JPWO2007037013A1 - Semiconductor analyzer - Google Patents

Abstract

An object of the present invention is to provide a semiconductor analyzer capable of obtaining a highly accurate measurement value with respect to fluctuations in the amount of electron beam. The semiconductor analyzer of the present invention is an analyzer configured to measure a substrate current induced in the semiconductor substrate when the semiconductor substrate is irradiated with an electron beam, and a semiconductor substrate support means for supporting the semiconductor substrate An electron beam generating means for generating an electron beam, an electron beam detecting means for detecting an irradiation amount of the electron beam, a substrate current induced in the semiconductor substrate, and an electron beam amount detected by the electron beam detecting means Current measuring means for measuring current.

Description

  The present invention relates to a semiconductor analyzer using an electron beam, and more particularly to a semiconductor analyzer suitable for evaluating a semiconductor device manufacturing process. More specifically, the present invention accurately measures the irradiation amount of the electron beam applied to the semiconductor substrate, thereby affecting the analysis result due to the variation of the electron beam amount due to the aging of the electron beam gun and the environmental change. It is related with the technique for suppressing.

  FIG. 10 schematically shows a configuration of a conventional semiconductor analyzer using an electron beam. This analysis apparatus is an apparatus for analyzing a fine structure formed on a semiconductor substrate for the purpose of managing the manufacturing process of the semiconductor device, and irradiates the semiconductor substrate with an electron beam. By measuring the substrate current generated in the substrate, the formation state of the fine structure on the semiconductor substrate is analyzed. Using this analyzer, the manufacturing process of the semiconductor device is managed in various time periods such as short term and long term.

  Here, in order to maintain the reliability of the measurement value of the substrate current by this type of semiconductor analyzer, the accuracy of the measurement value needs to be stable over a long period of time. It is required to be 1% or less. In order to stabilize the electron beam so that the fluctuation amount of the measurement value is 1% or less, it is essential to strictly maintain the temperature of the electron beam source within a range of ± 0.1 degrees. On the other hand, since the electron beam source itself is a consumable part, the characteristics of the electron beam change over time, and it is difficult to maintain the characteristics of the electron beam source constant over a long period of time.

  Therefore, conventionally, as shown in FIG. 10, a Faraday cup 8 for monitoring the irradiation amount of the electron beam 13 applied to the semiconductor substrate 4 is provided at the end of the tray 5, and the electron beam is applied to the Faraday cup 8. The amount of current that appears in the Faraday cup 8 at that time is measured with an ammeter B, and the amount of irradiation of the electron beam 13 is regularly managed.

  Here, the configuration of the conventional apparatus shown in FIG. 10 will be briefly described. Inside the vacuum chamber 7, a tray 5 attached to an XY stage 6 is arranged, and a semiconductor which is an object to be analyzed is placed in the tray 5. A substrate 4 is placed. An ammeter A is connected to the tray 5, and the substrate current of the semiconductor substrate 4 placed on the tray 5 is measured by the ammeter A. As described above, the Faraday cup 8 is attached to the end of the tray 5, and the ammeter B is connected to the Faraday cup 8. The irradiation amount of the electron beam 13 is measured by the ammeter B as a current amount.

  An electron gun 11 having an electron beam source 1 is attached to the upper portion of the vacuum chamber 7, and the beam direction of the electron gun 11 is directed to the semiconductor substrate 4 on the tray 5. Inside the electron gun 11, a condenser lens 2, an aperture 10, and an objective lens 3 are arranged in this order. The electron beam source 1 is supplied with a high voltage as an operating voltage from a high voltage power source 9.

  In general, a thermal field emitter is used as the electron beam emitting element constituting the electron beam source 1. The thermal field emitter is formed by coating the surface of a tungsten electrode having a sharp tip with ZrO or the like for lowering the work function, and is used in a state heated to about 1800 K in order to emit electrons. This thermal field emitter is susceptible to slight environmental changes such as vacuum conditions and temperature changes, and has the characteristic that the nature and amount of the emitted electron beam vary with environmental changes.

  Further, in this type of semiconductor analyzer, the amount of electron beam irradiated toward the semiconductor substrate corresponds to a very weak current amount of the order of picoamperes or less when converted to a current amount. The amount of irradiation with such a weak electron beam is likely to fluctuate due to the influence of various environmental factors as described above. When the amount of irradiation of the electron beam fluctuates, the measured value of the substrate current also fluctuates. Accuracy is reduced.

  Therefore, in this type of semiconductor analyzer using an electron beam, the measured value of the substrate current is normalized by the electron beam dose (that is, the measurement result is expressed by the ratio of the substrate current to the electron beam dose). Therefore, even if the irradiation amount of the electron beam fluctuates, the influence is prevented from appearing in the measured value.

Therefore, in this type of semiconductor analyzer that measures the substrate current induced in the semiconductor substrate by the electron beam, it is important to know the electron beam irradiation amount, unlike the conventional SEM. This is because if the electron beam irradiation amount is inaccurate, the measured value of the substrate current normalized by the electron beam irradiation amount is also inaccurate.
JP 2005-026449 A

  According to the prior art shown in FIG. 10, since the irradiation amount of the electron beam is measured using an ammeter B different from the ammeter A used for measuring the substrate current, the difference in the characteristics of the measurement system is a measured value. There is a problem that the substrate current cannot be normalized accurately.

  Further, according to the above-described prior art, in order to measure the irradiation amount of the electron beam, the electron beam 13 is irradiated by the XY stage 6 every time the measurement of the substrate current is completed for one wafer or one measurement point. It is necessary to move the position to the position of the Faraday cup 8 and irradiate the Faraday cup 8 with the electron beam 13.

  For this reason, there is a problem that the electron beam irradiation amount cannot be measured in real time during the measurement of the substrate current, and the electron beam irradiation amount can only be known roughly. Therefore, if the irradiation amount of the electron beam fluctuates during the measurement of the substrate current, there is a problem that the fluctuation appears as an error in the normalized measurement value of the substrate current.

  Furthermore, according to the above-described prior art, when measuring the irradiation amount of the electron beam, it is necessary to mechanically move the irradiation position of the electron beam to the position of the Faraday cup 8 on the tray 5. There is a problem that the measurement is complicated, time is required for the measurement, and the throughput of the measurement work is reduced.

  The present invention irradiates a semiconductor substrate with an electron beam, measures a substrate current induced in the semiconductor substrate by the electron beam, and outputs a value obtained by normalizing the substrate current with an irradiation amount of the electron beam. A semiconductor analysis apparatus comprising: a semiconductor substrate support means for supporting the semiconductor substrate; an electron beam generation means for generating the electron beam; an electron beam detector for detecting the electron beam; and the semiconductor The semiconductor analyzer includes a measurement means shared for measuring the substrate current induced in the substrate and the irradiation amount of the electron beam detected by the electron beam detector.

  According to this configuration, since the measurement means is shared by both the measurement of the substrate current induced in the semiconductor substrate and the irradiation amount of the electron beam detected by the electron beam detector, the characteristics of the measurement means (for example, measurement) The effect of (accuracy) on the measured values of the substrate current and the electron beam dose is the same. For this reason, the value obtained by normalizing the substrate current with the irradiation amount of the electron beam is not affected by the characteristics of the measuring means. Therefore, it is possible to normalize the substrate current accurately with the irradiation amount of the electron beam without being affected by the characteristics of the measurement system.

  The present invention irradiates a semiconductor substrate with an electron beam, measures a substrate current induced in the semiconductor substrate by the electron beam, and outputs a value obtained by normalizing the substrate current with an irradiation amount of the electron beam. A semiconductor analysis apparatus configured, wherein a semiconductor substrate supporting means for supporting the semiconductor substrate, an electron beam source for emitting electrons, and a part of an electron flow emitted from the electron beam source are selectively passed. An electron beam limiting member for limiting the passage of the electron flow to form an electron beam irradiated on the semiconductor substrate, electrically insulated from the electron beam limiting member, and the through hole And a shielding member that shields the electron flow emitted from the electron beam source, except for a predetermined region on the electron beam limiting member that surrounds the through hole, and a substrate induced on the semiconductor substrate. It has a first measuring means for measuring a current, and a second measuring means for measuring the electron beam limiting member induced current, the configuration of a semiconductor analyzer including.

  According to this configuration, as a result of irradiating the electron flow to a predetermined region on the electron beam limiting member surrounding the through hole, a peripheral electron flow having characteristics very close to those of the electron beam actually irradiated to the semiconductor substrate is generated. Detected by the beam limiting member, the amount of current is measured by the second measuring means. Therefore, the measured value of the second measuring means has a close correlation with the irradiation amount of the electron beam actually irradiated onto the semiconductor substrate, and the actual electron beam irradiation amount is calculated from the measured value of the second measuring means. It becomes possible to know. Therefore, it becomes possible to grasp the irradiation amount of the electron beam in real time during the measurement of the substrate current without affecting the electron beam actually irradiated onto the semiconductor substrate. Even if the irradiation amount varies, the substrate current can be normalized with high accuracy.

  The present invention irradiates a semiconductor substrate with an electron beam, measures a substrate current induced in the semiconductor substrate by the electron beam, and outputs a value obtained by normalizing the substrate current with an irradiation amount of the electron beam. A semiconductor analysis apparatus configured, wherein a semiconductor substrate supporting means for supporting the semiconductor substrate, an electron beam source for emitting electrons, and a part of an electron flow emitted from the electron beam source are selectively passed. An electron beam limiting member that has a through-hole for limiting the passage of the electron flow to form an electron beam irradiated on the semiconductor substrate, and an electron beam deflecting means for instantaneously deflecting the electron beam An electron beam detector for detecting an electron beam deflected by the electron beam deflecting means, a first measuring means for measuring a substrate current induced in the semiconductor substrate, Having the configuration of a semiconductor analyzer including a second measuring means for measuring the irradiation amount of the detected electron beam in a child beam detectors, a.

  According to this configuration, the irradiation direction of the electron beam that has passed through the through hole of the electron beam limiting member can be directed to the Faraday cup by the electron beam deflecting means. Therefore, it is possible to measure the irradiation amount of the electron beam that is actually irradiated onto the semiconductor substrate without mechanically moving the semiconductor substrate. Therefore, the measurement work can be performed quickly, and the measurement work throughput can be improved.

The present invention irradiates a semiconductor substrate with an electron beam, measures a substrate current induced in the semiconductor substrate by the electron beam, and outputs a value obtained by normalizing the substrate current with an irradiation amount of the electron beam. A semiconductor analysis apparatus configured, wherein a semiconductor substrate supporting means for supporting the semiconductor substrate, an electron beam source for emitting electrons, and a part of an electron flow emitted from the electron beam source are selectively passed. An electron beam limiting member for limiting the passage of the electron flow to form an electron beam irradiated on the semiconductor substrate, electrically insulated from the electron beam limiting member, and the through hole And a shield member for shielding the electron flow emitted from the electron beam source, and instantaneously deflecting the electron beam, except for a predetermined region on the electron beam limiting member surrounding the through hole. An electron beam deflecting means, an electron beam detector for detecting an electron beam deflected by the electron beam deflecting means, a first measuring means for measuring a substrate current induced in the semiconductor substrate, A second measuring means for measuring a current induced in the electron beam limiting member; a third measuring means for measuring an irradiation amount of the electron beam detected by the electron beam detector;
The structure of the semiconductor analyzer provided with.

  According to this configuration, the electron beam irradiation amount can be obtained in real time during the measurement of the substrate current without affecting the electron beam actually irradiated onto the semiconductor substrate. By using this, it becomes possible to perform normalization of the substrate current with high accuracy. Further, the irradiation amount can be measured by moving the irradiation direction of the electron beam to the Faraday cup by the electron beam deflecting means without mechanically moving the semiconductor substrate. Accordingly, the conversion formula for converting the current amount of the electron beam detected by the electron beam limiting member into the irradiation amount of the electron beam applied to the semiconductor substrate can be updated in real time, and the substrate can be more accurately obtained. It becomes possible to normalize the current.

  According to the present invention, since both the substrate current and the amount of electron beam are measured by sharing the measurement means, the measured value of the substrate current can be measured without being affected by the difference in the characteristics of the measurement system. It becomes possible to normalize by the dose. Accordingly, it is possible to improve the accuracy of the normalized substrate current value.

  According to the present invention, the electron flow in the vicinity of the electron beam that is actually irradiated onto the semiconductor substrate is detected via the electron beam limiting means (aperture), so that the actual electrons are measured in real time during the measurement of the substrate current. The amount of beam irradiation can be known. Therefore, even if the substrate current fluctuates due to the fluctuation of the electron beam irradiation amount, the measured value of the substrate current is normalized using the electron beam irradiation amount that caused the fluctuation of the substrate current. The measured current value is not affected by the fluctuation of the electron beam, and the substrate current can be normalized with high accuracy. In addition, even when measuring the substrate current over a long period of time, it is possible to measure the substrate current without worrying about fluctuations in the electron beam. Therefore, the work of adjusting and adjusting the irradiation amount of the electron beam is unnecessary, and the effective operating rate of the apparatus can be improved.

  Further, according to the present invention, since the electron beam irradiation amount can be measured in real time during the measurement of the substrate current, even if a sudden current increase / decrease phenomenon of the electron beam source occurs, this phenomenon is caused. It becomes possible to immediately detect fluctuations in the irradiation amount of the electron beam. Therefore, stable and highly accurate measurement can be performed without being affected by noise due to the above phenomenon.

  According to the present invention, since the electron beam irradiation amount is measured by instantaneously deflecting the electron beam, the electron beam irradiation position is mechanically moved when measuring the electron beam irradiation amount. There is no need. Therefore, the measurement time of the electron beam irradiation amount can be greatly shortened.

It is a figure for demonstrating the basic operation principle of a semiconductor analyzer. 1 is a diagram schematically showing a configuration of a semiconductor analyzer according to a first embodiment of the present invention. It is a figure for demonstrating operation | movement (1st operation example) of the analyzer which concerns on 1st Embodiment of this invention. It is a figure for demonstrating operation | movement (2nd operation example) of the analyzer which concerns on 1st Embodiment of this invention. It is a figure which shows roughly the structure of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 1st structural example of the aperture (electron beam limiting means) which is the principal part of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 2nd structural example of the aperture (electron beam limiting means) which is the principal part of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 3rd structural example of the aperture (electron beam limiting means) which is the principal part of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 4th structural example of the aperture (electron beam limiting means) which is the principal part of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the 5th structural example of the aperture (electron beam limiting means) which is the principal part of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the calibration method of the semiconductor analyzer which concerns on 2nd Embodiment of this invention. It is a characteristic view which shows the correspondence of the Faraday cup current and aperture current which are obtained by the calibration method of the analyzer which concerns on 2nd Embodiment of this invention. It is a figure which shows roughly the structure of the semiconductor analyzer which concerns on 3rd Embodiment of this invention. It is a figure which shows roughly the structure of the semiconductor analyzer which concerns on 4th Embodiment of this invention. It is a figure which shows schematically the structure of the conventional semiconductor analyzer.

Explanation of symbols

1 Electron Beam Source 2 Condenser Lens 3 Objective Lens 4 Semiconductor Substrate (Sample)
5 Tray 6 XY Stage 7 Vacuum Chamber 8 Faraday Cup 9 High Voltage Power Supply 10 Aperture 11 Electron Gun 12 Secondary Electron Detector 13 Electron Beam

Before describing the embodiment of the present invention, the operation principle premised on the semiconductor analyzer according to the present invention will be described. This principle of operation is common to the semiconductor analyzers of the embodiments described later.
FIG. 1 is a diagram for explaining the principle of operation premised on the semiconductor analyzer of the present invention. In the figure, “input” is the amount of electron beam irradiated to the semiconductor substrate as the analysis object, and “output” is the amount of substrate current induced in the semiconductor substrate by the electron beam irradiated to the semiconductor substrate. is there.

  When the semiconductor substrate is irradiated with a constant electron beam as “input”, a substrate current is induced in the semiconductor substrate. The amount of the substrate current depends on the amount of the electron beam reaching the semiconductor substrate, and the amount of the electron beam reaching the semiconductor substrate depends on the formation state of the microstructure on the semiconductor substrate at the electron beam irradiation position. It will be a thing. For example, since the amount of electron beam that passes through the portion where the thickness of the polysilicon that forms the microstructure is large decreases, the amount of the electron beam that reaches the substrate decreases, resulting in a decrease in the substrate current induced by the electron beam. . On the other hand, since the amount of electron beam passing increases at a portion where the film thickness of the fine structure is small, the amount of electron beam reaching the substrate increases, and as a result, the substrate current induced by this electron beam increases.

  Thus, the electron beam that has reached the semiconductor substrate induces a substrate current as the above-mentioned “output”, but this substrate current amount depends on the amount of electron beam that has reached the semiconductor substrate, and the electrons that reach the semiconductor substrate. The amount of beam is affected by the microstructure on the semiconductor substrate. Therefore, the formation state of the fine structure is reflected in the amount of substrate current induced by the electron beam reaching the semiconductor substrate, and it becomes possible to know the formation state of the fine structure formed on the semiconductor substrate from this substrate current. .

  Further, as described above, the amount of electron beam applied to the semiconductor substrate corresponds to a very weak amount of current of about 10 pA when converted to a current, and is likely to fluctuate due to the influence of environmental changes. Therefore, instead of outputting the measured substrate current value itself as the final measured value, as shown in FIG. 1, the substrate current amount that is “output” with respect to the irradiation amount of the electron beam that is “input”. The ratio (the amount of substrate current when the unit electron beam is irradiated), that is, the value obtained by normalizing the amount of substrate current measured when the electron beam is irradiated with the amount of electron beam is output as the final measured value. To do.

By outputting the normalized value as the final measurement value as described above, it becomes possible to analyze the fine structure on the semiconductor substrate with high accuracy without being affected by the fluctuation of the electron beam irradiation amount. . This is because if the electron beam irradiation amount varies, the substrate current amount induced by the electron beam irradiation also varies, and as a result, the electron beam variation does not appear in the normalized value.
As described above, the semiconductor analyzer according to the present invention irradiates the semiconductor substrate with the electron beam, measures the substrate current induced in the semiconductor substrate by the electron beam, and calculates the substrate current as the irradiation amount of the electron beam. It is configured to output standardized values. The operation principle assumed by the semiconductor analyzer of the present invention has been described above.

Next, embodiments according to the present invention will be described with reference to the drawings.
In addition, the same code | symbol is attached | subjected to the element which is common in each embodiment.
[First Embodiment]
FIG. 2 shows the configuration of the semiconductor analyzer according to the first embodiment of the present invention.
As shown in the figure, the present semiconductor analysis apparatus includes a vacuum chamber 7 that accommodates a semiconductor substrate 4 that is an analysis target, an electron gun 11 that is disposed above the vacuum chamber 7, and an interior of the vacuum chamber 7. The tray 5 and the XY stage 6, the Faraday cup 8 provided at the end of the tray 5, and an ammeter A electrically connected to both the tray 5 and the Faraday cup 8.

  The positional relationship between the tray 5 and the electron gun 11 is set so that the semiconductor substrate 4 is placed on the tray 5 and the surface of the semiconductor substrate 4 is irradiated with the electron beam 13 from the electron gun 11. The tray 5 is mounted on the XY stage 6, and the position of the tray 5 is moved by the XY stage 6, so that the irradiation position of the electron beam 13 on the semiconductor substrate 4 can be adjusted. Further, the irradiation position of the electron beam 13 can be adjusted to the Faraday cup 8 by moving the position of the tray 5 by the XY stage 6.

  The electron gun 11 includes an electron beam source 1, and a high voltage power source 9 is connected to the electron beam source 1. The electron gun 11 is provided with a condenser lens 2, an aperture 10, and an objective lens 3 in this order along the emission direction of the electron flow from the electron beam source 1. Further, although not shown in the figure, this semiconductor analyzer performs an A / D converter for A / D converting the current value measured by the ammeter A into a digital signal, and for processing the A / D converted digital signal. Equipped with a computer. This computer also executes processing for controlling the operation of each part of the apparatus.

  To capture and explain the correspondence with the claims, the tray 5 and the XY stage 6 constitute a semiconductor substrate supporting means for supporting the semiconductor substrate 4, and the electron gun 11 constitutes an electron beam generating means for generating an electron beam. The Faraday cup 8 constitutes an electron beam detector for detecting an electron beam, and the ammeter A includes a substrate current induced in the semiconductor substrate 4 and an irradiation amount of the electron beam detected by the electron beam detector. Constitutes a measuring means shared to measure

Next, the operation of this semiconductor analyzer will be described.
Schematically, the semiconductor analyzer measures the substrate current induced in the semiconductor substrate 4 by irradiating the semiconductor substrate 4 with the electron beam 13 with the ammeter A and irradiates the Faraday cup 8 with the electron beam 13. Thus, the current amount detected by the Faraday cup 8 (that is, the current amount corresponding to the irradiation amount of the electron beam) is also measured by the ammeter A. That is, the ammeter A is commonly used for the measurement of the substrate current induced in the semiconductor substrate 4 and the measurement of the irradiation amount of the electron beam detected by the Faraday cup 8. Then, a value obtained by normalizing the measured value of the substrate current with the measured value of the irradiation amount of the electron beam is output as the final measured value.

Subsequently, the operation of the semiconductor analyzer will be described in detail.
When the semiconductor substrate 4 is newly placed on the tray 5 in the vacuum chamber 7, the XY stage 6 is moved under the control of the computer of the apparatus, and the Faraday cup 8 is positioned directly under the electron gun 11. . In this state, the Faraday cup 8 is irradiated with the electron beam 13 from the electron gun 11 and an SEM image of the Faraday cup 8 is acquired. Then, by comparing the obtained SEM image of the Faraday cup 8 with a previously registered template for pattern matching, the Faraday cup 8 is positioned so that the electron beam 13 is irradiated to the center of the Faraday cup 8. .

  When the positioning of the Faraday cup 8 is completed, the Faraday cup 8 is irradiated with the electron beam 13 by the same amount as when the semiconductor substrate 4 is actually irradiated. The ammeter A connected to the Faraday cup 8 irradiates the electron beam. Measure.

  When the above-described measurement of the electron beam irradiation amount is completed, the analysis operation of the semiconductor substrate 4, that is, the measurement of the substrate current is performed. More specifically, the semiconductor substrate 4 is positioned by adjusting the position of the XY stage 6 so that the semiconductor substrate 4 is irradiated with the electron beam 13 under the control of the computer. Then, a measurement point on the semiconductor substrate 4 (microstructure to be analyzed) is irradiated with an electron beam 13, and a substrate current induced in the semiconductor substrate 4 by the irradiation of the electron beam 13 is passed through the tray 5 to an ammeter A. Measure with

  As described above, the two types of measurement values of the substrate current measured through the tray 5 and the electron beam irradiation amount measured through the Faraday cup 8 are measured by the single ammeter A. The two types of measurement values are converted into digital signals by an A / D converter (not shown) and then taken into a computer. The two types of measurement values captured by the computer are stored in a storage device in the computer.

Next, the computer reads the two kinds of current measurement values (the substrate current measurement value and the electron beam irradiation measurement value) stored in the storage device, and uses the substrate current measurement value as the electron beam irradiation amount. The value normalized by the measured value is output as the final measured value. Specifically, the measurement value of the substrate current measured in the substrate current measurement operation is normalized (divided) by the electron beam irradiation amount measured in the electron beam irradiation measurement operation, and is normalized. The measured value is output as the final measured value.
By normalizing the substrate current value measured in this way with the amount of electron beam, it is possible to eliminate the influence on the measured value of the substrate current due to the fluctuation of the electron beam irradiation amount.

In the above description, the measurement of the substrate current and the number of measurements of the electron beam irradiation amount are each one, but various substrate current measurement procedures and electron beam irradiation measurement procedures may be combined.
With reference to FIG. 3A and 3B, the example of a combination of each measurement procedure of a substrate current and the irradiation amount of an electron beam is demonstrated in order.
First, in the example of FIG. 3A, the semiconductor analyzer measures the irradiation amount of the electron beam 13 irradiated from the electron gun 11 using the Faraday cup 8 before and after the analysis operation of the new single semiconductor substrate 4. To do. That is, the irradiation amount of the electron beam 13 irradiated from the electron gun 11 is measured using the Faraday cup 8 before and after the substrate current measurement operation at a plurality of measurement points of the single new semiconductor substrate 4. Then, as the electron beam irradiation amount used to normalize the substrate current value measured at each measurement point, the average value of the two electron beam irradiation amounts performed before and after the substrate current measurement operation Is used.

  More specifically, in the flow of FIG. 3A, when the semiconductor substrate 4 is loaded into the semiconductor analyzer (step SA1), the first electron beam irradiation dose is measured by the Faraday cup 8, and the measurement is performed. The value is stored in the storage device (step SA2). Subsequently, the first measurement point of the semiconductor substrate 4 is irradiated with the electron beam, the first substrate current measurement is performed, and the measurement value is stored in the storage device (step SA3). Subsequently, the second measurement point of the semiconductor substrate 4 is irradiated with the electron beam, the second measurement of the substrate current is performed, and the measurement value is stored in the storage device (step SA4). Thereafter, the irradiation amount of the second electron beam by the Faraday cup 8 is measured again, the measured value is stored in the storage device (step SA5), and the semiconductor substrate 4 is unloaded (step SA6). As described above, the measurement value (measurement value of the electron beam irradiation amount) in the first and second electron beam irradiation measurement operations, and the measurement value (substrate current measurement value) in the first and second substrate current measurement operations. Pair with (measured value).

  Subsequently, the measurement value of the electron beam irradiation amount obtained by the first electron beam irradiation amount measurement operation performed before the substrate current measurement operation, and the second time performed after the substrate current measurement operation. An average value of the measured value of the electron beam irradiation amount obtained by the electron beam irradiation amount measurement operation is obtained. Then, the measurement value of the substrate current at each measurement point described above is normalized (specifically, divided) by the average value of the electron beam irradiation amount, and the normalized substrate current value at each measurement point is finally obtained. Output as a typical measurement.

By normalizing the substrate current value measured at each measurement point in this way with the average value of the electron beam irradiation amount, even if the electron beam irradiation amount fluctuates before and after the substrate current measurement operation, the fluctuation is The influence on the normalized substrate current value can be suppressed to a small level, and the normalized substrate current value can be stabilized against fluctuations in the electron beam irradiation amount.
In the example shown in FIG. 3A described above, the number of measurement points of the substrate current is two, but the number of measurement points can be arbitrarily determined.

  In the example shown in FIG. 3B, the electron beam irradiation measurement operation and the substrate current measurement operation are alternately performed, and the electron beam amount used for normalizing the substrate current value at an arbitrary measurement point is The average value of each electron beam amount measured immediately before and after the measurement point is adopted.

  Specifically, in the flow of FIG. 3B, when the semiconductor substrate 4 is loaded into the semiconductor analyzer (step SB1), the first electron beam irradiation dose is measured by the Faraday cup 8, and the measurement is performed. The value is stored in the storage device (step SB2). Subsequently, the first measurement point of the semiconductor substrate 4 is irradiated with the electron beam, the first substrate current measurement is performed, and the measurement value is stored in the storage device (step SB3). Subsequently, the irradiation amount of the second electron beam by the Faraday cup 8 is measured, and the measured value is stored in the storage device (step SB4).

  Subsequently, the second measurement point of the semiconductor substrate 4 is irradiated with the electron beam to measure the substrate current for the second time, and the measured value is stored in the storage device (step SB4). After that, although not shown, the third measurement of the electron beam irradiation amount by the Faraday cup 8 is performed, and the measurement by the Faraday cup 8 and the measurement of the substrate current are alternately performed. Then, after the substrate current is measured for the last measurement point, the irradiation amount of the electron beam by the Faraday cup 8 is measured, and the semiconductor substrate 4 is unloaded.

The measurement value of the substrate current and the measurement value of the electron beam irradiation amount obtained by the above measurement operation are processed by a computer, and the value obtained by normalizing the substrate current at each measurement point with the irradiation amount of the electron beam is finally obtained. Is output automatically. For example, for normalization of the substrate current obtained by the first measurement of the substrate current, an average value of the first and second measured values by the Faraday cup 8 is used. For normalization of the substrate current obtained by the second substrate current measurement, the average value of the second and third measured values by the Faraday cup 8 is used. Similarly, for normalization of the substrate current at each measurement point, an average value of the irradiation amount of the electron beam measured by the Faraday cup 8 immediately before and immediately after is used.
According to this example, as compared with the example shown in FIG. 3A described above, it is possible to further suppress the influence of fluctuations in the electron beam irradiation amount on the normalized substrate current value.

[Second Embodiment]
FIG. 4 shows the configuration of the semiconductor analyzer according to the second embodiment of the present invention.
The semiconductor analyzer irradiates the semiconductor substrate 4 with an electron beam, measures the substrate current induced in the semiconductor substrate 4 by the electron beam, and normalizes the substrate current with the electron beam dose. And includes a thermal field emitter 41, a suppressor electrode 42, a lead electrode 43, a shade 44, an aperture 45, an objective lens 46, an ammeter A1, and an ammeter A2. Various driving power sources Vex, Vf, and Vb are connected to the electron beam emitting element 41.

  To capture and explain the correspondence with the claims, the tray 5 constitutes a semiconductor substrate support means, and the thermal field emitter 41 constitutes an electron beam generation source. The aperture 45 constitutes an electron beam limiting member, the shade 44 constitutes a shielding member, the ammeter A2 constitutes first measurement means, and the ammeter A2 constitutes first measurement means. Although not shown in FIG. 4, in this embodiment as well, the semiconductor substrate 4 is placed on the tray 5 as in the first embodiment, and the tray 5 is XY as shown in FIG. 2. It is attached to the stage 6.

  Here, the amount of electrons emitted from the thermal field emitter 41 is susceptible to environmental changes and is unstable. For example, there may be a sudden and very fast current fluctuation called Schottky noise. The thermal field emitter 41 is made of a material such as ZrO attached to the surface of a tungsten electrode having a sharp tip. Since the tip shape and surface state of the electrode, the degree of ZrO adhesion, and the temperature of the emitter itself change easily, the amount of electron beam irradiation always changes. Therefore, even if the electron beam irradiation amount is suddenly changed even if the electron beam irradiation amount is normalized as in the first embodiment, an error may occur in the measurement value. Therefore, in order to cope with sudden fluctuations in the electron beam irradiation amount, it is necessary to measure the electron beam irradiation amount in real time. In view of this, the present embodiment proposes an apparatus for measuring the electron beam irradiation amount in real time, and has a feature in the peripheral configuration including the aperture.

In the following, description will be given focusing on the peripheral configuration including the aperture.
In FIG. 4, the electron flow emitted from the thermal field emitter 41 jumps out with various energies in various directions and is distributed in a substantially conical shape. Since electrons having various energy amounts are mixed in the electron flow emitted from the thermal field emitter 41, the convergence as an electron beam is lowered and high resolution cannot be obtained.

  Therefore, by the aperture 45 having a through-hole 45A of several tens of microns formed in the center, the central portion having the uniform energy is selectively extracted from the electron flow that has jumped out of the thermal field emitter 41 in a conical shape. Used as. Of the electrons emitted from the thermal field emitter 41, the amount of electrons actually taken out as the electron beam 13 is 1 / 1,000,000 or less of the total amount of electrons emitted from the thermal field emitter 41. For example, the total amount of electrons emitted from the thermal field emitter 41 is about 100 microamperes, and the amount of electrons actually irradiated onto the semiconductor substrate as an electron beam is about 10 pA or less. By selectively extracting the electron beam emitted from the same spatial position using the aperture 45 having the minute through hole 45A in this way, the electron energy in the electron beam is made uniform, thereby converging the electron beam. Improve the performance and resolution.

  As described above, the amount of electron beam actually irradiated onto the semiconductor substrate corresponds to the slight amount of electrons that have passed through the through hole 45A of the aperture 45 out of all the electrons emitted from the thermal field emitter 41. Variations in the beam amount affect the measured substrate current. Therefore, as described in the first embodiment, in order to determine the irradiation amount of the electron beam used for normalizing the measured value of the substrate current, the semiconductor substrate is actually passed through the aperture 45 and is actually used. 4 is preferably measured.

  However, according to the first embodiment described above, the amount of electron beam irradiation cannot be measured during the measurement of the substrate current, and the substrate current of the semiconductor substrate 4 cannot be measured in real time. Therefore, in the present embodiment, an electron beam in the vicinity of the periphery of the electron beam 13 actually irradiated onto the semiconductor substrate 4 and detected by the aperture 45 is detected, and the current value is measured. The amount of electron beam applied to the semiconductor substrate 4 is indirectly grasped.

  In the present embodiment, in order to detect the amount of electron beam near the periphery of the electron beam irradiated to the semiconductor substrate 4, the shade 44 having a predetermined hole diameter slightly larger than the through hole 45A of the aperture 45 is used as an insulator. And is attached to one surface of the aperture 45 (the surface over which the thermal field emitter 41 is desired). The ammeter A1 is connected to the aperture 45, and the shade 44 is grounded.

FIG. 5 shows a detailed configuration around the aperture 45.
In the figure, an aperture 45 is formed on a disk-like support 47 having a through hole, and a through hole having a diameter of, for example, about 10 μm to 30 μm smaller than the through hole of the support 47 is formed at the center of the aperture 45. 45A is formed. This through-hole 45Aha is for selectively allowing a part of the total electron flow emitted from the thermal field emitter 41 of the electron beam source to pass therethrough. An electron beam 13 is formed.

  An ammeter A1 is connected to the aperture 45, and the amount of current induced in the aperture 45 by the electron flow can be measured. On the support body 47 on the outer peripheral side of the aperture 45, a shade 44 having a through hole larger than the through hole 45A is formed via an insulator 46. The shade 44 allows the through hole 45A of the aperture 45 to Except for a predetermined region on the aperture 45 surrounding the through-hole 45A, the electron flow emitted from the thermal field emitter 41 is shielded. The shade 44 is grounded and electrically insulated from the aperture 45. The center of the through-hole of the support 47, the through-hole 45A of the aperture 45, and the through-hole of the shade 44 substantially coincides, and the diameter of the through-hole 45A of the aperture 45 determines the amount of electrons emitted from the thermal field emitter 41. The amount of passage is limited.

  By providing the shade 44 through the insulator 46 in this way, electrons in a region relatively far from the through hole 45A of the aperture 45 are shielded by the shade 44, and on the aperture 45 located in the vicinity of the through hole 45A. The amount of electron beam applied to a predetermined region (in this example, the surface of the aperture 45) is measured by the ammeter A1 through the aperture 45. Further, if electrons shielded by the shade 44 accumulate in the shade 44, the electric field formed by the electrons may affect the trajectory of the electron beam. However, since the shade 44 is grounded, Does not accumulate electrons, and the effects of such electrons are prevented.

  The amount of current measured by the ammeter A1 is not the amount of current due to the electron beam 13 applied to the semiconductor substrate 4, but the amount of current due to the electron beam near the periphery thereof. The irradiation amount of the electron beam 13 is not directly represented. However, since the electron beam 13 passing through the through hole 45A of the aperture 45 and the electron beam irradiated on the aperture 45 in the vicinity of the periphery of the electron beam 13 are very close to each other, the spatial positions thereof are very close. Characteristics (energy, phase, etc.) are very close. Therefore, for example, the irradiation amount of the electron beam 13 can be estimated from the measured value of the ammeter A1 based on the relationship between the area of the through hole 45A and the surface area of the aperture 45 (area irradiated with the electron current).

  Therefore, according to the present embodiment, an electron beam 13 in the vicinity of the periphery that is very close in characteristics to the electron beam 13 actually irradiated to the semiconductor substrate 4 is detected, so that the electron beam 13 actually irradiated to the semiconductor substrate 4 Without disturbing the irradiation, it becomes possible to grasp the irradiation amount of the electron beam 13 in real time during the measurement of the substrate current.

  The through hole of the shade 44 described above is preferably about 2 to 10 times the area of the through hole 45A of the aperture 45. Since the area of the through hole of the shade 44 directly affects the amount of electron beam irradiated on the shade 44, it is desirable to accurately form the through hole of the shade 44. Further, as the material of the shade 44, it is desirable to use it by doping silicon or the like which is a material having a secondary electron emission ratio close to 1 (that is, a material in which charge is difficult to accumulate).

  The aperture 45 is made of a conductive material, and is preferably a material that efficiently converts an electron beam into an electric current when irradiated with an electron beam. Depending on the type of material, even when the electron beam is irradiated, secondary electrons are emitted in the same amount, and the electron beam may not be efficiently converted into a current. Therefore, in this embodiment, for example, W, copper, or aluminum is used as the material of the aperture 45. The amount of electrons absorbed by the aperture 45 may be increased by forming narrow and deep grooves or holes on the surface of the aperture 45 (the surface irradiated with the electron beam).

  On the other hand, even if a material that emits more secondary electrons than the amount of the irradiated electron beam (a material having an electron multiplication effect) is used as the material of the aperture 45, similarly, the material near the periphery of the electron beam 13 is used. An electron beam can be detected with high sensitivity. Examples of such materials include metal oxides and conductive ceramics. Since the aperture 45 and the shade 44 may be heated to 100 degrees or more in use, the aperture 45 and the shade 44 are made of a material that can withstand the heating.

Next, a second configuration example around the aperture will be described with reference to FIG. 5B.
In the example shown in the figure, the shade 44 and the aperture 45 are formed in a Faraday cup shape in the configuration of FIG. 5A described above. That is, the wall portions 44 </ b> B are formed along the inner peripheral edge and the outer peripheral edge of the shade 44. By forming the wall portion 44B in this way, scattering of the electron beam hitting the shade 44 to the periphery can be prevented, and the influence on the electrons irradiated to the aperture 45 can be suppressed. Similarly, a wall 45B may be formed along the inner peripheral edge of the aperture 45 to prevent the influence on the electrons passing through the through hole 45A.

FIG. 5C shows a third configuration example around the aperture.
The configuration example shown in FIG. 5C includes a region (current measurement region) for detecting the electron beam in the central region of the through hole 60A through which the electron beam passes. That is, in this configuration example, the support body 60 made of a conductive member is formed in a substantially annular shape, and the ammeter A <b> 1 is connected to the support body 60. A portion 60B of the support 60 extends in a cross shape toward the center of the through-hole 60A, and a diameter of several microns is present at an intersection of the cross-portion 60B, that is, a central region of the through-hole 60A of the support 60. A disk-shaped electron beam detection region 61 is provided. The cross portion 60B of the support 60 described above functions as a wiring between the electron beam detection region 61 and the support 60, and the current converted in the electron beam detection region 61 passes through the cross portion 60B. Measured with an ammeter A1 connected to. A shade 63 is formed on the support 60 via an insulator 62, and the shade 63 is grounded so as not to accumulate charges due to the electron beam.

  In this configuration example, the semiconductor substrate is irradiated with an electron beam passing through a region excluding the electron beam detection region 61 and the cross portion 60B in the through hole 60A of the support 60. Such a fine aperture structure can be easily formed by using an etching technique such as silicon micromachining in recent years. Further, as in the example shown in FIG. 5B, the shade 63 may be formed in a Faraday cup shape.

FIG. 5D shows a fourth configuration example around the aperture.
The configuration example shown in the figure further includes two concentric electron beam detection regions 70A and 70B in the configuration of FIG. 5C described above. According to this configuration example, it is possible to estimate the electron beam amount with higher accuracy by reflecting the electron beam energy distribution. That is, the energy of the electron beam emitted from the thermal field emitter 41 is normally distributed with the center of the beam being the maximum value, and is distributed concentrically with similar properties. Therefore, strictly speaking, the energy distribution differs between the central portion of the electron beam and the peripheral portion thereof. In the example shown in FIG. 7, since the electron beam located outside the central region is also detected by the concentric electron beam detection regions 70A and 70B, the energy dispersion of the detected electron beam is reduced, and the electron beam The absolute value of the detection amount can be increased. Therefore, compared to the example shown in FIG. 5C described above, the amount of electron beam applied to the semiconductor substrate can be estimated with higher accuracy.

  The electron beam absorption regions 61, 70A and 70B are formed by silicon micromachining or the like, and the surface thereof is covered with a material having high electron beam current conversion efficiency. As described above, the shade 63 is preferably selected from materials that do not accumulate charges when irradiated with an electron beam, and is preferably silicon. Further, the electron beam detection regions 61, 70A, 70B and the shade 63 are electrically insulated, and the shade 63 is grounded. Further, as in the example shown in FIG. 5B, the shade 63 may be formed in a Faraday cup shape.

FIG. 5E shows a fifth configuration example around the aperture.
The example shown in the figure further includes radial electron beam detection regions 71A to 71F in the configuration shown in FIG. 5C described above. By forming the electron beam detection regions in a radial manner in this way, it becomes possible to estimate the amount of electron beams by reflecting the above-described electron beam energy distribution with higher accuracy. In this example, four electron beam detection regions 71A to 71D are provided, but the number and arrangement position can be appropriately set without being limited thereto.

  In the second embodiment shown in FIGS. 4 and 5A to 5E described above, the amount of electron beam measured by the ammeter A1 is not the amount of electron beam actually passing through the aperture and irradiating the semiconductor substrate, but the aperture. This is the amount of electron beam applied to (or the electron beam detection region). Therefore, in order to know the amount of electron beam actually irradiated onto the semiconductor substrate from the measured value of the ammeter A1, the correspondence between the measured value of the ammeter 1 and the amount of electron beam passing through the aperture 45 is grasped in advance. It is necessary to convert the measured value of the ammeter A1 based on this predetermined correspondence.

  Below, with reference to FIG. 6, the method to convert the measured value of ammeter A1 into the irradiation amount of the electron beam irradiated to the semiconductor substrate 4 is demonstrated. In order to perform this conversion, it is necessary to grasp the correspondence between the measured value of the ammeter 1 connected to the aperture 45 and the amount of electron beam passing through the aperture 45.

  FIG. 6 shows an apparatus configuration for obtaining the correspondence relationship. The apparatus configuration shown in FIG. 8 is basically the same as the apparatus configuration shown in FIG. 4 except that the irradiation position of the electron beam that has passed through the aperture 45 is connected to an ammeter A2 instead of the semiconductor substrate. The only difference is that the Faraday cup 80 is arranged.

Hereinafter, the procedure for obtaining the correspondence will be described using the apparatus configuration shown in FIG.
First, the amount of the electron beam emitted from the thermal field emitter 41 is gradually increased from 0, and the current amount of the electron beam irradiated to the Faraday cup 80 at that time (hereinafter referred to as the Faraday cup current) is an ammeter. While measuring by A2, the current amount of the electron beam irradiated to the aperture 45 (hereinafter referred to as the aperture current amount) is measured by an ammeter A1. When the measured value (aperture current) of the ammeter A1 and the measured value (Faraday cup current) of the ammeter A2 obtained in this manner are plotted, the characteristic diagram shown in FIG. 7 is obtained. In FIG. 7, the horizontal axis indicates the aperture current (measured value of the ammeter A1), and the vertical axis indicates the Faraday cup current (measured value of the ammeter A2).

  Since there is a substantially linear relationship between the two, a regression equation is obtained and a conversion equation from the aperture current to the Faraday cup current is obtained. For example, a conversion formula “aperture current = 10 * Faraday cup current” is obtained. By using this conversion formula, it is possible to estimate the irradiation amount of the electron beam applied to the semiconductor substrate from the measured value (aperture current) of the ammeter A1. The correspondence relationship between the aperture current and the Faraday cup current shown in FIG. 7 is stored in the computer of this semiconductor analyzer as the above conversion formula, and the computer converts the measured value of the aperture current to The irradiation amount of the electron beam used for normalizing the substrate current value is determined.

[Third embodiment]
FIG. 8 shows the configuration of the semiconductor analyzer according to the third embodiment of the present invention.
The semiconductor analyzer irradiates a semiconductor substrate 4 with an electron beam, measures a substrate current induced in the semiconductor substrate by the electron beam, and measures a value obtained by normalizing the substrate current with an irradiation amount of the electron beam. It is configured to output as a value, thermal field emitter 41, suppressor electrode 42, extraction electrode 43, aperture 106, blank electrode 106, blanking control device 107, Faraday cup 108, objective lens 46, ammeter A2, ammeter A3 including. Various driving power sources Vex, Vf, and Vb are connected to the electron beam emitting element 41.

  Here, the aperture 105 has a through hole for selectively allowing a part of the electron flow emitted from the thermal field emitter 41 to pass therethrough, and the semiconductor substrate 4 is irradiated while restricting the passage of the electron flow. It forms an electron beam. A blanking electrode 106 is provided in the vicinity of the through hole of the aperture 105, and a blanking control device 107 is connected to the blanking electrode 106. The blanking electrode 106 is for instantaneously deflecting the electron beam that has passed through the aperture 105 under the control of the blanking control device 107. At the irradiation position of the electron beam deflected by the blanking electrode 106, a Faraday cup 108 connected to the ammeter A3 is provided. The Faraday cup 108 detects the deflected electron beam.

Next, the operation of this embodiment will be described.
In the normal operation of measuring the substrate current of the semiconductor substrate 4, the deflection by the blanking electrode 106 is not performed, and the electron beam that has passed through the aperture 105 is irradiated to the semiconductor substrate 4 as it is, and the substrate current generated at that time is the ammeter A2. Measured by.

  In the operation of measuring the irradiation amount of the electron beam, under the control of the blanking control device 107, the electron beam that has passed through the aperture 105 is instantaneously deflected by the blanking electrode 106 and guided to the Faraday cup 108. The irradiation amount of the deflected electron beam is detected by the Faraday cup A3 and measured by the ammeter A3. That is, according to this example, the irradiation amount of the electron beam 13 actually irradiated onto the semiconductor substrate 4 is directly measured.

  Normally, the time for measuring the substrate current at the measurement point on the semiconductor substrate is about 1 second. However, the electron beam is deflected by the blanking electrode 106 before and after the measurement or as necessary, and is incident on the Faraday cup 108. . At that timing, the current value is measured by the ammeter A3. The value measured by the ammeter A3 is stored in a computer (not shown) and is used for normalization of the substrate current measured by the ammeter A2, as described above.

  According to this embodiment, it is possible to directly measure the electron beam irradiation amount as compared with the second embodiment in which the electron beam irradiation amount is indirectly estimated. Also, by adjusting the speed and timing of the blanking operation (instantaneous deflection operation), it is possible to instantaneously measure the electron beam irradiation amount without substantially affecting the substrate current measurement operation of the semiconductor substrate. I can do it. For example, since the blanking speed can be performed at a speed of several megahertz or more, the current is measured by the ammeter A3 by instantaneously deflecting the electron beam in the direction of the Faraday cup 108 during the measurement of the substrate current, It is possible to measure the substrate current with the ammeter A2 by returning the irradiation direction of the electron beam to the direction of the semiconductor substrate 4 at the next moment.

[Fourth embodiment]
FIG. 9 shows the configuration of the fourth embodiment of the present invention.
The semiconductor analyzer shown in the figure is a combination of the second embodiment and the third embodiment described above.

The operation of this embodiment will be described.
The operation of this apparatus is based on the operation of the second embodiment, that is, the operation of estimating the electron beam irradiation amount from the electron beam amount irradiated to the aperture 45, and the electron beam measured via the Faraday cup 108. The correspondence relationship between the aperture current and the Faraday cup current shown in FIG. 7 is updated using the current value of the irradiation amount.

  According to the present embodiment, by deflecting the electron beam to the Faraday cup 108 during the measurement of the substrate current, the irradiation amount of the electron beam that has passed through the aperture can be accurately measured by the ammeter A3. Then, by using the measured value of the ammeter A3 and the measured value of the ammeter A1, the conversion formula based on the correspondence between the aperture current and the Faraday cup current shown in FIG. 7 can be updated almost in real time. Become. Therefore, it is possible to convert the actual electron beam irradiation amount from the aperture current at high speed and with high accuracy, and it is possible to estimate the electron beam amount with high accuracy. Therefore, it becomes possible to normalize the substrate current by the electron beam amount with higher accuracy.

  Further, according to the present embodiment, in the same manner as in the second embodiment described above, real-time high-speed current fluctuation that occurs during measurement of the substrate current is measured by the ammeter A1 as fluctuation of the aperture current, and the measured value is used as the substrate current. Can be used as a value for normalization of the measurement, so that it is possible to immediately cope with variations in measured values due to sudden variations in the electron beam.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, the analysis apparatus using an electron beam has been described as an example. However, the present invention is not limited to this, and the present invention can also be applied to an apparatus using an ion beam.

  INDUSTRIAL APPLICABILITY The present invention is useful for a semiconductor device or an apparatus used for analysis, manufacturing, measurement, or evaluation in a manufacturing process thereof, and a semiconductor device manufacturing method. For example, the present invention can be used in the fields of analysis technique, measurement technique, evaluation technique, inspection technique, and semiconductor device manufacturing apparatus and method using a method of irradiating a semiconductor substrate such as a wafer with an electron beam or ion beam. .

Claims (18)

A semiconductor configured to irradiate a semiconductor substrate with an electron beam, measure a substrate current induced in the semiconductor substrate by the electron beam, and output a value obtained by normalizing the substrate current with an irradiation amount of the electron beam An analyzer,
A semiconductor substrate support means for supporting the semiconductor substrate;
Electron beam generating means for generating the electron beam;
An electron beam detector for detecting the electron beam;
Measurement means shared for measuring the substrate current induced in the semiconductor substrate and the electron beam irradiation detected by the electron beam detector;
Semiconductor analyzer equipped with. A semiconductor configured to irradiate a semiconductor substrate with an electron beam, measure a substrate current induced in the semiconductor substrate by the electron beam, and output a value obtained by normalizing the substrate current with an irradiation amount of the electron beam An analyzer,
A semiconductor substrate support means for supporting the semiconductor substrate;
An electron beam source that emits electrons;
An electron beam having a through hole for selectively passing a part of the electron flow emitted from the electron beam source, and forming an electron beam irradiated to the semiconductor substrate by restricting the passage of the electron flow A limiting member;
A shield that is electrically insulated from the electron beam limiting member and shields the electron flow emitted from the electron beam source except for the through hole and a predetermined region on the electron beam limiting member surrounding the through hole. A member,
First measuring means for measuring a substrate current induced in the semiconductor substrate;
Second measuring means for measuring a current induced in the electron beam limiting member;
Semiconductor analyzer equipped with. A semiconductor configured to irradiate a semiconductor substrate with an electron beam, measure a substrate current induced in the semiconductor substrate by the electron beam, and output a value obtained by normalizing the substrate current with an irradiation amount of the electron beam An analyzer,
A semiconductor substrate support means for supporting the semiconductor substrate;
An electron beam source that emits electrons;
An electron beam having a through hole for selectively passing a part of the electron flow emitted from the electron beam source, and forming an electron beam irradiated to the semiconductor substrate by restricting the passage of the electron flow A limiting member;
Electron beam deflecting means for instantaneously deflecting the electron beam;
An electron beam detector for detecting the electron beam deflected by the electron beam deflecting means;
First measuring means for measuring a substrate current induced in the semiconductor substrate;
Second measuring means for measuring an irradiation amount of the electron beam detected by the electron beam detector;
Semiconductor analyzer equipped with. A semiconductor configured to irradiate a semiconductor substrate with an electron beam, measure a substrate current induced in the semiconductor substrate by the electron beam, and output a value obtained by normalizing the substrate current with an irradiation amount of the electron beam An analyzer,
A semiconductor substrate support means for supporting the semiconductor substrate;
An electron beam source that emits electrons;
An electron beam having a through hole for selectively passing a part of the electron flow emitted from the electron beam source, and forming an electron beam irradiated to the semiconductor substrate by restricting the passage of the electron flow A limiting member;
A shield that is electrically insulated from the electron beam limiting member and shields the electron flow emitted from the electron beam source except for the through hole and a predetermined region on the electron beam limiting member surrounding the through hole. A member,
Electron beam deflecting means for instantaneously deflecting the electron beam;
An electron beam detector for detecting the electron beam deflected by the electron beam deflecting means;
First measuring means for measuring a substrate current induced in the semiconductor substrate;
Second measuring means for measuring a current induced in the electron beam limiting member;
Third measuring means for measuring an irradiation amount of the electron beam detected by the electron beam detector;
Semiconductor analyzer equipped with.   The semiconductor analysis apparatus according to claim 1, wherein the electron beam detector is a Faraday cup.   Before and after the measurement of the substrate current, the electron beam generated from the electron beam generating means is detected by the electron beam detector, and the irradiation amount of the electron beam detected by the electron beam detector is measured by the measuring means. 2. The semiconductor analyzer according to claim 1, wherein an irradiation amount of the electron beam measured by the measuring means is used to normalize the substrate current.   The semiconductor analyzer according to claim 2, wherein an electron beam detection region is provided in a central region of the through hole.   The semiconductor analyzer according to claim 2, wherein a concentric electron beam detection region is provided in the through hole.   The semiconductor analyzer according to claim 2, wherein a radial electron beam detection region is provided in the through hole.   The semiconductor analyzer according to any one of claims 7 to 9, wherein a wiring portion for taking out the current detected in the electron beam detection region to the outside is provided in the through hole.   The measurement value of the second measurement means is converted to the electron beam using a predetermined conversion formula based on the correspondence between the measurement value of the second measurement means and the dose of the electron beam applied to the semiconductor substrate. The semiconductor analysis apparatus according to claim 2, wherein the semiconductor analysis apparatus converts the amount of irradiation into an amount of irradiation.   5. The semiconductor analyzer according to claim 2, wherein the measurement value of the first measurement unit is normalized using the measurement value of the second measurement unit.   5. The semiconductor analyzer according to claim 2, wherein the shielding member is formed in a Faraday cup shape.   5. The semiconductor analyzer according to claim 2, wherein the electron beam limiting member is formed in a Faraday cup shape.   The semiconductor analysis apparatus according to claim 2, wherein the shielding member is made of a material having a property of absorbing the electron current. The semiconductor analysis apparatus according to claim 2, wherein the shielding member includes silicon.   5. The semiconductor analyzer according to claim 2, wherein the electron beam limiting member is any one of tungsten (W), copper (Cu), and aluminum (Al).   5. The semiconductor analyzer according to claim 2, wherein the electron beam limiting member is one of a metal oxide and a conductive ceramic.

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