JPH0436109Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention has an element pattern for forming a predetermined element on a substrate by wet etching, and a plurality of etching patterns are prepared corresponding to a plurality of etching processes. The present invention relates to masks, and particularly to improvements to make them suitable for detecting the end point of etching.

[Summary of the invention] The etching mask according to the invention has a mask pattern for forming elements on a substrate and a mask pattern for detecting the etching end point for confirming the etching end point of each step of the etching process. A recognition mark is formed to clearly indicate the position of the pattern to be etched.

[Prior Art] Detection of the etching end point in wet etching for forming predetermined elements on a wafer is performed using a film thickness measuring device on the back side of the wafer or at the scribe line in the early stage of the etching process. However, in the latter half of the process, even the scribe line is often not completely etched, and the actual pattern must be used to detect the etching end point. However, even if an actual pattern is used, the film thickness may vary depending on the process, especially when drilling holes such as contacts, and the contact dimensions are often the smallest pattern on the mask. It is also difficult to detect the end point using a film thickness measuring device. Since a considerable proportion of process defects are caused by poor contact due to under-etching or over-etching, it is desirable to accurately detect the end point.

[Problems to be solved by the invention] However, conventional etching end point detection requires empirical techniques, and the degree of etching is
There was a problem in that it also depended on the pattern shape.

An object of the present invention is to provide an etching mask that makes it possible to easily detect the end point of etching without requiring any empirical techniques.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plurality of etching processes, each of which is prepared in correspondence with a plurality of etching processes, and in which an etching pattern for an element is formed for forming an element on a substrate. In the mask for
An etching pattern for detecting the etching end point corresponding to the etching process performed by the mask is formed on each etching mask, and an etching position indicating the position to be etched by the etching pattern for detecting the end point of each mask. A feature is that a recognition mark is formed on each of the masks.

[Operation] A pattern for detecting the end point of etching is used in each etching step, and the degree of omission of the pattern, that is, the end point of etching is determined by visually observing the pattern or using a film thickness measuring device.

[Example] Embodiments of the present invention shown in the drawings will be described below.

1 and 2 show an embodiment of an etching mask according to the present invention.

As is well known, the etching process for forming a predetermined element on a substrate usually consists of a plurality of etching steps, and a plurality of etching masks having etching patterns corresponding to each step are used.

In Fig. 1, numeral 1 shows, for example, 11 etching mask patterns of the present invention used in each etching process necessary to form a certain element, and Fig. 2 shows these mask patterns. Each step of ~ used is shown. That is, in each step of
The shaded area represents the etching mask pattern used in each of these steps.
The figure can also be seen as showing the entire etching process to obtain the device.

In addition, in FIG. 1, 2 is an etching position recognition mark, and in each etching process shown in FIG. .

When checking the etching, the portion of the end point detection pattern indicated by the mark 2 is visually inspected or by using a film thickness measuring device to determine the extent to which the pattern is missing. At the same time, a mark indicating a pattern that is completely missing at that point is shown.

By adding to the above pattern a pattern that is likely to be under-etched or over-etched, as shown in FIG. 3, it becomes possible to perform etching corresponding to various patterns on the mask. In FIG. 3, numeral 3 represents a standard etching pattern, and 4 represents a pattern where under-etching and over-etching problems are likely to occur.

[Effects of the Invention] As explained above, according to the present invention, when determining the end point of etching, it is sufficient to always check the pattern indicated by the mark, and stable etching becomes possible. Furthermore, even when a plurality of workers perform etching work, it is possible to obtain an average etching pattern by uniformly using this pattern as a reference.

[Brief explanation of drawings]

FIG. 1 is a plan view of a stack of etching mask patterns having etching end point detection mask patterns according to the present invention, and FIG. 2 is a plan view showing an etching process using each of the etching mask patterns according to the present invention. 3 are plan views showing a modification of the etching end point detection mask pattern according to the present invention. 1...Etching pattern, 2...Etching position recognition mark, 3...Reference etching pattern, 4...Pattern that tends to cause under-etching and over-etching troubles.

Claims (1)

[Scope of utility model registration request] In a plurality of etching masks prepared in correspondence with a plurality of etching processes, in which an etching pattern for an element is formed for forming an element on a substrate, an etching end point detection device corresponding to the etching process performed by the above-mentioned mask is used. Etching characterized in that an etching pattern is formed on each of the etching masks, and a mark for recognizing an etching position indicating a position to be etched by the end point detection etching pattern of each mask is formed on each of the masks. mask.