JPH02121252A - Charged particle beam compound device - Google Patents

Abstract

PURPOSE:To make it possible to scan electron beams and ion beams simultaneously and in the same area by composing a deflecting device with an electromagnetic deflecting coil and an electrostatic deflecting plate. CONSTITUTION:A deflector 13 which consists of an electrostatic deflecting plate 14 and an electromagnetic deflecting coil 15 is used to scan electron beams EB and ion beams IB. The ion beams IB are deflected by the electrostatic deflecting plate 14, while the electron beams EB are deflected by the electrostatic deflecting plate 14 and the electromagnetic deflecting coil 15, and the scanning area of the ion beams IB and the scanning area of the electron beams EB are unified by regulating the intensity of the deflecting signals applied to both the electrostatic deflecting plate 14 and the electromagnetic deflecting coil 15. Consequently, the same area in a target 7 can be scanned with the electron beams and the ion beams simultaneously.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention irradiates a target with an ion beam and an electron beam at the same time, and performs etching and debossing of the target with the ion beam, and surface observation of the target with the electron beam. The present invention relates to a charged particle beam composite device that simultaneously performs the following operations.

(Prior Art) An Auger electron analyzer analyzes a sample by spectroscopy of Auger electrons generated from a target such as a sample by electron beam irradiation. In this device, in order to perform depth analysis, an ion source such as a duoplasmatron is attached to the side of the electron beam column, and the ion beam from this ion source is irradiated onto the sample, etching the sample while etching the electrons. A beam is irradiated to perform analysis and observation.

In this method, it is troublesome to align the axes of the electron beam and ion beam, and because the sample is irradiated with a relatively large ion beam from the duo-plasmatron ion source, it is difficult to etch small areas. Have difficulty.

(Problem to be Solved by the Invention) In order to solve this problem, the electron beam/ion beam combined device shown in FIG. 3 can be considered. In this device, an electron gun 1 and an ion gun 2 are mounted on the same column. The electron beam EB from the electron gun 1 is focused by a focusing lens 3, and the ion beam IB from the ion gun 2 is focused by a focusing lens 4, and both beams form a crossover at the center of the electromagnetic deflector 5. . The electron beam and the ion beam are aligned on the same optical axis O by an electromagnetic deflector 5, and narrowly focused onto a target 7 by an objective lens 6.

With such an optical system, it is possible to simultaneously irradiate the target 7 with an electron beam and an ion beam, but if an electrostatic deflector is used to scan both beams on the target 7, the electrons will have a negative charge. Since the ions have a positive charge, the scanning directions of the electron beam and ion beam are opposite, and two beams are simultaneously scanned in the same scanning area.
Unable to scan seed bim.

The present invention has been made in view of these points, and its purpose is to realize a charged particle beam combination device that can simultaneously scan the same area with an electron beam and an ion beam.

(Means for Solving the Problems) Based on claim 1 of the present invention, the <mi'N particle beam composite device has an ion beam generation source, an electron beam generation source, and an ion beam and an electron beam that are aligned on the same optical axis. a lens for focusing the ion beam and the electron beam on the target; and a deflection means for scanning the ion beam and the electron beam two-dimensionally on the target; It is characterized in that the deflection means is composed of an electromagnetic deflection coil and an electrostatic deflection plate.

The charged particle beam composite device according to claim 2 of the present invention includes:
an ion beam generation source, an electron beam generation source, means for guiding the ion beam and the electron beam onto the same optical axis;
A lens for focusing an ion beam and an electron beam on a target, a deflection means for scanning the ion beam and an electron beam two-dimensionally on the target, and a secondary electron detector, The device is characterized by comprising an electromagnetic deflection coil and an electrostatic deflection plate, and an energy filter is provided between the target and the secondary electron detector.

(Function) In the first aspect of the invention, a deflector including an electrostatic deflection plate and an electromagnetic deflection coil is used to scan the electron beam and the ion beam. The ion beam is deflected by an electrostatic deflection plate, and the electron beam is deflected by an electrostatic deflection plate and an electromagnetic deflection coil. The intensity of the deflection signal applied to both the electrostatic deflection plate and the electromagnetic deflection coil is adjusted to match the scanning area of the ion beam and the scanning area of the electron beam.

In the invention of claim 2, an energy filter is provided between the target and the secondary electron detector in order to detect only secondary electrons based on electron beam irradiation.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the main parts of a charged particle beam composite device according to the present invention, in which a composite beam CB of an electron beam and an ion beam is narrowly focused onto a target 7, which is a sample, by an objective lens 6. Objective lens 6 is electrostatic lens 1
1 and an electromagnetic lens 12, and since the ion beam IB has a large mass, it is almost focused only by the electrostatic lens 11, as shown by the solid line in the figure. Further, the electron beam EB passes through the electrostatic lens 11 as shown by the dotted line in the figure.
and the electromagnetic lens 12. By appropriately adjusting the lens strengths of both the electrostatic lens 11 and the electromagnetic lens 12, the ion beam and electron beam can be narrowly focused onto the target 7 at the same time.

The irradiation positions of the electron beam and the ion beam on the target 7 are changed by the deflector 13.
It is composed of an electrostatic deflection plate 14 and a deflection coil 15.

Secondary electrons generated by irradiating the target 7 with the beam are detected by a secondary electron detector 16 such as a microchannel plate. A mesh electrode 17 is arranged between the target 7 and the secondary electron detector 16, and a voltage of approximately IOV is applied to the mesh electrode 17 from a power source 18.

The operation of the above-described configuration is as follows. When etching the surface of the target 7 with an ion beam and observing this etched portion with a secondary electron image produced by electron beam irradiation, the ion beam and electron beam are simultaneously narrowly focused by the objective lens 6 and irradiated onto the target 7. be done.

In order to move the irradiation positions of the ion beam and electron beam on the target 7, a deflection signal is supplied to the deflector 13.

FIG. 2 is a conceptual diagram showing the state of deflection of the electron beam EB and ion beam IB when a deflection signal is supplied to the electrostatic deflection plate 14 and the deflection coil 15.

Now, without supplying a signal to the deflection coil 15, the electrostatic deflection plate 14
If a deflection signal is supplied only to the electric field E, the electron beam EB and the ion beam IB will be deflected only by the electric field E. As mentioned above, since the charges of the electron beam and the ion beam are opposite in polarity, they are deflected in opposite directions, as shown in FIG. 2<a).

Next, if a deflection signal is also supplied to the electromagnetic deflection coil 15,
A deflecting magnetic field is generated, but the ions are hardly affected by this magnetic field because of their large mass. However, the electrons are strongly acted upon by the magnetic field B, for example, if the force exerted by the magnetic field B is much larger than the force exerted by the electrostatic field E, then the 71'-beam EB as shown in FIG. is deflected to a greater extent in the same direction than the ion beam IB.

When the electrostatic field E and the magnetic field B exert equal forces on the electrons, the electrons are not deflected and travel straight as shown in FIG. 2(c).

As is clear from the explanation using this conceptual diagram,
By adjusting the strength of the electric field and magnetic field appropriately for one week, it becomes possible to simultaneously scan a predetermined area on the target 7 with the electron beam and the ion beam. Of course, this scanning area can be arbitrarily changed by widening the electron beam and limiting the ion beam scanning area to the central part of the electron beam scanning area, or vice versa.

Secondary electrons are generated as the target 7 is irradiated with the electron beam and ion beam, but since the energy of the secondary electrons from the electron beam is higher than that of the secondary electrons from the ion beam, the electron beam When obtaining a secondary electron image, a voltage of about 1.0 V is applied to the mesh electrode 17 from the power supply 18 to form an energy filter, and only the secondary electrons generated by the electron beam are transmitted through the mesh electrode 17. It may be detected by the secondary electron detector 16. Of course, when observing the surface image of the target by the electron beam, reflected electrons generated only by the electron beam irradiation may be detected.

In this way, while etching a predetermined region of the target 7 with the ion beam, it is possible to observe the secondary electron image of the portion etched with the electron beam. In this example, etching using an ion beam was explained as an example, but the present invention can also be applied to deposition using an ion beam, and can also be applied to analysis in the depth direction in Auger electron spectroscopy. be able to.

(Effects of the Invention) As explained above, in the invention of claim 1, since an electrostatic deflection plate and an electromagnetic deflection coil are used in combination as a deflector, the same area of the target is simultaneously scanned by an electron beam and an ion beam. can do.

In the invention of claim 2, an energy filter is provided between the secondary electron detector and the target so that only secondary electrons based on electron beam irradiation can be detected, so that it is possible to observe a secondary electron image caused by the electron beam. can.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of a charged particle beam composite device that is an embodiment of the present invention, MS2 diagram is a conceptual diagram showing the deflection states of an electron beam and an ion beam, and FIG. 3 is a diagram showing the electron beam - It is a diagram showing a conventional example of an ion beam composite device.

Claims (2)

[Claims] (1) an ion beam generation source, an electron beam generation source, means for guiding the ion beam and the electron beam onto the same optical axis, and a lens for focusing the ion beam and the electron beam on a target; A charged particle beam composite device comprising a deflection means for two-dimensionally scanning an ion beam and an electron beam on a target, the deflection means comprising an electromagnetic deflection coil and an electrostatic deflection plate. . (2) an ion beam generation source, an electron beam generation source, means for guiding the ion beam and the electron beam onto the same optical axis, and a lens for focusing the ion beam and the electron beam on a target; Deflection means for two-dimensionally scanning the ion beam and the electron beam on the target;
A charged particle beam comprising a secondary electron detector, wherein the deflection means is constituted by an electromagnetic deflection coil and an electrostatic deflection plate, and an energy filter is provided between the target and the secondary electron detector. Composite device.