JPH0513922A - Etching inspection plate - Google Patents

Abstract

PURPOSE:To quantitatively detect the excess and deficiency of etching by a method wherein etching is conducted in the same condition as the etching treatment process of a manufactured substrate, and the etching condition is observed. CONSTITUTION:An etching inspection plate, on which an etching pattern is formed, is put in the etching treatment process, and the inspection masking part after etching treatment and an inspection non-masking part are observed. At this time, when the widths 1a to 4a, which change microscopically, are smaller than the measured value, it means overetching, and the microscopically changing widths 1a to 4a of the non-masking part 5 are larger than the prescribed width, it is judged as insufficient etching. The excess and shortage of etching can be known by the prescribed value of the position where the width of the masking part 2 or the non-masking part 5 becomes zero. The detection of the position, where the width of the masking part 2 or the non- masking part 5 becomes zero, can easily be observed using an optical microscope.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching inspection plate for detecting an error due to an excess or deficiency of an etching process used in an electronic circuit board, a thin film forming technique and the like.

[0002]

2. Description of the Related Art A pattern forming technique by etching, which starts with an electronic circuit wiring substrate, in which a copper foil adhered on an insulating substrate is formed into a predetermined pattern by wet etching, is also required to be compact and highly integrated. Now, it has been miniaturized even under the condition of an electron microscope. Therefore, it is not easy to measure the formation accuracy of the formation pattern,
There is no choice but to rely on expensive equipment such as electron microscope observation and electronic measurement equipment. Examples of the measuring device are shown in FIGS.
Shown in. This is an example of measuring the dimensional error in the arrow direction of a fine pattern formed on a substrate as shown in FIG. As shown in FIG. 3, a beam gun 32 that projects a beam of an electron beam or a laser beam is moved at a constant speed on the patterned substrate 30, and a reflection from the substrate 30 is received by a detector 33 to be formed on the substrate 30. The dimensional accuracy of the formed pattern 31 is measured. When the projection beam passes through a portion of the substrate 30 where the pattern 31 is not formed, the reflection of the projection beam does not change, and diffuse reflection occurs only at the edge of the pattern 31, so the input to the detector 33 changes. The input signal of the detector 33 when the beam gun 32 scans on the substrate 30 in the direction of the arrow is as shown in FIG. 4, and the point where the reflection intensity changes abruptly is the pattern 31.
The edge position of the pattern 31. Therefore, the dimension of the pattern 31 can be measured by measuring the distance or time of this change point.

Since the dimensional accuracy of pattern formation by etching depends on the excess or deficiency of the etching process, the dimension of the etched pattern is measured and the etching is performed so that there is no error from a predetermined value. The treatment process must be controlled at all times. However,
As the formation pattern becomes finer, the inspection becomes more and more difficult, and as described above, it is necessary to rely on expensive measuring equipment, and it is not possible to easily measure and inspect. An object of the present invention is to provide an etching inspection plate capable of detecting a dimensional error due to excess or deficiency of etching processing of a finely processed formation pattern in the area of an optical microscope.

[0003]

The present invention for achieving the above object is an etching inspection plate in which a thin film-shaped masking portion is formed on the surface of a substrate to be etched, and the masking portion has a predetermined width. And a plurality of inspection non-masking portions in which the width of the non-masking portion formed between the masking portions changes by a predetermined minute amount. It is configured as a characteristic etching inspection plate.

[0004]

The etching inspection plate on which the inspection pattern as described above is formed is put into the etching process, and the inspection masking portion and the inspection non-masking portion after the etching treatment are observed. At this time, when the width of the masking portion that changes by a small amount is smaller than the measured value, the etching is excessive, and when the width of the non-masking portion that changes by a small amount is larger than a predetermined value, the etching is insufficient. You can judge. The degree of excess or deficiency of etching can be known from a predetermined value at the position where the width of the masking portion or the non-masking portion becomes zero. The detection of the position where the width of the masking portion or the non-masking portion becomes zero can be easily observed with an optical microscope.

[0005]

EXAMPLES Next, concrete examples will be shown to provide an understanding of the present invention. FIG. 1 shows an example of an inspection pattern formed on an etching inspection plate that is etched in the etching process under the same conditions as the product substrate to be etched. The substrate 1 has a pattern as shown in the figure formed by masking and etching a predetermined pattern on a thin film provided on the surface thereof, and the hatched portion is the masking portion remaining after the etching process. The other white background is the non-masking portion 5 whose thin film is removed by etching. C1 to C5 composed of the masking unit 2
B1 to B5 composed of the non-masking portion 5 are circular with the same radius, C1 is in point contact with the linear portion 3 of the masking portion 2 at the circular outer edge, and the circle from C2 to C5 is the linear portion 3
The close distances to and are increasing sequentially at a predetermined interval of 1a-4a. Further, B1 is in point contact with the edge 4 of the substrate 1 at the outer edge of the circle, and the circle from B2 to B5 has the distance between the edge 4 and the edge 4 gradually increases at predetermined intervals 1a-4a. When the minute intervals indicated by 1a-4a described above are used as reference dimension values, and the intervals 1a-4a are measured for actually etched patterns, the dimension error of etching can be known. This measurement can be performed by observing the portion of the intervals 1a-4a with an optical microscope. When the etching is performed too much, the fine processing tends to be small, so that the contacts between B1 to B5 and the edge 4 are observed after the etching processing. At that time, for example, if B3 and the edge 4 are in contact with each other, it can be seen that the width of the etched pattern is shorter than the reference value (inspection pattern) by the distance 2a. Since the etching time required for the etching to proceed by the interval 2a is empirically known, an appropriate amount of etching will be possible from the next time if the etching is shortened by that amount.

Further, when etching is insufficient, fine processing tends to increase, so that C1 to C5 and the straight line portion 3
Observe the contact point with. At that time, for example, C4 and straight part 3
It can be seen that the width of the pattern etched by a distance of 3a is wider than the reference value if the two are in contact with each other. Proper etching is possible if the etching time is extended by the amount corresponding to the increase in thickness. When the etching is normally performed, the formed inspection pattern is a pattern according to the reference value in which C1 and the linear portion 3 are in point contact with each other and B1 and the edge 4 are in point contact with each other. If the etching process is controlled so that it can be obtained, normal etching will be performed on the product substrate that is etched under the same conditions. In FIG. 1, C1 to C5 and B
Although 1 to B5 are circular patterns, they may not necessarily be circular as long as they have a shape capable of making point contact with the straight line portion 3 or the edge 4.

[0007]

As described above, according to the present invention, if the etching inspection plate is etched under the same conditions as the etching process of the product substrate and the etching state is observed, the excess or deficiency of the etching can be quantitatively determined. Can be detected. Since the change in the formed pattern can be easily measured by an optical microscope, normal etching can be performed by controlling the process so that the etching is performed according to the reference value of the inspection pattern.

[Brief description of drawings]

FIG. 1 is an inspection pattern diagram of an embodiment according to the present invention.

FIG. 2 is a formation pattern diagram showing a conventional measuring method.

FIG. 3 is a schematic diagram of a conventional measuring device.

FIG. 4 is a graph of an input signal to a detector by a conventional measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Thin film 3 ... Remaining formed straight line part 4 ... Substrate edge straight line part B1-B5 ... Removal figure C1-C5 ... Remaining figure 1a-4a ... Predetermined space | interval

Claims (1)

Claim: What is claimed is: 1. An etching inspection plate in which a thin film-shaped masking portion is formed on the surface of a substrate to be etched, wherein the width of the masking portion changes by a predetermined minute amount. An etching inspection plate comprising: a masking portion for inspection; and a plurality of non-masking portions for inspection in which the width of the non-masking portion formed between the masking portions changes by a predetermined minute amount.