JPH0777208B2 - Fine pattern formation method - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates relates to a method of forming a fine pattern on a substrate, in particular, pressurized <br/> example the required electron beam pattern information is given to the substrate heating light energy beam, The present invention also relates to a method of forming a fine pattern on the substrate by utilizing the reaction effect with the reactive excitation particles.

[0002]

2. Description of the Related Art Conventionally, when a fine pattern is formed on a substrate, a resist mask or the like is usually provided on the substrate. However, a desired fine pattern can be formed by direct drawing without using such a mask. A method of forming a pattern has also been considered. For example, there is a method in which a gaseous molecule is excited by a photochemical reaction to form a reactive excited particle, and a substrate is exposed to the reactive excited particle to irradiate a light pattern. On the other hand, as a fine pattern forming method using annealing, an annealing method using only an electron beam, an annealing method using only a light energy beam, and the like have been proposed.

[0003]

However, the method of irradiating a light pattern using reactively excited particles excited by plasma or reactively excited particles by a photochemical reaction is often used in comparison with electron beam drawing or the like. , Inferior in fine workability. Further, the fine pattern forming method (annealing method) using only an electron beam has a problem in terms of crystallinity and crystal uniformity of the substrate to be processed. On the other hand, when the light energy beam such as a laser beam alone is used, there are problems of grain boundaries and non-uniformity. In the case of using the electron beam alone or the light energy beam alone, there are many restrictions on the degree of freedom in setting various parameters relating to pattern writing, and there is a difficulty in fine adjustment at the time of pattern writing. In view of such circumstances, the present invention proposes a new method that has not been proposed so far as a direct drawing method of a fine pattern, and aims to enrich the technology relating to the fine pattern formation. This paper proposes a method that can draw fine patterns with wider range and higher efficiency, or with more precise and finer control, while making use of the ability to directly form fine patterns by.

[0004]

In order to achieve the above object, the present invention is directed to irradiating an electron beam having required pattern information to a substrate contained in a reaction chamber in an atmosphere containing reactively excited particles. At the same time, the substrate is
By significantly be irradiated with the light energy beam having an energy (intensity) capable of local heating, only the portion corresponding to the pattern information be on the substrate, the electron beam reaction
We propose a method for direct formation of fine patterns, in which a material is changed by a synergistic effect of the optically excited particles and the light energy beam . Furthermore, the desirable lower level in the present invention
As one of the embodiments of the above,
Generated away from and transported to the reaction chamber
Fine pattern characterized by consisting of long-lived radicals
A forming method is also proposed.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the apparatus configuration for carrying out one embodiment of the present invention. The electron optical system shown in the center of the figure will be described from above. There is an electron gun 1 for supplying electrons, and a first diaphragm 2, an aligner 3, a first electromagnetic lens 4 and a blanking are provided below the electron gun 1. The plate 5, the second diaphragm 6, the second electromagnetic lens 7, and the third electromagnetic lens 9 are continued. A double deflection coil 8a and a stigmator 8b are arranged in the third electromagnetic lens 9. The electron beam emitted by such an apparatus system enters the reaction chamber 16 through the second diaphragm 10.

A reaction chamber 16 in which the substrate 12 is installed,
Since the required degree of vacuum is significantly different from the electron beam optical system described above, differential evacuation is performed by multiple evacuation systems to prevent the electron beam optical system from being contaminated by the reactive excitation particles present in the reaction chamber. However, the degree of vacuum required for electron beam scanning and control is secured.

The substrate 12 is irradiated with the electron beam 11 focused by the electron beam optical system, and a predetermined pattern is drawn. The substrate 12 is installed on a support table 13, and the support table 13 is also configured so that the substrate temperature can be controlled by heating at a low temperature or the like as required. The support base 13 is installed on the X-Y moving mechanisms 14 and 15, and can perform the precision alignment and precision movement similar to those of a normal electron beam drawing apparatus. Various materials in the reaction chamber 16 are composed of materials that are not corroded by the reactive excitation particles described later.

In the illustrated embodiment, the electron beam optical system performs the above-described differential evacuation through the respective exhaust ports 17, 18 and 19, and the reaction chamber 16 is exhausted through the exhaust port 20.
The pressure in the reaction chamber 16 is determined by the exhaust capacity from the exhaust ports 19 and 20.

On the other hand, the electric field-excited plasma, which is one important element among the reactive excitation particles, is introduced through the transport tube 21. In front of the transport tube 21, a microwave of 24.5 GHz generated by magnetron oscillation is introduced into the waveguide 22a, and the quartz tube reaction part 23 is inserted in a part of the waveguide 22a. The end of the waveguide 22a is impedance-matched by a matching device 22b.
CF ₄ + O ₂ gas is supplied at 0.1 Torr through the introduction pipe 23a.
When the plasma is introduced at a pressure of about r, the generated plasma hardly spreads even when the electric power is increased, becomes a stable state, and the matching condition does not collapse even when the gas flow rate changes. Therefore, if the plasma transport tube 21 is coated with Teflon, the active species generated in the discharge part can be introduced into the reaction chamber 16 at a distance of about 1 m without being significantly attenuated. In other words, in such plasma. Particularly, long-lived radicals can be introduced into the reaction chamber 16.

There have been reports from the past regarding the plasma etching method itself using such long-lived radicals excited by microwaves at 2.45 GHz. That is, according to this method, polycrystalline silicon, Si ₃ N ₄ , SiO
Various thin films such as ₂ , Nb, W, Mo and photoresist can be etched. The condition is that the pressure of CF ₄ is 0.12.
When it is set to about Torr, Pr = P _o2 / P _CF4 is 0 to 4
To the extent. The advantage of plasma etching by this excitation method is that no electrode for discharge is required in the reaction chamber 16. Further, if O ₂ or N ₂ is used as the introduction gas in the same plasma excitation method, plasma oxidation or plasma nitridation by plasma-activated oxygen or nitrogen can be performed depending on the conditions.

In the above description, the reactive excitation particles in the reaction chamber 16 are not attenuated so much even if they are generated at a distance of about 1 m, as described above.
6 is a plasma-excited so-called long-lived radical that can reach within 6. However, the means for forming the reactive excitation particles in the reaction chamber 16 is not limited to the above-mentioned excitation method. Recently, there have been many reports of reactive gas particles caused by photoexcitation reactions such as infrared light, visible light, ultraviolet light, and deep UV (deep ultraviolet) light. In some cases, the deepUV described above is used.
Even with electromagnetic light waves of short wavelength from light to X-rays,
Excitation of gas phase particles can be performed by an electromagnetic light wave chemical reaction. As the photochemical reaction process, for example, Si is Cl ₂ or B.
It is known that dry etching can be performed by optically exciting the gas of r ₂ with a laser beam of 4880Å or 2570Å. Also, for GaAs and InP, CH ₃ Br
Etching is possible by reaction of deep UV excitation light of the above gas. As described above and as will be described later with respect to the present embodiment, the present invention mainly focuses on forming a predetermined fine pattern on the substrate by the change of the substance due to the reaction effect of the light beam and the electron beam. However, the pattern formation method by electron beam drawing, which is also proposed in this embodiment as one of its subordinate embodiments and which also incorporates the effect of the reactive gas particles by the electromagnetic light wave photochemical reaction, is a finding of the reports of various reactions described above. Is based on.

Now, in the apparatus configuration of FIG. 1, the light beam 24 is a scannable light beam for exciting a photochemical reaction. A light flux control system 25 is provided for temporally switching the light flux 24L emitted from a light source (not shown) or for spatially changing the direction, position, etc. of the light flux. The light flux 24M emitted from the light flux control system 25 is introduced into the reaction chamber 16 through the reflection mirrors 26 and 27 and the light flux transmission window 28, and the reaction chamber 16
It becomes a light beam 24a that reaches the sample (substrate 12) through a flat or concave reflecting mirror 29 provided inside. The gas for photochemical reaction to be excited is introduced into the reaction chamber 16 from the gas sources 31 and 32 through the valve 30. The introduced photochemical reaction gas is in the light beam 24 and is in the portion 2 in the reaction chamber.
In the light passing space as shown in 4b, it is subjected to photochemical excitation under a reduced pressure atmosphere. Further, the light flux 24a directly irradiated to the vicinity of the sample surface or the sample acts more strongly on the photochemical reaction. Especially when the sample surface is directly irradiated,
Since the local heating effect, the activation effect, the electron-hole excitation effect, and the like due to the light irradiation on the sample surface are taken into consideration, a multi-element reaction mechanism is added. Of course, this luminous flux 24a is
According to the present invention, the luminous flux is so high as to have an annealing effect on the sample (substrate).

The effect of local heating and annealing is also observed in the electron beam. Select the relevant parameters such as the focusing condition and scanning condition such as the spot size of the electron beam as appropriate, and repeat the scan in the x direction at a speed faster than the thermal response time of the substrate to obtain the beam energy density per unit area. The value may be increased to a value of, and the heating or melting portion may be moved little by little in the y direction orthogonal to the scan width.

Further, regarding the light beam, at least one of the introduced one or a plurality of light beams is used in the present invention.
Therefore, if the substrate is a light energy beam having energy that can significantly locally heat the substrate (of course,
(Including the case of irradiating only) , the annealing by electron beam and the annealing by light energy beam can be superposed at the same place on the substrate. In this way, the energy density is insufficient for annealing by electron beam only. Even if there is, there is a light energy beam
It is possible to provide an annealing method according to a new process form such as compensation according to a desired distribution ratio.

Further, as in the prior art, when the electron beam or the light energy beam is used alone, there are many restrictions on the degree of freedom in setting various parameters relating to pattern writing, and for fine adjustment during pattern writing. However, according to the present invention, finer control becomes possible.

In addition to this , the present invention also introduces long-lived plasma radicals or reactive excitation particles by an electromagnetic light excitation reaction into the vicinity of the substrate, and only in a portion on the substrate corresponding to desired pattern information, Since the change in the substance due to the reaction effect between the electron beam or the light energy beam and the reactive excitation particles is also used, the patterning result varies depending on the nature of the reactive excitation particles, and the etching pattern, the plasma oxidation region pattern, A fine deposition pattern or the like can be obtained.

It is also possible to make the light beam 24 scannable to increase the uniformity and controllability of light irradiation on the sample surface. Mechanically, the mirrors 26, 27, 29 may be driven by a minute moving mechanism. For higher speed operation, an electronic optical switch or an optical path changing device may be provided in the light flux control system 25. Also,
By using an optical switch with several polarizations, a half mirror, a microlens array, an optical fiber, etc., it is possible to process a plurality of light beams simultaneously and in parallel. As a result, each of a plurality of light fluxes can be independently timed and spatially arranged. Illustrated light flux control system 25, mirrors 26, 2
The optical system such as 7, 29 is just an example. It is apparent from known publicly known techniques that there are various light flux group control methods other than the above.

A plurality of light beam transmitting windows are separately provided in a structure similar to the electron beam pattern drawing system as shown in the figure, and a plurality of light beam groups are spatially and temporally intermittently incident on each light beam transmitting window. You can also let it. Since there is an advantage in that there is no difference in the control of the light flux between the vacuum and the atmosphere, it is possible to bring the control system of the various light flux groups described above into the reaction chamber 16. However, whether it is one or more,
It is preferable to make such a light beam enter obliquely from above the substrate in the reaction chamber. When a light flux control system is provided in the reaction chamber, a container for protecting the control system with a material such as a quartz plate or Teflon coat is provided so that the control system is not damaged by the reactive excitation particles. There is a need.

[0019] As described above, in accordance with the present invention, Mazumo'
It is possible to provide a new method called pattern annealing by the synergistic effect of the electron beam and the light energy beam.

Furthermore, it is possible to utilize also the effect of an atmosphere containing reactivity excitation particles, or plasma treatment of long life radicals by microwave plasma excitation, photo-chemical treatment by photochemical reactive excited particles, further reaction thereof two It is possible to directly form a desired pattern in accordance with predetermined pattern information while incorporating the process in the presence of the sex-excited particles.

Regarding the oxidation process using reactively excited particles such as long-lived radicals of oxygen, the depth of the oxide layer is controlled and patterned, and the film quality is modified and patterned by pattern beam annealing after oxidation. It is also effective.

The electron beam in the present invention is, as defined in the technical field of this kind, based on electron optical engineering technology, a known existing electron beam acceleration system or deceleration system, electron beam focusing / traveling system, A literal electron beam that can be manipulated or controlled by an electron beam deflection system or an electron beam optical system. Therefore, although an apparatus system similar to a normal scanning electron beam control system is shown in FIG. 1, other known existing electron beam drawing systems such as a variable shaped beam drawing system and an appropriate condition setting are used. Any device having an electron beam focusing control system similar to a known electron beam transfer system or the like may be used.

Further, in such an electron beam optical focusing system for controlling and driving the electron beam, the related parameters are variably controlled or changed to control the energy of the electron beam and the spatial distribution of the beam bundle. ,
Appropriate parameters can be selected, and the degree of freedom in design can be given to a certain extent to the resistless pattern direct formation technique which is an application of the present invention.

On the other hand, as the photochemical excitation beam, various laser beams in the far ultraviolet region to the infrared region can be used. As the drawing mode, for example, scanning or transfer of an electron beam is performed within one frame, and after one frame is completed, the step and repeat is repeated. On the other hand, conventionally, as a pattern drawing technique using various beams such as lithography using charged particles or a light beam, by precisely moving the moving table on which the substrate is installed, it is necessary to write on the substrate in the manner of writing with a brush. Although there is a technique for forming a pattern, the well-known conventional technique is also applicable to the present invention.

[0025]

According to the present invention, a controlled atmosphere is used.
The resistless direct process for the substrate in the chamber enables pattern annealing based on a new mechanism.
In addition to this, the reaction effect with reactive excitation particles is also added
And fine pattern formation can and Do Runode are expected future progress, it can be advantageously utilized as part of a fine pattern directly patterning process. Naturally, this contributes to improvement in manufacturing efficiency and performance of various electronic devices and integrated circuits.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus configuration that can be used for carrying out an embodiment of a fine pattern forming method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electron gun, 11 electron beam, 12 substrate, 13 support stand, 14, 15 XY movement mechanism, 16 reaction chamber, 17, 18, 19 exhaust port, 20 exhaust port, 21 plasma transport tube, 22a microwave waveguide , 23 quartz reaction tube, 24 light beam, 25 light flux control system, 26, 27 reflecting mirror, 28 transmission window, 29 reflecting mirror, 31 gas source, 32 gas source.

Claims (2)

[Claims] 1. A reaction chamber capable of differential evacuation.
An electron beam focusing optical system is arranged; in the atmosphere containing the reactive excitation particles in the reaction chamber,
The electron beam collection is performed on the substrate stored in the reaction chamber.
Electrons to which predetermined pattern information is added in advance from the bundle optical system
Optical energy that locally heats the substrate while irradiating the beam
Irradiating the electron beam with the pattern information and the reactivity excitation
Substances produced by the synergistic effect of particles and the light energy beam
Changes the pattern to form a predetermined fine pattern on the substrate.
Fine pattern forming method comprising; Rukoto. 2. The method for forming a fine pattern according to claim 1.
There; the reactive excited particles, at a distance from the reaction chamber
Is it a long-lived radical that is generated and transported to the reaction chamber?
Fine pattern forming method of the said; be comprised et.