JPS5856338A - Dry etching - Google Patents

Abstract

PURPOSE:To equalize concentration of radical extending over the whole region of a substrate to be treated being put on a supporting substrate by a method wherein a resin material is arranged around the substrate to be treated. CONSTITUTION:The supporting substrate 11 itself to be put thereof with the substrate 2 to be treated having a mask consisting of a photo resist film on the surface is formed of resin like Teflon or vinyl chloride. When the resin material is made to be exposed around the substrate 2 to be treated like this, the radicals are not only consumed on the substrate 2 to be treated when reactive dry etching is performed, but also the radicals react with the resin face exposed around the substrate 2 and are consumped. As a result, concentration of radical is equalized extending over the whole region of the substrate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry etching method, and more particularly to an improvement in a reactive dry etching method carried out by placing a substrate to be processed on a support plate.

As shown in Figure 1, silicon (
Sl) When a reactive dry etching such as plasma etching or reactive ion etching is applied to a substrate 8 to be processed, such as the substrate 2, the etching rate is generally significantly higher at the periphery than at the center of the substrate 2. becomes. This is because on the substrate 2 to be processed, as the reaction progresses, the Fuji force μ is consumed and the concentration is reduced, whereas on the outside of the substrate 2 to be processed, the Fuji force μ is not consumed because there is no reactant, and therefore the concentration It is shown that the value is reduced. Even if radicals are consumed in the periphery of the rounded substrate 20, they are quickly supplied from the periphery, and the radical concentration is always maintained at a higher concentration than in the center.

Since the concentration distribution of the Fuji force as described above is generated on the substrate 2 to be processed, the etch rate depending on the physical concentration is large at the periphery of the substrate 20 to be processed and small at the center.

Such problems are common in round plasma etching and reactive ion etching for patterning insulating films on the surface of semiconductor substrates, or in reactive dry etching such as ashing for removing cystic films on semiconductor substrates. This is especially noticeable when a parallel plate type dry etching device is used.

An object of the present invention is to uniformize the physical concentration over the entire substrate to be processed, which is placed on a support substrate, and for this purpose, the present invention provides a resin material around the substrate to be processed.

FIG. 2, FIG. 8, and FIG. 4 show the first embodiment of the present invention. FIG. 7 is a sectional view of a main part showing second and eighth embodiments.

First, the first embodiment shown in FIGS. 8(a) and 8(K) uses a parallel plate type dry etching apparatus, in which a support plate on which a substrate to be processed 2 having a mask made of photoresist (Ill) is placed on the surface thereof is used. In this example, the turtle is made of resin, and 11 is a support plate made of resin such as Teflon or vinyl chloride. The shape of the support plate 11 may be a flat plate or a shape of the substrate 2 to be processed, as shown in FIGS.
The portion on which the substrate is placed may be formed into a recessed portion 12, and the upper surfaces of the substrate to be processed 2 and the support plate 11 surrounding it may be made approximately at the same height.

The eighth embodiment shown in FIGS. 8(f) and (6) is an example in which a resin plate 18 is provided on the above-mentioned ordinary support plate l, and in the same figure, the upper surface of the resin plate 18 is set to a flat surface. In the same figure (1), the recess 1
The resin plate 18 (shown in the same figure) may be a sheet made of resin.

The eighth embodiment shown in FIG. 4 is an example in which a resin plate (t or sheet) 16 having a through hole 14 capable of accommodating a substrate 2 to be processed is disposed on a normal support plate 1. In this case, even if the resin plate (t or sheet) 15 is a single continuous plate (t or sheet), it is created by dividing it into several parts and combining them. Good too.

In any of the above cases, when reactive dry etching is performed using this, Fujika P is not only consumed on the substrate 2 to be processed, but also on the resin surface exposed around the substrate 2 to be processed. The fusicals are consumed by the reaction, and as a result, the concentration of radicals becomes significantly uniform over the entire area on the substrate 2 to be processed, and the difference in the etched rate between the center and the periphery is significantly reduced.

Note that the resin that can be used in the present invention is not limited to the above-mentioned Teflon and vinyl chloride, but may be any resin such as polyimide and polyisoprene.

Further, the dry etching method of the present invention is effective when using a photoresist film as a mask, but is not so effective when using other materials as a mask.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rounded main part used to explain a conventional reactive dry etching method, and FIG. FIG. 1 shows the first embodiment of the present invention, respectively. FIG. 7 is a sectional view of a main part showing second and eighth embodiments. In the figure, 1 is a support plate, 2 is a substrate to be processed, 11 is a resin support plate, and 18.15 is a resin plate or sheet F.

Claims (1)

[Claims] A substrate to be processed having a mask such as a photoresist film on its surface is placed on a support plate, and when performing reactive dry etching on the substrate to be processed, a resin material is exposed around the substrate to be processed. A dry etching method characterized by: