JPS61123144A - Superfine processing - Google Patents

Abstract

PURPOSE:To eliminate a particular process for removing inorganic material pattern and resulting problems by eliminating inorganic material pattern mask when the etching of organic material film is completed. CONSTITUTION:An organic material film 3 is formed on a processing film 2 on a substrate 1 and the surface is then flattened. Next, an inorganic material film 6 of desired pattern is formed and thereafter the film 3 is etched with the film 6 used as the mask. In this case, the film 6 is also removed by etching simultaneously with the end of the etching of the film 3. Thereby, an organic film pattern 3a can be obtained. Thereby, deterioration of formed pattern accuracy and damage on the base material substrate which can be estimated to be generated when removing the film 6 can be avoided.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an improvement in a microfabrication method for forming a micropattern using an all-organic material film mask on a workpiece, and is applicable, for example, to the field of manufacturing technology for semiconductor devices. can.

[Conventional technology]

When manufacturing semiconductor devices, a resist (hereinafter referred to as "photoresist", "column beam resist" and "B A fine etching process is performed on the surface.

However, with this simple method, when there is a step on the underlying substrate, there is a difference in the thickness of the resist above and below the step, making it difficult to perform fine processing with the same accuracy above and below the step.

FIGS. 2A-2F' are cross-sectional views showing the main stages of a conventional three-layer resist process that has been improved in this respect. First, as shown in FIG. 2A, an organic material film (3) such as photoresist is coated on the substrate (1) to be processed (2), and the surface with the stepped portion is coated by baking. After planarizing, an intermediate II (4) such as silicon oxide (S10□) is formed, and a resist film (5) such as photoresist is further applied thereon and baked, as shown in FIG. 2B. As shown in FIG. Middle @ (
4) After forming the intermediate pattern (4a) by k-etching, as shown in the second diagram, both of the above patterns (
Using 5a) and 4a' as a mask, the organic material film (3) is anisotropically etched with oxygen (0□) plasma to form an organic material film pattern (3a). Next, the three-layer patterns (5a) and (4a) formed as described above
, (3a) as a mask and etching the workpiece waste (2) to obtain the desired fine pattern (2a), as shown in FIG. 2E. As shown in FIG. 2F, the process is completed by removing the resist pattern (5a), the intermediate layer pattern (4a), and the organic material film pattern (3a).

[Problems to be Solved by the Invention] In addition to requiring a very large number of steps, the conventional method described above has a drawback in that it is difficult to remove the intermediate pattern (4a) at the stage of FIG. 2F.

That is, as the intermediate till (4), the above S10
Aluminum (Al) has been used to remove this, but in the case of EIiO, 7' acid ('H?'), AI! In case of grief, use phosphoric acid (HPO)
) Aqueous solutions are used, but these solutions have the problem of corroding the target fine pattern (2a) made of the film material to be processed, deteriorating the pattern accuracy, or damaging the substrate (1). There was a point.

It is an object of the present invention to provide a microfabrication method that can be obtained without solving these problems.

[Means for solving problems]

In the microfabrication method according to the present invention, an inorganic film pattern is formed on a required part of the food material stop for surface flattening, and the organic material film is etched using this pattern as a mask. When the etching of the organic material film is completed and the organic material pattern is completed, the etching removal of the inorganic film is also completed at the same time.

[Effect]

In this invention, when forming the organic material pattern that serves as a mask for etching the workpiece + 111, the etching of the inorganic film pattern, which is the etching mask, is completed at the same time. This makes it possible to eliminate the special process and the problems associated with it.

- [Embodiment] @1 Figures A-D are cross-sectional views showing the state at the main stages of an embodiment of the present invention. First, as shown in FIG. 1A, a film of organic material (3) such as photoresist or polyimide resin is spun onto a film to be processed (2) on a substrate (1).
It is coated to a thickness of 1 to 3 fimmK using a polishing agent or the like, and baked to flatten the uneven surface. Next, as shown in FIG. 1B, an inorganic film (6) of a desired pattern such as amorphous silicon is locally deposited at a desired location by a chemical vapor deposition reaction using light.
ooo Formed to a thickness of 8H. After that, as shown in Fig. 1C, using the inorganic material III (fl) as a mask, the organic material film (3) was first exposed to oxygen (0□) gas plasma under the conditions of gas pressure: 5 Pa and high frequency electric crab 500 W. After etching about three-fourths of the film thickness, a gas pressure of
By etching the remaining organic film (3) under the conditions of 3 Pa and 300 W of high frequency electric knife, the inorganic film (6) can also be removed at the same time. In this way, an organic material pattern (3a) is obtained, and then this organic material film pattern (3a) is used as a mask to be processed! 11
When (2) is etched and then the organic material pattern (3a) is removed using oxygen plasma, a desired fine pattern (2a) is obtained as shown in the first diagram.

In the above example, a chemical vapor deposition reaction using light was used to locally form an inorganic film, but it is also possible to selectively irradiate with an ion beam or an electron beam. Alternatively, a method may be used in which chemical anti-Ff5 is caused locally.

〔Effect of the invention〕

As explained above, the method of the present invention not only requires a small number of steps, but also forms an inorganic film pattern on the organic material film for flattening the surface of the sliding door to be processed, and uses this as a mask to form the organic material film. When etching the organic material film to obtain an organic material mask for etching the film to be processed, the inorganic film pattern mask was also removed when the etching of the organic material film was completed, so that the inorganic film pattern mask It is possible to avoid problems such as deterioration of the accuracy of the formed pattern and damage to the underlying substrate that would occur when the remaining particles are removed, and accurate microfabrication is possible.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the main stages of an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the main stages of a conventional microfabrication method. In the figure, (1) is the substrate, (2) is the film to be processed, and (3)
(3a) is an organic material film, (3a) is an organic material stop pattern, and (6) is an inorganic material film. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (3)

[Claims] (1) Form an organic material film on the surface of the film to be processed on the substrate to flatten the top surface, form an inorganic film in a desired pattern locally at a desired location on the organic material film, and When etching the organic material film using the film as a mask to obtain an organic material film pattern that serves as a mask for processing the film to be processed,
A microfabrication method characterized in that the inorganic material film is also etched away when the etching of the organic material film is completed. (2) A silicon film is used as the inorganic film, and the organic material film is etched using a first etching step using a gas plasma containing oxygen as a main component and a second etching step using a mixed gas plasma containing oxygen and a halogen compound. 2. A microfabrication method according to claim 1, comprising: (3) The microfabrication method according to claim 1 or 2, characterized in that a chemical vapor deposition method using light is used to form the inorganic film.