KR20170040786A - Micro-electron column having an electron emitter improving the density of an electron beam emitted from a nano structure tip - Google Patents

Abstract

The present invention relates to a microelectronic column comprising a nanostructure tip having a structure in the form of a tube, a column, or a lump of a nanometer to several tens of nanometers, and more specifically to a microelectronic column which has a nanostructure tip capable of easily emitting an electron due to a high electric field formed at an end part when a voltage is applied, and is easy to use and be aligned with another electron lens component, an electron lens aperture hole. The microelectronic column has a nanostructure tip having a size bigger than the diameter of a source lens.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a micro-electron column having an electron emission source for improving the density of electron beams of a nanostructure tip. [0002]

The present invention relates to a miniature electron column having a nanostructure tip having a structure of a tube, a column or a lump shape having a size of nano to tens of nanometers. More specifically, when a voltage is applied, a high electric field is formed at the end portion, The electron microscope is equipped with a nanostructure tip which can easily emit light, and other electron lens components, that is, electrons emitted from the nanostructured tip are introduced into the electron lens aperture hole (aperture) .

The microelectronic column associated with the present invention was first introduced in the 1980s on the basis of electro-optic components of electron emission sources and microstructures operating under the basic principles of a scanning tunneling microscope (STM). The microelectronic column can finely assemble fine parts to minimize optical aberration to form an improved electron column, and a small structure can be arranged in multiple and used in a parallel or series multi-electron column structure. The microelectronic column has been applied not only to manufacturing apparatuses and inspection apparatuses used in semiconductor industry and display industry but also to apparatuses using electron beam such as electron microscope.

1 is a view showing a structure of a microcolumn, and shows that an Einzel lens is aligned as an electron emission source, a source lens, a deflector, and a focus lens, and an electron beam is scanned.

In general, a microcolumn, which is a typical example of a microcolumn, includes an electron emission source 10 for emitting electrons, a source lens 20 for forming the emitted electrons as an effective electron beam B, a deflector 30 for deflecting the electron beam, And a focus lens (Einzel lens) 40 for focusing the electron beam onto the sample (s).

The electron emitter is classified into FE (field emitter), TE (thermal emitter) and Schottky emitter as TFE (thermal field emitter) as one of the key components in electron beam devices such as electron columns and electron microscopes. Ideal electron emission sources require stable electron emission, high brightness, small virtual beam size, high density current emission, low energy spread, and long lifetime.

As a kind of the miniature electron column, there is a single electron column composed of one electron emitting source and electron lenses for controlling the electron beam generated in the electron emitting source, and a plurality of electron beams emitted from a plurality of electron emitting sources And a multi-type electron column composed of a plurality of electron lenses. The multi-type electron column includes an electron lens having an electron emission source having a plurality of electron emission source tips in one layer, such as a semiconductor wafer, and an electron lens in which a plurality of apertures are formed in one layer, A combination electron column for controlling an electron beam emitted from an individual electron emission source to a single lens layer having a plurality of apertures, such as a single electron column, a single electron column, a single electron emission source in one housing, And a method in which the apparatus is mounted and used. In the case of the combination type, the electron emission sources are separately classified, and the lenses can be used in the same manner as the wafer type.

Such a microelectronic column is a very important part in various fields using electron beams such as via holes and through holes, such as a semiconductor hole inspection apparatus, for example, an electron beam lithography or an electron microscope.

Also, in an electron column or other electron beam application field, an electron emission source must be precisely aligned at the center of an optical axis of an electron lens (particularly, a source lens), so that an apparatus or apparatus using an electron column or an electron beam can exhibit maximum performance. Also, the higher the density of the electron beam scanned toward the sample along these optical axes, the better the resolution and performance. It is therefore important that many electrons can be introduced into the aperture of the source lens to improve the density of the electron beam.

Particularly, semiconductor and display fields are getting larger and smaller due to the structure of the devices being manufactured. As a technology and equipment for precisely and quickly processing, measuring and inspecting such fine structures, there is a need for various equipment using electron beams, The demand for a multi-type electron column is becoming more evident, and the need for an electron emission source in accordance with a multi-type electron column is increasing.

Korean Patent Publication No. 10-2010-0037095 (Apr. 4, 2010)

It is an object of the present invention to provide a miniature electron column having a nano-structured tip which can emit electrons at a low voltage and which is easy to manufacture and use, unlike a conventional electron emission source.

It is also an object of the present invention to provide a microelectronic column in which electrons emitted from the nanostructure tip are attracted to the aperture of the source lens so that the density of the electron beam in the microelectronic column is increased.

According to an aspect of the present invention, there is provided an electron microcolumn including an electron emission source, a source lens, a deflector, and a focus lens, wherein the electron emission source comprises a plurality of nanostructured tips, And an incoming electrode is further disposed between the electron emission source and the source lens so that the electrons emitted from the electron emission source are well drawn into the aperture of the first lens electrode layer of the source lens.

Further, the present invention is characterized in that the diameter of the first electron lens electrode of the source lens is smaller than the diameter of the second electron lens electrode on the basis of the electron emission source.

In addition, the present invention is characterized in that the diameter of the second electrode is 5 times larger than the diameter of the first electrode.

And the lead-in electrode is composed of two or more electrode pieces.

The present invention also provides a multi-type microcolumn in which the above-mentioned microcolumns are unit microcolumns.

In order to solve the above-described problems, the micro-electron column of the present invention has advantages of being able to emit electrons even at low voltage, and being convenient to manufacture and use, unlike the conventional electron emission sources.

Also, the microcolumn of the present invention has the effect of increasing the density of the electron beam by inducing electrons emitted from the nanostructured tip to enter the aperture of the source lens.

Further, in the electron microcolumn of the present invention, the electron emission source can produce a large number of electron emission sources on a substrate such as a single silicon wafer, thereby making it possible to manufacture the electron emission source at a low cost. The electron emission source may be fabricated on a wafer to form a multi-type electron emission source as an electron lens, or may be individually cut into a single electron emission source to produce a multi-type microcolumn.

1 is a cross-sectional view conceptually showing a structure of a microcolumn.
FIG. 2 is a plan view and a cross-sectional view showing an example of a microcolumn having a nanostructure tip of the present invention.
Fig. 3 is a plan view and a cross-sectional view showing the case where the electron column of Fig. 2 is of a multi-type.
FIG. 4 is a plan view and a cross-sectional view showing another embodiment of a microcolumn having a nanostructure tip of the present invention.
5 is a plan view and a cross-sectional view illustrating another embodiment of a microcolumn having a nanostructured tip according to the present invention.

In order to achieve the above object, the present invention is characterized in that the nanostructured tips of the electron emission sources are distributed on a surface wider than the aperture area of the first electron lens electrode of the source lens on the basis of the electron emission source.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

FIG. 2 shows an embodiment of a microelectronic column having a nanostructured tip according to the present invention. In FIG. 2, a left side view is a plan view in which a nanostructure tip is positioned on a bottom layer, and a right side view is a cross- .

The microelectronic column according to the present invention shows that the source lens 200 is aligned on an electron emission source 100 having a plurality of nanostructured tips 150. An inlet electrode 190 is provided around the ends of the plurality of nanostructured tips 150. The inlet electrode 190 may have the same structure and shape as the conventional electrostatic lens electrode. However, the outer diameter, the diameter, and the thickness of the inlet electrode 190 are different from the diameters of the electrodes of the general lens, . For example, as shown in FIG. 2, the diameter of the lead-in electrode 190 is smaller than the diameter of the lens electrode of the source lens, and the outer diameter and thickness are made small. The outer shape of the incoming electrode 190 is a thickness that can be disposed between the nanostructure tip 150 and the source lens 200. The diameter of the incoming electrode is larger than the diameter or cross sectional size of the nanostructure tip, The nanostructured tips may be formed so as to include all of the nanostructured tips. Preferably, the diameter of the lead-in electrode 190 is smaller than the diameter of the first electrode of the source lens. A negative voltage larger than a negative voltage applied to the nanostructure tip 150 and smaller than a negative voltage applied to the first electrode layer 260 of the source lens 200 is applied to the input electrode 190 . The tips of the nano-structured tips 150 are positioned within the thickness of the lead-in electrode 190 from the same plane of the contact surface of the lead-in electrode 190, so that electrons emitted from the nano- It is preferable to be directed to the inner diameter of the source lens electrode layer 260 while passing the inner diameter of the lead electrode 190.

The source lens is composed of three electrode layers 220, 240 and 260, one electrode layer is highly doped and the silicon layer is 210, 230 and 250. One electrode layer is highly doped to the silicon base material such as an electron emission source to form a membrane And a bore 222 is formed in the center of the membrane so that an electron beam can pass through the bore. The bottom electrode layers 250 and 260 are called extracorrators in the electron column and allow electrons to be well emitted from the tips 150 of the electron emitter 100. The electrode layers 230 and 240 as an intermediate layer are called accelerators and are for accelerating the emitted electrons. The last electrode layers 210, 220 are called limiting electrodes and form electrons into an effective electron beam. That is, the source lens 200 mainly serves to make electrons emitted from an electron emission source into an electron beam, and also serves as a focusing or other role. Some layers 210,230, 250 may be removed as needed.

In the source lens 200, an insulating layer 300 such as Pyrex is inserted between the electrode layers for insulation. An insulating layer 300 such as Pyrex is also inserted between the extractor and the electron emission source for insulation.

The structure as shown in FIG. 2 is an example of a micro-electron column having an electron emission source according to the present invention. The source lens itself may be combined with a separate electron emission source. However, And fabrication can be simplified.

In the present invention, the nanostructured tip 150 is disposed in a tip base 110 made of a silicon wafer to form an electron emission source 100. The nanostructured tip 150 may be a nanotube, a nanotube, a nanopile, a nanowire, or a nanoparticle, or a tube, a column, or a lump of nanotubes to several tens of nanometers in size, such as a carbon nanotube (CNT) And a tip capable of easily discharging electrons by forming a high electric field at the tip when a voltage is applied.

FIG. 3 shows a case where the microcolumn of FIG. 2 is multi-type. 3, the electron emitting source 100 of the present invention can arrange a plurality of nanostructured tips 150, and thus an electron lens of the same type (in particular, a source lens ) Are arranged in the same manner as in Fig.

In FIG. 3, a multi-type microcolumn including five unit electron columns is shown as a unit column in which electrons are emitted from each nanostructured tip to form an electron beam. In FIG. 3, the nanostructured tips of the electron emitter are all formed on one plate, and the same voltage or voltage may be applied to the nanostructured tips of the individual electron emitters as needed. If a voltage needs to be separately applied to the nanostructured tip, the periphery of the nanostructured tip may be separately divided to apply a voltage, or the electrode layer closest to the electron emission source may be divided to apply voltage to each nanostructure tip And the individual voltage difference between the adjacent electrode layers. In FIG. 3, the electrode layer 220 is formed as one whole layer (plate) and only the bores 222 are formed for each unit column. However, each of the electrode layers 220, 240, So that the voltage can be separately applied to the bores 222. [0051] As shown in FIG. This can be done, for example, according to a conventional multi-column production method such as WO 2006/004374 (published Jan. 12, 2006).

FIG. 4 is a plan view and a cross-sectional view showing another embodiment of a microcolumn having a nanostructure tip of the present invention. 4, the incoming electrode 190 between the electron emission source 100 and the source lens 200 is divided into four pieces, as compared with the microcolumn of FIG. 2. The entrance electrode is used to guide electrons generated from the nano-structured tip 150 into the aperture 222 of the source lenses 200 as well as to correct the direction of the emitted electron beam. May be arranged with a larger diameter than the diameter 222, but smaller than the diameter 222 as shown in FIG. The inlet electrode pieces 190a, 190b, 190c, and 190d of the inlet electrode are preferably four pieces, but they may be two or more. For directionality, three or more inlet electrode pieces 190a, 190b, Calibration may be precise, but a number of adjustment electrodes and controls are required, so it is better to have eight or less. Therefore, it is preferable to form four or eight electrode pieces.

Voltages may be applied to the respective lead-in electrode pieces 190a, 190b, 190c, and 190d, so that electrode pieces to which a relatively larger negative voltage is applied can push the direction of the electrons in opposite directions, Direction can also be corrected. Therefore, if the electrons do not move along the optical axis, the effect of the correction increases.

5 is a plan view and a cross-sectional view illustrating another embodiment of a microcolumn having a nanostructured tip according to the present invention. 5, the aperture 262 of the electrode layer 260 through which the electrons emitted from the electron emission source first passes through the source lens 200 is relatively different from that of the microelectron columns of FIGS. 2 and 4. In FIG. (222) of the electrode layers (240, 220) of the source lens. The reason why the aperture diameter 262 of the electrode layer 260 is small is that only electrons having a good linearity along the electron optical axis of the aperture center of the source lenses 200 among the electrons emitted from the electron emission sources can be selected will be. That is, although the amount of electrons passing through the source lens can be reduced, preferable electrons having a good linearity along the electro-optical axis are selected and focusing is better, and the spot of the electron beam reaching the sample is small and resolution can be greatly increased. The diameter 262 of the electrode layer 260 is preferably 5 times or more smaller than the diameter 222 of the electrode layers 240 and 220 of other source lenses, The diameter of the electrode arranged third or further behind the source lens may be made smaller than the diameter of the second electrode if necessary. Therefore, it is preferable that the diameter 262 of the electrode layer 260 is smaller than the diameter of the next second electrode. The embodiment of FIG. 5 is applicable to both the embodiment of FIG. 2 and the embodiment of FIG.

5, a plurality of nanostructured tips 150 may be distributed over a larger area than the aperture 262 as the aperture 262 of the electrode layer 260 becomes smaller. Also, as necessary, in other embodiments, a plurality of nanostructured tips 150 may be distributed over a larger area than the bore 262.

Also, in the exemplary embodiment of FIG. 2, various embodiments including the embodiment of FIGS. 4 and 5 may be made of the multi-type microcolumn of FIG.

Nanostructure tip - 150 electron emitter - 100
Source Lens - 200 Inlet Electrode - 190

Claims (3)

In a microcolumn including an electron emission source, a source lens, a deflector, and a focus lens,
The electron emitter is comprised of a plurality of nanostructured tips to emit electrons,
The source lens is made up of three electrode layers. The first electrode layer (called an extractor in a microcolumn) allows electrons to be emitted from the tip of the electron emission source. The electrode layer as an intermediate layer is called an accelerator, And the last electrode layer comprises an electrode layer which is a limiting upper layer and which forms electrons into an effective electron beam,
An incoming electrode is further disposed between the electron emission source and the source lens so that the electrons emitted from the electron emission source are well drawn into the aperture of the first lens electrode layer of the source lens,
The diameter of the first electron lens electrode of the source lens is smaller than the diameter of the second electron lens electrode on the basis of the electron emission source,
Characterized in that the micro-column comprises a plurality of columns. The method according to claim 1,
Wherein the inlet electrode comprises two or more electrode pieces. A multi-type microcolumn in which the microcolumns of claims 1 or 2 are unit microcolumns.

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