Device and method for measuring impurity content in diborane mixed gas

Abstract

The invention discloses a device and a method for measuring impurity content in diborane mixed gas, the device comprises a sample introduction system and a gas chromatograph connected with an outlet of the sample introduction system, the gas chromatograph is connected with a cooling device, an inlet of the sample introduction system is connected with a steel cylinder, and the steel cylinder is connected with a gas outlet of the gas chromatograph. And diborane standard gas or an impurity-containing diborane mixed gas sample to be detected is filled in the steel cylinder. The gas chromatograph method is used for analyzing and detecting the butyl borane and pentaborane impurities in the diborane mixed gas sample to be detected, the accuracy is higher, the cost is lower, and a technical support is provided for quality improvement and industrial development of the diborane mixed gas.

Description

Technical Field

[0001] This invention belongs to the field of diborane mixed gas detection technology, specifically relating to an apparatus and method for determining the impurity content in diborane mixed gas. Background Technology

[0002] Diborane mixtures are high-performance laser electron gases, colorless and odorless, highly toxic, flammable and explosive, and are important dopants in semiconductor processes. Diborane is extremely reactive and decomposes at room temperature to produce high-boride impurities such as butyrone and pentylborane. Therefore, controlling and detecting the content of butyrone and pentylborane impurities is particularly critical and challenging.

[0003] Currently, in the domestic industry, the detection of butorane and pentborane impurities in diborane mixtures mainly relies on low-temperature chromatography. The detector is a DID (Dihydrodi ... Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an apparatus and method for determining the impurity content in a borane mixture, so as to improve the accuracy of detecting the impurity content in a borane mixture.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An apparatus for determining the impurity content in a borane mixture includes a sample injection system and a gas chromatograph connected to the outlet of the sample injection system. The gas chromatograph is connected to a cooling device. The inlet of the sample injection system is connected to a steel cylinder containing borane standard gas or a borane mixture sample containing impurities to be tested.

[0007] Furthermore, the gas chromatograph includes a closed chamber, a sample inlet pipe fixedly disposed on one side of the chamber, a sample outlet pipe fixedly disposed on the other side of the chamber, and an automatic six-way valve, a chromatographic column, and a detector connected sequentially between the sample inlet pipe and the sample outlet pipe. The sample inlet pipe is connected to the outlet of the injection system, the detector is disposed on the top of the chamber, the automatic six-way valve and the chromatographic column are both disposed inside the chamber, and the cooling device is connected to the interior of the chamber.

[0008] Furthermore, the cooling device is a cylindrical tank containing liquid nitrogen coolant. The cylindrical tank has a radius of 10cm and a height of 30cm. One side of the bottom of the cylindrical tank is connected to the inside of the box through a stainless steel pipe. An outlet solenoid valve is provided on the stainless steel pipe. A filling pipe is provided on the other side of the bottom of the cylindrical tank. An inlet manual valve is provided on the filling pipe.

[0009] Furthermore, the detector is a flame photometric detector, which is equipped with a filter with a wavelength of 384 nm. Only boron and its compounds absorb light at this wavelength and generate a light signal. The response value of boron is proportional to the number of boron atoms.

[0010] Furthermore, the impurity is at least one of butoronane or pentoborane.

[0011] Furthermore, a filter is connected between the inlet of the injection system and the gas cylinder.

[0012] Furthermore, the injection system includes a diaphragm valve, a flow meter, and a pressure reducer connected in sequence to the gas chromatograph, the pressure reducer being connected to a gas cylinder.

[0013] A method for determining the impurity content in a diborane mixture, using the aforementioned apparatus for determining the impurity content in a diborane mixture, includes the following steps:

[0014] S1, Detection of diborane standard gas:

[0015] S1.1 Connecting a cylinder containing diborane standard gas: Connect the cylinder containing diborane standard gas to the inlet of the filter, and then open the outlet valve of the cylinder to introduce the diborane standard gas into the gas chromatograph.

[0016] S1.2, Start the cooling device: Open the inlet manual valve, add liquid nitrogen into the cooling device, then open the outlet solenoid valve to introduce liquid nitrogen into the gas chromatograph chamber for cooling, and set the column temperature to 0℃ in the gas chromatograph's chromatographic control program.

[0017] S1.3, Setting Instrument Parameters and Creating a Standard Curve: Turn on the gas chromatograph, set the gas chromatograph parameters, and discharge the diborane standard gas from the cylinder. Then, it passes through the filter, pressure reducer, flow meter, and diaphragm valve in sequence. After passing through the sample inlet tube, the automatic six-way valve controls the diborane standard gas to pass through the chromatographic column and enter the detector. Through the detector detection, the diborane response spectrum of the diborane standard gas is obtained, and the ratio of diborane content to peak area, i.e., the diborane correction coefficient, is recorded.

[0018] S2, Determination of butorane and pentoborane impurity content in diborane mixed gas sample:

[0019] S2.1 Connecting the cylinder containing the standard gas of diborane: Connect the cylinder containing the sample of diborane mixed gas to the inlet of the filter, then open the outlet valve of the cylinder to pass the diborane mixed gas into the gas chromatograph to obtain the spectra of butorane and pentorane components in the diborane mixed gas sample; the content of butorane component in the diborane mixed gas sample = diborane correction factor × 2 × peak area of ​​butorane in the sample to be tested, and the content of pentorane component = diborane correction factor × 2.5 × peak area of ​​pentorane in the sample to be tested.

[0020] Furthermore, in S1.2, the sample introduction system pipeline is treated to meet the requirements by evacuating and filling it with diborane standard gas.

[0021] Furthermore, the chromatographic parameters used for testing with a gas chromatograph were as follows: the carrier gas was helium with a purity of not less than 99.999%, and the carrier gas flow rate was 15 ml / min; the chromatographic column was a Se-30 capillary column with a specification of 60 m × 0.32 mm, and the packing material was polymethylsiloxane; the column temperature was 0 °C; the flame photometric detector temperature was 120 °C, and the injection flow rate was 10–20 ml / min.

[0022] The positive effects of this invention are:

[0023] 1. This invention utilizes gas chromatography to analyze and detect butyronine and pentyronine impurities in a sample of borane mixture, achieving higher accuracy and lower cost, thus providing technical support for improving the quality and industrial development of borane mixture.

[0024] 2. In a mixture of diborane and borane, diborane decomposes to produce butborane and pentoborane. Based on the characteristic that the response of boron to a specific wavelength filter is proportional to the number of boron atoms in the compound, the contents of butborane and pentoborane can be calculated proportionally by the relationship between the content of diborane and the peak area, thus solving the problem of quantitative determination of butborane and pentoborane.

[0025] 3. The automatic six-way injection valve in the gas chromatograph can remove diborane from the diborane mixture, allowing butoron and pentylborane to enter the detector. This method uses a Se-30 column and a flame photometric detector. Based on the temperature sensing element of the gas chromatograph, the flow rate of liquid nitrogen coolant is controlled via the outlet solenoid valve to reduce and maintain a low temperature. Automatic integration events can be set based on the peak times of the diborane mixture, butoron, and pentylborane to achieve automated integration detection. Attached Figure Description

[0026] Figure 1 This is a system schematic diagram of the present invention;

[0027] In the picture:

[0028] 1. Gas chromatograph; 2. Chromatographic column; 3. Automatic six-way valve; 4. Sample inlet tube; 5. Diaphragm valve; 6. Sample outlet tube; 7. Sample injection system; 8. Flow meter; 9. Pressure reducer; 10. Filter; 11. Sample to be tested; 12. Detector; 13. Outlet solenoid valve; 14. Cooling device; 15. Inlet manual valve. Detailed Implementation

[0029] Example 1

[0030] like Figure 1 As shown, an apparatus for determining the impurity content in a borane mixture includes a sample injection system 7 and a gas chromatograph 1 connected to the outlet on the right side of the sample injection system 7. A cooling device 14 is connected to the right side of the gas chromatograph 1. The inlet on the left side of the sample injection system 7 is connected to a steel cylinder 11. The steel cylinder 11 contains borane standard gas or a borane mixture sample containing impurities to be tested, wherein the impurities are at least one of butorane or pentborane.

[0031] The gas chromatograph 1 includes a closed housing, a sample inlet pipe 4 fixedly installed on the left side near the top of the housing, a sample outlet pipe 6 fixedly installed on the right side near the top of the housing, and an automatic six-way valve 3, a chromatographic column 2, and a detector 12 connected sequentially from left to right between the sample inlet pipe 4 and the sample outlet pipe 6. The sample inlet pipe 4 is connected to the outlet of the injection system 7. The detector 12 is located at the top of the housing. The automatic six-way valve 3 and the chromatographic column 2 are both located inside the housing. The cooling device 14 is connected to the interior of the housing.

[0032] The cooling device 14 is a cylindrical tank containing liquid nitrogen coolant. The cylindrical tank has a radius of 10cm and a height of 30cm. The bottom left side of the cylindrical tank is connected to the inside of the box through a stainless steel pipe. An outlet solenoid valve 13 is provided on the stainless steel pipe. A filling pipe is provided on the bottom right side of the cylindrical tank. An inlet hand valve 15 is provided on the filling pipe.

[0033] The detector 12 is a flame photometric detector 12. The detector 12 is equipped with a filter with a wavelength of 384nm. Only boron and its compounds absorb at this wavelength and generate light signals. The response value of boron is proportional to the number of boron atoms.

[0034] The sample introduction system 7 includes a diaphragm valve 5, a flow meter 8, and a pressure reducer 9 connected from right to left to the sample inlet tube 4. The inlet of the left end of the pressure reducer 9 is connected to a filter 10, which is connected to a gas cylinder 11.

[0035] After the outlet solenoid valve 13 is opened, liquid nitrogen in the cooling device 14 enters the chamber of the gas chromatograph 1, thereby cooling the chromatographic column 2 and lowering the detection temperature of the diborane mixture to avoid or reduce the decomposition of diborane during detection, thereby improving the accuracy of detecting the content of butoronane and pentborane impurities in the diborane mixture.

[0036] Example 2

[0037] This embodiment discloses a method for determining the impurity content in a diborane mixture, using the apparatus for determining the impurity content in a diborane mixture disclosed in Example 1, and includes the following steps:

[0038] S1, Detection of diborane standard gas:

[0039] S1.1 Connect the steel cylinder 11 containing diborane standard gas: Connect the steel cylinder 11 containing diborane standard gas to the inlet of the filter 10, and then open the outlet valve of the steel cylinder 11 to introduce the diborane standard gas into the gas chromatograph 1.

[0040] S1.2, Start the cooling device 14: Open the inlet hand valve 15, add liquid nitrogen into the cooling device 14, then open the outlet solenoid valve 13, and introduce liquid nitrogen into the chamber of the gas chromatograph 1 for cooling. Set the temperature of the chromatographic column 2 to 0℃ in the chromatographic control program of the gas chromatograph 1.

[0041] S1.3, Setting Instrument Parameters and Creating a Standard Curve: Turn on the gas chromatograph 1, set the parameters of the gas chromatograph 1, and discharge the diborane standard gas from the cylinder 11. Then, it passes through the filter 10, pressure reducer 9, flow meter 8, diaphragm valve 5 in sequence, and then through the sample inlet tube 4. The automatic six-way valve 3 controls the diborane standard gas to pass through the chromatographic column 2 and enter the detector 12. Through the detection of the detector 12, the diborane response spectrum of the diborane standard gas is obtained, and the ratio of diborane content to peak area is recorded, which is the diborane correction coefficient.

[0042] S2, Determination of butorane and pentoborane impurity content in diborane mixed gas sample:

[0043] S2.1, Connect the steel cylinder 11 containing the standard gas of diborane: Connect the steel cylinder 11 containing the sample of diborane mixed gas to the inlet of the filter 10, and then open the outlet valve of the steel cylinder 11 to pass the diborane mixed gas into the gas chromatograph 1 to obtain the spectra of the butborane and pentborane components in the diborane mixed gas sample; the content of butborane component in the diborane mixed gas sample = diborane correction factor × 2 × peak area of ​​butborane in the sample 11 to be tested, and the content of pentborane component = diborane correction factor × 2.5 × peak area of ​​pentborane in the sample 11 to be tested.

[0044] Example 3

[0045] The difference between this embodiment and Embodiment 2 is that:

[0046] In S1.2, the sample introduction system 7 pipeline is treated to meet the requirements by evacuating and filling it with diborane standard gas, thereby reducing the impact of residual gas (such as air) in the original pipeline system on the accuracy of the measurement results.

[0047] The chromatographic parameters used in the gas chromatograph 1 were as follows: the carrier gas was helium with a purity of not less than 99.999%, and the carrier gas flow rate was 15 ml / min; the chromatographic column 2 was a Se-30 capillary column with a specification of 60 m × 0.32 mm, and the packing material was polymethylsiloxane; the temperature of the chromatographic column 2 was 0 °C; the temperature of the flame photometric detector 12 was 120 °C, and the injection flow rate was 10–20 ml / min.

[0048] The above-described embodiments are detailed and specific, illustrating preferred embodiments of the present invention. They are only used to illustrate the technical ideas and features of the present invention, with the aim of enabling those skilled in the art to understand the content of the present invention and implement it accordingly. However, they are not limited to the present invention, and the patent scope of the present invention cannot be limited by this embodiment alone. That is, any equivalent changes or modifications made to the spirit disclosed in the present invention, without departing from the structure of the present invention, such as local improvements within the system and modifications or transformations between subsystems, are still within the patent scope of the present invention.

Claims

1. An apparatus for determining the impurity content in a diborane mixture, characterized in that, The system includes an injection system (7) and a gas chromatograph (1) connected to the outlet of the injection system (7). The gas chromatograph (1) is connected to a cooling device (14). The inlet of the injection system (7) is connected to a gas cylinder (11). The gas cylinder (11) contains diborane standard gas or a diborane mixed gas sample containing impurities to be tested.

2. The apparatus for determining the impurity content in a diborane mixture according to claim 1, characterized in that, The gas chromatograph (1) includes a closed housing, a sample inlet pipe (4) fixedly installed on one side of the housing, a sample outlet pipe (6) fixedly installed on the other side of the housing, an automatic six-way valve (3), a chromatographic column (2), and a detector (12) connected in sequence between the sample inlet pipe (4) and the sample outlet pipe (6). The sample inlet pipe (4) is connected to the outlet of the injection system (7). The detector (12) is installed on the top of the housing. The automatic six-way valve (3) and the chromatographic column (2) are both installed inside the housing. The cooling device (14) is connected to the inside of the housing.

3. The apparatus for determining the impurity content in a diborane mixture according to claim 2, characterized in that, The cooling device (14) is a cylindrical tank containing liquid nitrogen coolant. The cylindrical tank has a radius of 10cm and a height of 30cm. One side of the bottom of the cylindrical tank is connected to the inside of the box through a stainless steel pipe. An outlet solenoid valve (13) is provided on the stainless steel pipe. A filling pipe is provided on the other side of the bottom of the cylindrical tank. An inlet hand valve (15) is provided on the filling pipe.

4. The apparatus for determining the impurity content in a diborane mixture according to claim 2, characterized in that, The detector (12) is a flame photometric detector (12). The detector (12) is equipped with a filter with a wavelength of 384nm. Only boron and its compounds absorb at this wavelength and generate light signals. The response value of boron is proportional to the number of boron atoms.

5. The apparatus for determining the impurity content in a diborane mixture according to claim 1, characterized in that, The impurity is at least one of butoronane or pentoborane.

6. The apparatus for determining the impurity content in a diborane mixture according to claim 1, characterized in that, A filter (10) is connected between the inlet of the injection system (7) and the cylinder (11).

7. The apparatus for determining the impurity content in a diborane mixture according to claim 1, characterized in that, The sample introduction system (7) includes a diaphragm valve (5), a flow meter (8) and a pressure reducer (9) connected in sequence to the gas chromatograph (1), and the pressure reducer (9) is connected to the gas cylinder (11).

8. A method for determining the impurity content in a diborane mixture, characterized in that, The apparatus for determining the impurity content in a diborane mixture according to any one of claims 1 to 7 comprises the following steps: S1, Detection of diborane standard gas: S1.1 Connect the cylinder (11) containing diborane standard gas: Connect the cylinder (11) containing diborane standard gas to the inlet of the filter (10), and then open the outlet valve of the cylinder (11) to pass the diborane standard gas into the gas chromatograph (1). S1.2, turn on the cooling device (14): open the inlet hand valve (15), add liquid nitrogen into the cooling device (14), then open the outlet solenoid valve (13), and pass liquid nitrogen into the chamber of the gas chromatograph (1) for cooling. Set the temperature of the chromatographic column (2) to 0°C in the chromatographic control program of the gas chromatograph (1). S1.3, setting instrument parameters and creating a standard curve: turn on the gas chromatograph (1), set the parameters of the gas chromatograph (1), the diborane standard gas is discharged from the steel cylinder (11), and then passes through the filter (10), pressure reducer (9), flow meter (8), diaphragm valve (5) in sequence, and then through the sample inlet tube (4). The automatic six-way valve (3) controls the diborane standard gas to pass through the chromatographic column (2) and enter the detector (12). Through the detection of the detector (12), the diborane response spectrum of the diborane standard gas is obtained, and the ratio of diborane content to peak area is recorded as the diborane correction coefficient. S2, Determination of butorane and pentoborane impurity content in diborane mixed gas sample: S2.1, Connect the cylinder (11) containing the standard gas of diborane: Connect the cylinder (11) containing the sample of diborane mixed gas to the inlet of the filter (10), and then open the outlet valve of the cylinder (11) to pass the diborane mixed gas into the gas chromatograph (1) to obtain the spectra of the butborane and pentoborane components in the diborane mixed gas sample; the content of butborane component in the diborane mixed gas sample = diborane correction coefficient × 2 × peak area of ​​butborane in the sample (11) to be tested, and the content of pentoborane component = diborane correction coefficient × 2.5 × peak area of ​​pentoborane in the sample (11) to be tested.

9. The method for determining the impurity content in a diborane mixture according to claim 8, characterized in that, In S1.2, the sample introduction system (7) pipeline is processed to meet the requirements by evacuating and filling it with diborane standard gas.

10. The method for determining the impurity content in a diborane mixture according to claim 8, characterized in that, The chromatographic parameters tested using a gas chromatograph (1) are as follows: the carrier gas is helium with a purity of not less than 99.999%, and the carrier gas flow rate is 15 ml / min; the chromatographic column (2) is a Se-30 capillary column with a specification of 60 m × 0.32 mm and the packing material is polymethylsiloxane; the temperature of the chromatographic column (2) is 0 °C; the temperature of the flame photometric detector (12) is 120 °C, and the injection flow rate is 10–20 ml / min.

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