JPS58110043A - Particle beam device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a particle beam apparatus, particularly when a particle beam is used to write, for example to form a mask used in the manufacture of semiconductor devices.
It concerns the direct control of a particle beam by a digital source.

The present invention combines electron beam and electrostatic deflection technology,
However, it will be appreciated that the principles of the present invention are equally applicable to electromagnetic deflection techniques and ion beam techniques. Thus, "deflector", "deflection plate set" or "plate set" as used herein includes a beam deflector, either electrostatic or electromagnetic. I'm being ignored.

In the field of electron optics, the use of electrostatic deflection plates to control the position of electron beams has of course been practiced for a long time in this technology, and current equipment does not handle the data processing required to perform electron resist exposure. It is known that digital electronic technology is used for this purpose. However, to actually control the electron beam, the digital signals from the digital processing and control circuits are converted to analog signals by electronic digital-to-analog converters. These analog signals are then applied to an electrostatic deflection plate. It is also known that the use of electronic digital-to-analog converters limits the control speed of the electron beam, and thus the entire device is limited by the speed of the digital-to-analog converters. For example, in today's equipment digital data signals can be processed in the Hz range, whereas the maximum speed of electronic digital-to-analog converters is sufficiently low ().

Thus, in order to increase the speed of the device, it is necessary to increase the control speed of the electron beam, and this also means that digital signals of the same amplitude from the data processing electronics directly control the electron beam optics. It will also be appreciated that a unique arrangement of electrostatic deflection plates along the beam length, such as, is satisfied in one embodiment of the invention. In other embodiments, the electrostatic deflection plates are selectively positioned along the beam length, with plates having different spacing between them such that the electric field strength in each set of plates controls the beam optics. In one embodiment of the present invention, digital signals of different amplitudes are applied to particles of different magnitudes, or digital signals of the same amplitude are applied to particle beams of different magnitudes. An in-column transducer having a plurality of particle beam deflectors within an optical column and spaced from selected points or planes according to a selected order. The distance between a selected point or plane in the optical column and an individual deflector is determined by the position value or number expressed by the position of the base in the numerical system. When digital signals of the same amplitude are applied to one or more deflectors, the deflection of the beam becomes a function of the radix position value in the selected method. In other embodiments, similar results are obtained by varying the electric field strength of particle beam deflectors placed selectively apart along the column.

Two different deflection devices and two different optical columns are disclosed.

1 and 2 of the accompanying drawings, it will be seen that an electron beam 10 from a typical beam source 12 and a reference plane 16 toward which the electron beam is directed are schematically represented. Typically, this reference surface is a resist layer for exposing the microcircuit pattern.

With reference to these figures, preferred embodiments of the invention will be described. It is an in-column transducer such that a digital signal of the same voltage is applied to the deflection plate, positioned in a selected sequence, in the electron beam. Thus, between the beam source 12 and the reference plane 16 there are a plurality of electrostatic deflection plate sets 20 (4 plates in each plate set) provided for the electron beam 10. The Taniboard set is provided with a pair of digital drive circuits whose inputs (X and Y) are connected to appropriate digital signal sources from the data processing and control electronics 22 of the device.

These plate sets 20 are separated from the reference plane 16 according to the order in which they are selected, that is, the distances between the reference plane 16 and the first plate set and between the reference plane and the other plate sets are as follows. It is a function of the selected numerical system (modulus). To be more specific, the positions of the pseudoset are distributed with respect to the position value or value expressed in the position of the modulus cardinality. Thus, in a binary system (radix-2), the position of the first set of plates from the selected reference point or plane is a length in units L'&)2''.The next set is 2L. (2''L), the next set is provided at a distance of 4L (22L), and so on, with the last board set at a distance of 2nL. Obviously, in the six-value system (base -6), the distances are 6°L, 31L
, 32L, and so on.

FIG. 2 shows the operation of the device. In this figure, L
The SB (lowest bit) plate set 20A is provided at a distance from the reference plane 16, or at a length unit of 2°, and the plate set 20A is
0B is at a distance of 2L from the plate 16.

or 21 length units, and the MSB (
The plate set 20C of the most significant bit is provided at a distance of 4L or 22 length units from the plate 16. By applying the same selected voltage to each set of plates, the beam is deflected by an angle θ at each set of plates. thus. If the selected voltage is applied to the temporary assembly 20A and nowhere else,
The beam is deflected by an angle θ, represented by beam node A, toward position 1 on reference plate 16. If no voltage is applied to plate set 20A and is applied to plate set 20B, the beam will be deflected by an angle .theta., represented by beam node B, toward position 2.

If a selected voltage is applied to both plates 20A and 20B at the same time, the beam is deflected first in plates 20B by an angle θ and then again in plates 20A by an angle θ, resulting in a position change. 3, form beam nodes A and B that reach the reference plane. Board set 20A and 2
If no voltage is applied to 0B but is applied to temporary assembly 20C, the beam is deflected by an angle θ and directed into beam segment C which ends up on the plane at position 4. The voltage applied to plate set 20C and plate set 20AK deflects the beam as in beam 9 reaching position 5, node A+C, and similarly the voltage applied to plate set 20B and plate set 20C reaches position 6. The beam is deflected to node B+C. Finally, the voltage applied to plate sets 200.20B and 20A deflects the beam to node A+B+C to position 7 on the reference plane.

Although the deflection of the beam is depicted in one direction in FIG. 2, the deflection occurs in two dimensions (X and Y) as shown in FIG. In a binary system, any line or shape can thus be converted to X and Y at the appropriate time in the selected board
Writing can be performed by driving in the direction. However, it will be appreciated that unidirectional writing may also be used by moving the reference plane in the X and Y directions to obtain a two-dimensional result if desired. It is also understood that a lens can be provided below the reference plane 16 if desired.

FIG. 4 shows a selection device that applies digital signals to the board assembly. In this case, the plates are individually connected to respective digital drive circuits, ie circuits for deflecting the beam in two directions. In this figure, a radix-6 device is disclosed. In this case, no deflection occurs when the opposite plate is in either the 1 or 0 state, but even if the left-hand plate (as seen) is positive and the right-hand plate is not driven. , a positive deflection result is obtained. There is a negative deflection between only the right plate. The right and left sides in this case are depicted in FIG.

This figure also shows that the digital signal is 6°L from the reference plane 16.
The results are shown for the LSB board set 20A provided in length units and the MSB board set 20B provided in 31L length units. The 0 to -4 position and the 0 to +4 position are the second
A signal is applied to each set of plates in a manner similar to that explained in connection with the figure.The result is ``Shiruta'', but in this case, the signal can be drawn on either the negative or positive side depending on the individual connections of each set of plates. Also, as in Figure 2, two-dimensional depiction can be achieved by applying an appropriate digital signal to the plate assembly, or if the deflection is in one direction, the reference plane can be moved in the X or Y direction. A two-dimensional depiction is made by moving the object to

FIG. 6 depicts the invention in which the lens arrangement 24 is inserted into the optical column between the plate set and the reference surface.

The objective plane 26 of the lens corresponds to a crossover point or a source image for the purposes of the present invention, and the reference plane 16 is the point on which the Lenska electron beam is focused. Furthermore, in this embodiment, the objective plane is the basis from which the plate set is placed in order in the optical column, and in this embodiment is positioned in a binary system (base-2). Moving from the previously described lensless device to the lens device of FIG. 6, the image projected onto the objective plane is inverted and the beam appearing at spots 1'-7' on the objective plane By the action of , beams appear at points 1 to 7 on the imaging plane 16 according to the same law as geometrical optics. In order to develop the writing on the image plane, the beam is focused onto the image plane by a lens 24, such that:
It is recognized by the corresponding action of the board set. The table close to FIG. 6 relates the imaging plane to the position of the activated plate set.

FIG. 7 depicts one modified embodiment of the sequential positioning apparatus shown in FIGS. 2-6. In this figure, components having similar functions as in the previous description are given the same reference numerals for simplicity. However, in this embodiment, multiple voltage dividers
(Voltage dividers) 30A-30C are connected between the data processing and control electronics 22 and the drives of the board sets 20A-20C. Any suitable voltage divider or voltage multiplier device may be used depending on the needs of the apparatus; the voltage divider shown here is one example. Although the plate set of this embodiment is selectively separated from selected planes and from each other (either the 'reference plane of FIGS. 2 and 5 or the crossover of FIG. 6), the voltage The function of the divider is to apply a digital voltage signal representing the base value of the selected numerical system.

As can be seen, the first voltage divider 30A represents the least significant bit (LSB), and the voltage divider 30C represents the most significant bit (MSB).

Thus, instead of sequential positioning of the plate set, positional conversion from electrons to beams is achieved by varying the voltage according to the selected radix position values. Although it is recognized that the disclosed embodiment utilizes voltage changes, the electric field strength applied to the beam pressure also depends on the size of the sliding plates in the plate set as well as the spacing between the plates in the plate set. It is also recognized that Thus, instead of a voltage divider that varies the voltage according to the radix 6 position value of the selected numerical system,
Varying the size of the plate sets and/or the spacing between the plate sets may also result in digital electron-to-beam position transformation such that the distance between the plate sets varies across the beam column.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram depicting the apparatus with data processing and drive electronics and the manner in which the digital signals therefrom are applied to the board set; FIG. 4 added to the board set
6 is a diagram depicting the beam deflection without the use of a lens device according to the digital signal of the amplitude, and FIG. FIG. 4 is a diagram showing different forms for applying a digital signal of the same amplitude to the board set, and FIG. 5 is a diagram showing the result in ternary system, Figure 6 is a diagram depicting the deflection of the beam due to the modified configuration; Figure 6 is a diagram depicting a binary system using the principles of the invention in a lens system; Figure 7 is a diagram depicting the deflection of the beam according to the invention; FIG. 3 depicts the application of digital signals applied to selectively spaced plates along a column as the electric field strength is varied. 10... Beam, 12... Beam source 16
...Reference surface, 20...Plate assembly 22...Data processing, control device 30...Voltage divider 8th place J-z' Engineering Uσノ. 9th place 1 ri?

Claims (1)

[Claims] 1. A particle beam device having a particle beam from a particle beam source and a reference plane in the path of the particle beam,
having a plurality of deflection devices for deflecting the particle beam;
Each of the deflection devices receives a digital signal from a digital source so that the combination of the deflection devices and the digital signal received by the deflection device causes the front d beam to be shaped according to the base of the numerical system. A particle beam device, characterized in that the columns are deflected; so that the beam position represents the value of the position of the radix in the numerical system. 2. Beam device according to claim 1, which is spaced apart in an orderly manner so that digital signals of the same amplitude applied to the deflection device are converted into a representation of the value of a radix position in a numerical system. 3.8 A beam device according to claim 2, further comprising a lens device, the reference plane being the imaging plane of the lens onto which the beam is focused by the lens. 4. The beam device according to claim 2, wherein the deflection device is an electrostatic device. 5. The deflection device is a plate set,
3. A beam device as claimed in claim 2, wherein each plate of the set is individually connected to a source of digital signals and is individually deflected by the application of digital signals thereto. 6. The beam device according to claim 2, wherein the deflection device includes a magnet η. Z. Beam device according to claim 2, wherein the digital signal source is the data processing and control electronics of the device. 8. The beam device according to claim 2, wherein the particle beam includes electrons. 9. The beam device of claim 2, wherein the particle beam includes ions. 10. Beam device according to claim 2, in which an electronic resist is provided on the reference surface. 11. A beam device according to claim 2, in which an electronic resist is provided on several sides. 12. The deflection device is selectively spaced along the beam path, A digital signal applied to a deflection device changes the electric field strength of the deflection force of said deflection device according to the radix of the numerical system, such that the deflection device converts the digital signal into a representation of the value of the position of the radix in the numerical system. , a beam arrangement according to claim 1. 16. Claims further comprising a lens arrangement, wherein the reference plane is the imaging plane of the lens onto which the beam is focused by the lens. 14. The beam device according to claim 12, wherein the deflection device is an electrostatic device. 15. The beam device according to claim 12, wherein the deflection device is a set of plates, and the deflection device is an electrostatic device. 13. A beam device according to claim 12, wherein each plate is individually connected to a source of digital signals, and application of a digital signal thereto causes the beam to be individually deflected.16. 13. The beam device of claim 12, wherein the digital signal source is a magnet. 1Z The beam device of claim 12, wherein the digital signal source is data processing and control electronics of the device. 18. The beam device of claim 12, wherein the particle beam includes electrons. 19. The beam device of claim 12, wherein the particle beam includes ions. 20. The beam device according to claim 12#, in which the electronic resist is provided on the reference surface. 21. The beam device according to claim 12, in which the electronic resist is provided on the reference surface. Beam device according to claim 12. 22. In a digital conversion particle beam device, a particle beam source for directing a particle beam toward a reference surface, and deflecting the particle beam in a path toward the surface. a deflection device, the deflection device being spaced sequentially from the plane by length units that are multiples of the quantity represented by the position of the radix of a base number; and a device for applying the beer pulse according to the position of the particle beam. 23. Beam device according to claim 22, including a lens.