KR100507460B1 - An extractor for an microcoloum and an alignment method of an extractor aperture and an electron emitter - Google Patents

Abstract

The present invention relates to an electron beam microcolumn, in particular a method for aligning the emitter and extractor aperture of an microcolumn with an electron emission source. The extractor according to the present invention comprises a plurality of sensing zones in which electrons of an electron beam emitted from an electron emission source can be electrically conducted, an insulator which blocks the flow of electrons, or a low-doped semiconductor that can reduce the flow of electrons. And an insulator for dividing each sensing zone, and a connecting portion for electrically conducting electrons impinged on each sensing zone. According to the present invention, a method of aligning an extractor aperture of a microcolumn with an electron emission source includes: detecting an electron beam emitted from the electron emission source in each detection zone of the extractor, the position of the detected detection zone and the split Confirming the amount of current, calculating the relative position of the extractor aperture and the electron emission source based on the location of each detected zone and the amount of current split, and the electron emission source, the extractor according to the calculated data Or moving the electron emission source and the extractor.

Description

How to align the microcolumn's extractor, the diameter of the extractor and the electron emission source {AN EXTRACTOR FOR AN MICROCOLOUM AND AN ALIGNMENT METHOD OF AN EXTRACTOR APERTURE AND AN ELECTRON EMITTER}

The present invention relates to an electron beam microcolumn, in particular to a method for aligning an extractor and an extractor aperture of an microcolumn with an electron emitter, and more particularly to a micron sized extractor using an electron beam emitted from an electron emitter. An extractor for aligning electrons emitted from an electron source tip of a microcolumn and a microcolumn, and a method of aligning them.

With the help of electron beam microcolumns and alignment principles based on micro-sized electronic lens components, electron emitters operating under a scanning transmission microscope (STM) or micro alignment positioner were introduced in the late 1980s. The electron beam microcolumns can be used in a wide range of applications, such as electron beam lithography or electron microscopy, by improving the electron beam current and providing very high resolution by forming finely focused electron beams with the advantages of small physical size and low cost fabrication. .

Alignment used in microcolumns is an accurate XYZ positioner similar to the STM function used to control the position of sharp tips, the electron emitter tip in the case of microcolumns, and to control and measure the position of the tip using the emission electrons from the tip. .

1 is an exploded view of an electron emission source 110 and an electron column 120. The electron emitter 110 includes an electron emitter tip 112, which may be an electron emitter tip 112, such as a single crystal tungsten, hafnium carbide, or diamond tip, or a Zr / O / W Schottky electron emitter tip. Electron emitter tip 112 is mounted on small triaxial micropositioner 114. The micropositioner 114 has a moving range of several nanometers to about 1 mm or more for each of the X-Y-Z directions. The micropositioner 114 is used to align the electron optical column 120 and the electron emitter tip 112. Typical dimensions of the small triaxial micropositioner 114 are about 2 × 2 × 1.1 cm.

Typical components of the electro-optical column 120 include microsource lenses 122 and electronic control components having electrodes 128 and extractors 124 each having a diameter of about several micrometers to several hundred micrometers. do. The extraction electrode 124 is made from a silicon (Si) film or a metal film of several hundreds of micrometers thick with a bore diameter of several microns. For best lens operation, the electron emitter tip 112 needs to be positioned so that it is very close and precisely aligned with the extractor aperture 126.

As the extractor 124 and the electron emitter 110 are in proximity, it is difficult to align the electron emitter tip 112 with the extractor aperture 126. This problem is exacerbated by the dimensions of the extractor aperture 126 and the overall column dimensions. For good alignment, STM type X-Y positioners have been used to scan the tip under vacuum over the extractor electrode. However, this approach requires inaccurate electron source tip positioning, requiring much time between alignment and extractor aperture.

Therefore, clearly there is a need for a method of easily and accurately aligning the extractor aperture of the microcolumns with the electron emission sources. In this connection, an alignment such as International Application No. PCT / US1999 / 25430 has been proposed, but this invention also uses four V-grooves for alignment, even if close alignment is possible outside the vacuum. There is a difficulty in having another device.

  In addition, when the electron column is used for a long time, the alignment of the electron emission source and the diameter of the extractor is changed, which is very difficult to detect.

Accordingly, an object of the present invention to solve the above problems is to easily detect the position of the electrons (electron beam) emitted from the electron emission source in the extractor to facilitate alignment of the diameter of the extractor of the microcolumn with the electron emission source. By simplifying and further enabling automatic alignment, it provides a method for easily and automatically correcting accurate alignment even when using an electronic column for a long time.

Another object of the present invention is to provide an extractor for use in the above alignment method.

In order to achieve the above object, the extractor according to the present invention reduces the flow of a plurality of sensing zones, insulators or electrons blocking the flow of electrons, through which electrons of the electron beam emitted from the electron emission source can be electrically conducted. It consists of a low-doped semiconductor that can be divided into an insulating portion for dividing each sensing zone, and a connecting portion for electrically connecting the electrons impinged on each sensing zone.

According to the present invention, a method of aligning an extractor aperture of a microcolumn with an electron emission source includes: detecting an electron beam emitted from the electron emission source in each detection zone of the extractor, the position of the detected detection zone and the split Confirming the amount of current, calculating the relative position of the extractor aperture and the electron emission source based on the location of each detected zone and the amount of current split, and the electron emission source, the extractor according to the calculated data Or moving the electron emission source and the extractor.

The present invention uses electron beams emitted from an electron emission source to be constantly shot into the extractor even though they are not exactly aligned with the diameter of the extractor. The electron beam can detect the flow and amount of electrons as the current measurement by the movement of the electrons. It is a principle that can be used. In this way, the emitted electron beam is directly detected by the extractor, and the detected data is used to align the electron emission source and the extractor aperture with a positioner such as a micro positioner. For this purpose, the extractor needs to be provided with a sensing part that can accurately detect the position where the electron beam is detected and the amount of electrons scanned (for example, measuring the amount of current), so as to detect the electron beam emitted from the electron emission source. These are fabricated to a micro size on a chip, including a metal plate or a pn junction layer that is divided and positioned opposite the electron emission source. The subdivision of this area allows you to see the exact location of the electron beam. This principle also allows automatic alignment of the extractor aperture with the electron emission source, as described below.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

2 to 4, first of all, Fig. 2 is a flow chart relating to automatic alignment of the extractor aperture and the electron emission source according to the present invention, showing in sequence each step of the alignment according to the present invention. 3 is a plan view of an extractor of a microcolumn according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of the embodiment of FIG. The extractor 210 is divided into four zones by an insulator aperture 211 and an insulator 213 made of four insulators or low-doped semiconductors at right angles about the extractor aperture 211 and the center of the extractor aperture 211. Detection zone 212. Each sensing zone 212 and each measuring instrument 230 are connected by a lead 220. The lower portion of the sensing zone 212 consists of a low-doped semiconductor layer 215, such as conventional low-doped silicon. The sensing zone 212 may be made of a conductor layer, such as a metal, through which current can flow well, or a semiconductor layer, such as high-doped silicon. In this embodiment, as the connection portion, the conductive wire 220 is used, and the role thereof is only for sending the electrons of the electron beam split into the detection zone 212 to the measuring device 230. Since the measuring unit 230 mainly checks the current sent from the connection and measures the amount of current, an ammeter or the like may be used. Insulation 213 is located between each sensing zone 212 to block or reduce the flow of electrons between each sensing zone 212. The width of the insulator 213 is determined by the diameter of the electron beam of electrons emitted from the electron emission source 110, and the detection zones 212 adjacent to the insulator 213 may be detected even if the insulator 213 is irradiated with an electron beam. Since scattered electron beams are measured to some extent and can be confirmed by the respective measuring instruments 230, the width of the insulation unit 213 may be sufficient to confirm the existence of the electron beams in the adjacent sensing zones 212. It will therefore depend on the electron emitter 110 of the system to be used and the object to be aligned. However, it is desirable to make the width of the insulating portion 213 as small as possible because the insulating portion 213 may be charged by the electron beam and be discharged at any moment. Therefore, it is preferable to select a semiconductor such as low-doped silicon, which is a material that is not easily charged by the electron beam, and the width of the insulating portion 213 may vary depending on the material, but blocks or prevents the flow of electrons between the sensing zones 212. It is desirable to use it with the smallest width that can be reduced. Therefore, the insulating portion 213 may also be made of the same semiconductor material as conventional low-doped silicon.

FIG. 5 shows the splitting of the electron beam emitted from the electron emitter 110 in the extractor 210 of FIG. The extractor 210 according to the present invention will be described with reference to FIG. 5, and the electron beam emitted from the electron emitter 110 is split into the detection zone 212a at the upper left of the extractor 210. Accordingly, the meter 230a corresponding to the detection zone 212a on the upper left senses the flow of current and measures the amount thereof. Therefore, it is possible to know in which detection zone 212 the electron beam is split and the amount split. If the electron beam is simultaneously split into the upper left and right detection zones 212a and 212b, the meter 220a and 230b will measure the flow and amount of current, respectively. In addition, when the electron beam is projected near the center of the extractor aperture 211, the current flow and the amount of current are respectively measured in the measuring units 230a, 230b, 230c, and 230d corresponding to the detection zones 212a, 212b, 212c, and 212d, respectively. Will be measured.

FIG. 6 is another variation of the embodiment of FIG. 3, wherein the sensing zones are more subdivided than the sensing zones of the FIG. 3 embodiment, and each sensing zone 212 is more pneumatic than the common conductor to facilitate identifying the flow and amount of current. It is made up of. In Fig. 6, the extractor 310 is a typical pn junction consisting of a p-type semiconductor material, denoted by 312, an n-type semiconductor material, denoted by 314, and a diffusion, denoted by 313, each of which is used. The meter 330 corresponding to the pn junction was also connected by a conductor 320. Each p-n junction is separated by an insulating portion 315.

Since the principle of the arrangement of the extractor aperture 211 and the electron emission source 110 according to the present invention is very similar in principle to any of the extractors 210 and 310, the embodiment of FIGS. 2 and 3-5 will be described below. This is explained in

Referring to the flowchart of FIG. 2 and FIG. 5 in the method of aligning the extractor aperture 211 and the electron emission source 110 according to the present invention, the electrons emitted from the electron emission source 110 are detected in the upper left detection zone 212a. ). Therefore, the flow and amount of electrons in the meter 230a are confirmed. If the extractor 210 is moved and aligned, the extractor 210 is moved to a left side and an upper side by a predetermined distance. And electrons will be detected again in the same and / or other sensing zone 212 if the electron emission source 110 and the extractor aperture 211 are not exactly matched. If detected in the same detection zone, it moves again a predetermined distance and continues the same process. If it is detected in the other detection zone, the extractor is moved back to a distance less than the movement distance in the opposite direction of the previous movement. For example, if it is detected in the detection zone in the lower right side, the extractor is moved to the right and the lower side again. Each of these distances travels less than the distance traveled in each of the immediately preceding directions. Repeatedly, the electron beam emitted from the electron emission source 110 may be centered on the insulation 213 either horizontally or vertically or penetrate the center of the extractor aperture 211. When the electron beam emitted from the electron emission source 110 is simultaneously detected in the plurality of detection zones 212a and 212b including the horizontal and vertical insulation portions 213, the electron emission source 110 is the center of the extractor aperture 211. Move the extractor 210 downward toward the center of the extractor aperture 211 so as to be located in the plurality of sensing zones, the plurality of sensing zones including the insulator 213 on the opposite side of the extractor 210 When electrons are detected at 212c and 212d, the extractor 210 again moves in the opposite direction less than the previous movement. Repeatedly, the center of the extractor aperture 211 and the electron emission source 110 are aligned. Although described as moving the extractor 210, the extractor 210 and the electron emission source 110 are located relatively, so that the electron emission source 110 is moved or the extractor 210 and the electron emission source 110 are moved. The same effect can also be achieved by moving () and simultaneously moving the predetermined direction and distance. By repeating the above method, the extractor aperture 211 and the electron emission source 110 are located on the same axis. Thereafter, the extractor 210 and / or the electron emitter 110 may be moved up and down to adjust the height gap between the extractor aperture 211 and the electron emitter 110. And the arrangement of the extractor apertures 211 may be performed.

Confirming the alignment of the electron emission source 110 and the extractor aperture 211 may be differently determined depending on the size of the electron beam and the size of the extractor aperture 211. If the diameter 211 of the extractor is much larger than the size of the electron beam, the flow of electrons in each detection zone 212 will not be detected, but in general, because the flow distribution of electrons is spread out from the electron emission source 110, The detection of the flow of electrons in each sensing zone 212 of the tractor 210 will be constant. That is, the amount of current measured by each measuring instrument 230 may be the same, or a difference in the amount of current may exist within an allowable range. This is located on the concentric axis of the electron emission source 110 and the extractor aperture 211. In this state, when the amount of current is checked in each of the measuring instruments 230, the distance between the extractor aperture 211 and the electron emission source 110 may be confirmed. Because the electron beam is generally distributed and spread by the electrons, the amount of electric current sensed by the meter 230 depends on the distance between the exit aperture 211 and the electron emission source 110 when the emitted electron beam is constant. Because of this difference, if data on the amount of current is prepared in advance, the alignment of the vertical intervals is sufficiently confirmed. In other words, if the amount of current sensed by the measuring device 230 is smaller than the reference value, the interval may be narrowed by a predetermined distance, and the opposite case may be widened.

Therefore, when the electron emission source 110 and the extractor aperture 211 are not aligned, the electron emission source 110 and the X are detected from the step of detecting the electron beam emitted from the electron emission source 110 in the extractor 210. By repeating the step of checking the alignment of the tractor aperture 211, the alignment of the electron emission source 110 and the extractor aperture 211 may be automatically performed.

As the detection zones 212 are further subdivided in this embodiment, the data of the relative distance between the electron emission source 110 and the extractor aperture 211 may be more accurate, thereby reducing the alignment time. That is, by using the relative coordinate data obtained by measuring the collision amount of the electrons identified in each detection zone 212, horizontal and vertical alignment may be performed at once.

In addition, the semiconductor circuit lamp may be used below the metal film lamp without using the measuring instruments 230 respectively corresponding to the detection zone 212 to check which zone the electrons are detected in. In other words, if various means for detecting the flow of electrons are included in the extractor 210, the above method of the present invention may be used.

In addition, the above-described extractors 210 and 310 may have a rectangular shape in the accompanying drawings, but may be manufactured in other shapes as required.

The above-described method of aligning the electron emission source and the extractor aperture and the extractors are only embodiments. Because the detection zone of the extractor is divided into four zones in the foregoing embodiment of the above description, the zones may be divided into a plurality of zones according to the situation in which the present invention is fully implemented by those skilled in the art. In addition, the distance to move the extractor according to the detected position of the electron beam in each zone is also a simple repetitive operation, and a person skilled in the art can set the distance sufficiently in advance, but use a computer program to reduce the distance of each step. You can also adjust it every time. In addition, the extractor of the second embodiment may measure the amount of current due to the collision of electrons or determine the position of the electrons at which position, and may shorten the alignment time by using the principle of pn junction. . The method of detecting the electron beam emitted from the electron emission source in this way is to use the pn junction principle or to detect the collision of electrons to detect the electrons. By measuring or by constructing using the principle of pn junction, those skilled in the art can make various embodiments by the detailed description of the present invention described above. This method can also be used for commonly used electron columns. However, even if a person skilled in the art applies the extractor in various configurations, a method of automatically aligning the electron emission source and the extractor aperture will be realized by the technical idea of the present invention.

In the method of aligning the extractor aperture and the electron emission source of the microcolumn according to the present invention, and the extractor according to the present invention, the diameter of the extractor and the electron emission source are automatically aligned using the novel extractor according to the present invention. can do. In addition, in the conventional alignment method, the electron beam emitted from the electron emitter does not align the tip of the emitter aperture and the electron emitter exactly as passing through the diameter of the extractor. Since the central axis of them can pass exactly to the central axis of the diameter of the extractor, the efficiency of the electronic column can be maximized. As the alignment is easily automated, the operation time and cost of the electronic column can be reduced.

In addition, there is an effect of accurately aligning by detecting a change in the alignment of the electron emission source and the extractor aperture generated when the electron column is used for a long time.

Those skilled in the art will recognize that the present invention is limited to specific embodiments, which are only for illustrative purposes and do not limit the scope of the present invention, and the scope of the present invention can be modified and modified without departing from the scope of the appended claims. Will understand.

1 is a development of a conventional microcolumn.

2 is a flow chart of an automatic alignment method in accordance with the present invention.

Figure 3 is a plan view of an extractor of a microcolumn according to an embodiment of the present invention.

4 is a cross-sectional view of the embodiment of FIG.

FIG. 5 is a plan view schematically illustrating that electrons emitted from an electron emission source are scanned in the extractor of FIG. 3; FIG.

6 is a cross-sectional view of an extractor of a microcolumn according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110: electron emission source

210, 310: Extractor

211, 311: Extruder aperture

Claims (5)

A plurality of sensing zones through which electrons in the electron beam emitted from the electron emission source can be electrically conducted; An insulator dividing each sensing zone by blocking the flow of electrons between the sensing zones; And A connection portion for electrically connecting the electrons collided with each of the detection zones; Microcolumn extractor comprising a. 2. The extract of claim 1, wherein the sensing zone is comprised of a conductor or a high-doped semiconductor. The microcolumn extractor of claim 1, wherein each sensing zone comprises a p-n junction. In the method of aligning the extractor aperture of a microcolumn with an electron emission source, Detecting the electron beam emitted from the electron emission source in each detection zone of the extractor; Confirming the location of the sensed detection zone and the amount of split current; Calculating the relative position of the extractor aperture and the electron emission source based on the location of each detected zone and the amount of current split; And Moving the electron emitter, the extractor, or the electron emitter and the extractor in accordance with the calculated data; Alignment method of the extractor aperture and the electron emission source of the microcolumn comprising a. The method of claim 4, wherein And comparing the data calculated in the calculating step with data about the alignment of the pre-calculated electron emission source and the extractor aperture, again when the electron emission source and the extractor aperture are not aligned. And repeating from the sensing step, and ending the alignment when the electron emission source and the extractor aperture are aligned.