JPS6245033A - Dry etching device - Google Patents

Abstract

PURPOSE:To form a specified pattern without using a resist by a method wherein a light source is provided to optically pump a substrate to be etched while a radical is led to a reaction chamber whereon the substrate to be etched is mounted to decompose a reactive gas for activation. CONSTITUTION:The light emitted from a light source 1 irradiates a semiconductor substrate 5 to be etched e.g. P-type or no-additive silicon substrate through a mask 4 with specified patterns drawn thereon provided in a reaction chamber 3. Reaction gas flowing from a reaction gas cylinder 6 is led to the reaction chamber 3 while another gas for producing radical flowing from another gas cylinder 9 is converted into a radical in a radical producer 11. An atomic hydrogen radical led to the reaction chamber 3 reacts to a reactive gas separately led thereto e.g. chlorine resultantly producing a chlorine radical. The a activated reactive gas can etch only a part of semiconductor substrate to be etched which is irradiated with the light emitted from the light source 1 through the intermediary of the mask 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an apparatus for dry etching semiconductor substrates and the like.

[Background of the invention]

Dry etching methods used in the manufacturing process of integrated circuits include plasma etching methods and reactive sputter etching methods. Conventionally, in these processes, a desired circuit pattern is formed through many steps such as resist coating, pattern exposure, development, etching, and resist peeling. A technology for pattern formation that greatly shortens such complicated steps has been made public, and details can be found in the Proceedings of the 5th Dry Process Symposium, page 97 (1983).
(2013) and Electronics, February 1983 issue, page 5.

In these known techniques, light with a wavelength of around 300 nm (Hg-Xe lamp or
This method utilizes the phenomenon that when e (U excimer laser light) is irradiated through a mask, only the areas hit by the light are etched. Although the mechanism of this phenomenon is not fully understood, chlorine molecules decompose into radicals by absorbing light with a wavelength of around 300 nm, and electrons generated on the silicon substrate surface due to photoexcitation attach to chlorine atoms, resulting in CA
It is explained that etching occurs as a result of being drawn into the SL lattice at a positive potential, breaking bonds in the silicon crystal, and vaporizing in the form of 5iCQx.

This technology can significantly reduce the manufacturing process for large-scale integrated circuits, but in order to efficiently photodecompose chlorine gas and increase the etching rate of the substrate, it is necessary to increase the wavelength to around 300 nm. A light source that emits bright light is essential, and excimer lasers such as XeCQ are considered effective. However, excimer lasers are expensive, their output gradually decreases as they are turned on, and the laser gas must be replaced periodically.

Another known example similar to the present invention is a maskless etching technique using laser irradiation. When using a laser as a light source, it is possible to take advantage of the laser's excellent directivity and focusing ability, and by scanning the surface of the substrate to be etched with a narrowly focused laser beam, etching can be performed without using a mask. It is possible to draw fine etching patterns directly on the surface. For example, there are examples in which fine etching patterns are drawn on single crystal and polycrystalline silicon using chlorine or hydrogen chloride as a reactive gas and an Ar+ laser as a means for activating the gas. For details, see Applied Physics Letters (Appl', Phys.

Lett, ) Volume 38, Page 1018, 198
It is described in the 1st year edition.

According to the above paper, the wavelength of the light emitted from the Ar+ laser is far from the center of the absorption wavelength of chlorine gas (330 nm), so in order to perform efficient etching, high power (approximately 7 W) laser irradiation is required. In need of. Regarding hydrogen chloride, whose absorption band is completely separated from the wavelength of the Ar+ laser light, a noticeable etching effect has been confirmed only when the Ar'' laser is irradiated with a power of 4 W or more. It is stated that etching is promoted by irradiating the substrate with light and heating it to a near molten state.In this way, in the conventional technology, when using an Ar+ laser, a high-power, expensive laser is used. There is a problem in that laser equipment is indispensable.Although it is possible to use the above-mentioned excimer laser instead of the Ar'' laser, the excimer laser has the above-mentioned problems and is difficult in practice.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a dry etching apparatus that can form a desired pattern without using a resist. Another object of the present invention is to provide an apparatus capable of dry etching using a light source that is stably lit for a long period of time.

Still another object of the present invention is to provide a dry etching apparatus that is relatively inexpensive and can use a low power laser.

[Summary of the invention]

In order to achieve the above object, the dry etching apparatus of the present invention is equipped with a light source for optically exciting the substrate to be etched, and the substrate to be etched is installed in order to decompose and activate the reactive gas. It is characterized by introducing radicals into the reaction chamber.

That is, the present invention provides a light source for irradiating a substrate to be etched installed in a reaction chamber, a means for introducing a reaction gas into the reaction chamber, a means for generating radicals, and a means for introducing the radicals into the reaction chamber. It is characterized by the following:

Radicals according to the present invention are different from metastable excited species. Radicals according to the present invention are gaseous atoms or molecules having unpaired electrons, such as atomic hydrogen. On the other hand, metastable excited species.

When transitions between levels are prohibited by selection rules, as typified by heterotonic transitions, they remain in an excited state for a long time while retaining high energy.

An example of this is a metastable excited state nitrogen molecule (A
3Σu+) and metastable excited atoms of noble gases (A r3P o
), etc. Hereinafter, the present invention will be explained in detail using examples.

[Embodiments of the invention]

FIG. 1 is a schematic diagram showing a dry etching apparatus according to a first embodiment of the present invention. The light emitted from the light source 1 passes through a lens 14 for creating a parallel beam and a light transmitting window 2, and then passes through a mask 4 installed in a reaction chamber 3, on which a desired pattern is drawn, and then onto a semiconductor substrate 51 to be etched. For example, the surface of a p-type or additive-free silicon substrate is irradiated. A reaction gas, for example a chlorine-containing gas, flowing out of the reaction gas reservoir 6 is introduced into the reaction chamber 3 via a valve 7 and a pipe 8. On the other hand, the gas used for radical generation,
For example, hydrogen or hydrogen diluted with a rare gas can be stored in the gas reservoir 9.
After passing through the valve 10, it is converted into radicals (atomic hydrogen) in the radical generating section 11. Radical generating part 1
As the means for converting into radicals in No. 1, a discharge method such as microwave discharge or salow discharge is suitable. Atomic hydrogen radicals generated in the radical generating section 11 are introduced into the reaction chamber 3 via a pipe 12. The atomic hydrogen radicals introduced into the reaction chamber 3 react with a separately introduced reaction gas, such as chlorine, to generate chlorine radicals. The activated reactive gas (chlorine radicals) etches the portion of the surface of the semiconductor substrate 5 to be etched that is irradiated with the light source 1 through the mask 4. In the embodiment shown in FIG. 1, 13 is an optical trap installed to prevent glare from entering the reaction chamber 3 in order to prevent etching caused by light generated in the radical generating section 11, and 15 is a gas exhaust pipe. .

With such a configuration, the reaction gas is transferred to the radical generating section 11.
Since the light source 1 is activated by a reaction with, for example, atomic hydrogen radicals generated in the process, the light source 1 only needs to have the function of optically exciting the substrate 5.

For example, various types of discharge tubes, low-power He-Ne lasers, Ar'' lasers, etc. can be used, and there is no need to use expensive excimer lasers. Because of this position, there is a very low possibility that the charged particles generated in the generation section 11 will enter the reaction chamber 3 and damage the substrate 5 to be etched.

FIG. 2 is a partial configuration diagram of an apparatus showing a second embodiment of the present invention. This embodiment is designed to uniformly mix a reactive gas and radicals for activating the reactive gas in the gap between the mask 4 and the semiconductor substrate 5 to be etched. FIG. 2(A) is a front view, and FIG. 2(B) is a top view thereof. Reaction gas reservoir (not shown, see 6 in Figure 1)
The reaction gas exiting from the pipe 16, branch pipes 17 and 17'
(It is not shown in FIG. 2(A).) Furthermore, it is introduced into the reaction chamber 3 through the jet ports 19, 20, 21, and 22 provided in the annular pipe 18. On the other hand, the radicals exit from the radical generation gas reservoir (not shown, see 9 in Figure 1) and are converted into radicals (for example, atomic hydrogen radicals) in the radical generating section (not shown, see 11 in Figure 1). The converted gas is
Pipe 231 branch pipes 24 and 24' (not shown in Fig. 2(A)), and further annular pipe 25 (Fig. 2(B)).
, it overlaps with the annular tube 18 and cannot be seen. ) is introduced into the reaction chamber 3 through jet ports 26, 27, 28, and 29 provided in the chamber. In this embodiment, an annular pipe 1 for guiding the reaction gas is used.
The spout 19.20.21.22 extending downward from 8 is
It is installed on the same plane as the annular tube 25 which is provided below the annular tube 18 and which guides radicals. That is, the reaction gas outlet 19.degree. 20.21.22 and the radical outlet 26.27.28.29 are provided at equal intervals on the same plane. Therefore, in this embodiment, the angles formed by the reactive gas outlet 19 and the radical outlets 26 and 27 are each 45 degrees when viewed from the center of the mask 4.

In this embodiment, the mask 4 and the semiconductor substrate 5 to be etched placed opposite the mask 4 are shown below the annular tube 25, but when performing etching, the substrate table 30 is moved by the moving mechanism ( (not shown) upwards (in the direction of arrow B), and the reaction gas jet ports 19, 20, 21 .
22 and a radical outlet 2 for activating the reaction gas.
6.27. '28. Adjust so that the position of 29 and the surface of the substrate 5 are on the same plane.

Note that the light for passing through the mask 4 and irradiating the semiconductor substrate 5 to be etched is made to enter from the direction of arrow A in FIG. 2(A). With such an apparatus configuration, active species of the reactive gas can be uniformly introduced into the gap between the mask 4 and the semiconductor substrate 5 to be etched.

In addition, in FIG. 2(A), the light transmission window and gas exhaust pipe that should be provided in the reaction chamber 3 are omitted (
See Figure 1. ).

FIG. 3 is a diagram showing a third embodiment of the present invention. This embodiment is designed to simultaneously etch a plurality of substrates. The figure shows a method for simultaneously processing four substrates. In this embodiment, the apparatus shown in the embodiment of FIG. 2 is installed in the same reaction chamber (not shown) on almost the same plane. It has a configuration of 4 pieces combined in parallel. Radical gas such as atomic hydrogen radicals passes through branch pipes 32, 33, 34, and 35 extending radially from pipe 31, and then
It is ejected into the reaction chamber through the route described in the example of FIGS. 2(A) and 2(B). On the other hand, although not shown, the reaction gas passes through a reaction gas reservoir and further through a flow rate adjustment mechanism before being split into four branch pipes, pipes 36, 37, and 38 in Figure 3.
．． It flows to 39. The inflowing gas is shown in Figure 2 (
It is ejected into the reaction chamber through the route described in Examples A) and (B). In FIG. 3, 40, 41 and 42, 43 indicate masks installed near each outlet. With such a device configuration.

A plurality of semiconductor substrates to be etched can be etched uniformly and simultaneously.

FIG. 4, FIG. 5 (A), and (B) are the fourth embodiment of the present invention, respectively.
and a diagram showing a fifth example. In the fourth and fifth embodiments, a laser is used as a light source, and by scanning a narrowly focused laser beam over the surface of the semiconductor substrate 5 to be etched, a desired pattern is etched without using a mask. The embodiment shown in FIG. 4 corresponds to the embodiment shown in FIG. 1, and the embodiment shown in FIG. 5 corresponds to the embodiments shown in FIGS. 2(A) and 2(B). In the figure, 44 is a laser light source;
5 is a laser beam, and the other symbols are the same as those shown in FIGS. 1 and 2.

In the embodiment shown in FIG. 5, in order to introduce the reactive gas and the radicals that activate the gas into the vicinity of the laser beam irradiation area on the surface of the substrate 5 to be etched, which is irradiated with the narrowly focused laser beam 45, the reaction gas and the radicals that activate the gas are introduced. Spout 19.20.21
．． 22, 26, 27, 28, and 29 are slightly different from the embodiment shown in FIG. 2 in that they extend to the vicinity of the laser beam irradiation section.

In the embodiments shown in FIGS. 4 and 5, radicals such as atomic hydrogen generated in the radical generating section 11 are introduced into the reaction chamber 3, react with the reaction gas introduced from the reaction gas reservoir 6, and the reaction gas is Activate. The activated reaction gas is applied to the semiconductor substrate 5 to be etched installed in the reaction chamber 3.
The portions on the surface that are irradiated and photoexcited with the laser beam 45 are etched. In the embodiments shown in FIGS. 4 and 5, a desired etching pattern can be obtained by fixing the laser beam radiation space and moving the sample stage on which the semiconductor substrate 5 to be etched is mounted.

Note that in FIG. 5(A), similarly to FIG. 2(A), the light transmission window and gas exhaust pipe that should be provided in the reaction chamber 3 are not shown.

FIG. 6 is a diagram showing a sixth embodiment of the present invention, in which a desired etching pattern is drawn on the surface of a semiconductor substrate to be etched by scanning a laser beam using an optical fiber and a photocoupler. It is. In this embodiment, the laser beam 45 is sent by an optical fiber cable 46, and a photocoupler 45 incorporating a microlens etc.
7. Irradiate the half-substrate 5 to be etched through the light transmission window 2.

The photocoupler 47 fixed by the fixture 48 moves to draw a desired pattern under the action of the control unit 49 and irradiates the semiconductor substrate 5 to be etched.

FIGS. 7(A) and 7(B) are diagrams showing a seventh embodiment of the present invention. In this embodiment, two laser beams are made to interfere, and interference fringes are used to remove dirt. Etching This method is used to draw a fine striped etching pattern on a semiconductor substrate. In the embodiment shown in FIG. 7, structures such as one reaction chamber, a reaction gas, an introduction port for radicals activating the reaction gas, a gas exhaust port, a light transmission window, etc. are omitted from illustration. In this embodiment, the laser light source 4
A laser beam 45 emitted from the laser beam 4 is split into two laser beams 51 and 52 by a half mirror 50.

The laser beam 51 then passes through the mirrors 53.54.5
5 to become a laser beam 56, while the laser beam 52 is reflected by mirrors 57, 58 to become a laser beam 59. The two laser beams 56 and 59 interfere with each other and form interference fringes 60 on the semiconductor substrate 5 to be etched. In the bright portions of the interference fringes 60, the reaction between the activated reactive gas generated by the reaction between the radicals and the reactive gas progresses and the semiconductor substrate 5 to be etched undergoes etching.

In the embodiments shown in FIGS. 4 to 7, a laser is used as a light source, and the light emitted from the laser light source may be a low-power He-Ne laser, Ar+ laser, etc. that excites the semiconductor substrate to be etched. It is sufficient to have enough. Therefore, expensive excimer lasers and high power A
It is not necessary to use the r+ laser.

FIG. 8 is an eighth embodiment of the present invention, and is a schematic diagram of an apparatus for optically exciting the semiconductor substrate 5 to be etched using radicals and light emission simultaneously observed in the radical generating section. In fig.

Since the radical generating section 11 is installed directly above the mask 4 and the semiconductor substrate 5 to be etched, the light generated in the generating section 11 is irradiated onto the substrate 5 through the mask 4. This embodiment has the advantage that it is not necessary to provide a light source or a light transmission window for irradiating the substrate 5, and the device configuration can be simplified.

Although the etching mechanism of semiconductor substrates mentioned above is not fully understood, for example, when using atomic hydrogen as the radical, chlorine or hydrogen chloride as the reaction gas, and p-type or additive-free silicon as the substrate, CQ , +H・→Ca−+HCl1 (1
)H(J + H・→口・+HCnorth (2)(
6 chlorine radicals formed in the reactions of 1) and (2)
It is thought that this is related to the etching reaction, in which electrons generated on the silicon substrate surface by forced excitation attach to chlorine atoms and become Ca-, which is then drawn into the silicon lattice at a positive potential, forming a silicon crystal. 5iCI
It is predicted that etching will occur as a result of vaporization in the form of L.

As described above, in the present invention, radicals generated outside the reaction chamber are introduced into the reaction chamber and reacted with the reaction gas, thereby activating the reaction gas. On the other hand, for optical excitation of the semiconductor substrate to be etched, stable and long-life light sources such as various discharge tubes, low-power He-Ne lasers,
Ar+laser or the like can be used. This occurs when an excimer laser is used as a light source. Resistanceless etching has become possible by solving problems such as high cost, reduced brightness during lighting, and frequent replacement of discharge gas, and maskless etching is also possible by using a narrowly focused laser beam. Become. Also,
Even when an Ar'' laser beam is used as a light source, etching can be performed without irradiating a high power laser beam as in the conventional case.

In the present invention, the light emitted from the light source is:

It is used to optically excite a specific region to be etched on the surface of a semiconductor substrate to be etched. Therefore, the light or laser beam may not have the function of photolyzing or photoactivating one reaction gas, but may have the function of photolyzing or photoactivating. For example, when using chlorine gas as the reaction gas, light with a wavelength of around 300 nm that matches the absorption band of chlorine gas, such as Xe (+1 excimer laser) or light from a high-pressure mercury lamp, may be irradiated. The substrate may be heated to near the melting point by irradiating the substrate with an Ar4" laser located at the base of the absorption band with a high power of about 4 W. In this case, the radicals generated in the radical generating part (11 in Figure 1) In addition to activating the reaction gas in the reaction chamber 3, a synergistic effect is obtained in which the reaction gas is also activated by the light irradiation effect, and the etching efficiency can be increased.

In the embodiments of FIGS. 2A and 2B and 5A and 5B, the annular tube 18 conducts the reaction gas and the annular tube 25 conducts the radicals, but the annular tubes 18 and 25 Reversing the vertical relationship, the radicals are passed through the annular pipe 18, and the radicals are passed through the annular pipe 25.
The reactant gas may also be introduced through the reactor.

Furthermore, in the embodiments shown in FIGS. 2 and 5, the annular pipes 18 and 25 are each provided with four spout ports.
You may increase or decrease the number as desired. However, in that case, it is necessary to uniformly mix the radicals and the reaction gas on the semiconductor substrate 5 to be etched, so as the number of jet ports increases or decreases, the number of branch pipes 17, 17' and 24, 24' also increases or decreases. Therefore, it is desirable to equalize the gas flow rate introduced from each jet port for each gas.

In the embodiment of FIG. 5, by reducing the overall size and diameter of the annular tubes 18 and 25, a plurality of spouts can be formed directly in the annular tube 18, 25 without forming any spouts protruding from the annular tube. It may be perforated. In that case, the diameter of the upper annular tube 18 should be smaller than the diameter of the lower annular tube 25, and the jet port provided in the annular tube 18 should be located below the center of the tube (as opposed to the surface of the substrate to be etched). desirable. With this configuration, activated reactive gas can be efficiently formed on the semiconductor substrate to be etched.

In the embodiments shown in Figures 1 and 2, a mask of the same size as the desired etching pattern is placed facing the substrate surface, but the desired pattern is etched onto the substrate to be etched using a reduction projection exposure optical system. A method of forming it on a surface can also be applied.

In this specification, light with pattern information on the surface of the substrate to be etched (light passing through a mask, narrowly focused laser light, interference fringe pattern of laser light, light irradiated by a projection optical system, etc.)
This article focuses on the case where the entire surface of the semiconductor substrate to be etched is irradiated with light to etch the entire surface of the substrate, or when a resist film with a desired pattern is formed on the surface of the semiconductor substrate to be etched. Needless to say, this method can also be effectively used as a method for etching the uncovered areas of the resist film. Even in such cases,
Since the radical generating section (11 in FIG. 1) is provided at a position away from the reaction chamber 3, even if a discharge technique such as microwave discharge or glow discharge is applied as the method for generating the radicals, This avoids the problem of charged particles flowing into the reaction chamber and damaging the surface of the substrate to be etched.

In the above embodiments, chlorine and hydrogen chloride are used as reactive gases, but other etching gases containing halogen elements that are widely used in semiconductor processes can also be used for the purpose of etching the semiconductor substrate to be etched. Furthermore, in the above embodiments, atomic hydrogen was used as the radical, but it goes without saying that other radicals may be used.

In all of the above examples, in order to prevent the charged particles generated in the radical generating section from flowing into the reaction chamber,
For example, an ion collector as exemplified in Japanese Patent Publication No. 60-34013 may be installed on the gas downstream side of the radical generating section.

Another known example similar to the present invention is a method of forming a solid thin film by a radical reaction between atomic hydrogen radicals and a source gas, the details of which are described in Japanese Patent Publication No. 60-34012.

【Effect of the invention〕

As explained above, according to the dry etching apparatus of the present invention, the reactive gas can be activated using radicals such as atomic hydrogen, so the light source is sufficient to optically excite the substrate to be etched. Therefore, a cheap, stable and long-life light source can be used, and resistless etching or maskless etching can be put to practical use.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a dry etching apparatus according to a first embodiment of the present invention, FIGS. 2(A) and (B) are schematic diagrams of a dry etching apparatus according to a second embodiment of the present invention, and FIG. 4 is a schematic diagram of a device according to a fourth embodiment of the present invention, and FIGS. 5(A) and 5(B) are diagrams of a device according to a fourth embodiment of the present invention. Outline 1 of the apparatus according to the fifth embodiment [Causes] FIG. 6 is a schematic diagram of the apparatus according to the sixth embodiment of the present invention, FIG. 7 is a schematic diagram of the apparatus according to the seventh embodiment of the present invention, FIG. 8 shows the eighth embodiment of the present invention.
FIG. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention. 1... Light source 2... Light transmission window 3...
Reaction chamber 4,40,41,42,43...Mask 5...Semiconductor substrate to be etched 6...Reaction gas reservoir 9...Radical generating gas reservoir 11...Radical generating section 13... light trap 1
7.17', 24.24', 32.33.34.35.
36.37.38゜39... Branch pipe 18.25... Annular pipe 19.20.21.22.26.27.28.29...
・Spout port 44...laser light source

Claims (22)

[Claims] (1) A reaction chamber, a light source that irradiates a substrate to be etched installed in the reaction chamber, a means for introducing a reaction gas into the reaction chamber, a means for generating radicals, and a means for introducing the radicals into the reaction chamber. 1. A dry etching apparatus comprising: (2) The dry etching apparatus according to claim 1, wherein the light includes pattern information. (3) The dry etching apparatus according to claim 1 or 2, wherein the light is light that passes through a mask having a predetermined pattern drawn thereon. (4) The dry etching apparatus according to any one of claims 1 to 3, wherein the light is light emitted by a reduction projection exposure optical system. (5) The dry etching apparatus according to any one of claims 1 to 4, wherein the light is light in a wavelength range involved in photodecomposition or photoactivation of a reactive gas. (6) The dry etching apparatus according to any one of claims 1 to 4, wherein the light is in a wavelength range that is not involved in photodecomposition or photoactivation of the reactive gas. (7) The dry etching apparatus according to claim 1, wherein the light is light generated by the radical generating means. (8) An annular tube in which a plurality of ejection ports for the reaction gas and the radicals are arranged in an annular manner in substantially the same plane is provided in the reaction chamber, and the substrate to be etched is placed inside the annular tube. A dry etching apparatus according to claim 1. (9) At least one of the plurality of annularly arranged reaction gas and radical ejection ports is constituted by an open end protruding inside the annular tube or a plurality of openings formed in the annular tube. Claim 8 characterized by
Dry etching equipment described in Section 1. (10) The dry etching apparatus according to claim 8, characterized in that the substrate to be etched can be moved in a direction perpendicular to the plane. (11) A plurality of sets of the annular tubes are provided in the reaction chamber, the substrate to be etched is installed inside each of the annular tubes, and the reaction gas and the radicals are separated from each other. 9. The dry etching apparatus according to claim 8, wherein the dry etching apparatus is introduced into the reaction chamber from each of the ejection ports via a plurality of branched pipes to simultaneously etch a plurality of substrates to be etched. (12) The dry etching apparatus according to claim 1, wherein a laser light source is used as the light source. (13) A desired pattern is drawn by using a laser light source as the light source, fixing the radiation space of the laser beam irradiated from the laser light source, and moving the substrate stand on which the substrate to be etched is mounted. A dry etching apparatus according to claim 1. (14) Using a laser light source as the light source, transmitting a laser beam emitted from the laser light source to a photocoupler through an optical fiber, emitting a laser beam emitted from the photocoupler to the substrate to be etched, and moving the photocoupler. The dry etching apparatus according to claim 1, wherein a predetermined pattern is drawn by etching. (15) A laser light source is used as the light source, the laser beam emitted from the laser light source is divided into two, and the interference effect of the divided laser beams forms interference fringes on the surface of the substrate to be etched to form fine fringes. 2. The dry etching apparatus according to claim 1, wherein the dry etching apparatus forms a shape etching pattern. (16) The dry etching apparatus according to claim 1, characterized in that the light generated by the radical generating means is trapped and the light is prevented from entering the reaction chamber. (17) The dry etching apparatus according to claim 1, wherein the radical is an atomic hydrogen radical. (18) The dry etching apparatus according to claim 1, wherein the reaction gas is a gas containing a halogen element. (19) The dry etching apparatus according to claim 1, wherein the reaction gas is a gas containing chlorine. (20) The dry etching apparatus according to claim 1, wherein the substrate to be etched is a p-type or additive-free silicon semiconductor substrate. (21) The dry etching apparatus according to claim 1, wherein gas discharge is used as the radical generating means. (22) Claim 1, characterized in that an ion collector is installed on the gas outflow side of the radical generating means.
Dry etching equipment described in Section 1.