JPS606942A - Photoresist - Google Patents

Abstract

PURPOSE:To form a photoresist subjectable to high-speed reactive ion etching and yet ensuring a function as a blocking agent by incorporating a polar material in a photosensitive resin base. CONSTITUTION:A photoresist is obtained by mixing (A) 99.9wt% photosensitive resin base, such as a compsn. consisting of cyclic polyisoprene or cyclic polybutadiene and a photosensitive compd. in the case of a negative type, and a compsn. consisting of a novolak resin and a photosensitive compd. in the case of a positive type, and (B) 0.1-90wt% fine magnetic particles, such as fine acicular magnetic particles of gamma-Fe2O3 or Cr2O3 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a photoresist used particularly in an etching process such as a semiconductor manufacturing process.

[Technical background of the invention and its problems]

Generally, in semiconductor manufacturing processes, etc., an etching process is one of the essential steps required to form a pattern of various shapes on the surface of a square. In such an etching process, a photoresist is usually used, and by applying this photoresist as a mask onto the surface of the object to be etched, only unnecessary portions are removed.

Incidentally, in recent years, the production of highly integrated conductor integrated circuits requires highly accurate microfabrication, so reactive ion etching (hereinafter referred to as R, I etching) has been frequently used as an etching process. ing. Also in this RI etching method, a photoresist is used as a mask (which acts as an ion blocking material). The RI etching method that utilizes glow discharge is often used, but this method has a problem in that the etching speed is relatively low. For example.

The etching rate is about 400 kl for sin (silicon oxide) and about 100 kl for aluminum and polysilicon. For this reason, a method using magnetron discharge has been developed as a high-speed RI etching method. However, although this method enables high-speed etching, it has the drawback that the entire wafer is surrounded by magnetron discharge (high-density gashism), resulting in significant deterioration of the photoresist, which is a block material. Furthermore, the uniformity of etching is also relatively poor.

[Purpose of the invention]

The present invention was developed in view of the above circumstances, and its purpose is to realize a high etching rate in a reactive ion etching process using photoresist, and to develop a photoresist that can function reliably as a block material. Our goal is to provide the following.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing a manufacturing process of a semiconductor device using a photoresist according to an embodiment. The photoresist used in such an RI etching process is
As shown in the figure, a magnetic powder 1 is applied to a normal photosensitive resist 10.
1 is mixed and dispersed. The photosensitive resist 10 is, for example, a photosensitive resin base material that is sensitive to ultraviolet rays, deep ultraviolet rays, X-rays, or electron beams. It is mainly composed of polybutadiene and a photosensitive compound, and in the case of a positive resist, it is mainly composed of a novolak resin and a photosensitive compound. Further, the magnetic powder 11 is made of, for example, r-Fe20.
(It is a powder of ferromagnetic fine particles (oblique shape of 1 μm or less) such as iron dioxide, C[208, and cobalt alloy). ~9
It is uniformly mixed and dispersed in the photosensitive resist IO at a ratio of 0%. in this case.

The content of the magnetic powder 11 will be adjusted depending on the viscosity of the resist IO, the magnetic strength used, etc.

The RI etching (reactive ion etching) process using such a photoresist 12 (usually having a composition of 30 layers of magnetic powder 11) is shown in Figure 2 (5).
This will be specifically explained with reference to (1)). First, let's start with the same figure (
As shown in 5), a photoresist 12 as described above is applied onto the surface of a material to be etched (for example, a 5I02% polysilicon or aluminum film, hereinafter referred to as the workpiece) 140 on a substrate (for example, a semiconductor substrate) 13. For example, lμrT
It is applied to a thickness of about 1 to 2 μm. Sara K.

The photoresist 12 is exposed to mist light using ultraviolet light or the like, and is further developed to form a predetermined resist pattern (FIG. 2(B)). For the resist 12, a butyl acetate-based etching solution is used, and for the positive resist 12, a Colin thread etching solution is used.

Then, baking is performed on the photoresist I2 after % development, and as shown in FIG.
is added. This magnetic field I5 causes the photoresist 12 to
The magnetic domains of the magnetic powder therein are aligned. Using such a photoresist 12 as a block material, the workpiece 14 is subjected to an R1 etching process using, for example, glow discharge. As a result, unnecessary portions of the workpiece 14 corresponding to one block material (photoresist 12) are etched, and a uniform pattern is formed on the workpiece 14, as shown in FIG.

In this way, by the H1 etching process, a uniform pattern is formed on the workpiece 14, making it possible to perform fine processing necessary for manufacturing highly integrated circuits such as LSIs, for example. In this case, even in the case of RI etching treatment that conventionally uses glow discharge with low ionization efficiency, the photoresist 12 containing magnetic powder is used as a block material as described above, so the ionization is promoted by the magnetic powder. That will happen. Therefore, a high density magnetron discharge occurs around the magnetic field, and the etching rate becomes relatively fast. For example, the workpiece 14 is 5in2. In the case of polysilicon or aluminum, a high etching rate of 8 degrees lpm/w can be obtained. Furthermore, in the magnetron discharge, since loose high-density plasma is generated only in locations where a magnetic field is generated, the workpiece 14 can be selectively etched with precision.

Therefore, since the action range L'11 of the magnetron discharge on the photoresist 12, which is the block material, is limited, it is possible to prevent the photoresist 12 from being significantly deteriorated.

〔Effect of the invention〕

As described above, according to the present invention, by using a photoresist containing magnetic powder, it is possible to achieve a high etching speed in a reactive ion etching process, and also to perform etching with high precision. .

In addition, since the generation of magnetron discharge used in one-reactive ion etching can be limited to only the location where a magnetic field is generated, it is possible to prevent the photoresist as a block material from being significantly deteriorated.

Therefore, as a result, the reactive ion etching process can be performed reliably with high efficiency, resulting in the effect of reliably manufacturing highly integrated semiconductor integrated circuits that require microfabrication. It is.

[Brief explanation of drawings]

FIG. 1 is a block diagram to show the structure of a photoresist according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view to explain a reactive ion etching process using the photoresist of FIG. 1. . 12... Photoresist, 13... Substrate, 14...
Material to be etched. Applicant's agent Patent attorney Takehiko Suzue = Koshi-'° Strike 2 117 dimensions + 11 To 1012

Claims (1)

[Scope of Claims] (1) A photoresist comprising a photosensitive resin base material mixed with fine particles of magnetic material. (2. The photoresist according to claim 1, wherein the magnetic material has a weight content of 0.1 to 90%, and the remaining photosensitive resin base material is mainly made of cyclized polyimbrane and cyclized polybutadiene, and is photosensitive. (3) The photoresist according to claim 1, wherein the magnetic material is 0.1 to 90% by weight, and the remainder is the photosensitive resin group. A photoresist characterized in that the material is mainly composed of a novolak resin and a photosensitive compound.