured based on Smart Cut technology. Specifically, two silicon (Si) wafers are first oxidized at high temperature to form a surface oxide layer. Then, a large amount of hydrogen ions (H+) are injected into the oxide layer of one of the wafers using an ion implanter to form a hydrogen ion implantation layer on the silicon substrate. Subsequently, the two oxide layers are bonded to each other by hydrophilic bonding and heated to 400°C to 600°C to break the hydrogen ion implantation layer and separate the excess Si layer. Finally, after annealing and chemical mechanical polishing (CMP), an SOI structure is formed.

[0034] When using Smart Cut technology to manufacture SOI wafers, it is necessary to monitor the stability and uniformity of the ion implantation dose to improve the problem of silicon wafers being unable to split or splitting abnormally due to unstable ion implantation doses. Usually, the stability and uniformity of the ion implantation dose is measured by performing high-temperature rapid thermal treatment after ion implantation and then measuring the block resistance. However, the block resistance test requires a high-temperature annealing process to activate the implanted ions, and hydrogen ions are prone to form H2 at high temperatures due to their own characteristics, causing wafer peeling or fragmentation. That is, when the hydrogen ion implantation dose and its stability are monitored by using block resistance, the silicon wafer is easily damaged, reducing the production yield of SOI wafers.

[0035] In view of this, the present invention provides a method for monitoring ion implantation dose, which determines the ion implantation dose and its stability by the reflectivity of the semiconductor wafer surface, thereby avoiding a high-temperature heat treatment environment, thereby effectively monitoring the implantation dose and its stability of ions that may cause damage or cracking to the wafer in a high-temperature heat treatment environment.

[0036] The ion implantation dose monitoring method provided by the present invention can be used in semiconductor manufacturing processes such as ion implantation and rapid thermal processing.

[0037] Figure 1 FIG. 1 is a flow chart of a method for monitoring ion implantation dose according to an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0038] Step S101, performing ion implantation on a semiconductor wafer.

[0039] Specifically, an ion implanter may be used to perform ion implantation on a semiconductor wafer, wherein process parameters of the ion implantation (such as ion type and ion implantation energy, etc.) may be determined by a designer according to process requirements.

[0040] The present invention does not specifically limit the ion type. For example, the ion type can be hydrogen ions, helium ions, argon ions or xenon ions that easily generate gas molecules at high temperatures, or the ion type can be conventional implantation type ions such as arsenic ions or phosphorus ions.

[0041] Exemplarily, the semiconductor wafer may be a P-type substrate doped wafer or an N-type substrate doped wafer.

[0042] Step S102, determining a first reflectivity of the semiconductor wafer after ion implantation.

[0043] Specifically, the first reflectivity refers to the absolute reflectivity of the semiconductor wafer after ion implantation.

[0044] After the semiconductor wafer is ion implanted, the absolute reflectivity of the target position (such as the center of the semiconductor wafer) can be directly determined as the first reflectivity, or the absolute reflectivity of multiple preset positions can be determined as the first reflectivity. The multiple preset positions can be set by the designer based on experience.

[0045] For example, Figure 2 As shown, the absolute reflectivity of 49 positions on the surface of the semiconductor wafer can be determined, and then the average value (Average) of the absolute reflectivity of the 49 positions is determined as the first reflectivity. Moreover, the two-dimensional map (Map) presented by the measured 49-point absolute reflectivity can reflect the uniformity (uniformity) of the ion implantation dose to a certain extent. Specifically, the uniformity can be characterized based on the standard deviation of the measured 49-point absolute reflectivity.

[0046] Exemplarily, the ion implantation dose monitoring device can use an optical measuring instrument to determine the absolute reflectivity by detecting the spectral characteristics of light after reflection from the surface of the semiconductor wafer; the ion implantation dose monitoring device can also emit polarized light to the semiconductor wafer, and determine the absolute reflectivity by measuring the change in the polarization state (such as amplitude and phase) of the reflected light; the ion implantation dose monitoring device can also emit light to the surface of the semiconductor wafer from multiple angles, and determine the absolute reflectivity by the intensity of the reflected light at different angles.

[0047] Step S103: monitoring the ion implantation dose based on the first reflectivity.

[0048] Specifically, after determining the first reflectivity, it can be determined whether the ion implantation dose is stable based on the first reflectivity, or it can be determined whether the ion implantation dose reaches the target dose based on the first reflectivity. The target dose can be configured by the designer according to the process requirements.

[0049] For example, after determining the first reflectivity, whether the ion implantation dose is stable may be monitored by means of statistical process control (SPC).

[0050] The SPC method is a statistical method for monitoring the production process. By statistically analyzing the data, it is possible to determine whether the production process is stable and controlled. In the present invention, the data refers to the reflectivity of the semiconductor wafer, and the production process refers to the ion implantation process.

[0051] Specifically, after determining the first reflectivity, if the first reflectivity is within the statistical control range, the ion implantation dose is stable; if the first reflectivity is outside the statistical control range, the ion implantation dose is unstable, and the technicians can be notified through alarms and other devices to handle the situation (such as inspection or maintenance, etc.).

[0052] The statistical control range may be determined based on historical data or a pre-set standard. For example, the statistical control range may be [(X-3σ), (X+3σ)]. X represents the average reflectivity, σ represents the standard deviation, the average reflectivity refers to the average value of the absolute reflectivity of the semiconductor wafer after ion implantation obtained from the previous N months, the standard deviation refers to the standard deviation of the absolute reflectivity of the semiconductor wafer after ion implantation obtained from the previous N months, and N is greater than 0. For example, N may be 1, 1.5, 3, or 5, etc.

[0053] That is, in the first reflectivity less than or greater than When the ion implantation dose is unstable, the first reflectivity is greater than or equal to and the first reflectivity is less than or equal to When , ion implantation is stable.

[0054] Specifically, whether the ion implantation dose is stable can be determined online by SPC, or offline by SPC. Online determination is to continuously measure the first reflectivity of the semiconductor wafer during the production process, and determine whether the ion implantation is stable based on the first reflectivity. Offline determination is to select semiconductor wafers by sampling after the semiconductor wafers are removed from the production line, detect the first reflectivity of the extracted semiconductor wafers, and then determine whether the ion implantation is stable based on the first reflectivity.

[0055] Online determination can quickly discover potential problems and adjust production parameters in a timely manner, while offline determination can reduce the number of tests and improve production efficiency.

[0056] The ion implantation dose monitoring method provided in this embodiment determines a first reflectivity after ion implantation is performed on a semiconductor wafer, and then monitors the ion implantation dose based on the first reflectivity. This can avoid a high-temperature heat treatment environment, thereby effectively monitoring the ion implantation dose and reducing product risks caused by unstable ion implantation dose.

[0057] Figure 3 FIG. 1 is a flow chart of another method for monitoring ion implantation dose according to an embodiment of the present invention. Figure 3 As shown, the method comprises the following steps:

[0058] Step S301, performing ion implantation on the semiconductor wafer.

[0059] For details, please see Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0060] Step S302, determining a first reflectivity of the semiconductor wafer after ion implantation.

[0061] In this embodiment, an optical measuring instrument is used to determine the first reflectivity based on spectral reflectance (SR).

[0062] Specifically, Figure 4 As shown, when a beam of light (i.e., incident light 421) irradiates the surface of the semiconductor wafer 410, a portion of the light is transmitted (i.e., transmitted light 422) and the other portion of the light is reflected (i.e., reflected light 423). The optical measuring instrument decomposes the reflected light into lights of different wavelengths through a spectroscopic device (such as a grating), and then measures the intensity of the reflected light at each wavelength. The ratios of these reflected light intensities to the incident light intensities at different wavelengths constitute a spectral reflectance curve, and the first reflectance can be determined based on the spectral reflectance curve.

[0063] Step S303 , based on the reflectivity of the semiconductor wafer corresponding to a plurality of different ion implantation doses, a first corresponding relationship is determined by fitting.

[0064] The first corresponding relationship is used to characterize the sensitivity of the first reflectivity to the ion implantation dose.

[0065] Specifically, after obtaining the maximum ion implantation dose and the minimum ion implantation dose, the ion implantation doses are grouped in a certain gradient to obtain a plurality of different ion implantation doses, and then the semiconductor wafer is subjected to ion implantation treatment in order from small to large ion implantation doses to determine the reflectivity corresponding to each different ion implantation dose. The maximum ion implantation dose, the minimum ion implantation dose and the gradient can be determined by the designer, and the ion implantation energy is the same, for example, the ion implantation energy can be greater than 1000eV.

[0066] After determining the reflectivity of the semiconductor wafer under multiple different ion implantation doses, the first corresponding relationship can be determined by fitting software (such as Excel, etc.). The first corresponding relationship can be as follows Figures 5 to 7 As shown, Figure 5 It represents the first corresponding relationship at 633nm wavelength, Figure 6 Indicates the first correspondence at 248nm wavelength, Figure 7 It represents the first corresponding relationship at a wavelength of 193 nm.

[0067] The first corresponding relationship at 633 nm wavelength can be y=(7E-20)x+0.3471. At this time, the correlation coefficient R 2 =0.994; the first corresponding relationship at 248nm wavelength can be y=(2E-19)x+0.6734. At this time, the correlation coefficient R 2=0.9989; the first corresponding relationship at 193nm wavelength can be y=(9E-20)x+0.6713. At this time, the correlation coefficient R 2 =0.9908.

[0068] Specifically, at a wavelength of 248 nm, the reflectivity corresponding to different ion implantation doses may be as shown in Table 1, wherein the absolute reflectivity for each 1% change in ion implantation dose is 0.00012.

[0069] Table 1

[0070]

[0071] Step S304: determining whether the ion implantation dose is stable based on the first reflectivity.

[0072] Specifically, the above step S304 includes:

[0073] Step S3041, determining a first reflectivity variation range based on the first corresponding relationship and the first preset reflectivity.

[0074] Among them, the first preset reflectivity can be configured by the designer based on historical data. For example, the first preset reflectivity can be the average value of the absolute reflectivity of the ion semiconductor wafer after ion implantation treatment obtained in the previous N months, where N is greater than 0, and the first reflectivity variation range represents the variation range (interval) of the first reflectivity caused by the dose deviation allowed by the designer.

[0075] Specifically, (first preset reflectivity ±3ΔR1) can be determined as the first reflectivity variation range, wherein ΔR1 represents the first reflectivity variation value corresponding to a 1% change in ion implantation dose, and ΔR1 can be determined through the first corresponding relationship.

[0076] Step S3042: if the first reflectivity is within the first reflectivity variation range, the ion implantation dose is stable.

[0077] Specifically, when the first reflectivity is greater than the maximum value of the first reflectivity variation range or the first reflectivity is less than the minimum value of the first reflectivity variation range, the ion implantation dose is unstable; when the first reflectivity is greater than or equal to the minimum value of the first reflectivity variation range and the first reflectivity is less than or equal to the maximum value of the first reflectivity variation range, the ion implantation dose is stable.

[0078] For example, if the first reflectivity is greater than (the first preset reflectivity + 3ΔR1) or the first reflectivity is less than (the first preset reflectivity - 3ΔR1), the ion injection is unstable; if the first reflectivity is greater than or equal to (the first preset reflectivity - 3ΔR1) and the first reflectivity is less than or equal to (the first preset reflectivity + 3ΔR1), the ion injection is stable.

[0079] Step S305 , determining whether the ion implantation dose is within a target dose fluctuation range based on the first reflectivity.

[0080] Among them, the target dose fluctuation range can be configured by the designer based on process requirements.

[0081] Specifically, when the first reflectivity is within the target reflectivity variation range, the ion implantation dose is within the target dose fluctuation range; when the first reflectivity is not within the target reflectivity variation range, the ion implantation dose is not within the target dose fluctuation range. The maximum value of the target reflectivity variation range is the absolute reflectivity of the semiconductor wafer surface when the ion implantation dose is the maximum value of the target dose fluctuation range, and the minimum value of the target reflectivity variation range is the absolute reflectivity of the semiconductor wafer surface when the ion implantation dose is the minimum value of the target dose fluctuation range. The target reflectivity variation range can be determined based on the first corresponding relationship and the target dose fluctuation range, or can be determined based on an experiment.

[0082] Step S306, when the ion implantation dose is within the target dose fluctuation range, stop the ion implantation process on the semiconductor wafer.

[0083] Specifically, during the ion implantation process of the semiconductor wafer, the first reflectivity is determined at preset time intervals, and then whether the ion implantation dose is stable is determined based on the first reflectivity, and whether the ion implantation dose is within the target dose fluctuation range is determined based on the first reflectivity. When the ion implantation dose is stable and not within the target dose fluctuation range, the ion implantation process of the semiconductor wafer continues; when the ion implantation dose is unstable or the ion implantation dose is within the target dose fluctuation range, the ion implantation process of the semiconductor wafer is stopped.

[0084] Exemplarily, the step of monitoring the ion implantation dose based on the first reflectivity may include steps S304 to S306, or may only include step S304, or may only include steps S305 and S306.

[0085] In this embodiment, after the semiconductor wafer is subjected to ion implantation, the first reflectivity is determined based on SR using an optical measuring instrument, and the measurement can be completed without contact, thereby avoiding the introduction of contaminants or loss of the semiconductor wafer surface. Moreover, the SR measurement can detect slight changes in the wafer surface, thereby improving the accuracy of the determined first reflectivity. After determining the first corresponding relationship, the first reflectivity variation range is determined based on the first corresponding relationship and the first preset reflectivity, and then the ion implantation dose is determined to be stable based on whether the first reflectivity is within the first reflectivity variation range, thereby improving the accuracy of the judgment. After determining the first reflectivity, the ion implantation dose is determined to be within the target dose fluctuation range based on the first reflectivity. After determining that the ion implantation dose is within the target dose fluctuation range, the ion implantation process on the semiconductor wafer is stopped, so that the ion implantation dose can be understood in real time, thereby avoiding excessive ions in the semiconductor wafer.

[0086] Figure 8 FIG. 1 is a flow chart of another method for monitoring ion implantation dose according to an embodiment of the present invention. Figure 8 As shown, the method comprises the following steps:

[0087] Step S801, determining a second reflectivity of the semiconductor wafer before ion implantation.

[0088] The second reflectivity refers to the absolute reflectivity of the semiconductor wafer before ion implantation. Before ion implantation, the absolute reflectivity of the target position (such as the center of the semiconductor wafer) can be directly determined as the second reflectivity, or the absolute reflectivity of multiple preset positions can be determined as the second reflectivity.

[0089] Specifically, the second reflectivity may be determined in the same manner as the first reflectivity. For example, an optical measuring instrument may be used to measure the second reflectivity based on SR.

[0090] Step S802, performing ion implantation on the semiconductor wafer.

[0091] For details, please see Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0092] Step S803, determining a first reflectivity of the semiconductor wafer after the ion implantation process.

[0093] For details, please see Figure 1 Step S102 of the embodiment shown or Figure 3 Step S302 of the illustrated embodiment will not be described in detail here.

[0094] Step S804: determining whether the ion implantation dose is stable based on the first reflectivity.

[0095] Specifically, the above step S804 may include step S8041 and step S8042:

[0096] Step S8041, determining a relative reflectivity based on the first reflectivity and the second reflectivity.

[0097] Specifically, the ratio of the second reflectivity to the first reflectivity may be determined as the relative reflectivity, that is, R3 = R2 / R1, wherein R3 represents the relative reflectivity, R2 represents the second reflectivity, and R1 represents the first reflectivity.

[0098] Exemplarily, the absolute value of the difference between the second reflectivity and the first reflectivity may also be determined as the relative emissivity, ie, R3 = |R1-R2|.

[0099] Step S8042: determine whether the ion implantation dose is stable based on the relative reflectivity.

[0100] Specifically, the above step S8042 may include step a1 and step a2:

[0101] Step a1: determining a relative reflectivity variation range based on a second corresponding relationship and a second preset reflectivity.

[0102] The second corresponding relationship is used to characterize the sensitivity of the relative reflectivity to the ion implantation dose. The second preset reflectivity can also be configured by the designer based on historical data. For example, the second preset reflectivity can be the average value of the relative reflectivity of the ion semiconductor wafer obtained in the previous N months before and after the ion implantation process, where N is greater than 0, and the relative reflectivity variation range represents the variation range (interval) of the relative reflectivity caused by the dose deviation allowed by the designer.

[0103] Specifically, (second preset reflectivity ±3ΔR2) can be determined as the relative reflectivity variation range, wherein ΔR2 represents the relative reflectivity variation value corresponding to a 1% change in ion implantation dose, and ΔR2 can be determined through the second corresponding relationship.

[0104] Exemplarily, after determining the second reflectivity, the semiconductor wafer is subjected to ion implantation to determine the first reflectivity corresponding to a plurality of different ion implantation doses, and then the relative reflectivity corresponding to the different ion implantation doses can be determined based on the second reflectivity and the first reflectivity corresponding to the plurality of different ion implantation doses. Afterwards, the second corresponding relationship can be determined by fitting software.

[0105] Step a2: if the relative reflectivity is within the relative reflectivity variation range, the ion implantation dose is stable.

[0106] Specifically, when the relative reflectivity is greater than the maximum value of the relative reflectivity variation range or the relative reflectivity is less than the minimum value of the relative reflectivity variation range, the ion implantation dose is unstable; when the relative reflectivity is greater than or equal to the minimum value of the relative reflectivity variation range and the relative reflectivity is less than or equal to the maximum value of the relative reflectivity variation range, the ion implantation dose is stable.

[0107] For example, if the relative reflectivity is greater than (the second preset reflectivity + 3ΔR2) or the relative reflectivity is less than (the second preset reflectivity - 3ΔR2), the ion injection is unstable; if the relative reflectivity is greater than or equal to (the second preset reflectivity - 3ΔR2) and the relative reflectivity is less than or equal to (the second preset reflectivity + 3ΔR2), the ion injection is stable.

[0108] In this embodiment, ion implantation is performed after determining the second reflectivity, and then the relative reflectivity is determined based on the first reflectivity and the second reflectivity. Based on the relative reflectivity, it is determined whether the ion implantation dose is stable. This can reduce interference from external factors such as the test environment and test instruments, and further improve the accuracy of determining whether the ion implantation dose is stable.

[0109] In this embodiment, a monitoring device for ion implantation dose is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware of a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware is also possible and conceived.

[0110] This embodiment provides a device for monitoring ion implantation dose, such as Fig. 9 As shown, including:

[0111] The ion implantation processing module 901 is used to perform ion implantation processing on the semiconductor wafer;

[0112] A first determination module 902 is used to determine a first reflectivity of the semiconductor wafer after ion implantation;

[0113] The monitoring module 903 is used to monitor the ion implantation dose based on the first reflectivity.

[0114] In some optional implementations, the monitoring module 903 includes:

[0115] The first monitoring unit is used to monitor whether the ion implantation dose is stable based on the first reflectivity.

[0116] In some optional implementations, the first monitoring unit includes:

[0117] A first determining unit, configured to determine a first reflectivity variation range based on a first corresponding relationship and a first preset reflectivity, wherein the first corresponding relationship is used to characterize a sensitivity of the first reflectivity to an ion implantation dose;

[0118] The second determining unit is configured to determine that the ion implantation dose is stable if the first reflectivity is within a first reflectivity variation range.

[0119] In some optional embodiments, the device further comprises:

[0120] The second determination module is used to fit and determine the first corresponding relationship based on the reflectivity corresponding to the semiconductor wafer under multiple different ion implantation doses.

[0121] In some optional embodiments, the device further comprises:

[0122] A third determination module is used to determine a second reflectivity of the semiconductor wafer before ion implantation;

[0123] The first monitoring unit further includes:

[0124] a third determining unit, configured to determine a relative reflectivity based on the first reflectivity and the second reflectivity;

[0125] The fourth determining unit is used to determine whether the ion implantation dose is stable based on the relative reflectivity.

[0126] In some optional implementations, the fourth determining unit includes:

[0127] A first determining subunit is used to determine a relative reflectivity variation range based on a second corresponding relationship and a second preset reflectivity, wherein the second corresponding relationship is used to characterize the sensitivity of the relative reflectivity to the ion implantation dose;

[0128] The second determining subunit is used to determine that the ion implantation dose is stable if the relative reflectivity is within the relative reflectivity variation range.

[0129] In some optional implementations, the monitoring module 903 includes:

[0130] a fifth determining unit, configured to determine whether the ion implantation dose is within a target dose fluctuation range based on the first reflectivity;

[0131] The stop unit is used to stop the ion implantation process on the semiconductor wafer when the ion implantation dose is within the target dose fluctuation range.

[0132] In some optional embodiments, the semiconductor wafer is a P-type substrate doped wafer or an N-type substrate doped wafer.

[0133] In some optional embodiments, the ion type of the ion implantation process includes at least one of hydrogen ions, helium ions, argon ions, and xenon ions.

[0134] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0135] The ion implantation dose monitoring device in this embodiment is presented in the form of a functional unit, where the unit refers to an application specific integrated circuit (ASIC) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0136] In some optional embodiments, the device for monitoring the ion implantation dose further includes an ion implanter and an optical measuring instrument.

[0137] The embodiment of the present invention also provides a computer device, such as Fig.10 As shown, the computer device includes: one or more processors 1010, memory 1020, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.10 A processor 1010 is taken as an example.

[0138] The processor 1010 may be a central processing unit, a network processor or a combination thereof. The processor 1010 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0139] The memory 1020 stores instructions executable by at least one processor 1010, so that at least one processor 1010 executes the method shown in the above embodiment.

[0140] The memory 1020 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 1020 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 1020 may optionally include a memory remotely arranged relative to the processor 1010, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0141] The memory 1020 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 1020 may also include a combination of the above types of memory.

[0142] The computer device also includes a communication interface 1030, which is used for the computer device to communicate with other devices or a communication network.

[0143] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0144] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0145] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0146] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0147] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0148] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A method for monitoring ion implantation dose, characterized in that: The method comprises: Perform ion implantation on semiconductor wafers; determining a first reflectivity of the semiconductor wafer after ion implantation; Based on the first reflectivity, an ion implantation dose is monitored.

2. The method according to claim 1, characterized in that The step of monitoring the ion implantation dose based on the first reflectivity includes: Based on the first reflectivity, whether the ion implantation dose is stable is monitored.

3. The method according to claim 2, characterized in that The step of monitoring whether the ion implantation dose is stable based on the first reflectivity includes: Determine a first reflectivity variation range based on a first corresponding relationship and a first preset reflectivity, wherein the first corresponding relationship is used to characterize the sensitivity of the first reflectivity to an ion implantation dose; If the first reflectivity is within the first reflectivity variation range, the ion implantation dose is stable.

4. The method according to claim 3, characterized in that Before monitoring whether the ion implantation dose is stable based on the first reflectivity, the method further includes: The first corresponding relationship is determined by fitting based on the reflectivity corresponding to the semiconductor wafer under a plurality of different ion implantation doses.

5. The method according to claim 2, characterized in that: Before performing ion implantation on the semiconductor wafer, the method further comprises: determining a second reflectivity of the semiconductor wafer before ion implantation; The step of monitoring whether the ion implantation dose is stable based on the first reflectivity includes: determining a relative reflectivity based on the first reflectivity and the second reflectivity; Based on the relative reflectivity, it is determined whether the ion implantation dose is stable.

6. The method according to claim 5, characterized in that The step of determining whether the ion implantation dose is stable based on the relative reflectivity includes: Determining a relative reflectivity variation range based on a second corresponding relationship and a second preset reflectivity, wherein the second corresponding relationship is used to characterize the sensitivity of the relative reflectivity to an ion implantation dose; If the relative reflectivity is within the relative reflectivity variation range, the ion implantation dose is stable.

7. The method according to any one of claims 1 to 6, characterized in that The step of monitoring the ion implantation dose based on the first reflectivity includes: Based on the first reflectivity, determining whether the ion implantation dose is within a target dose fluctuation range; When the ion implantation dose is within the target dose fluctuation range, the ion implantation process on the semiconductor wafer is stopped.

8. The method according to any one of claims 1 to 6, characterized in that The semiconductor wafer is a P-type substrate doped wafer or an N-type substrate doped wafer.

9. The method according to any one of claims 1 to 6, characterized in that The types of ions used in the ion implantation process include hydrogen ions, helium ions, argon ions, or xenon ions.

10. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 9 by executing the computer instructions.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 9.

12. A computer program product, characterized in that The method comprises computer instructions for causing a computer to execute the method according to any one of claims 1 to 9.

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