Sample preparation method for detecting carbon content in copper sample by glow discharge mass spectrometry and detection method

Abstract

The invention provides a sample preparation method and a detection method for detecting carbon content in a copper sample by glow discharge mass spectrometer.The sample preparation method comprises the steps that the copper sample is subjected to turning, acid pickling, water washing and drying in sequence, and a to-be-detected copper sample is obtained; the acid pickling and the water washing are alternately carried out for at least two times, and the drying sequentially comprises blow-drying and drying. The detection method comprises the following steps: putting the to-be-detected copper sample obtained by the sample preparation method into a glow discharge mass spectrometer, vacuumizing, pushing into a discharge chamber, and detecting after discharge sputtering to obtain the carbon content in the copper sample. According to the method, the copper sample is alternately subjected to acid pickling and water washing, surface impurities are removed as much as possible, and then the copper sample is subjected to blow-drying and drying operation, so that re-adsorption of the impurities is avoided, the influence of the impurities on a glow discharge mass spectrometry detection result can be effectively avoided, the detection time is shortened, the stability of the detection result is kept, and the detection accuracy is improved; the method is simple and convenient to operate, the detection efficiency is improved, and the operation cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis and detection, and relates to a sample preparation method and a detection method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. Background Art

[0002] The detection of trace impurity elements is one of the important prerequisites for the application of metal samples. The current detection methods include inductively coupled plasma emission spectroscopy, inductively coupled plasma mass spectrometry, X-ray fluorescence spectroscopy, infrared spectroscopy, glow discharge mass spectrometry, etc. Different methods are suitable for detecting different types of samples, and have their own advantages and disadvantages. Taking glow discharge mass spectrometry as an example, this method is currently a common method for purity analysis and impurity component analysis of high-purity solid conductive materials. It uses a glow discharge source as an ion source and a mass spectrometer to perform mass spectrometry. It has the advantages of high sensitivity, high resolution, small matrix effect, and full element analysis.

[0003] Copper is a commonly used metal element and is used in many fields, especially in the semiconductor field. When used as a sputtering coating material, copper has high purity requirements. If the impurity element content is high, such as carbon content, it may cause the problem of excessively large microparticles during the sputtering process, thereby causing wafer defects. For the detection of carbon content in metal samples, carbon gas analyzers are currently used, but the detection accuracy of this instrument is limited and it cannot detect trace impurity elements in metal samples.

[0004] CN 118706565A discloses a sample preparation method and a detection method for detecting the carbon content in an aluminum sample by glow discharge mass spectrometry. The sample preparation method comprises: sequentially subjecting a high-purity aluminum sample to acid washing, water washing and argon ion polishing treatment to obtain an aluminum sample to be detected; the acid washing and water washing are performed alternately at least three times; the pickling solution for the acid washing is a mixture of nitric acid, hydrofluoric acid and water. CN 118533597A discloses a tantalum sample pretreatment method and a detection method for glow discharge mass spectrometry detection. The pretreatment method comprises: sequentially subjecting a high-purity tantalum sample to acid washing, water washing and argon ion polishing treatment to obtain a tantalum sample to be detected; the acid washing and water washing are performed alternately at least three times. The methods in the above patents are respectively for pre-detection treatment of the carbon content in the aluminum sample and the impurity content in the tantalum sample. Different types of metals to be detected have different material properties, and the corresponding processing methods and parameter selections will also be different, and there is no direct correlation.

[0005] CN 118654970A discloses a method for preparing a copper sample for detection by a glow discharge mass spectrometer, the method comprising: mixing high-purity copper powder and doped element powder, compacting to obtain a mixed powder; subjecting the mixed powder to vacuum electron beam melting and casting to obtain an ingot; subjecting the ingot to mechanical processing and heat treatment to obtain a copper sample. The method focuses on the preparation of the copper sample, which is to correct the sample by artificially adding impurity elements to improve the accuracy of the precise measurement, rather than a sample preparation method for the existing copper sample before detection, and the two have different focuses.

[0006] In summary, for the sample preparation method of copper samples for glow discharge mass spectrometry detection, it is necessary to adopt appropriate pretreatment operations according to the type of sample and the type of impurity elements to be detected, so as to reduce the surface impurity content and improve the accuracy of detection. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a sample preparation method and a detection method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The sample preparation method can effectively remove impurities on the surface of the copper sample through operations such as washing and drying to reduce the subsequent impact on glow discharge mass spectrometry detection, and can achieve detection of lower carbon content, with high detection accuracy and efficiency, and stable detection results.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In one aspect, the present invention provides a method for preparing a sample for detecting carbon content in a copper sample by glow discharge mass spectrometry, the method comprising the following steps:

[0010] The copper sample is sequentially turned, pickled, washed with water, and dried to obtain a copper sample to be tested;

[0011] Wherein, the acid washing and water washing are alternately performed at least twice, for example, twice, three times or four times, and the drying includes blowing and drying in sequence.

[0012] In the present invention, for the preparation of glow discharge mass spectrometry detection samples, different pre-treatment operations need to be adopted according to the different types of metals to be detected and impurities; in the present invention, the copper sample is first turned to make its structural size and surface characteristics meet the requirements of subsequent detection, and then acid washing and water washing are alternately performed in sequence to remove surface impurities as much as possible, and then drying and drying operations are performed to avoid re-adsorption of impurities. After the above treatment, the influence of impurities on the glow discharge mass spectrometry detection results can be effectively avoided, the detection time can be reduced, the detection results can be kept stable, and the detection accuracy can be improved; at the same time, the method is simple to operate, which is helpful to improve the detection efficiency and reduce the operation cost.

[0013] The following are preferred technical solutions of the present invention, but are not intended to be limitations of the technical solutions provided by the present invention. Through the following technical solutions, the technical objectives and beneficial effects of the present invention can be better achieved and realized.

[0014] As a preferred technical solution of the present invention, the copper sample is a high-purity copper sample.

[0015] Preferably, the purity of the high-purity copper sample is above 99.99%, for example, 99.99%, 99.992%, 99.994%, 99.995%, 99.996%, 99.998%, 99.999% or 99.9995%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the carbon content in the high purity copper sample is less than 1 ppm, for example, 1 ppm, 0.9 ppm, 0.8 ppm, 0.7 ppm, 0.6 ppm, 0.5 ppm, 0.3 ppm, 0.1 ppm or 0.05 ppm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] As a preferred technical solution of the present invention, the turning is to process the surface of the copper sample using a lathe.

[0018] Preferably, the shape of the copper sample after turning is a rod, and its size is For example or The above range is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0019] Preferably, the surface roughness of the copper sample after turning is less than 1 μm, for example, 1 μm, 0.9 μm, 0.8 μm, 0.7 μm, 0.6 μm, 0.5 μm, 0.3 μm or 0.1 μm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In the present invention, the copper sample to be tested needs to be processed into a structure suitable for glow discharge mass spectrometry detection, so turning can be adopted, and the surface can be fine-turned to control the surface roughness. The roughness should be reduced as much as possible to facilitate the subsequent removal of surface impurities. At this time, the size of the copper sample is slightly larger than the size required for detection, and can be reduced to the required size after the pickling step.

[0021] As a preferred technical solution of the present invention, the pickling agent used in the pickling includes nitric acid.

[0022] Preferably, the nitric acid is electronic grade nitric acid, and its concentration is 68-70wt%, for example, 68wt%, 68.2wt%, 68.5wt%, 68.8wt%, 69wt%, 69.2wt%, 69.5wt%, 69.8wt% or 70wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the pickling method is ultrasonic cleaning.

[0024] Preferably, the frequency of the ultrasonic cleaning is 35 to 45 kHz, for example 35 kHz, 36 kHz, 38 kHz, 40 kHz, 42 kHz, 44 kHz or 45 kHz, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the ultrasonic cleaning time is 20 to 60 s, for example 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, 55 s or 60 s, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] As a preferred technical solution of the present invention, the water washing method is flushing.

[0027] Preferably, the volume ratio of the water used for flushing to the pickling agent is 1:0.5 to 1:1, for example, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9 or 1:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the flushing time is 5 to 10 seconds, for example 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds or 10 seconds, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the acid washing and water washing are performed alternately 2 or 3 times.

[0030] In the present invention, during the pickling, the copper sample can be placed in a polytetrafluoroethylene container and then placed in an ultrasonic cleaning machine for cleaning.

[0031] As a preferred technical solution of the present invention, the drying is performed by purging with a protective gas.

[0032] Preferably, the protective gas includes an inert gas or nitrogen, and the inert gas includes argon, neon or helium.

[0033] Preferably, the pressure of the protective gas during the purging is 4 to 6 bar, for example, 4 bar, 4.5 bar, 5 bar, 5.5 bar or 6 bar, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] Preferably, the purging is performed until no moisture remains on the surface of the copper sample.

[0035] As a preferred technical solution of the present invention, the drying temperature is 80-120°C, for example 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C or 120°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the drying time is 20 to 60 min, for example 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the drying atmosphere is air.

[0038] In the present invention, the copper sample is dried and placed in a drying box, and heated to a certain temperature to prevent carbon in the air from being adsorbed onto the sample surface, thereby avoiding the problem of re-adsorption of impurities after surface impurities removal. After drying, the sample needs to be sampled as soon as possible for subsequent testing to avoid cooling down before testing.

[0039] On the other hand, the present invention provides a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, characterized in that the detection method comprises:

[0040] The copper sample to be tested obtained by the above sample preparation method is placed in a glow discharge mass spectrometer, pushed into a discharge chamber after evacuation, and tested after discharge sputtering to obtain the carbon content in the copper sample.

[0041] As a preferred technical solution of the present invention, the copper sample to be tested is first placed in a sample chamber, and then transferred to a discharge chamber after evacuation.

[0042] Preferably, the pressure in the discharge chamber after evacuation is 5×10 -5 mbar or less, for example 5×10 - 5 mbar, 4.5×10 -5 mbar, 4×10 -5 mbar, 3×10 -5 mbar, 2×10 -5 mbar, 1×10-5 mbar, 8×10 -6 mbar or 5×10 -6 mbar, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the discharge voltage of the glow discharge mass spectrometer is 1200-1300V, for example, 1200V, 1220V, 1240V, 1250V, 1260V, 1280V or 1300V, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the discharge current of the glow discharge mass spectrometer is 3-4 mA, such as 3 mA, 3.2 mA, 3.4 mA, 3.5 mA, 3.6 mA, 3.8 mA or 4 mA, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] As a preferred technical solution of the present invention, the discharge sputtering time is 5 to 20 minutes, for example, 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes or 20 minutes, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] Preferably, the carbon content in the copper sample is less than 1 ppm, for example, 1 ppm, 0.9 ppm, 0.8 ppm, 0.7 ppm, 0.6 ppm, 0.5 ppm, 0.3 ppm, 0.1 ppm or 0.05 ppm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] In the present invention, after the copper sample is prepared, a glow discharge mass spectrometer is used for detection, and a copper element matrix and a carbon element are selected for direct current glow discharge mass spectrometry analysis to obtain the carbon content in the copper sample.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The sample preparation method of the present invention first turns the copper sample to make its structural dimensions and surface characteristics meet the requirements of subsequent testing, then acid washing and water washing are performed alternately to remove surface impurities as much as possible, and then blow-dried and dried to avoid re-adsorption of impurities. After the above treatment, the influence of impurities on the detection results of glow discharge mass spectrometry can be effectively avoided, the detection time can be reduced, the detection results can be kept stable, and the accuracy of the detection can be improved;

[0050] (2) The detection method of the present invention can accurately detect trace carbon elements in copper samples by controlling the discharge parameters during detection, with a low detection limit, and can detect carbon with a content of less than 1 ppm;

[0051] (3) The method of the present invention is easy to operate, which helps to improve detection efficiency and reduce operating costs. DETAILED DESCRIPTION

[0052] In order to better illustrate the present invention and facilitate understanding of the technical solution of the present invention, the present invention is further described in detail below. However, the following embodiments are only simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0053] The specific implementation method of the present invention provides a method for preparing a sample for detecting the carbon content in a copper sample by glow discharge mass spectrometry, and the method comprises the following steps:

[0054] The copper sample is sequentially turned, pickled, washed with water, and dried to obtain a copper sample to be tested;

[0055] Wherein, the acid washing and water washing are alternately performed at least twice, and the drying includes blowing and baking in sequence.

[0056] The following are typical but non-limiting embodiments of the present invention:

[0057] Embodiment 1:

[0058] This embodiment provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the sample preparation method comprising the following steps:

[0059] The copper sample is turned, pickled, washed and dried in sequence. The copper sample is a high-purity copper sample with a purity of 99.99%. The turning is to process the surface of the copper sample using a lathe. The shape of the copper sample after turning is a rod, and its size is The surface roughness of the copper sample after turning is 0.8 μm, the pickling agent used in the pickling is electronic grade nitric acid, and its concentration is 68wt%, the pickling method is ultrasonic cleaning, the frequency of the ultrasonic cleaning is 40kHz, and the time is 30s, the water washing method is flushing, the volume ratio of the amount of water used for flushing to the amount of the pickling agent is 1:0.75, the flushing time is 8s, and the number of times the pickling and water washing are alternately performed is 2 times; the drying is purging with argon gas, the pressure of the argon gas during the purging is 5bar, the purging time is until there is no moisture remaining on the surface of the copper sample, the drying temperature is 100°C, the time is 30min, and the drying atmosphere condition is air, so as to obtain the copper sample to be tested.

[0060] Embodiment 2:

[0061] This embodiment provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the sample preparation method comprising the following steps:

[0062] The copper sample is turned, pickled, washed and dried in sequence. The copper sample is a high-purity copper sample with a purity of 99.995%. The turning is to process the surface of the copper sample using a lathe. The shape of the copper sample after turning is a rod, and its size is The surface roughness of the copper sample after turning is 0.6 μm, the pickling agent used in the pickling is electronic grade nitric acid, and its concentration is 69wt%, the pickling method is ultrasonic cleaning, the frequency of the ultrasonic cleaning is 45kHz, and the time is 40s, the water washing method is flushing, the volume ratio of the amount of water used for flushing to the amount of the pickling agent is 1:0.5, the flushing time is 10s, and the number of times the pickling and water washing are alternately performed is 2 times; the drying is purged by argon gas, and the pressure of the argon gas during the purging is 4bar, and the copper sample is purged until there is no moisture residue on the surface, the drying temperature is 90°C, the time is 40min, and the drying atmosphere condition is air, so as to obtain the copper sample to be tested.

[0063] Embodiment 3:

[0064] This embodiment provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the sample preparation method comprising the following steps:

[0065] The copper sample is turned, pickled, washed and dried in sequence. The copper sample is a high-purity copper sample with a purity of 99.999%. The turning is to process the surface of the copper sample using a lathe. The shape of the copper sample after turning is a rod, and its size is The surface roughness of the copper sample after turning is 1 μm, the pickling agent used in the pickling is electronic grade nitric acid, and its concentration is 70wt%, the pickling method is ultrasonic cleaning, the frequency of the ultrasonic cleaning is 35kHz, and the time is 20s, the water washing method is flushing, the volume ratio of the amount of water used for flushing to the amount of the pickling agent is 1:1, the flushing time is 5s, and the number of times the pickling and water washing are alternately performed is 2 times; the drying is purging with argon gas, and the pressure of the argon gas during the purging is 6bar, and the copper sample is purged until there is no moisture residue on the surface, the drying temperature is 110°C, the time is 25min, and the drying atmosphere condition is air, so as to obtain the copper sample to be tested.

[0066] Embodiment 4:

[0067] This embodiment provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the sample preparation method comprising the following steps:

[0068] The copper sample is turned, pickled, washed and dried in sequence. The copper sample is a high-purity copper sample with a purity of 99.992%. The turning is to process the surface of the copper sample using a lathe. The shape of the copper sample after turning is a rod, and its size is The surface roughness of the copper sample after turning is 0.5 μm, the pickling agent used in the pickling is electronic grade nitric acid, and its concentration is 68.5wt%, the pickling method is ultrasonic cleaning, the frequency of the ultrasonic cleaning is 38kHz, and the time is 50s, the water washing method is flushing, the volume ratio of the amount of water used for flushing to the amount of the pickling agent is 1:0.8, the flushing time is 6s, and the number of times the pickling and water washing are alternately performed is 3 times; the drying is purged with nitrogen, and the pressure of the nitrogen during the purging is 4.5bar, and the copper sample is purged until there is no moisture residue on the surface, the drying temperature is 120°C, the time is 20min, and the drying atmosphere condition is air to obtain the copper sample to be tested.

[0069] Embodiment 5:

[0070] This embodiment provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the sample preparation method comprising the following steps:

[0071] The copper sample is turned, pickled, washed and dried in sequence. The copper sample is a high-purity copper sample with a purity of 99.996%. The turning is to process the surface of the copper sample using a lathe. The shape of the copper sample after turning is a rod, and its size is The surface roughness of the copper sample after turning is 0.3 μm, the pickling agent used in the pickling is electronic grade nitric acid, and its concentration is 69.5wt%, the pickling method is ultrasonic cleaning, the frequency of the ultrasonic cleaning is 42kHz, and the time is 45s, the water washing method is flushing, the volume ratio of the amount of water used for flushing to the amount of the pickling agent is 1:0.6, the flushing time is 10s, and the number of times the pickling and water washing are alternately performed is 3 times; the drying is purged with nitrogen, and the pressure of the nitrogen during the purging is 5.5bar, and the copper sample is purged until there is no moisture residue on the surface, the drying temperature is 80°C, the time is 60min, and the drying atmosphere condition is air to obtain the copper sample to be tested.

[0072] Comparative Example 1:

[0073] This comparative example provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The sample preparation method refers to the sample preparation method in Example 1, with the only difference being that a drying step is not included.

[0074] Comparative Example 2:

[0075] This comparative example provides a sample preparation method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The sample preparation method refers to the sample preparation method in Example 1, with the only difference being that the acid washing and water washing are not performed alternately, but water washing is performed after the acid washing is completed.

[0076] Application Example 1:

[0077] This application example provides a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry, the detection method comprising:

[0078] The copper sample to be tested obtained by the sample preparation method described in Example 1 was placed in the sample chamber of the glow discharge mass spectrometer and evacuated to a pressure drop of 5×10 -5 mbar and then pushed into the discharge chamber, and tested after discharge sputtering. The discharge voltage was 1250V, the discharge current was 3mA, and the discharge sputtering time was 10min to obtain the carbon content in the copper sample.

[0079] Application example 2-5:

[0080] The above application examples all provide a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The detection method refers to Application Example 1, with the only difference being that the copper samples prepared in Examples 2-5 are respectively used.

[0081] Application Example 6:

[0082] This application example provides a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The detection method application example 1 is different only in that: the discharge voltage is 1200V, the discharge current is 3.5mA, and the discharge sputtering time is 15min.

[0083] Application Example 7:

[0084] This application example provides a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The detection method application example 1 is different only in that: the discharge voltage is 1300V, the discharge current is 4mA, and the discharge sputtering time is 5min.

[0085] Comparative application example 1-2:

[0086] The above comparative application examples all provide a method for detecting the carbon content in a copper sample by glow discharge mass spectrometry. The detection method refers to Application Example 1, with the only difference being that the copper samples prepared in Comparative Examples 1-2 are respectively used.

[0087] The above Application Examples 1-7 and Comparative Application Examples 1-2 were subjected to glow discharge mass spectrometry analysis, and the time required for the carbon content to stabilize from the start of detection and the carbon content in the copper sample were recorded. The results are shown in Table 1.

[0088] Table 1

[0089] Time required for carbon content to stabilize / min Carbon content in copper sample / ppm Application Example 1 40 0.38 Application Example 2 40 0.40 Application Example 3 46 0.37 Application Example 4 48 0.40 Application Example 5 36 0.33 Application Example 6 36 0.36 Application Example 7 32 0.33 Comparative application example 1 60 1.15 Comparative Application Example 2 80 0.34

[0090] As shown in Table 1, the carbon content in the copper sample can be effectively removed from the surface of the copper sample by using the above sample preparation and detection method. The time required for the carbon content to stabilize during the sample detection in the application example is within 50 minutes, and the detectable carbon content can be as low as 0.4ppm or less.

[0091] In comparative application example 1, no drying was performed, that is, the copper sample was only blown dry and stored after cleaning, which easily adsorbed carbon in the air again, thus affecting the accuracy of carbon content detection. At this time, the carbon content reached 1.15ppm; in comparative application example 2, acid pickling and water washing were not performed alternately, which easily caused excessive washing of the surface of the sample, which may cause corrosion and affect the surface microstructure, which is not conducive to subsequent detection, and the time required for carbon content stabilization is prolonged to 80min.

[0092] From the above embodiments and comparative examples, it can be seen that the sample preparation method of the present invention first turns the copper sample to make its structural dimensions and surface characteristics meet the requirements of subsequent detection, and then acid pickling and water washing are performed alternately to remove surface impurities as much as possible, and then blow-dried and baked to avoid re-adsorption of impurities. After the above treatment, the influence of impurities on the glow discharge mass spectrometry detection results can be effectively avoided, the detection time can be reduced, the stability of the detection results can be maintained, and the detection accuracy can be improved; the detection method can realize accurate detection of trace carbon elements in copper samples by controlling the discharge parameters during detection, and the detection limit is low, and carbon with a content of less than 1ppm can be detected; the method is simple to operate, which helps to improve detection efficiency and reduce operating costs.

[0093] The applicant declares that the present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the method of the present invention, addition of auxiliary steps, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a sample for detecting carbon content in a copper sample by glow discharge mass spectrometry, characterized in that: The sample preparation method comprises the following steps: The copper sample is sequentially turned, pickled, washed with water, and dried to obtain a copper sample to be tested; Wherein, the acid washing and water washing are alternately performed at least twice, and the drying includes blowing and baking in sequence.

2. The sample preparation method according to claim 1, characterized in that: The copper sample is a high-purity copper sample; Preferably, the purity of the high-purity copper sample is above 99.99%; Preferably, the carbon content in the high purity copper sample is less than 1 ppm.

3. The sample preparation method according to claim 1 or 2, characterized in that: The turning is to process the surface of the copper sample using a lathe; Preferably, the shape of the copper sample after turning is a rod, and its size is φ(2.8-3.2)×(20-22) mm; Preferably, the surface roughness of the copper sample after turning is less than 1 μm.

4. The sample preparation method according to any one of claims 1 to 3, characterized in that: The pickling agent used in the pickling includes nitric acid; Preferably, the nitric acid is electronic grade nitric acid with a concentration of 68-70 wt %; Preferably, the pickling method is ultrasonic cleaning; Preferably, the frequency of the ultrasonic cleaning is 35 to 45 kHz; Preferably, the ultrasonic cleaning time is 20 to 60 seconds.

5. The sample preparation method according to any one of claims 1 to 4, characterized in that: The water washing method is flushing; Preferably, the volume ratio of the amount of water used for flushing to the amount of pickling agent used is 1:0.5 to 1:1; Preferably, the flushing time is 5 to 10 seconds; Preferably, the acid washing and water washing are performed alternately 2 to 3 times.

6. The sample preparation method according to any one of claims 1 to 5, characterized in that: The drying is performed by blowing with protective gas; Preferably, the protective gas comprises an inert gas or nitrogen; Preferably, the pressure of the protective gas during the purging is 4 to 6 bar; Preferably, the purging is performed until no moisture remains on the surface of the copper sample.

7. The sample preparation method according to any one of claims 1 to 6, characterized in that: The drying temperature is 80-120°C; Preferably, the drying time is 20 to 60 minutes; Preferably, the drying atmosphere is air.

8. A method for detecting carbon content in a copper sample by glow discharge mass spectrometry, characterized in that: The detection method comprises: The copper sample to be tested obtained by the sample preparation method according to any one of claims 1 to 7 is placed in a glow discharge mass spectrometer, pushed into a discharge chamber after evacuation, and tested after discharge sputtering to obtain the carbon content in the copper sample.

9. The detection method according to claim 8, characterized in that: The copper sample to be tested is first placed in the sample chamber, and then transferred to the discharge chamber after vacuuming; Preferably, the pressure in the discharge chamber after evacuation is 5×10 -5 Below mbar; Preferably, the discharge voltage of the glow discharge mass spectrometer is 1200-1300V; Preferably, the discharge current of the glow discharge mass spectrometer is 3-4 mA.

10. The detection method according to claim 8 or 9, characterized in that: The discharge sputtering time is 5 to 20 minutes; Preferably, the carbon content in the copper sample is less than 1 ppm.