JPH0626209B2 - Etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an etching method which does not require a resist.

[Conventional technology]

Conventionally, a photo-etching technique is used as an etching method, an organic film called a resist is deposited on a substrate to be processed, and the film is selectively irradiated with an energy beam, for example, an electron beam to cause a chemical reaction in the film, There has been performed a step of patterning by utilizing the difference in solubility depending on the molecular weight, and thereafter, etching the object to be processed with the film as a mask in a corrosive liquid or a corrosive gas atmosphere, and then removing the resist film.

[Problems to be solved by the invention]

At this time, the process using a resist has a problem that the process is long and time-consuming.

Further, in a reaction in a gas atmosphere that produces corrosive active species, there is a problem that the device and the energy ray irradiation window are damaged by scattered energy such as reflected electrons.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an etching method which eliminates the above-mentioned conventional defects, significantly shortens the manufacturing process, and causes less damage to the apparatus and the energy ray irradiation window, and can reduce the number of defects generated in the object to be processed. And

[Means for solving problems]

The etching method of the present invention comprises a step of depositing a film on a substrate to be processed, which produces a chemical component that etches an object to be processed by irradiation with energy rays, and selectively irradiating the film with energy rays. It includes a step of etching an object to be processed with the generated reactive active species, and a step of removing the film that generates the reactive active species.

[Action]

According to the method of the present invention, it is expected that the manufacturing process can be greatly shortened and the defects can be reduced by omitting the resist phenomenon process and the etching process.

Further, since the reaction is limited to the interface of the substrate to be processed, it is expected that the influence on the device will be minimized.

〔Example〕

Next, the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram for explaining the principle of the etching method of the present invention, and FIGS. 2 (a) and 2 (b) are explanatory diagrams of a pre-process and a post-process of an embodiment of the present invention.

First, as shown in FIG. 2 (a), a film 2 to be processed is deposited on the surface of the substrate 1, and then a film 3 which produces reactive active species by irradiation with energy rays is deposited on the film 2 to be processed. For example, as the substrate 1, the semiconductor substrate processing target film 2 is made of Al having a thickness of 0.5 to 2 μm, and a film 3 for generating reactive active species is formed.
In this case, it is formed by spin coating a solution of chloromethylated polystyrene in an aqueous solution of polyvinyl alcohol.

Next, as shown in FIG. 1, an acceleration voltage of 5 to 50 kV formed by the energy ray source 6 and the deflector 5 is added to the above structure.
When the chloromethylated polystyrene, which is the film 3 for generating the reactive species on the film 2 to be processed, is irradiated with the energy beam (electron beam) 4 of the above, the HCl generated by the polymerization of the chloromethylated polystyrene and the residual water in the film are irradiated. As a result, hydrochloric acid is generated, and the Al film 2 is corroded in the reaction region 7.

Next, when the film 3 which produces the reaction active species is removed, FIG.
A pattern having a desired opening 8 is formed in the film to be processed as shown in (b).

In this example, an electron beam was used as the energy beam, but this is described because the amount of the reaction active species is stoichiometrically easily controlled because the dose of the electron beam is accurately controlled. However, it is clear that the same effect can be obtained with other energy rays such as laser, ion beam, and ultraviolet ray.

〔The invention's effect〕

As described above, according to the etching method of the present invention, since the reaction occurs at the exposure stage, the process is greatly simplified as compared with the conventional process, the production cost is reduced, and the processing substrate is moved. Since the number is small, the number of defects is greatly reduced.

Especially, the film thickness of the object to be processed is 2 μm as in the semiconductor process.
The present invention is particularly effective when it is as thin as the following.

[Brief description of drawings]

FIG. 1 is a conceptual diagram for explaining the principle of the etching method of the present invention, and FIGS. 2 (a) and 2 (b) illustrate a pre-process and a post-process of an embodiment of the present invention. FIG. 1 ... Substrate (semiconductor substrate), 2 ... Target film (Al
Membrane), 3 ... Membrane that produces reactive species (chloromethyl polystyrene), 4 ... Energy beam (electron beam), 5 ...
... deflector, 6 ... energy ray source, 7 ... reaction area, 8
……Aperture.

Claims (1)

[Claims] 1. A step of depositing a film on a substrate to be processed, which produces a chemical component that etches the object to be processed by energy beam irradiation, and selectively irradiating the film with an energy beam, which is produced at the time of energy beam irradiation. And a step of removing a film that produces the reaction active species, the etching method comprising: