Device and method for measuring trace elements

Abstract

The present invention provides a device and method for measuring trace elements, the device comprising an analytical instrument; a switching module for selectively connecting the ports of a first multi-way valve to a liquid to be tested, a standard liquid and a cleaning liquid; two ends of a first liquid storage component are connected to the ports of the first multi-way valve; two ends of a second liquid storage component are connected to the ports of a second multi-way valve; two ends of a third liquid storage component are connected to the ports of a third multi-way valve; by switching the second multi-way valve, a second pump is connected to the analytical instrument through or without the third liquid storage component; a plurality of pumps, a first pump is connected to the ports of the first multi-way valve, a second pump is connected to the ports of the third multi-way valve, and a third pump is connected to the second multi-way valve; a fourth pump and a fifth pump are used to provide liquid and connect to the ports of the second multi-way valve. The present invention has the advantages of accurate detection and the like.

Description

Technical Field

[0001] The invention relates to element detection, and in particular to a device and method for measuring trace elements. Background Art

[0002] Semiconductor device manufacturing requires strict control of pollution sources. Industry insiders estimate that pollution causes about 50% of production losses. Alkali metal and alkaline earth metal (Li, Na, K, Ca, Mg, Ba, etc.) pollution can cause leakage of components and cause low breakdown; transition metal and heavy metal (Fe, Cr, Ni, Cu, Au, Mn, Pb, etc.) pollution can shorten the life of components or increase the dark current when the components are working; penetrating element (S, P, Si, As, Sb, B, Al, etc.) pollution has a diffusion effect, affecting the number of electrons and holes. There are many types of chemicals in the process, inorganic ones include strong acids such as hydrochloric acid, hydrogen peroxide, sulfuric acid, hydrofluoric acid, and cleaning solutions SC-1 and SC-2 mixed solutions, and organic ones include methanol, isopropanol, etc. The matrix of each chemical is different, and the concentration of the required detection element is at the ng / L level. Although the current detection method is the precision instrument inductively coupled plasma mass spectrometer (ICP-MS), pre-treatment such as sample dilution and standard solution preparation may introduce pollution.

[0003] The current practice is to use the external standard method, which is to add a certain amount of standard substance to the blank solvent in a gradient to prepare a standard sample, and to process and test the sample in parallel with the unknown sample. This method is suitable for the case where the standard sample and the sample matrix are basically the same, but it is difficult to obtain accurate results when the matrix is ​​complex;

[0004] In the process of testing large quantities of samples, the fatigue of the peristaltic pump tube of the ICP-MS detection equipment makes it difficult to test under the same conditions. For samples with different matrices, the traditional external standard method is difficult to meet the requirements.

[0005] To deal with complex matrices, laboratory analysts can also use the manual standard addition method for measurement, manually dividing the sample to be tested into several parts and manually adding standard solutions of different concentrations to achieve simultaneous detection of standard solutions and unknown samples; however, the manual standard addition method in the semiconductor industry is very easy to contaminate samples with spiked ng / L-level content, and has great difficulties in environmental requirements and operation. Summary of the invention

[0006] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides a device for measuring trace elements.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A device for measuring trace elements, the device comprising an analytical instrument; the device further comprising:

[0009] A switching module, the switching module is used to make the ports of the first multi-way valve selectively connect the test liquid and the standard liquid;

[0010] A first multi-way valve and a first liquid storage component, wherein both ends of the first liquid storage component are connected to ports of the first multi-way valve; by switching the first multi-way valve, the second multi-way valve is connected to the switching module through and without the first liquid storage component, and the first pump is connected to the analytical instrument through and without the first liquid storage component;

[0011] a second multi-way valve and a second liquid storage component, wherein both ends of the second liquid storage component are connected to the ports of the second multi-way valve; through the switching of the second multi-way valve, the first multi-way valve is connected to the third pump through and without passing through the second liquid storage component, and the third multi-way valve is connected to the fourth pump through the second liquid storage component, and the third multi-way valve is connected to the fifth pump without passing through the second liquid storage component;

[0012] a third multi-way valve and a third liquid storage component, wherein both ends of the third liquid storage component are connected to ports of the third multi-way valve; through the switching of the second multi-way valve, the second pump is connected to the analytical instrument through or without the third liquid storage component;

[0013] Multiple pumps, the first pump is connected to the port of the first multi-way valve, the second pump is connected to the port of the third multi-way valve, and the third pump is connected to the second multi-way valve; the fourth pump and the fifth pump are used to provide liquid and are connected to the port of the second multi-way valve.

[0014] Another object of the present invention is to provide a method for measuring trace elements using the above-mentioned trace element measuring device, and the object of the invention is achieved through the following technical solutions:

[0015] A method for measuring trace elements using the device for measuring trace elements of the present application comprises the following steps:

[0016] (A1) switching the first multi-way valve, the second multi-way valve and the switching module so that the selected sample to be tested enters the first liquid storage component under the action of the third pump, and the selected standard solution corresponding to the sample to be tested enters the second liquid storage component without passing through the first liquid storage component;

[0017] (A2) switching the second multi-way valve and the third multi-way valve, the fourth pump provides fluid and pushes the standard solution in the second liquid storage component into the third liquid storage component, the fifth pump provides diluent and sends it into the third liquid storage component through the second multi-way valve, and the standard solution is diluted by the diluent;

[0018] (A3) switching the first multi-way valve and the third multi-way valve, so that the first pump pushes the sample to be tested in the first liquid storage component into the mixing area, and the second pump pushes the diluted standard solution in the third liquid storage component into the mixing area;

[0019] (A4) the sample to be tested and the diluted standard solution are mixed in the mixing zone and then sent to the analysis instrument, which outputs a detection signal;

[0020] Return to step (A2), provide standard solutions with different dilution multiples until the analytical instrument outputs at least two detection signals;

[0021] (A5) Analyze the at least two detection signals and the concentration of the corresponding diluted standard solution to obtain the content of the trace element in the sample to be tested.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Accurate detection;

[0024] Standard solutions with gradient element concentrations are added to the same sample to be tested, and the content of the element in the sample to be tested is obtained by using the mapping relationship between the detection signal and the element concentration in the standard solution; the sample to be tested and the standard solution are tested under the same conditions, and the content of trace elements (such as elements at the ng / L level) can be accurately obtained even for complex samples to be tested;

[0025] Use syringe pump to accurately control the speed of injection to ensure the consistency of each injection, avoid fatigue and pulse influence of other pumps such as peristaltic pump, and ensure the accuracy of detection;

[0026] 2. Good detection stability;

[0027] Before the formal test, the liquid storage components and pipelines are cleaned and emptied, so that the liquid flows and mixes in a closed and clean pipeline during the test. The whole process is not affected by human and environmental factors, ensuring the stability of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings:

[0029] Figure 1 Schematic diagram of the structure of a device for measuring trace elements according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] Figure 1The following description describes the optional embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. It should be understood by those skilled in the art that variations or substitutions derived from these embodiments will be within the scope of the present invention. It should be understood by those skilled in the art that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional embodiments, but is only limited by the claims and their equivalents.

[0031] Embodiment 1:

[0032] Figure 1 A schematic diagram of the structure of a device for measuring trace elements according to an embodiment of the present invention is given. Figure 1 As shown, the measuring device for trace elements comprises:

[0033] Analytical instruments, such as ICP-MS;

[0034] A switching module, such as a single or multiple multi-way selector valves, the switching module is used to selectively connect the ports of the first multi-way valve to the test liquid and the standard liquid;

[0035] A first multi-way valve and a first liquid storage component, wherein both ends of the first liquid storage component are connected to ports of the first multi-way valve; by switching the first multi-way valve, the second multi-way valve is connected to the switching module through and without the first liquid storage component, and the first pump is connected to the analytical instrument through and without the first liquid storage component;

[0036] a second multi-way valve and a second liquid storage component, wherein both ends of the second liquid storage component are connected to the ports of the second multi-way valve; through the switching of the second multi-way valve, the first multi-way valve is connected to the third pump through and without passing through the second liquid storage component, and the third multi-way valve is connected to the fourth pump through the second liquid storage component, and the third multi-way valve is connected to the fifth pump without passing through the second liquid storage component;

[0037] a third multi-way valve and a third liquid storage component, wherein both ends of the third liquid storage component are connected to ports of the third multi-way valve; through the switching of the second multi-way valve, the second pump is connected to the analytical instrument through or without the third liquid storage component;

[0038] Multiple pumps, the first pump is connected to the port of the first multi-way valve, the second pump is connected to the port of the third multi-way valve, and the third pump is connected to the second multi-way valve; the fourth pump and the fifth pump are used to provide liquid and are connected to the port of the second multi-way valve.

[0039] In order to achieve the simultaneous connection of the fourth pump and the fifth pump to the second multi-way valve, and to deliver the standard solution in the second liquid storage component and the diluent provided by the fifth pump to the third liquid storage component, further, when the third multi-way valve is connected to the fourth pump through the common port of the second multi-way valve and the second liquid storage component in sequence, the third multi-way valve is connected to the fifth pump through the common port but not through the second liquid storage component.

[0040] In order to achieve the selective connection of different standard solutions, different test solutions and air, the switching module further comprises:

[0041] a first switching component, the first switching component being used to selectively connect the port of the first multi-way valve to the second switching component and the third switching component;

[0042] a second switching component, the second switching component being used to enable the first switching component to selectively connect various standard liquids, cleaning liquids and air;

[0043] A third switching component is used to enable the first switching component to selectively pass various samples to be tested.

[0044] In order to ensure the consistency of each injection, further, the multiple pumps are syringe pumps.

[0045] In order to know whether the test liquid enters the first liquid storage part and whether the standard liquid enters the second liquid storage part, a liquid sensor is further arranged between the third pump and the port of the second multi-way valve connected thereto.

[0046] The method for measuring trace elements of the embodiment of the present invention, that is, the method for measuring trace elements using the device for measuring trace elements of the embodiment, comprises the following steps:

[0047] (A1) switching the first multi-way valve, the second multi-way valve and the switching module so that the selected sample to be tested enters the first liquid storage component under the action of the third pump, and the selected standard solution corresponding to the sample to be tested enters the second liquid storage component without passing through the first liquid storage component;

[0048] (A2) switching the second multi-way valve and the third multi-way valve, the fourth pump provides fluid and pushes the standard solution in the second liquid storage component into the third liquid storage component, the fifth pump provides diluent and sends it into the third liquid storage component through the second multi-way valve, and the standard solution is diluted by the diluent;

[0049] (A3) switching the first multi-way valve and the third multi-way valve, so that the first pump pushes the sample to be tested in the first liquid storage component into the mixing area, and the second pump pushes the diluted standard solution in the third liquid storage component into the mixing area;

[0050] (A4) the sample to be tested and the diluted standard solution are mixed in the mixing zone and then sent to the analysis instrument, which outputs a detection signal;

[0051] Return to step (A2), provide standard solutions with different dilution multiples until the analytical instrument outputs at least two detection signals;

[0052] (A5) Analyze the at least two detection signals and the concentration of the corresponding diluted standard solution to obtain the content of the trace element in the sample to be tested.

[0053] In order to eliminate the influence of the environment and improve the detection accuracy, before step (A1), cleaning and emptying steps are performed in sequence, specifically:

[0054] The switching module switches to the cleaning liquid and air at different times. Under the action of the third pump, the cleaning liquid passes through the first liquid storage component and does not pass through the second liquid storage component to clean the first liquid storage component and the pipeline. Then, the air passes through the first liquid storage component and does not pass through the second liquid storage component to empty the liquid in the first liquid storage component and the pipeline.

[0055] In order to ensure that liquid (test liquid and standard liquid) enters the liquid storage component, in step (A1), when the liquid sensor between the third pump and the second multi-way valve detects liquid, the switching module switches.

[0056] In order to accurately obtain the element content of the sample to be tested, further, in step (A5), the analysis method is:

[0057] Establishing a mapping relationship y=f(x) between the detection signal y and the concentration x of the trace element in the diluted standard solution;

[0058] According to the mapping relationship y=f(x), the content x of the trace element in the sample to be tested is obtained. 0 =|g(0), y=g(x) is the inverse function of y=f(x).

[0059] Embodiment 2:

[0060] An application example of the device and method for measuring trace elements according to Example 1 of the present invention.

[0061] In this application example, Figure 1As shown, the first to fifth pumps all use syringe pumps; the switching module includes the first to third switching components, the first switching component uses a two-position three-way valve, the second switching component uses a four-way valve, which is used to switch the standard liquid, the cleaning liquid and the air, and the third switching component uses a 12-way valve to switch the samples to be tested of different matrices; the first multi-way valve uses a two-position six-way valve, and the second multi-way valve uses a two-position seven-way valve, which has a common port, so that when the third multi-way valve is connected to the fourth pump through the common port of the second multi-way valve and the second liquid storage component in sequence, the third multi-way valve is connected to the fifth pump through the common port but not through the second liquid storage component; the third multi-way valve uses a two-position six-way valve; each liquid storage component uses a liquid storage ring;

[0062] The liquid sensor is arranged between the third pump and the port of the second multi-way valve connected thereto; and the analytical instrument adopts ICP-MS.

[0063] The method for measuring trace elements of the embodiment of the present invention, that is, the method for measuring trace elements using the device for measuring trace elements of the embodiment, comprises the following steps:

[0064] (B1) the switching module is switched to the cleaning liquid, and the first multi-way valve and the second multi-way valve are switched, so that under the suction action of the third pump, the cleaning liquid passes through the first liquid storage component and does not pass through the second liquid storage component to clean the first liquid storage component and the pipeline;

[0065] (B2) When the liquid sensor detects liquid, the second switching component switches to air, and the first multi-way valve and the second multi-way valve do not need to be switched, so that under the suction action of the third pump, the air passes through the first liquid storage component and does not pass through the second liquid storage component to empty the liquid in the first liquid storage component and the pipeline, thereby ensuring the cleanliness of the first liquid storage component and the pipeline;

[0066] (A1) switching the first multi-way valve, the second multi-way valve and the switching module (relative to steps (B1) and (B2), the first multi-way valve and the second multi-way valve do not need to be switched), so that under the suction action of the third pump, the selected sample to be tested enters the first liquid storage component; when the liquid sensor detects liquid, the first switching component and the second switching component are switched to switch to the standard liquid;

[0067] Switching the first multi-way valve and the second multi-way valve so that under the suction action of the third pump, the selected standard solution corresponding to the sample to be tested enters the second liquid storage component without passing through the first liquid storage component;

[0068] When the liquid sensor detects liquid, the third pump stops working;

[0069] (A2) switching the second multi-way valve and the third multi-way valve, the fourth pump provides a carrier flow and pushes the standard solution in the second liquid storage component into the third liquid storage component through the common port, the fifth pump provides a diluent and delivers the diluent into the third liquid storage component through the common port of the second multi-way valve, and the standard solution is diluted by the diluent;

[0070] (A3) switching the first multi-way valve and the third multi-way valve, the first pump pushes the sample to be tested in the first liquid storage component into the mixing area (mixing pipeline), and the second pump pushes the diluted standard solution in the third liquid storage component into the mixing area (mixing pipeline);

[0071] (A4) the sample to be tested and the diluted standard solution are mixed in the mixing zone and then sent to the analysis instrument, which outputs a detection signal;

[0072] Returning to step (A2), providing standard solutions with different dilution multiples until the analytical instrument outputs at least two detection signals, such as three detection signals;

[0073] (A5) analyzing the at least two detection signals and the concentration of the corresponding diluted standard solution to obtain the content of the trace element in the sample to be tested, and the specific analysis method is:

[0074] Establishing a mapping relationship y=f(x) between the detection signal y and the concentration x of the trace element in the diluted standard solution;

[0075] According to the mapping relationship y=f(x), the content x of the trace element in the sample to be tested is obtained. 0 =|g(0), y=g(x) is the inverse function of y=f(x).

[0076] The above embodiment is only an example of using the first multi-way valve, the second multi-way valve and the third multi-way valve. By switching the three multi-way valves, the extraction of the sample to be tested and the standard solution, the dilution of the standard solution after the extraction and transfer of the diluent, and the transfer and mixing of the sample to be tested and the diluted standard solution are realized, and finally the mixed solution is sent to the analysis instrument. It can be seen that the first multi-way valve, the second multi-way valve and the third multi-way valve are only a way to realize the above-mentioned flow path switching. At least two of the first multi-way valve, the second multi-way valve and the third multi-way valve can also be combined into a multi-way valve with more ports. For technicians in this field, the design of such a multi-way valve with more ports does not require creative labor.

Claims

1. A method for measuring trace elements using a device for measuring trace elements, wherein the device for measuring trace elements comprises an analytical instrument and further comprises: A switching module, the switching module is used to make the ports of the first multi-way valve selectively connect the test liquid and the standard liquid; A first multi-way valve and a first liquid storage component, wherein both ends of the first liquid storage component are connected to ports of the first multi-way valve; by switching the first multi-way valve, the second multi-way valve is connected to the switching module through and without the first liquid storage component, and the first pump is connected to the analytical instrument through and without the first liquid storage component; a second multi-way valve and a second liquid storage component, wherein both ends of the second liquid storage component are connected to the ports of the second multi-way valve; through the switching of the second multi-way valve, the first multi-way valve is connected to the third pump through and without passing through the second liquid storage component, and the third multi-way valve is connected to the fourth pump through the second liquid storage component, and the third multi-way valve is connected to the fifth pump without passing through the second liquid storage component; a third multi-way valve and a third liquid storage component, wherein both ends of the third liquid storage component are connected to the ports of the third multi-way valve; through the switching of the third multi-way valve, the second pump is connected to the analytical instrument through and without passing through the third liquid storage component; while the third multi-way valve is connected to the fourth pump through the common port of the second multi-way valve and the second liquid storage component in sequence, the third multi-way valve is connected to the fifth pump through the common port but without passing through the second liquid storage component; A plurality of pumps, wherein the first pump is connected to the port of the first multi-way valve, the second pump is connected to the port of the third multi-way valve, and the third pump is connected to the second multi-way valve; the fourth pump and the fifth pump are used to provide liquid and are connected to the port of the second multi-way valve; The method for measuring trace elements comprises the following steps: The cleaning and emptying steps are performed in sequence, specifically: the switching module switches to the cleaning liquid and the air at different times, and under the action of the third pump, the cleaning liquid passes through the first liquid storage component and does not pass through the second liquid storage component to clean the first liquid storage component and the pipeline, and then the air passes through the first liquid storage component and does not pass through the second liquid storage component to empty the liquid in the first liquid storage component and the pipeline; (A1) switching the first multi-way valve, the second multi-way valve and the switching module so that the selected sample to be tested enters the first liquid storage component under the action of the third pump, and the selected standard solution corresponding to the sample to be tested enters the second liquid storage component without passing through the first liquid storage component; (A2) Switching the second multi-way valve and the third multi-way valve, the fourth pump provides fluid and pushes the standard solution in the second liquid storage component into the third liquid storage component, the fifth pump provides diluent and sends it into the third liquid storage component through the second multi-way valve, and the standard solution is diluted by the diluent; (A3) switching the first multi-way valve and the third multi-way valve, the first pump pushes the sample to be tested in the first liquid storage component into the mixing area, and the second pump pushes the diluted standard solution in the third liquid storage component into the mixing area; (A4) The sample to be tested and the diluted standard solution are mixed in the mixing area and then sent to the analysis instrument, which outputs a detection signal; Return to step (A2), provide standard solutions with different dilution multiples until the analytical instrument outputs at least two detection signals; (A5) Analyze the at least two detection signals and the concentration of the corresponding diluted standard solution to obtain the content of the trace element in the sample to be tested.

2. The method for measuring trace elements according to claim 1, characterized in that: In step (A1), when the liquid sensor between the third pump and the second multi-way valve detects liquid, the switching module switches.

3. The method for measuring trace elements according to claim 1, characterized in that: In step (A5), the analysis is performed as follows: Establish a mapping relationship y=f(x) between the detection signal y and the concentration x of the trace element in the diluted standard solution; According to the mapping relationship y=f(x), the content of trace elements in the sample to be tested is obtained as x0=|g(0)|, which is the inverse function of y=g(x).

4. The method for measuring trace elements according to claim 1, characterized in that: In step (A2), the fourth pump and the fifth pump push the liquid simultaneously.

5. The method for measuring trace elements according to claim 1, characterized in that: The switching module comprises: a first switching component, the first switching component being used to selectively connect the port of the first multi-way valve to the second switching component and the third switching component; a second switching component, the second switching component being used to enable the first switching component to selectively connect various standard liquids, cleaning liquids and air; The third switching component is used to enable the first switching component to selectively connect various samples to be tested.

6. The method for measuring trace elements according to claim 1, characterized in that: The plurality of pumps are syringe pumps.

7. The method for measuring trace elements according to claim 1, characterized in that: A liquid sensor is arranged between the third pump and the port of the second multi-way valve connected thereto.

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