JPH04206518A - Photo-etching method - Google Patents

Abstract

PURPOSE:To contrive increase in etching speed by a method wherein the excitation and dissociation of reactive gas is conducted by microwave discharge, and a light emission is conducted. CONSTITUTION:Among the various chemical species grown in a quartz tube 12 by microwave discharge, a Cl neutral active species, which has a relatively long life, is led out into an etching chamber 16. This neutral active species is not adsorbed to the inner wall part of the chamber 16 which is heated up by a heater 22, but it is selectively adsorbed to the wafer which is held in a cooled state. At the time, a light is projected on the wafer 19 from a light source 21, and Cl<-> ions are generated on the surface of the polycrystalline Si layer on the wafer 19 by the help of surface excitation effect of the light emission. The Cl<-> ions are intruded into the particles of the polycrystalline Si layer, they reacted with Si, and Clx(x=1 to 4) is grown. The etching of the polycrystalline Si layer makes a progress in a defectless and anisotropic manner by the above-mentioned reaction product.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoetching method, and particularly to improving the etching speed and precision thereof.

[Summary of the invention]

The present invention uses microwave discharge to excite and dissociate a reactive gas in photoetching, and draws out the generated neutral active species into an etching chamber.
The etching rate is greatly improved by efficiently adsorbing neutral active species onto a substrate to be etched which has been cooled in advance in a chamber and by irradiating light.

Further, in the present invention, neutral active species generated by microwave discharge are drawn out into a first chamber and adsorbed onto a substrate to be etched which has been cooled in advance, and then the substrate to be etched is transferred to a second chamber. By heating and holding the substrate and irradiating the substrate to be etched with light, precise etching on the order of a single atomic layer can be performed.

[Conventional technology]

As seen in recent VLSI and ULS I, semiconductor device design rules have already been put into practical use at the submicron level, and research is progressing at the half-micron and even auto-micron levels. Needless to say, reactive ion etching (RIE), which utilizes the directionality of ions in plasma, has played a leading role in such microfabrication technology.

However, in RIE, etching proceeds by a mechanism in which accelerated reactive ions collide with the substrate and promote reaction with active species, so it is essentially difficult to achieve a high selectivity to the substrate. Further, the collision of charged particles having such kinetic energy causes various types of irradiation damage, such as the generation of crystal defects in the silicon substrate and the generation of fixed charges and neutral traps in the oxide film. Furthermore, when the mask is negatively charged in the plasma, dielectric breakdown may occur in thin oxide films such as capacitor films and gate insulating films.

Under these circumstances, in recent years, magnetron RIE and magnetic field microwave plasma etching using ECR discharge have become mainstream as dry etching techniques that enable processes with less damage than conventional RIE.

In addition, as another approach aiming at reducing damage, the 37th
Regenerative Applied Physics Related Union Lecture (1990)! li presentation proceedings volume 2, page 459, presentation number 28a-ZF-9
Recently, a technique has been reported in which a layer of material to be etched is etched on the order of a single atomic layer. According to this technology, the etching gas is first dissociated by microwave discharge in a first chamber, and the generated neutral active species are transported downstream and cooled to a low temperature that does not cause spontaneous chemical reactions. It is adsorbed onto the etched surface of the substrate to be etched. Next, this substrate to be etched is transferred to a second chamber, where it is irradiated with Ar'' ions that generate the minimum necessary energy, thereby causing an etching reaction and desorption of the reaction products. This adsorption and desorption is 1
Processing is performed by repeating this cycle for the required number of cycles. According to this technique, the ion bombardment applied to the substrate to be etched is significantly reduced compared to the conventional method. However, as long as charged particle irradiation such as Ar+ is used, it cannot be a completely damage-free process. Furthermore, even if one cycle is carried out with almost no damage, in practice it is necessary to repeat this cycle several dozen to several thousand times, so damage gradually accumulates during this time, and the process There are concerns that this effect may reach a level that cannot be ignored in some cases.

Furthermore, photo-etching is a technology that is expected to realize a damage-free process. Focusing on the fact that the electron impact energy required to initiate a chemical reaction is only a few eV diameter, we developed a mercury lamp (5 to 6 eV), an ArF
This method uses a short wavelength light source such as an excimer laser (6.4 eV) or a KrF excimer laser (5 eV) to directly cleave chemical bonds in a reactive gas. Since plasma discharge unlike conventional RIE is not required, this method is characterized by the fact that no charged particles are included in the reaction system.

However, there are still many problems that need to be solved before the practical application of photoetching. One of these is securing anisotropy, and various techniques have been proposed in the past.

For example, in Japanese Patent Application Laid-open No. 187238/1987, a reactive gas is supplied into a chamber in which a cooled substrate to be etched is installed, the reactive gas is adsorbed onto the surface of the substrate to be etched, and the substrate is irradiated with light. A technique for selectively allowing a photoetching reaction to proceed is disclosed. With this technology,
Anisotropic processing is achieved by taking advantage of the fact that reactive gases are not excited on the vertical walls of the pattern where no light is incident. Specifically, dry etching of Sl using X e F x gas is exemplified.

In addition, the applicant of the present application previously reported in Japanese Patent Application Laid-Open No. 1-298723 that DOPO3 (dope
An example is disclosed in which a layer of dpoLysilicon was etched. In this technology, not only radical reactions are suppressed by low-temperature cooling, but also the reaction product Sicf (x = 1 to 4) cannot be desorbed on the vertical walls of the pattern where no light is irradiated. It is a major feature in achieving high anisotropy that it contributes as a kind of sidewall protective film.

[Problem to be solved by the invention]

However, photoetching still has one major problem: overcoming low etching speed.

This is probably due to the fact that the light absorption cross section of molecules for photons is one to two orders of magnitude smaller than the electron collision dissociation cross section of molecules in plasma, and therefore photoetching is essentially less effective than RIE. It is inferior in etching speed. Even with the techniques described in the above-mentioned publications, this problem has not been solved. However, in the field of dry etching, single-wafer dry etching equipment is becoming mainstream as wafer diameters increase, and it is essential to significantly improve etching speed in order to maintain the same productivity as before. be.

Therefore, an object of the present invention is to provide a method that achieves a practically sufficient high speed even in photoetching, and also enables advanced control on the order of a single atomic layer.

[Means to solve the problem]

The photoetching method according to the present invention is proposed to achieve the above-mentioned object.

That is, in the photoetching method according to the first aspect of the present invention, a substrate to be etched is cooled and held in an etching chamber, and a plasma generated by microwave discharge is generated in a plasma generation chamber connected to the etching chamber. The method is characterized in that neutral active species are drawn into the etching chamber and adsorbed onto the substrate to be etched, and the substrate to be etched is irradiated with light to selectively advance an etching reaction in the light irradiation area. It is.

Further, in the photoetching method according to the second aspect of the present invention, the substrate to be etched is cooled and held in a first chamber, and a plasma generated by microwave discharge is generated in a plasma generation chamber connected to the first chamber. After drawing the neutral active species from the plasma into the first chamber and adsorbing them onto the substrate to be etched, the substrate to be etched is transferred to the second chamber where it is heated and held, and light is applied to the substrate to be etched. The method is characterized in that the etching reaction is selectively progressed in the light irradiated area.

[Function] The present inventor believes that one of the reasons why high speed is not achieved in conventional photoetching is that the dissociation of the reaction gas, the desorption of the reaction product, and in some cases the surface excitation of the substrate to be etched are all caused by light energy. We focused on the fact that they are being paid for by looking at the situation.

In the first aspect of the present invention, the reaction gas is first dissociated by microwave discharge, thereby separating it from the use of light energy. A technique in which a reactive gas is dissociated by microwave discharge has been known as so-called hybrid photo-etching. This is because when high-power laser light is irradiated in pursuit of high speed, the surface temperature of the material to be etched rises, causing negative effects such as part of it being removed or the resist being blown away. Therefore, this was proposed as a countermeasure.

Therefore, in the present invention, these adverse effects are naturally avoided. Furthermore, since the plasma generation chamber and the etching chamber are provided as separate rooms and the substrate to be etched is isolated from the plasma generation region, charged particles do not enter the substrate to be etched, resulting in a certain degree of long life. The neutral active species having the etching reach the substrate to be etched.

In the present invention, the substrate to be etched is further cooled and maintained, so that neutral active species arriving from a separate chamber are efficiently adsorbed and light irradiation is performed. This results in
The surface of the substrate to be etched is excited in the light irradiation part,
The etching reaction proceeds at high speed through a mechanism in which the reaction with the adsorbed neutral active species is promoted and the desorption of the reaction product is promoted by the heating effect of the irradiated light. In addition, in systems where the substrate to be etched is cooled and a reaction product is generated that develops a low vapor pressure at the cooling temperature, this can be used to protect the sidewalls and achieve high anisotropy. .

As described above, in the present invention, the light energy is used only to excite the surface of the substrate to be etched and promote the desorption of reaction products by the heating effect, but not to dissociate the reaction gas. Therefore, there is an advantage that the wavelength of the light source can be selected from a relatively wide range. However, if a short wavelength light source is used, the straightness of the light will be improved accordingly, which will be advantageous in performing anisotropic processing. Particularly in a system in which a reaction product with a low vapor pressure is obtained, it is deposited on the side wall portion of the pattern that is not exposed to light, making it possible to perform good anisotropic processing of the layer.

On the other hand, in the second invention of the present invention, the adsorption of the neutral active species and the light irradiation in the first invention are performed in separate rooms. That is, first, the neutral active species generated in the plasma generation chamber are drawn out to the first chamber, and are efficiently adsorbed onto the surface of the substrate to be etched, which has been cooled in advance.

At this stage, since the substrate to be etched has been cooled, either no reaction occurs between the neutral active species and the surface of the substrate to be etched, or even if reaction occurs, the reaction product does not come off. Next, this substrate to be etched is transferred to a second chamber, where it is heated and held, and is irradiated with light. At this stage, if the reaction has already progressed, the removal of the reaction product is promoted by direct heating of the substrate to be etched and the heating effect of light irradiation; if the reaction has not progressed, the removal of the reaction product is accelerated by the heating effect of light irradiation. Surface excitation by irradiation accelerates the reaction and likewise promotes desorption. These processes proceed on the order of a monoatomic layer on the surface of the substrate to be etched without any incidence of charged particles.

Therefore, by moving back and forth between the first chamber and the second chamber the required number of times, a highly controllable and damage-free process is achieved.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

Example 1 This example is an example in which the first aspect of the present invention was applied and neutral active species were generated using a microwave discharge tube.

First, FIG. 2 shows a schematic configuration example of the etching apparatus used in this example.

In this device, what corresponds to the microwave generation chamber is a microwave discharge tube (11). This microwave discharge tube (11) was arranged so as to sandwich the quartz tube (12) by supplying microwaves from a magnetron oscillator (15) with an oscillation frequency of 2.45 GH2 through a waveguide (14). An electric field is formed between a pair of electrodes (13), and microwave discharge is performed in the quartz tube (12) into which a reactive gas is introduced from the direction of arrow A in the figure, thereby generating plasma P.

is generated.

The other end of the microwave discharge tube (11) is connected to an etching chamber (16). A sample stage (17) on which a wafer (19) as a substrate to be etched is placed is installed inside the etching chamber (16).
In order to keep the wafer (19) cool, the sample stage (17) is equipped with a cooling pipe (18) that can circulate a coolant supplied from a cooling system (not shown) in the direction of arrow B in the figure. Built-in.

A light source (2) is provided outside the etching chamber (16).
1) is provided, and the light from the light source (21) is transmitted through a window (2o) provided on the upper wall surface of the etching chamber (16).
The beam passes through the beam and enters the wafer (19) almost perpendicularly. A heater (22), for example, as a heating mechanism is built in at least a portion of the inner wall of the etching chamber (16) excluding the window (20). This heater (22) is provided in order to efficiently adsorb the neutral active species extracted from the plasma P0 only to the surface of the etching chamber (19) without adsorbing them to the inner wall of the etching chamber (16). This is what is being done. Further, the reaction gas, reaction products, etc. in the etching chamber (16) are exhausted in the direction of arrow C in the figure by an exhaust system (not shown) connected through an exhaust port (23).

Using this apparatus, photoetching was performed to form a gate electrode made of a polycrystalline silicon layer into which n+ type impurities were introduced (hereinafter referred to as DOPO3 layer). The state of the wafer (19) before photo-etching is, for example, as shown in FIG. 1(A).
An OPO3 layer (3) is formed, and the DOPO3 layer (3) is formed.
3) A resist pattern (4) is formed thereon. Here, C12 gas was supplied into the quartz tube (12) from the direction of arrow A in Fig. 2 at a flow rate of 50 SCCM, the gas pressure was 250 mTarr, and the microwave current was 25.
Microwave discharge was performed under the condition of 0 mA. On the other hand, ethanol refrigerant was circulated from a chiller through the cooling pipe (18) to maintain the temperature of the sample stage (17) at about -70°C. Further, as the light source (21), a KrF echima laser light source with a wavelength of 249 nm was used. Along with this, windows (20)
The constituent material was quartz.

The mechanism of photo-etching in the present invention can be roughly considered as follows. First, by microwave discharge, the quartz tube (12)
Among the various chemical species generated within the etching chamber (16), a relatively long-lived Cl-based neutral active species is drawn out into the etching chamber (16). This neutral active species is not adsorbed to the inner wall of the etching chamber (16) which is heated by the heater (22), but rather is attached to the wafer (I9) which is kept cool.
) is selectively adsorbed onto the surface. At this time, the wafer (19) is irradiated with light almost perpendicularly from the light source (21), and the surface excitation effect of this light irradiation also helps the DOPOS
Electrons are transferred from the surface of the layer (3) to the Cl-based neutral active species to generate C1- ions. CI! -Ion is DOPO3
Penetrates into the grain boundaries of layer (3) and spontaneously reacts with Si.
Generate iCC (x=1 to 4). This reaction product is
On the surface irradiated with light, it immediately desorbs into the gas phase due to its heating effect, but on the sidewalls of the pattern that are not directly irradiated with light, it accumulates and exerts a sidewall protection effect. Therefore, anisotropic processing is possible without particularly adding a deposition gas to the atmosphere.

As a result, as shown in FIG. 1(B), Dopos
Etching of the layer (3) proceeded without damage and anisotropically, and a gate electrode (3a) having vertical walls was formed with deposition of a sidewall protective film (5). In this photo-etching process, no charged particles were incident on the wafer (19) surface, so damage was also avoided. The etching speed at this time was approximately 1,000 people/min, which was more than three times higher than the conventional general photoetching method that does not involve microwave discharge or substrate cooling.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, in the above embodiment, the light source (21) is KrF.
The purpose of the light irradiation in the present invention is to excite the surface of the wafer (19) and desorb the reaction products due to the heating effect, and not to dissociate the reaction gas. There is no need to limit the wavelength by considering absorption maximum. Therefore, in addition to other ultraviolet light sources such as mercury lamps, visible light sources and infrared light sources can also be used. However, a short wavelength light source is more advantageous in achieving high anisotropy.

The cooling temperature of the wafer (19) is such that reaction products do not volatilize,
The temperature is not particularly limited to the above-mentioned temperature as long as the temperature is such that the desorption rate-limiting conditions can be achieved.

However, excessive cooling causes a decrease in the reaction rate, so temperature control is required depending on the reaction system.

Further, the gas pressure is not particularly limited as long as it is low enough to suppress scattering and recombination of neutral active species.

Example 2 This example is an example in which the first aspect of the present invention is applied and neutral active species are generated using a plasma generation chamber of a magnetic field microwave plasma etching apparatus.

FIG. 3 shows a schematic configuration example of the magnetic field microwave plasma etching apparatus used in this example. This device generates high-density plasma under low gas pressure by resonating with the circular motion frequency of electrons in a magnetic field (echo cyclotron resonance; ECR) and generating high-density plasma under low gas pressure. When applied to this system, a mesh electrode for trapping charged particles in the plasma, a light irradiation mechanism, a cooling mechanism for the wafer-mounted electrode, and a heating mechanism for the inner wall of the sample chamber are added.

That is, this device includes a magnetron oscillator (33) that generates microwaves of 2.45 GHz, a rectangular waveguide (32) that guides the microwave, and a microwave that is made of a quartz glass plate or the like in the rectangular waveguide (32). A plasma generation chamber (30) connected through an introduction window (34) to generate plasma by ECR, and a partial gas supply pipe for supplying reaction gas from the direction indicated by the arrow in the figure to the plasma generation chamber (3o). (31
), a solenoid coil (36) arranged to orbit around the plasma generation chamber (3o), a plasma draw-out window (35) for drawing out a part of the plasma P1, and the drawn-out plasma P. Sample chamber for various processing (
39), a wafer placement electrode (4o) for placing the wafer (19) in the sample chamber (39), and a wafer placement electrode (4o) for introducing auxiliary gas from the direction of arrow E into the sample chamber (39) as necessary. A secondary gas supply pipe (38), an exhaust system (not shown) for exhausting the reaction gas, reaction products, etc. in the sample chamber (39) in the direction of arrow F through the exhaust port (42), etc. be a constituent element.

In addition to these basic configurations, this device has a mesh electrode (3) between the plasma generation chamber (30) and the sample chamber (39).
7) was installed. This is because the density of the plasma P1 generated by this apparatus is higher than that in Example 1 described above, and the distance from the plasma P generation region to the wafer (19) is short, so charged particles are trapped on the way. This is provided because it is necessary to prevent the light from entering the wafer (19). The mesh electrode (37) is made of a heat-resistant conductive material such as a high-melting point metal in consideration of heat resistance against the radiant heat of the plasma P1.

The sample stage (40) has a built-in cooling pipe (4I) for circulating the coolant in the direction of arrow G.
19) can be kept cool.

Further, a light source (44) is provided outside the sample chamber (39), and the light from the light source (44) is transmitted through a window (43) provided on the side wall of the sample chamber (39). It is made to be incident perpendicularly to the wafer (19). In addition, the sample chamber (
A heater (45), for example, is built in as a heating mechanism in at least a portion of the inner wall of the housing (39) excluding the window (43).

According to this device, plasma P2 containing neutral active species is drawn out from plasma P to the sample chamber (39) along a divergent magnetic field, adsorbed to the surface of a wafer (19) kept cool, and irradiated with light. As a result, the etching reaction and the elimination of the reaction products proceed.

Here, as in Example 1, photoetching was performed to form a gate electrode made of DOPOS. - Cl t gas is supplied into the plasma generation chamber (30) from the next gas supply pipe (31) at a flow rate of 50 SCCM, and the gas pressure is 10 mT.
Microwave discharge was performed under the conditions of 850 W of microwave power and 850 W of microwave power. The secondary gas supply pipe (38) was not used. On the other hand, ethanol refrigerant was circulated through the cooling pipe (41) to maintain the temperature of the wafer-mounted electrode (40) at about -70°C. Usually, many devices of this type are of the type in which an RF bias is applied to the wafer mounting electrode (40), but in the present invention, since charged particles are not used for etching, no RF bias is applied. Further, as a light source (44), an Hg-Xe lamp with a wavelength of 313 nm was used.

In this example as well, based on the above-described etching mechanism, a gate electrode (3a) having a good anisotropic shape as shown in FIG. 1(B) was formed at high speed.

In addition, in the above-mentioned apparatus, the sample chamber (39) is
Since the wafer (19) is not designed to face the plasma P2 drawn out in a downward flow, in order to improve the uniformity of processing within the plane of the wafer (19), for example, the wafer mounting electrode (40 ) may be equipped with a rotating susceptor, etc.

Example 3 This example is an example in which the second aspect of the present invention is applied and the sample chamber of a magnetic field microwave plasma etching apparatus is used as the first chamber.

FIG. 4 shows a schematic configuration example of the optical etching apparatus used in this example.

This apparatus is a sample chamber (58; corresponds to the first chamber) of a magnetic field microwave plasma etching apparatus.

and an etching chamber (64; corresponding to the second chamber) are connected under high vacuum via a gate valve (63).

The basic configuration of the magnetic field microwave plasma etching apparatus is almost the same as described above in Example 2, so a detailed explanation will be omitted. , plasma generation chamber (50), partial gas supply pipe (51) that introduces the reaction gas in the direction of arrow H, solenoid coil (56), plasma extraction window (55), menyu electrode (57), sample chamber (58) ), a wafer mounting electrode (60), a cooling pipe (61) that circulates coolant in the direction of arrow 1, and an exhaust system (not shown) that exhausts air in the direction of arrow J through an exhaust port (62). Here, the sample chamber (5
8) No particular heating mechanism such as a heater was provided on the inner wall. In this example, it is sufficient that the amount of neutral chemical species necessary to cause a monoatomic layer reaction on the surface of the wafer (19) is adsorbed in the sample chamber (58), and the adsorption in one operation is sufficient. This is because the amount is extremely small compared to Example 2.

The sample chamber (58) further includes a gate valve (63).
) is connected to the etching chamber (64) under high vacuum. A sample stage (68) with a built-in heater (69) is disposed inside the etching chamber (64), and it is possible to heat and hold the wafer (19) placed thereon. ing. This heater (69
) has enough power to keep the wafer (19) at about room temperature. Further, a window (66) is provided on the upper wall surface of the etching chamber (64), and light from an external light source (67) is transmitted through this window (66).
66) so that it is almost perpendicularly incident on the wafer (19). Reaction products generated within the etching chamber (64) are discharged in the direction of the arrow through the exhaust port (i5).

According to this apparatus, a wafer (19) is first carried into a sample chamber (58) via a gate valve (59) by a suitable load-lock mechanism, and is cooled and held on a wafer mounting electrode (60). Here, plasma P containing neutral active species is extracted from the plasma P to the sample chamber (58), and the neutral active species are adsorbed onto the surface of the wafer (19).

At this stage, the etching reaction does not proceed. Next, the wafer (19) is transported to an etching chamber (64) via a gate valve (63), heated and held on a sample stage (68), and is irradiated with light. This results in
Etching reaction and desorption of reaction products proceed, but the reaction stops when the adsorbed neutral active species are consumed. This completes the etching reaction for almost a single atomic layer.

If further etching is performed, the gate valve (6
3) to repeat the adsorption and light irradiation steps described above. When the desired etching depth is obtained, the gate valve (70) is opened and the wafer 1 (19) is taken out of the apparatus.

Using such an apparatus, Example 1 and Example 2 described above
Similarly, photoetching was performed to form a gate electrode made of DOPO3. Here, the secondary gas supply pipe (5
1), the Ci 2 gas was supplied into the plasma generation chamber (50) at a flow rate of 503 CCM, and the gas pressure was 1OmTorr,
Microwave discharge was performed under the condition of microwave power of 850W. In addition, ethanol refrigerant is circulated in the cooling pipe (6I) to maintain the temperature of the wafer-mounted electrode (60) at approximately -70°C.
was held at On the other hand, in the etching chamber (64), the heater (69) is energized and the wafer (19) is
It was maintained at around °C. A KrF excimer laser beam was used as the light source (67).

Also in this example, based on the above-mentioned etching mechanism, excellent anisotropic processing was achieved as shown in FIG. 1(B).

By the way, in each of the above-mentioned embodiments, the case where the gate electrode is formed by photo-etching the DOPoS layer has been explained, but photo-etching has the greatest feature of low damage.For example, the damage that is formed after normal dry etching is It is also suitable for light etching to remove layers and natural oxide films.

In addition, in each of the above-mentioned examples, anisotropic processing was performed by making the light from the light source almost perpendicular to the wafer. For this purpose, it is possible to appropriately combine measures such as providing a tilting mechanism in the light source, or providing a tilting mechanism or a rotating mechanism in the wafer mounting electrode or sample stage. Such a mechanism is effective, for example, when removing the sidewall protective film using a gas system such as CF, 102, etc. after silicon trench etching.

〔Effect of the invention〕

As is clear from the above description, according to the first aspect of the present invention, the excitation and dissociation of the reactive gas are performed by microwave discharge, and the substrate to be etched is cooled, thereby improving the efficiency of use of light energy. The etching rate can be significantly increased by improving the adsorption efficiency of neutral active species. Further, according to the second aspect of the present invention, precise etching on the order of a single atomic layer can be performed in principle without damage. Therefore, the present invention can provide photoetching as a truly practical process.

[Brief explanation of the drawing]

FIG. 1(A) and FIG. 1(B) are schematic cross-sectional views showing an example of applying the photoetching method of the present invention to the formation of a gate electrode by etching three layers of DOPO in the order of steps. A) is a resist pattern forming process,
FIG. 1(B) shows the etching process of the three DOPO layers. FIG. 2 is used when carrying out the first invention of the present invention,
1 is a schematic side view showing an example of the configuration of an etching apparatus equipped with a microwave discharge tube. FIG. 3 is used when carrying out the first invention of the present invention,
1 is a schematic side view showing an example of the configuration of an etching apparatus equipped with an ECR discharge tube. FIG. 4 is a schematic side view showing an example of the configuration of an apparatus used when carrying out the second invention of the present invention. ■...Silicon substrate 2...Gate oxide film 3...DOPO8 layer 3a...Gate electrode 4...Resist pattern 5...Side wall protective film 11...Microwave discharge tubes 15, 33 .5
3... Magnetron oscillator 16, 64... Etching chamber 17, 68... Sample stage 18, 41.61... Cooling pipe 19... Wafer 21, 44.67... Light source 30, 50 ...Plasma generation chambers 36, 56
... Solenoid coils 37, 57 ... Mesh electrodes 39, 58 ... Sample chambers 40, 60 ... Wafer mounting electrode 69
... Heater P (for wafer heating) 0. P1.
P x, P -, P 4... Plasma patent applicant Sony Corporation representative Patent attorney Koike Mima Sakae Tamura - Masaru Sahara Figure 2 Figure 3

Claims (2)

[Claims] (1) The substrate to be etched is cooled and maintained in an etching chamber, and neutral active species are drawn into the etching chamber from plasma generated by microwave discharge in a plasma generation chamber connected to the etching chamber. A photo-etching method characterized in that the substrate to be etched is adsorbed onto the substrate and the substrate to be etched is irradiated with light to selectively advance an etching reaction in the light irradiated portion. (2) The substrate to be etched is cooled and maintained in a first chamber, and neutral active species are introduced into the first chamber from plasma generated by microwave discharge in a plasma generation chamber connected to the first chamber. After pulling out the substrate to be etched and adsorbing it onto the substrate to be etched, the substrate to be etched is
1. A photo-etching method, which comprises transporting the substrate to a chamber, heating and holding the substrate, irradiating the substrate with light, and selectively allowing an etching reaction to proceed in the light-irradiated portion.