JP4498817B2 - Element concentration measuring device - Google Patents

Description

  The present invention relates to an element concentration measuring apparatus using an electron beam.

  An electron probe microanalyzer (hereinafter referred to as EPMA) is known as an apparatus for measuring the concentration of an element contained in a sample in the sample. As a method for measuring the concentration of an element in a sample using such an apparatus (concentration analysis method), a concentration measuring method described in Japanese Patent Laid-Open No. 61-70444 (hereinafter referred to as Patent Document 1) is known. Yes. Below, the density | concentration measuring method described in the said patent document 1 is demonstrated using drawing.

  In the concentration measuring method described in Patent Document 1, an analyzer having an EPMA configuration (referred to as an electron beam microanalyzer in Patent Document 1) is used. This analyzer is configured as shown in FIG. 4, and the electron beam 101 is irradiated in a state of being focused on the surface of the sample 102 by an objective lens (condenser lens) (not shown). The sample 102 is placed on a sample stage (not shown). Then, the sample 102 is two-dimensionally scanned by the electron beam 101 by the movement of the sample stage. Note that by stopping the movement of the sample stage and fixing the position of the sample 102 as appropriate, spot irradiation can be performed in a state where the electron beam 101 is fixed at a predetermined position on the sample 102.

  When the electron beam 101 irradiates the sample 102, a characteristic X-ray 104 is generated from an analysis point (measurement point) on the irradiated sample 102, and the characteristic X-ray 104 is dispersed by the spectral crystal 103. The characteristic X-ray 104 dispersed by the spectral crystal 103 is detected by the X-ray detector 105.

  The X-ray detector 105 outputs an electrical signal (pulse signal) corresponding to the detected characteristic X-ray intensity of the characteristic X-ray 105. The electric signal is counted as a characteristic X-ray intensity by the X-ray measurement circuit 106 and stored in a storage area corresponding to each analysis point on the sample 102 in the storage device 108 via the arithmetic control device 107. Thereby, the element concentration of each analysis point on the sample 102 can be obtained.

  A display device 109 is connected to the arithmetic and control unit 107, and a concentration map representing the element concentration at each analysis point on the sample 102 is displayed on the display device 109.

  By using such an analyzer, the concentration of the element contained in the sample in the sample can be obtained.

JP-A-61-70444

  In the concentration measurement of an element in a sample using the above-mentioned EPMA, the concentration measurement may be performed by setting a predetermined concentration measurement lower limit value. In this case, when the irradiation current value of the electron beam is determined, an appropriate guideline for the measurement time corresponding to the set concentration measurement lower limit value is not established, and the measurement is performed based on the experience of the operator who operates the apparatus. The time was decided. Therefore, the concentration measurement may be performed in a state where the measurement time is insufficient, or the concentration measurement may be performed in a state where the measurement time is unnecessarily long.

  Moreover, when the measurement time is determined, an appropriate guideline for the irradiation current value of the electron beam corresponding to the set concentration measurement lower limit value has not been established, and the irradiation current value is determined by operator experience. It was. Therefore, concentration measurement may be performed in a state where the irradiation current of the electron beam is small, or concentration measurement may be performed in a state where the irradiation current is large.

  The present invention has been made in view of such points, and when performing an element concentration measurement in which a predetermined concentration measurement lower limit value is set, an appropriate measurement time or an irradiation current value of an electron beam is obtained by calculation, Accordingly, an object of the present invention is to provide an element concentration measuring apparatus capable of efficiently performing highly accurate measurement.

A first element concentration measuring apparatus according to the present invention irradiates a sample with an electron beam, detects characteristic X-rays generated corresponding to the element contained in the sample, and thereby the concentration of the element in the sample. a element concentration measuring apparatus for measuring, comprising an input unit, and an arithmetic control unit for controlling the measuring operation to calculate the measurement condition, the arithmetic control unit, the analysis sample data for the standard sample of the element Apply the irradiation current value of the electron beam input from the input unit to the arithmetic expression obtained by the proportionality coefficient that derives the background intensity corresponding to the irradiation current value of the electron beam when measuring the element concentration of Thus, a measurement time corresponding to a predetermined concentration measurement lower limit value is calculated .

The second element concentration measuring apparatus according to the present invention irradiates a sample with an electron beam and detects characteristic X-rays generated corresponding to the element contained in the sample, thereby detecting the element in the sample. a element concentration measuring device for measuring the concentration of an input unit, and an arithmetic control unit for controlling the measuring operation to calculate the measurement condition, the arithmetic control unit, and analyzing data for the standard sample of the element By applying the measurement time input from the input unit to the arithmetic expression obtained by the proportionality coefficient for deriving the background intensity corresponding to the irradiation current value of the electron beam at the time of element concentration measurement of the target sample, An irradiation current value of the electron beam corresponding to a predetermined concentration measurement lower limit value is calculated .

In the first element concentration measurement apparatus according to the present invention, the calculation control unit determines the measurement time corresponding to the predetermined concentration measurement lower limit value, the data related to the standard sample of the element and the electron at the time of element concentration measurement of the analysis target sample. Calculated by applying the irradiation current value of the electron beam input from the input unit to the arithmetic expression obtained by the proportionality coefficient for deriving the background intensity corresponding to the irradiation current value of the line, and the measurement time concerned Measurement will be executed based on the above. Therefore, the measurement time can be appropriately determined according to the concentration measurement lower limit value, and highly accurate measurement can be performed efficiently.

Further, in the second element concentration measuring apparatus according to the present invention, the calculation control unit calculates the irradiation current value of the electron beam according to the predetermined concentration measurement lower limit value, the data relating to the standard sample of the element and the element of the analysis target sample. Calculated by applying the measurement time input from the input unit to the arithmetic expression obtained by the proportionality coefficient for deriving the background intensity corresponding to the irradiation current value of the electron beam at the concentration measurement, and the irradiation Measurement is performed based on the current value. Therefore, the irradiation current value of the electron beam can be appropriately determined according to the concentration measurement lower limit value, and highly accurate measurement can be performed efficiently.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an example of an element concentration measuring apparatus based on the present invention. This element concentration measuring apparatus has an EPMA configuration.

  In the figure, reference numeral 1 denotes an electron gun, from which an electron beam 6 is accelerated and emitted. The electron beam 6 emitted from the electron gun 1 is finely focused on the sample 7 by the focusing lens 2 and the objective lens 4. Thereby, the electron beam 6 becomes an electron probe on the sample 7. At this time, the electron beam 6 is appropriately deflected by the scanning coil 3. Thereby, the electron beam 6 can scan a predetermined area on the sample 7 as an analysis area, or can also perform spot irradiation with one point on the sample 7 fixed as an analysis point.

  From the sample 7 irradiated with the electron beam 6, characteristic X-rays 8 are generated corresponding to the elements contained in the sample 7. The characteristic X-ray 8 is dispersed by the spectral crystal 9, and the characteristic X-ray 8 after the spectroscopy is detected by the X-ray detector 11. Here, for example, TAP or the like is used as the spectral crystal 9.

  The X-ray detector 11 outputs a detection signal (pulse signal) corresponding to the detected characteristic X-ray intensity of the characteristic X-ray 8. The detection signal from the X-ray detector 11 is counted in the processing unit 17 and the counted data is sent to the arithmetic control unit 18 as the characteristic X-ray intensity.

  The electron gun 1, the focusing lens 2, the scanning coil 3, and the objective lens 4 are disposed in a lens barrel 12 that constitutes an element concentration measuring apparatus. The sample 7 is placed on the sample stage mechanism 5 disposed in the sample chamber 13 located below the lens barrel 12.

  The interior of the lens barrel 12 and the sample chamber 13 are evacuated and evacuated by an evacuation unit (not shown). When the sample 7 is irradiated with the electron beam 6, the inside of the lens barrel 12 and the sample chamber 13 are each evacuated to a predetermined degree of vacuum.

  An electron optical system 23 is configured by the focusing lens 2, the scanning coil 3, and the objective lens 4 in the lens barrel 12. The electron gun 1 and the electron optical system 23 are driven by the drive unit 14.

  The spectroscopic crystal 9 and the X-ray detector 11 are attached to the drive mechanism 10. The spectroscopic crystal 9 and the X-ray detector 11 are each moved in a predetermined direction by the drive mechanism 10. The drive mechanism 10 is driven by the drive unit 15.

  The sample stage mechanism 5 on which the sample 7 is placed is driven by the drive unit 16. As a result, the sample 7 moves in the horizontal direction, the vertical direction, the tilt direction, and the rotation direction.

  The drive units 14 to 16 and the processing unit 17 are connected to the calculation control unit 18. Further, a storage unit 19 is connected to the arithmetic control unit 18. These drive units 14 to 16, the processing unit 17, the calculation control unit 18, and the storage unit 19 constitute a control system 20.

  Here, the calculation control unit 18 controls the measurement operation by controlling each component of the element concentration measuring apparatus, and performs calculations necessary for executing the control. The storage unit 19 stores driving conditions for driving the electron optical system 23, arithmetic expressions (functions) described later, and the like.

  A display unit 21 and an input unit 22 are connected to the arithmetic control unit 18. The display unit 21 is composed of a display device such as an LCD or a CRT, and displays the measurement result after the element concentration measurement is performed as necessary. The input unit 22 includes a pointing device such as a mouse and a joystick, a keyboard, and the like. An operator who measures the element concentration in the sample 7 using this element concentration measuring apparatus can set measurement conditions such as an electron beam irradiation current value and a measurement time by operating the input unit 22.

  The above is the configuration of the element concentration measuring apparatus in the present invention. Next, the element concentration measuring method in the present invention will be described.

  When the element concentration measurement is performed using the element concentration measuring apparatus having the above-described EPMA configuration, if the concentration measurement lower limit value is L [%], the concentration measurement lower limit value L is expressed by the following equation (1 equation). The

この１式において、Ｉは測定対象元素の標準試料での特性Ｘ線の強度（カウント数）［ｃｐｓ］であり、Ｃは当該標準試料における当該元素濃度［％］である。なお、この例では、この標準試料における当該元素濃度は１００［％］とする。また、Ｔは測定時間［秒］、Ｊは電子線の照射電流値［アンペア（Ａ）］である。そして、１式中のＡは所定の係数である。なお、Ｂ＝ＡＪとすると、Ｂはバックグラウンド強度に相当する。

In this equation, I is the characteristic X-ray intensity (count) [cps] of the measurement target element in the standard sample, and C is the element concentration [%] in the standard sample. In this example, the element concentration in this standard sample is 100 [%]. T is the measurement time [seconds], and J is the electron beam irradiation current value [ampere (A)]. A in the formula is a predetermined coefficient. If B = AJ, B corresponds to the background intensity.

  When the above formula 1 is modified to derive a formula for calculating the measurement time T, the measurement time T is expressed by the following formula (formula 2).

この２式において、測定対象となる元素の標準試料に関するデータ（上記強度Ｉ及び上記元素濃度Ｃ）及び上記係数Ａが既知であれば、これらの値をこの２式に入れることができる。そのようにすると、上記２式に示すように、測定時間Ｔは、濃度測定下限値Ｌと電子線の照射電流値Ｊとの関数Ｆ（Ｌ，Ｊ）で表すことができる。

In these two formulas, if the data relating to the standard sample of the element to be measured (the intensity I and the element concentration C) and the coefficient A are known, these values can be entered in the two formulas. If it does so, as shown in said 2 type | formula, the measurement time T can be represented by the function F (L, J) of the density | concentration measurement lower limit L and the irradiation current value J of an electron beam.

  In the first embodiment, this function F (L, J) representing the measurement time T is obtained. Therefore, first, as a preliminary measurement, each background intensity B with respect to a plurality of irradiation current values J of the electron beam when the sample to be analyzed is irradiated with the electron beam is measured. As a specific example, here, it is assumed that the sample to be analyzed (unknown sample) is mainly composed of Fe (iron), and the concentration of, for example, Si (silicon) contained in the sample Consider the case of measuring Moreover, the spectral crystal used at the time of the said density | concentration measurement is set to TAP as an example.

  In the preliminary measurement, a sample to be analyzed is placed on the sample stage mechanism 5 in the sample chamber 13 of this apparatus (see FIG. 1), and in this state, the electron gun 1 and the electron optical system 23 are operated under predetermined driving conditions. While controlling the drive, the irradiation current value J of the electron beam 6 irradiated to the sample (sample 7) is appropriately changed. Then, the X-ray background intensity B detected through the spectral crystal 9 is measured according to each value of the irradiation current value J.

  It is known that the background intensity B is substantially proportional to the irradiation current value J of the electron beam. Therefore, the value of the coefficient A when the background B is expressed as B = AJ can be obtained from this measurement result. If the value of the coefficient A can be obtained by this preliminary measurement, the value is put into the above two equations.

  Further, in an Si standard sample having a Si concentration of 100 [%], the characteristic I-ray intensity I when TAP is used as a spectroscopic crystal and the concentration C (100 [%]) of the standard sample. Into the above two formulas. The concentration C and the intensity I for this standard sample are known.

  As a result, numerical values are assigned to I, C, and A in the above two formulas, and the variables in the two formulas are only L and J. Therefore, as shown in the above two formulas, the measurement time T is represented by a function F (L, J) of the concentration measurement lower limit L and the electron beam irradiation current value J. Thereafter, the above two expressions representing the function F (L, J) are stored in the storage unit 19 of the present apparatus.

  After the preliminary measurement is performed and the function F (L, J) based on the result is stored in the storage unit 19, the process proceeds to the main measurement for measuring the concentration of Si as the measurement target element in the sample.

  In the main measurement, first, a desired density measurement lower limit L (predetermined density measurement lower limit L) is set by the operator. The concentration measurement lower limit L is set by an operator operating the input unit 22 in the apparatus and inputting the set value. In this embodiment, the concentration measurement lower limit is set to 0.01 [%], for example.

  The input operation at this time will be described with reference to FIG. Here, FIG. 2 is a diagram illustrating an example of an input operation screen on the display unit 21 when the input operation is executed.

  When performing the input operation, the display screen of the display unit 21 is changed to the input operation screen 50 shown in FIG. Then, the mouse constituting the input unit 22 is operated to move and click the cursor 56 on the screen, so that the setting frame 51 for the density measurement lower limit L is selected. As a result, a desired numerical value of the density measurement lower limit L can be input in the setting frame 51.

  Thereafter, the keyboard constituting the input unit 22 is operated to input the desired numerical value into the setting frame 51. Here, the input operation screen 50 shown in FIG. 2 is a state in which “0.01”, which is a desired value, is input in the setting frame 51. It should be noted that a pull-down menu is provided at a predetermined location on the input operation screen 50, and a desired value can be selected and input by a cursor from a plurality of preset values by operating the mouse. Good.

  The data of the concentration measurement lower limit L input by the input unit 22 in this way is sent to the calculation control unit 18. The arithmetic control unit 18 reads the above-mentioned two functions F (L, J) stored in the storage unit 19 and substitutes the set value for L of the function F (L, J).

As a result, L in the function F (L, J) for calculating the measurement time T expressed by the above two formulas is fixed. Therefore, the measurement time T in accordance with the setting value L becomes a fact determined based on the irradiation current value J of the electron beam, T = F L _(J) consisting function F _{L (J)} is derived. This function F _L (J) is stored in the storage unit 19 in this apparatus.

  Thereafter, the operator operates the input unit 22 to input a desired irradiation current value J of the electron beam. As the input operation at this time, a desired numerical value is input to the irradiation current value J setting frame 52 on the input operation screen 50 shown in FIG. The input operation is also performed by the same method as the above-described operation.

The input irradiation current value J data is sent to the arithmetic control unit 18. Arithmetic control unit 18, the function F _L which is stored in the storage unit 19 reads the _(J), and substitutes the input value (irradiation current value) J of the function F _{L (J).} Then, the measurement time T is calculated by calculating the function F _L (J). The calculated measurement time T is displayed on the display unit 21. The display of the measurement time T is displayed in a display frame 53 for the measurement time T on the input operation screen 50 shown in FIG.

  Next, the operator visually checks the measurement time T displayed on the display unit 21 in this way, and determines whether or not the numerical value of the measurement time T is appropriate. In this determination, if the operator determines that the displayed value of the measurement time T is appropriate, the operator operates the mouse and clicks the execution button 54 in the input operation screen 50 with the cursor 56. Thereby, the measurement time T calculated according to the irradiation current value J is set to this apparatus. The apparatus performs the concentration measurement of the sample based on the measurement time T and the irradiation current value J set in this way. If the operator determines that the displayed value of the measurement time T is not appropriate, the operator operates the mouse and clicks the reset button in the input operation screen 50 with the cursor 56. Thereby, the irradiation current value J can be re-input (reset), and a desired value of a different irradiation current value J can be input again.

  At the time of the concentration measurement, the electron beam 6 is irradiated to the sample 7 placed on the sample stage mechanism 5 in the sample chamber 13. Then, characteristic X-rays generated corresponding to the element (Si) contained in the sample 9 are detected, and thereby the concentration of the element in the sample 9 is measured. The measurement time and the irradiation current value of the electron beam at this time are set to the above set values T and J, respectively.

  Thus, in this embodiment, the measurement time T corresponding to the predetermined concentration measurement lower limit L is calculated and displayed based on the irradiation current value J of the electron beam, and based on the displayed measurement time T. Measurement. Therefore, the measurement time T can be appropriately determined according to the concentration measurement lower limit L, and highly accurate measurement can be performed efficiently.

  After the measurement time T calculated by the calculation control unit 18 based on the data of the irradiation current value J is displayed on the display unit 21, the calculation control unit 18 does not determine whether the measurement time T is appropriate by the operator. It is also possible to automatically set the calculated measurement time T and execute the concentration measurement of the sample based on the set measurement time T and the irradiation current value J.

  Similarly to Example 1, when performing element concentration measurement using an element concentration measuring apparatus having an EPMA configuration, assuming that the concentration measurement lower limit value is L [%], the concentration measurement lower limit value L is expressed by the above formula 1. expressed.

  Then, when the above equation 1 is modified to derive an equation for calculating the electron beam irradiation current value J, the irradiation current value J is expressed by the following equation (3 equations).

この３式においても、測定対象となる元素の標準試料に関するデータ（上記強度Ｉ及び上記元素濃度Ｃ）及び上記係数Ａが既知であれば、これらの値をこの３式に入れることができる。そのようにすると、上記３式に示すように、電子線の照射電流値Ｊは、濃度測定下限値Ｌと測定時間Ｔとの関数Ｇ（Ｌ，Ｔ）で表すことができる。

Also in these three formulas, if the data regarding the standard sample of the element to be measured (the intensity I and the element concentration C) and the coefficient A are known, these values can be entered in the three formulas. If it does so, as shown in said 3 type | formula, the irradiation current value J of an electron beam can be represented by the function G (L, T) of the density | concentration measurement lower limit L and the measurement time T. FIG.

  In the second embodiment, the function G (L, T) representing the irradiation current value J of the electron beam is obtained. Therefore, as in the first embodiment, first, as a preliminary measurement, each of the background intensities B with respect to the plurality of irradiation current values J of the electron beam when the sample to be analyzed is irradiated with the electron beam is measured. In this example as well, the sample (unknown sample) to be analyzed is assumed to be composed mainly of Fe (iron), and the concentration of, for example, Si (silicon) contained in the sample is measured. Consider the case. In addition, the spectral crystal used for the concentration measurement is also TAP as an example.

  As in the first embodiment, in the preliminary measurement, a sample to be analyzed is placed on the sample stage mechanism 5 in the sample chamber 13 of the present apparatus (see FIG. 1), and in this state, the electron is subjected to a predetermined driving condition. While driving and controlling the gun 1 and the electron optical system 23, the irradiation current value J of the electron beam 6 irradiated to the sample (sample 7) is appropriately changed. Then, the X-ray background intensity B detected through the spectral crystal 9 is measured according to each value of the irradiation current value J.

  It is known that the background intensity B is substantially proportional to the irradiation current value J of the electron beam. Therefore, the value of the coefficient A when the background B is expressed as B = AJ can be obtained from this measurement result. When the value of the coefficient A can be obtained by this preliminary measurement, the value is put into the above three equations.

  Further, in an Si standard sample having a Si concentration of 100 [%], the characteristic I-ray intensity I when TAP is used as a spectroscopic crystal and the concentration C (100 [%]) of the standard sample. Into the above three formulas. As in Example 1, the concentration C and the intensity I for this standard sample are known.

  As a result, numerical values are assigned to I, C, and A in the above three formulas, and the variables in the three formulas are only L and T. Therefore, as shown in the above three formulas, the irradiation current value J of the electron beam is represented by a function G (L, T) of the concentration measurement lower limit L and the measurement time T. Thereafter, the above three expressions representing the function G (L, T) are stored in the storage unit 19 of the present apparatus.

  After the preliminary measurement is performed and the function G (L, T) based on the result is stored in the storage unit 19, the process proceeds to the main measurement for measuring the concentration of Si as the measurement target element in the sample.

  Also in the actual measurement, first, a desired density measurement lower limit L (predetermined density measurement lower limit L) is set by the operator. The concentration measurement lower limit L is set by an operator operating the input unit 22 in the apparatus and inputting the set value. Also in this embodiment, the concentration measurement lower limit is set to 0.01 [%], for example.

  The input operation at this time will be described with reference to FIG. Here, FIG. 3 is a diagram illustrating another example of the input operation screen on the display unit 21 when the input operation is executed.

  When performing the input operation, the display screen of the display unit 21 is changed to the input operation screen 60 shown in FIG. Then, the mouse constituting the input unit 22 is operated to move and click the cursor 66 on the screen, so that the setting frame 61 for the density measurement lower limit L is selected. As a result, it is possible to input a desired numerical value of the density measurement lower limit L in the setting frame 61.

  Thereafter, the keyboard constituting the input unit is operated to input the desired numerical value into the setting frame 61. Here, the input operation screen 60 shown in FIG. 2 is in a state in which “0.01”, which is a desired value, is input in the setting frame 61. It should be noted that a pull-down menu is provided at a predetermined location on the input operation screen 60, and a desired value can be selected and inputted from a plurality of preset values by operating the mouse. Good.

  Data of the concentration measurement lower limit L input to the input unit 22 in this way is sent to the arithmetic control unit 18. The arithmetic control unit 18 reads the function G (L, T) of the above three expressions stored in the storage unit 19 and substitutes the set value for L of the function G (L, T).

As a result, L in the function G (L, T) for calculating the irradiation current value J expressed in the above three formulas is fixed. Therefore, the irradiation current value J in accordance with the setting value L becomes a fact determined by the measurement time T based, J = G L _(T) becomes a function G _{L (T)} is derived. This function G _L (T) is stored in the storage unit 19 in this apparatus.

  Thereafter, the operator operates the input unit 22 to input a desired measurement time T. As an input operation at this time, a desired numerical value is input to the setting frame 63 for the measurement time T on the input operation screen 60 shown in FIG. The input operation is also performed by the same method as the above-described operation.

The data of the measurement time T thus input is sent to the calculation control unit 18. Arithmetic control unit 18 reads out the function G _{L (T)} stored in the storage unit 19 substitutes the input value (measurement time) T of the function G _{L (T).} Then, the irradiation current value J is calculated by calculating the function G _L (T). The calculated irradiation current value J is displayed on the display unit 21. The display of the irradiation current value J is displayed in a display frame 62 for the irradiation current value J on the input operation screen 60 shown in FIG.

  Next, the operator visually confirms the irradiation current value J displayed on the display unit 21 in this manner, and determines whether or not the numerical value of the irradiation current value J is appropriate. In this determination, when the operator determines that the displayed value of the irradiation current value J is appropriate, the operator operates the mouse and clicks the execution button 64 in the input operation screen 60 with the cursor 66. Thereby, the irradiation current value J of the electron beam calculated according to the measurement time T is set in this apparatus. The apparatus performs the concentration measurement of the sample based on the measurement time T and the irradiation current value J set in this way. When the operator determines that the displayed irradiation current value J is not appropriate, the operator operates the mouse and clicks the reset button in the input operation screen 60 with the cursor 66. As a result, the measurement time T can be re-input (reset), and a desired value for a different measurement time T can be input again.

  At the time of the concentration measurement, the electron beam 6 is irradiated to the sample 7 placed on the sample stage mechanism 5 in the sample chamber 13. Then, characteristic X-rays generated corresponding to the element (Si) contained in the sample 9 are detected, and thereby the concentration of the element in the sample 9 is measured. The measurement time and the irradiation current value of the electron beam at this time are set to the above set values T and J, respectively.

  Thus, in this embodiment, the irradiation current value J of the electron beam corresponding to the predetermined concentration measurement lower limit L is calculated and displayed based on the measurement time T, and the displayed irradiation current value J is displayed. Measurement will be performed based on this. Therefore, the irradiation current value J of the electron beam can be appropriately determined according to the concentration measurement lower limit L, and highly accurate measurement can be performed efficiently.

  In addition, after displaying the irradiation current value J of the electron beam calculated by the calculation control unit 18 based on the data of the measurement time T on the display unit 21, the operator does not determine whether the irradiation current value J is appropriate or not. The calculated irradiation current value J may be automatically set in the arithmetic control unit 18, and the concentration measurement of the sample may be executed based on the set measurement time T and irradiation current value J.

  In Example 1 and Example 2, the concentration measurement lower limit L, the irradiation current value J, and the measurement time T are displayed by the display unit 21 in the same screen. Therefore, the operator can simultaneously confirm the numerical values of the concentration measurement lower limit L, the irradiation current value J, and the measurement time T, and can efficiently determine whether the measurement conditions are appropriate.

  In the first and second embodiments, an execution button for executing measurement and a reset button for resetting conditions are displayed in the screen. Therefore, when the displayed measurement conditions are appropriate, the execution button can be clicked, so that the measurement can be performed quickly. If the displayed measurement conditions are not appropriate, the conditions can be quickly reset by clicking the reset button.

It is a schematic block diagram which shows the element concentration measuring apparatus in this invention. It is a figure which shows an example of the input operation screen in a display part. It is a figure which shows the other example of the input operation screen in a display part. It is a schematic block diagram which shows the apparatus which has the structure of EPMA.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electron gun, 2 ... Condensing lens, 3 ... Scanning coil, 4 ... Objective lens, 5 ... Sample stage mechanism, 6 ... Electron beam, 7 ... Sample, 8 ... Characteristic X-ray, 9 ... Spectral crystal, 10 ... Drive mechanism , 11 ... X-ray detector, 17 ... processing unit, 18 ... calculation control unit, 19 ... storage unit, 21 ... display unit, 22 ... input unit

Claims (4)

In an element concentration measuring apparatus for irradiating a sample with an electron beam and detecting characteristic X-rays generated corresponding to the element contained in the sample, thereby measuring the concentration of the element in the sample, an input unit; and an arithmetic control unit for controlling the measuring operation to calculate the measurement condition, the arithmetic control unit corresponds to the irradiation current value of the electron beam at the time of element concentration measurement data and the analysis sample for the standard sample of the element Calculate the measurement time according to the predetermined concentration measurement lower limit by applying the irradiation current value of the electron beam input from the input unit to the calculation formula obtained by the proportionality coefficient that derives the background intensity. An element concentration measuring device. In an element concentration measuring apparatus for irradiating a sample with an electron beam and detecting characteristic X-rays generated corresponding to the element contained in the sample, thereby measuring the concentration of the element in the sample, an input unit; and an arithmetic control unit for controlling the measuring operation to calculate the measurement condition, the arithmetic control unit corresponds to the irradiation current value of the electron beam at the time of element concentration measurement data and the analysis sample for the standard sample of the element Calculate the irradiation current value of the electron beam according to the predetermined concentration measurement lower limit value by applying the measurement time input from the input unit to the calculation formula obtained by the proportionality coefficient that derives the background intensity An element concentration measuring device. 3. The element concentration measuring apparatus according to claim 1 , wherein the data relating to the standard sample is intensity data and concentration data of characteristic X-rays of the element in the standard sample . 4. The element concentration measuring apparatus according to claim 3, wherein the concentration data is 100% .

Images