SU1211825A1 - Method and apparatus for corpuscular irradiaton of substrate - Google Patents

Abstract

1. A method of corpuscular irradiation of a substrate, including surface treatment with an electron beam, structured in accordance with a pattern, characterized in that, in order to increase the processing speed, beam structuring is carried out by projection exposing a pattern assembled by installing electrical and / or magnetic fields on a substrate in the storage device. (L N0

Description

2. The method according to claim 1, 1 and 2, so that the set of the pattern and the storage device is carried out simultaneously with the exposure,

3. A device for corpuscular irradiation of the substrate, consisting of the first electro-optical means and containing a successively installed emitter, the elements of forming and focusing the beam and the second electro-optical means installed on the same axis, containing the elements of deflection and focusing, that, in order to speed up the processing, they are entered into it

one

The invention relates to a method of matrix rewriting of any given information (picture) in the first plane (in the floor plane) and transferring the zagssanny information to the energy carrier (electron beam), which is created by drawing B of the irradiation plane (target), which is an image (reproduction) of a given pattern . The method can be applied in corpuscular-beam devices for treating the product, j in particular, in an electron-beam device for non-thermal processing of semi-conductor 1x plates.

There is a known method for electron irradiation, in which the pattern is rewritten as a template that is uniformly irradiated with electrons and projected onto a target using an electron-optical system (H. Koops, Optic 36 (1972) p.93, ME E. Heritage, T. Vac. Sei 12 (1975), 1135).

The pattern in the places corresponding to the non-irradiated target areas is impermeable to electrons, while in the places corresponding to the irradiated areas of the target it is provided with openings, positions and shapes of which correspond to the pattern. However, due to the relative diversity of possible patterns, the method is not universal.

the third optics are installed on the optical axis of the perpendicular rnor of the first, and containing deflection focusing elements, aperture and electronic mirror,

4. The device according to claim 3, which is based on the fact that the electronic mirror is made in the form of a surface with a potential relief,

5. The device according to p. 3, about tl and - that the electronic mirror mirrors the surface of the surface containing the scattering and reflecting elements, installed in accordance with the ex -IJIM pattern.

2

In another method, described in US Pat., GDR No. 126A38 ,, cl. H 09 J 37/30, 1977, the mosaic pattern is decomposed predominantly into rectangular

surface elements of various shapes and sizes, and the data describing position 5 of the shape and size of surface elements j by setting deflection fields sequentially affect the electron beam,

The disadvantages of this method are that, based on the final data rate of the digital-to-analog converter and beam deflection, downtime occurs during which the target is not irradiated. The amount of time of these downtime sets the upper limit of productivity, which can not be improved even by increasing the sensitivity of the irradiated varnish ,,

Yic therefore, was proposed a method known as

Character projection Pat. GDR No. 128/436, Cl, H 01 J 37/30, 1977, claim 11 M.C.Pfeiffer, S.O. Langner 8th IntiConf. on Electron and Ion

Beam Science and Technology p.893, Electroch Soc (Prenoeton 1978), in which the shape and dimensions of the beam sections are set so that, in the case of the formation of oblique a

3

circular shapes to achieve a higher working speed compared with the point method, in which the change in beam shape is limited. Despite the improvement associated with the expansion of the type of patterns, the performance of the method is low.

The purpose of the invention is to lower the processing speed.

The invention is based on a method and a corresponding device that communicates any given information (figure) energy carrier (electron beam) in such a space-time manner that when an energy carrier interacts with a target (a lacquer layer on a semiconductor), a structure appears that presents an exact image ( reproduction) of a given pattern. In this case, the processing speed should be extremely high, dependent on the sensitivity of the irradiated varnish and independent of the irradiated pattern on the chip, regardless of whether there are figures with beveled edges, an arched shape, etc., and despite the number of such figures.

According to the method of corpuscular irradiation of the substrate, which includes surface treatment with an electron beam structured in accordance with the pattern, the beam is structured by projection exposure of the pattern to the substrate, set up by installing electrical and / or magnetic fields in an additional device.

In this case, the set of the pattern in the memory device can be carried out simultaneously with the exposure.

The recording area in the storage device, contacted by the radiation field, generally exceeds the pattern transferred by the electron beam to the substrate, while the first in the irradiation state contacts the beam, while the other in the accumulation state interacts with the external data preparation device and does not is in contact with the beam.

fljfii implementation of the proposed method in the device for the corpuscular irradiation of the substrate, consisting of the first electron-optical means and containing sequentially installed emitter

1825

elements of the formation and focusing of the beam and mounted on the same optical axis, as well as second electron-optical means and

5 containing the elements of deflection and focusing, the third electron-optical means, installed on the optical axis perpendicular to the first one, and containing deflection focusing elements, diaphragms and an electronic mirror, are introduced.

According to the invention, the electron mirror is made in the form of a surface with a potential relief or in

5 as a surface containing scattering and reflecting elements, installed in accordance with the exposed pattern.

Electron beam produced

0 by the first electron-optical means and preformed, deflected by a deflecting prism in the direction of the second optical axis, where it is formed in the radiation field, directed toward the electron mirror, and focused.

The named radiation field after repeated return from the electron mirror is structured according to

Q in the pattern and when passing through the return path, it is deflected by a deflecting prism in the direction of the first optical axis, where it is projected onto the substrate through a deflecting lens. The interaction of electrons with the field accumulator can consist in dispersion on a potential relief formed from the topography of the mirror surface and the applied field or in reflection or absorption depending on the potential of the corresponding electrode.

On the surface of the electron mirror can be located two or more systems of electrodes of the described type, which can be parallel charged in time. Further, a screen can be positioned at the focal point of the electron mirror to screen the scattered radiation.

 Between the electronic mirror and the diaphragm there is a deflection system.

An interface 5 passes through the surface of the electronic mirror 5, on one side of which electron-optical devices are placed (a) projecting radiation field, about 5

0

five

$

developed by a capacitor system and deflected through a magnetic prism, onto the surface of the electron mirror. In the latter, the electrons of the radiation field, depending on the potential of the storage electrodes (for example, O or 10 V relative to the potential of the cathode) are reflected or absorbed. Further, the field of radiation structured by electron-optical means on the return path through the deflecting prism and the deflecting lens is projected onto the target.

On the other side of the interface, there can be a control electronic system mounted on the storage electrodes exposed to the radiation field, the potential corresponding to the irradiated pattern, and on the storage electrodes not exposed to the radiation field, the potential prescribed by the control program.

A deflecting lens, the task of which is limited to designing a structured radiation field on the machine plane, can be moved in steps of the length of the face of the molded radiation field, thereby increasing the size of the pattern being processed.

The control of irradiation is limited by the step deviation of the sub-sources in the plane of the target and in the plane of the array of the drive field.

In this case, large establishment times are allowed, which does not significantly affect the performance, since the target irradiation time can be relatively long (for example, 100 µs) due to the large processing size (for example, 100-100 µm), and the beam intensity in a structured field radiation due to the filtering of the scattered radiation of the anti-diffusive diaphragm is small. Therefore, when applying the invention, there are no problems associated with the action of spatial charge and short-term current accumulations.

In addition, it is possible to add optical tools of the type of dispersion optics based on quadrupole systems containing deflecting systems and cylindrical

6

five

These lenses provide advantages for electron-optical interaction and for alignment. In this case, it is possible to focus the electron beam 5 onto the storage array matrix of its deflection in a raster manner, so that another kind of controlled influence on the storage array matrix is obtained, which, for example,

0 can be applied for corrections, information accumulated on the field matrix, with an arbitrary selection of storage electrodes.

FIG. 1 shows an electron5 optical device using rewriting as a template; figure 2 - the same, using a flat beam structuring; in figs, 3 is the same, according to the invention.

0 As represented in FIG. 1, the structuring of the radiation field 4 is performed by template 12. For this, the template 12 is illuminated by the fluff of the rays 2 from the crossover of the radiator 1, the main rays of which are directed parallel to the optical axis by means of the condenser lens 3. The pattern consists, for example, of a support grid of thin jumpers that matrix but subdivide the pattern surface into cells. For example, the cells in places 10 and 11 have a metal coating and are impermeable to electrons, while in the rest

5 places permeable to electrons. The radiation field thus structured through the lens 5 by the deflecting objective 6 is projected onto the plane of the target 7 in order to irradiate

0 located on her lacquer layer. In order for this to occur with a high current density and without aberrations, the crossover of the radiator 1 through the lenses 3 and 5 is projected onto

5 entrance pupil 8 deflecting lens 6.

The duration of the irradiation is, depending on the magnitude of the transmitted radiation field, for example,

0 1 millisecond, and for this duration the potential of the drawing electrode on the emitter 1 is set so that the beam current corresponds, for example, to 100 μA. With the help of the cloning system 9 it is possible to move the image of the template 12 on the target, so that other areas can be irradiated with the same pattern

7

target Due to the relatively long irradiation time (1 millisecond) and the short duration (e.g., 1/100 millisecond), the deviation step in the transition from the irradiated to the still unirradiated area of the beam current shutdown is not required.

However, when changing the pattern of the pattern, it is necessary to replace the correspondingly filled with another pattern, which leads to an idle time during which irradiation is not performed.

In order to create variable irradiation patterns and at high speed, it has been proposed, as shown in Fig. 2, to influence the radiation field with an electric or magnetic force in order to change its shape and size. The pattern in accordance with the predominantly mounted rectangular beam sections is mosaically separated, and the irradiation is performed according to the appropriate control program specifying the position, shape and magnitude of the current pulses on the target. Since the mosaic irradiation is performed sequentially, the individual irradiation must be very short (1 microsecond), and thus is not a very small amount compared to the installation time from 1 to 3 systems. Therefore, it is necessary to manipulate the intensity of the electron beam, causing a simple and limiting performance.

The radiation field is limited by two angular diaphragms 19 and 16 so that the first angular diaphragm 19 is displayed in the second 16 plane through both condenser lenses 3 and 5, where its image 14 occupies an additional position relative to the angular diaphragm 16. The image position is determined by the intensity of the field created the deflecting system 18, so that its modulation ultimately controls the shape and size of the beam section in the plane of the target 7. The planes of the first angular diaphragm 19 and the second angular diaphragm 16 are optically conjugated 7 tnositelno target plane.

The deflecting action of the deflection of the system 18 on the radiation field is carried out symmetrically to the intermediate image 13 of the crossover, so

11823

that the position of its intermediate i image in the plane 8 of the entrance pupil of the deflecting lens 6 in the case of a format change remains 5 unchanged.

The electron beam is quenched by the fact that the deflecting system 17 creates a field strength that leads it out of the quenching diaphragm opening 15.

FIG. 3 shows an exemplary embodiment of the method in accordance with the invention, using the principle of a flat beam, shown in FIG. 2). The deflecting system 18 for controlling the format of FIG. 2 is here replaced by a magnetic deflecting prism 20 which deflects a radiation field, pre-molded by 2Q angular diaphragm 19, from the optical axis of the first optical system consisting of radiator 1 and condenser 3 to 90 into the optical axis of the third optical system. It consists of condenser lenses 21 and 22, as well as an electronic mirror 24.

A second optical system, configured with a condenser lens 5 and a deflecting lens 6, the deflecting system 9 of which serves to move the radiation field on a target that is identical to the optical system (figure 2), which is under the deflecting system of format 18, and dampers 17 and the damping diaphragm 15 are omitted because

the functions of these nodes during the irradiation process within the working field are no longer needed. Instead, a deflecting system 25 and an anti-diffuse screen 26 are installed in the third optical system in the plane of the intermediate pupil 23. The second angle diaphragm 16 (Fig. 2) is transferred to the third optical system and is indicated 27. The function of the deflecting system 17 is in interaction with the diaphragm 15 (Fig. 2) as a beam lock, it is possible due to the deflecting system 28 in cooperation with the 50 screen 26.

The device works as follows.

After the beam from, the crossover of the radiator 1 was for the first time 5 limited by the angular aperture 19, it is asymtotically focused by the condenser 3 to the middle of the deflecting prism 20. The magnetic field is deflected by 30

, 9

A prism is created by two pole tips with a circular cross section, located in a direction perpendicular to the axis, and connected by a magnetic circuit located opposite the third optical system and carrying the excitation winding. The beam rays enter predominantly orthogonal to the lateral surface of the pole tip and also exit, distorting the trajectory under the action of a magnetic field. The excitation of the magnetic field occurs so that the angle between the incident and outgoing rays is predominantly 90. Lenses 3 and 21 constitute the telescopic system. The corner diaphragm 1-9 is projected into the plane of the corner diaphragm 27, where it occupies an additional position.

The angular diaphragms 19 and 21 are set so that the radiation field, formed by them in the plane of the angle LO of the diaphragm 27, has a predominantly square cross section. However, it is possible to install other radiation field shapes with a rectangular beam section, input of a flat electric capacitor into the gap of the pole tip of a deflecting prism, the intensity of the electric field of which is directed parallel to the intensity of the magnetic field and both of the field strengths are adjustable.

Lens 22 must project the generated radiation field onto the surface of the electron mirror 24. The latter is located so that an intersection image of the crossover appears at the electron mirror focus in the plane 23, therefore the rays fall orthogonal to the mirror surface and return in the case of an ideal electron mirror after reflection of the way. If the surface of the mirror is not uniform, then an angular spread arises upon reflection, which degrades the resolution of the mirror image in connection with this in the focal plane 23 of the electronic mirror an anti-diffusion screen 26 is installed. It is adjusted so that the intermediate image of the beam crossover is located in the hole there screen 26,

If the surface of the mirror is homogeneous, then it remains homogeneous and insensitive.

the intensity in the radiation field, and on the way back in planes 27 and 14, an intermediate image of the molded floor again arises, which is transmitted by the deflecting lens 6 to the target 7.

If the surface of the mirror is not uniform, for example, due to scratches, it forms 1 around the scratches (1 s potential relief, resulting in a corresponding intensity heterogeneity in the radiation field. Due to the large scatter on the scratch in the image of the electron mirror on the target plane, it is dark on light background. In order to reproduce a specific and rigid pattern, the surface of the mirror can be topographically prepared in the form of a template, and this does not require a reference grid, while the surfaces can be properties at which the electron mirror will dissipate a little, i.e. almost perfectly reflect, in the regions corresponding to the template locations that are permissible for electrons, and in the regions corresponding to the sites impenetrable for the electrons strongly dissipated, and due to filtering by anti-diffusion screen 26 will appear almost black.The intensity of the electric field created in the deflecting system 25 shifts the radiation field in the plane of the surface of the electron mirror. This movement on the return path is again canceled, so that when the deflection system 25 is modulated by

  The edge of the radiation field, fixed on the target plane and defined by the angular diaphragms 19 and 27, moves the structure of the radiation field relative to the edge. Since regardless of this, you can also set the radiation field format, the proposed device can charakter projection. In addition, in the proposed device, the electronic mirror can be constructed as a super-orthonic, and the radiation field is projected light-optically onto the back side of the electronic mirror. Last on the inside

5.) The electron mirror is transformed into a charge image, the potential relief of which is reflected by the radiation field.

thirty

eleven

The surface of the electron mirror according to the type of matrix can be covered with a large number of electrode plates (for example, an area of 8-8 microns in the distance x, for example, 2 microns) separated by resistive slugs (see K.Gozer and –G.Yo. Electronics, 1974, No. 1, p. Z). The electrodes are associated with a semiconductor storage device underneath them and a voltage of, eg, O or 10 V can be applied to them. The interaction of this field accumulator matrix is now not in the scattering of reflected electrons, in reflection or absorption of these electrons, Dependences of potential of electrode of maritsa relative to potential

The charging time can be within milliseconds, and the entire array of the field accumulator is divided into separate (for example, nine) subfields by means of deflection of the beam by a deflecting system 25, the first subfield of the matrix of the accumulator is in contact with the field of the storage device. Each subfield is in contact with an external data preparation device (in the state of charge).

In the subfield of the memory matrix, the field contains, for example, 1000-1000 electrodes on a surface of 10-10 mm.

As a result of this mode of operation, downtime can be avoided between irradiations during the irradiation process in a working field, for example, mm. Irrespective of the pattern, it is irradiated in 1 second, if the value of the subfields on the target was 2

em 100-100 microns and the irradiation of one subfield is 100 microseconds. If the charging time of one subfield of the storage array matrix is less than 1 millisecond, the varnish sensitivity is required depends only on the beam S in the radiation field (subfield) on the target

q SA pendant (s). As a result of the angular spread on the memory matrix of the floor and the anti-diffusion screen filtering, the current passing towards the target in the second optical system is less than the current emulated by the radiator in the first

j you 15 20

25

50

55

thirty

35

40

45

H2S12

optical system. This results in a loss offset by an increase in varnish sensitivity. Therefore, the productivity of an electron beam radiation device operating according to the invention depends on the sensitivity of the varnish.

Electron-optical nodes (fig.Z) have a symbolic character, and their realization is possible not only within the framework of the proposed scheme.

Instead of an electronic mirror with a curved surface, a mirror with a flat surface can also be used. By introducing an intermediate electrode (Venelt electrode) between the surface of the mirror (cathode) and the anode, you can also get a real focus in front of the anode. A flat cathode facilitates the technological implementation of the array of a storage box made in a lithographic manner.

The cross section of the pole tip of the deflecting prism should not necessarily be circular. Other forms have been described in the literature (R.Castaing L.Henry, Jour. Micr.3 (1964) pp.133), with the end surfaces of the deflecting prism inclined relative to the respective axes, which provides a stigmatic image of the angle diaphragms for setting the field radiation format, as well as an image of the anti-diffuse screen (pupil).

The stigmatic image requirement should be fulfilled only from the side of the electronic mirror and the deflecting lens, so that the use of quadrupole systems is possible, for example, instead of both lenses 21 and 22, which facilitates the adjustment of the crossover image to the opening of the anti-diffusion screen. Quadrupole systems may contain deflecting systems and cylindrical lenses.

In connection with this, alignments of the beam of rays on the plane of the entrance pupil 23 of the electronic mirror and on the entrance pupil 8 of the deflecting lens can be carried out independently of each other. This involves moving the image of the crossover towards the surface of the mirrors a, so that it is also possible to focus the radiation field on the electrode of the storage array matrix.

13

In addition, adjustments to the shape and structure of the radiation field can be carried out independently of one another and without interruptions of work, which are inevitable when the plate is mechanically moved, but not caused by electron-optical and electronic phenomena. The beam is quenched by the fact that the electron beam emitted by the emitter and focused on the opening of the anti-diffusion screen in front of it is deflected by the deflecting system 28. The anti-diffusion screen 26 therefore also has the function of extinguishing the orifice plate.

Since the limitation of the radiation floor and the pupil in the second optical

1211825

This system, in which the diverting lens is located, is projected from the orifices located in the third optical system, there is no need to install an aperture restricting the beam into the second optical system. This improves the evacuation and simplifies the maintenance of the vacuum tube clean. the area of the first and, above all, the third optical system, it is possible to maintain an ultrahigh vacuum, while this is in the area of the deflecting 15 lens, which is close to the lens, it is not necessary, since all means creating le, are outside the vacuum chamber.

ten

LY-J

one

five

uj, 2

ig.Z

V / TTy / TTTT /

Claims (5)

METHOD OF BODY SUBJECT IRRADIATION AND DEVICE FOR ITS IMPLEMENTATION (57) 1. The method of corpuscular irradiation of the substrate, including surface treatment with an electron beam structured in accordance with the figure, characterized in that, in order to increase the processing speed, the beam is structured by projection exposure onto the substrate drawing typed by the installation of electric and / or magnetic fields in the storage device 2. The method according to claim 1, characterized in that the set of drawing on the storage device is carried out simultaneously with exposure. 3. A device for corpuscular irradiation of the substrate, consisting of the first electron-optical means and containing sequentially mounted emitter, elements of beam formation and focusing and mounted on the same axis of the second electron-optical means containing elements of deviation and focusing, characterized in that, in order to increase the processing speed, third optical means were introduced into it, mounted on the optical axis perpendicular to the first and containing focusing elements, deviations, aperture and electric ktronnoe mirror. 4. The device according to claim 3, characterized in that the electronic mirror is made in the form of a surface with a potential relief. 5. The device according to p. that the electronic mirror is made in the form of a surface containing scattering and reflecting elements installed in accordance with the exposed pattern.