JPS5852827A - Dry etching method and device - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and an apparatus for tri-etching a photoresist, which can be used in the manufacture of semiconductor devices.

Conventionally, as a method for etching a photoresist coated on the surface of a conductor substrate, etc., an oxygen gas atmosphere is discharged with high-frequency power, and the obtained active oxygen, for example, 0. ．． 0.0- etc?
A so-called dry etching method has been used in which the photoresist is contacted with the photoresist and converted into 0-o bonds or on@ bonds by reactions such as 00, 001, HmO, etc. The irises TG is a device commonly called an asher for carrying out this method, and a jig 2 installed in the reaction tube/discharge tube 1 is loaded with a 3% Vc sample, a gas is introduced 4 into the reaction tube from the lower part, and the gas is introduced from the upper part. The exhaust gas groove is discharged, and electric power is supplied from the high-waste wave generator 7 to the electrode plate 6.6 to energize the gas discharge in the reaction tube 1, generating active # on single molecules or atoms to form a sample. The photoresist on the surface appears to be removed.

By the way, in this method of removing photoresist with active oxygen molecules and atoms generated by discharge caused by high-frequency power, the sample surface is exposed to shock waves due to electrons and ions accelerated in the electric field because the sample is placed in a high-frequency electric field. This often causes negative effects on the sample characteristics. In addition, the friend plasma obtained by discharging high-frequency power has 01 molecules in an excited state,
Since there are chemical species such as 03-ion and 0-ion, the chemical reaction involved in removing the photoresist becomes extremely complicated. Therefore, due to these factors, conventional dry etching does not necessarily provide good debonding properties, but N occurs.

The object of the present invention is to generate excited state oxygen atoms by decomposing nitrogen oxides with ultraviolet light absorption, and to form oxygen atoms in a photoresist. In addition, it eliminates the need to place the sample volume in a high-frequency electric field, prevents bombardment by electrons and ions, and simplifies the photoresist chemistry and improves processing efficiency.
It is an object of the present invention to provide a dry etching method and an apparatus for the dry etching method that can increase the cost by +%.

The present invention will be explained below using illustrated embodiments.

Figure 2 shows an embodiment of the present invention. First, the embodiment device ti
The method of the present invention is carried out in conjunction with the following actions. This dry etching apparatus 10 has a sample stage 12t inside and a glass reaction tank 11 which can be installed therein, and a gas supply device 14t which supports a gas source 13 connected to the upper part of the reaction tank 11 from an opening 15. Inside the tank [NO snow gas is flowing in, while
At the bottom of the cypress, there is a discharger 16, a pressure regulator 17, and a pressure regulator 17! The gas exhaust device 1st is connected to exhaust the gas from the opening 19.

In addition, a pair of concave surfaces @20.
11 and 11, and one concave mirror 20 receives ultraviolet rays of 23 kft7 from an ultraviolet 922 provided outside the tank. In this case, UV 23 or UV 11
1)! A window 11 made of quartz or the like is formed in a part of the tank to allow the ultraviolet sushi to pass through well.

In the figure, 3 is a conductor wafer as a sample.According to the above 11I, the dry etching of the present invention is carried out by using the gas supply device 14 and the gas exhaust device [118]. This is carried out by irradiating the concave mirror 20 with ultraviolet light from ultraviolet ##22 while passing the gas through it. That is, the ultraviolet rays are exposed to the concave surfaces 11120, 21
[Therefore, the reflection field is reflected multiple times, so the M
The O gas is excited and decomposed more efficiently than if the outside # of the building were simply irradiated and leaked, resulting in a high concentration of active* elements.

hγ(λ=2450~3750μ) MOI, MO+0(3F), this active oxygen is absorbed by the photoresist on the test IP+aW surface.
The constituent O-0 bonds and O-B@ combinations are attacked, and these are decomposed into t and finally oo, oo, .

A reaction product such as HIO. As a result, the photoresist is not removed and dry etching is completed.

Therefore, according to the present invention, which has the above-described structure, since the sample is not affected by the high frequency electric field, there is no impact of VC electrons or ions on the sample substrate (coated conductor wire/-), and the electrical conductivity of the substrate is reduced. However, since the photoresist is decomposed only with active oxygen, the decomposition reaction tube can be made simple. Furthermore, since it is not subjected to Nt treatment in a high-frequency discharge, it is possible to perform a still-temperature treatment, and it is possible to prevent thermal diffusion of ions such as Ma+Oa in the photoresist that occur during high-temperature treatment to the substrate, and to maintain good electrical properties of the substrate. can.

FIG. 3 shows another embodiment of the present invention.
Components that are the same as those in the illustrated embodiment are designated by the same reference numerals, and their descriptions are omitted. In this embodiment, at least the upper seven quartz walls of the reaction tank 11 are made of a material that transmits ultraviolet 11!
On the outside of the upper part of this cypress 11A, there is a pair of concave surfaces -20mm, 21
Arrange the questions so that the A tank is in between, and I! One of the concave mirrors 21 was irradiated with ultraviolet light from the ultraviolet source 22. Note that in this example, sample 3 is placed on sample stage 1.
Place it horizontally on the 2nd floor.

According to this embodiment, ultraviolet a! Mo by the energy of 23
1 gas is decomposed to produce active oxygen, and this oxygen decomposes and removes the photoresist on the sample, just as in the previous example. However, in this example, the concave surfaces @ 20mm and 21mm are installed outside the 11mm reaction tank, so the aluminum in the alkali vapor deposition film constituting the mirror surface will diffuse into the gas in the reaction tank. However, it will not only remove the photoresist but also have no adverse effect on the substrate.

Here, the reaction gas is not limited to the above-mentioned MO and gases, but may be other gases as long as they contain nitrogen oxides. Also, the wavelength of ultraviolet rays i! It is preferable to use the concave mirror for wavelengths from 2450 to 3750 µm, or for wavelengths below 2280 Å.Furthermore, the concave mirror may be a flat or polygonal mirror, but it is capable of reflecting ultraviolet rays multiple times and is suitable for the sample. Avoid exposing the skin to direct UV rays.

As described above, according to the dry etching method and device of the present invention, excited nitrogen atoms are generated by decomposing nitrogen oxides with ultraviolet *'r absorption, and these atoms are used to decompose nitrogen oxides. Since the photoresist is decomposed and removed, there is no need to place the sample in a high-frequency electric field, preventing electrons and ions from impacting the sample substrate, thereby preventing negative effects on the electrical properties of the sample substrate. At the same time, it is possible to simplify the reaction of the photoresist, increase the processing efficiency, and also enable the processing tube to be operated at a low temperature, thereby preventing contamination of the substrate by N& and Cal5 ions.

[Brief explanation of the drawing]

FIG. #1 is a schematic diagram of a conventional device, FIG. 2 is a diagram of an embodiment of the present invention, and FIG. 3 is a diagram of another embodiment of the device. 3...Sample, 11.11m...Reaction tank, 14...
Gas supply jifl, 18... gas exhaust device, 20.2
1.20m. 21mu...concave casting (reflection@), 22...ultraviolet source,
23...Ultraviolet light. Part 1 Figure 3

Claims (1)

[Claims] 1. Irradiating nitrogen oxides with ultraviolet light and absorbing it;
#11jll! Oxide [decomposes into excited state acid #! A dry etching method in which II-W mold is generated by an atomic reaction and removed by photoresist decomposition from the MIIL atoms r. ! Dry etching method described in LLLER section. 3. One of the samples coated with photoresist! ff1l! A reaction tank that can be placed in public; a gas supply device and a gas exhaust device for passing a reaction gas into the reaction tank; *1
After several reflections, the irradiation field inside the reaction tank must be fully prepared! Dry etching equipment with special features. 4. The dry etching device according to claim 3, wherein a mirror is provided inside the reaction tank, and -m of the reaction tank through which ultraviolet light from an ultraviolet source passes is made of quartz. 5. A dry etching device according to claim 3, in which a reflecting mirror is provided outside the reaction tank, and the reaction tank is made of quartz.