KR100527816B1 - Method for manufacturing a microstructure pattern by using micromachining technology - Google Patents

Abstract

The present invention relates to a method for manufacturing a microstructure pattern using micromachining, and in particular, a method of manufacturing the present invention includes a first etching mask defining a microstructure pattern region on a semiconductor substrate on which a sacrificial layer and an etching target are stacked, Forming a second etching mask having a plurality of minute etching patterns spaced apart from each other in an open area between the structure patterns, patterning an etching object exposed by the first and second etching masks, and below the etching object Patterning the sacrificial layer to remove a portion of the sacrificial layer of the first etching mask, and removing the second etching pattern and the etching object under the sacrificial layer patterning while removing the first etching pattern and the etching residue. Removing to form a microstructure pattern. Accordingly, the present invention uses a mask having a plurality of uniform or non-uniform etching patterns in the open areas between the microstructure patterns to leave a portion of the etch structure of the open region and then removes it, thereby resulting in an etch rate difference due to the difference between the microstructure patterns. This prevents loading, footing, etc. from occurring.

Description

METHOD FOR MANUFACTURING A MICROSTRUCTURE PATTERN BY USING MICROMACHINING TECHNOLOGY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a microstructure pattern of a semiconductor device using micromachining. In particular, in the etching process of a microstructure pattern of a highly integrated semiconductor device, a structure is produced by unintended effects that have occurred in a conventional etching process. The present invention relates to a method for producing a microstructure pattern using micromachining, which can prevent the deterioration of properties.

In general, MEMS (MicroElectroMechanical Systems) is a technology (micromachining) or processed product that applies a semiconductor processing method to form microstructures of several micrometers or less in size, and has uniform processing and enormous mass productivity. It is characterized by having. In addition, when the MEMS is implemented on a semiconductor substrate, electrical and mechanical devices such as circuits are integrated together by the same processing method, and thus, there is an advantage in that quality and cost are excellent. Currently, the application range of MEMS technology is diversified from automotive airbag acceleration sensors and inkjet printer heads, such as wireless parts, optical parts, and micromechanical fields.

Meanwhile, as one of techniques for forming a microstructure pattern of MEMS on a semiconductor substrate, an etching process is performed as shown in FIG. 1. 1A to 1C are process flowcharts illustrating a manufacturing process of a microstructure pattern using micromachining according to the prior art.

As shown in FIG. 1A, a silicon on insulator (SOI) structure having a sacrificial layer 12 on a silicon substrate 10 and a single crystal or polycrystalline silicon layer 14 thereon is provided as a semiconductor substrate. The photolithography process is used to form a photoresist pattern or etch mask 16 pattern defining a microstructure pattern region. In this case, a portion where the etch mask 16 is formed is a region for patterning an etch target, which is the lower silicon layer 14, and an open region without the etch mask 16 is a region where the lower silicon layer 14 is to be removed.

As shown in FIG. 1B, the silicon layer 14 exposed in the etch mask 16 is patterned 14a to expose 18 the surface of the sacrificial layer 12.

Subsequently, as shown in FIG. 1C, the sacrificial layer 12 is etched according to the silicon pattern 14a and the etch residue is removed to form a microstructure pattern. In this case, in order to form the floating microstructure pattern on the substrate 10, a portion of the sacrificial layer 12 under the silicon pattern 14a is removed by a wet etching process during the sacrificial layer 12 etching process.

However, the etching process of the silicon layer 14, which is the main etching target, in the manufacturing process of the microstructure pattern using micromachining according to the prior art is generally a dry etching technique using a high density plasma source rather than wet etching to obtain a fine sidewall profile. It is used. However, when the area of the silicon layer 14 to be etched is different, the loading effect (see 20 in FIG. 2) and the silicon layer 14 are completely etched to be in contact with the bottom surface. There was a problem in which a footing effect (see 22 in FIG. 3), in which an undercut occurred to the side, occurred.

By such loading and footing, an etching imbalance occurs in etching microstructure patterns having different pattern areas. In order to fully etch a narrow structure pattern compared to a wide pattern, overetching is inevitably performed. At this time, undercut occurs in the lower part of the substrate on which the microstructure is to be formed, and thus the microstructure patterns cannot be accurately patterned. Due to this, the mechanical properties of the MEMS semiconductor device change, causing problems that behave differently from the intended design.

An object of the present invention is to remove the fine structure by leaving a portion of the etch structure of the open area by using a mask having a plurality of uniform or non-uniform etching patterns in the open area between the microstructure pattern in order to solve the above problems of the prior art. The present invention provides a method of manufacturing a microstructure pattern using micromachining to prevent the etching defects due to the gap between the structure patterns in advance so that the physical size and characteristics of the MEMS semiconductor device microstructure can be realized as designed by the designer. have.

In order to achieve the above object, the present invention provides a method for manufacturing a microstructure pattern of a semiconductor device using a micromachining technique, the first etching pattern for defining the microstructure pattern region on the semiconductor substrate on which the sacrificial layer and the etching target is laminated And forming an etching mask having a plurality of fine second etching patterns spaced apart from each other in the open region between the microstructure patterns, patterning an etching object exposed by the etching mask, and a sacrificial layer under the etching object. Patterning to remove a portion of the sacrificial layer of the first etching pattern, and removing the first etching pattern and the etching residue while removing the second etching pattern and the etching object under the sacrificial layer patterning. To form a microstructure pattern.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

4A to 4D are process flowcharts illustrating a process of manufacturing a microstructure pattern using micromachining according to the present invention. Referring to these drawings, the manufacturing process of the microstructure pattern using the micromachining of the present invention is as follows.

As shown in FIG. 4A, the present invention provides a silicon on insulator (SOI) structure in which a sacrificial layer 102 is formed on a silicon substrate 100 as a semiconductor substrate, and an etch target 104 of a single crystal or polycrystalline silicon layer is disposed thereon. The microstructure pattern manufacturing process of MEMS is performed to a board | substrate. In this embodiment, although the substrate structure for manufacturing the MEMS microstructure pattern is an SOI substrate, a sacrificial layer 102 having a thin film on the semiconductor substrate as compared with the etching target 104 is formed as an insulating film, and the etching target 104 is formed. May be formed of any one of an insulating film, a conductive film, and a semiconductor film having an etching selectivity with respect to the sacrificial layer 102.

In this embodiment, the etching mask 106 pattern defining the microstructure pattern region is formed on the substrate of the SOI structure. In this case, the etching mask 106 pattern may be formed of any one of an etching target 104 and an insulating layer, an conductive layer, and a semiconductor layer having an etching selectivity.

By the manufacturing process of the etching mask 106 pattern, the first etching pattern 106a defining a region of the microstructure pattern to be formed later, is spaced apart from each other in the open region between the microstructure pattern on the etching object 104. An etching mask 106 having a plurality of fine second etching patterns 106b is formed. Meanwhile, the first and second etching patterns 106a and 106b may be formed as photoresist patterns using a photolithography process. At this time, the width (W ₂ ) of the second etching pattern 106b is adjusted according to the minimum distance (W ₁ ) between the first etching pattern 106a, the regular or irregular polygon, line or circle, etc. In the form of

Conventionally, although the surface of the object to be etched was completely open between the microstructure patterns, in the present invention, the microstructure pattern is added to the open region between the patterns by adding an etching mask pattern having a regular or irregular fine etching pattern 106b. In order to prevent the etching imbalance caused by the excessive gap between the patterns in the region between the microstructure pattern by patterning the etching target region of the region to be opened later during the etching process of the etching target.

As shown in FIG. 4B, the etching object 104 exposed by the first and second etching patterns 106a and 106b is patterned 104a and 104b to expose 108 the surface of the sacrificial layer 102. In this case, the etching object 104 is etched by the first etching pattern 106a defining the microstructure pattern region 104a, and the open region between the microstructure patterns is formed by the plurality of fine second etching patterns 106b. The etching object region, which is a region where the etching object is removed, is also etched 104b. Here, the etching for the etching target pattern 104a, 104b proceeds to dry or wet etching, it is preferable to use a dry etching process to obtain an accurate side profile.

Since the etching target etching process of the present invention is patterned not only by the etching target region for the microstructure pattern by the first etching pattern 106a but also by the second etching pattern 106b, the etching target region of the open region to be subsequently removed. The etching process may be uniformly performed by preventing the etching imbalance caused by the gap between the microstructure patterns. That is, when the fine pattern spacing of the second etching pattern 106b is designed in accordance with the spacing of the first etching pattern 106a defining the microstructure pattern, the etch loading of the entire etching object becomes uniform, thereby causing loading phenomenon and footing phenomenon. Is minimized.

Subsequently, as illustrated in FIG. 4C, the sacrificial layer 102 under the etch target patterns 104a and 104b is patterned 102a by a dry or wet etching process. In this case, in order to form a floating microstructure pattern on the substrate 10, a sacrificial layer under the etching target pattern 104b of the second etching pattern 106b may be formed by wet etching during the sacrificial layer 102 etching process. Allow 102a) to be partially removed. In this case, when the sacrificial layer of the region between the microstructure patterns is removed, the second etching pattern 106b and the etching object pattern 104b below it are separated from the substrate and floated.

Then, as shown in FIGS. 4D and 4E, the first etching pattern 106a and the etching residue are removed while the second etching pattern 106b and the etching target pattern 104b under the etching process are removed. As a result, the microstructure pattern of the MEMS semiconductor device in which a portion of the surface of the substrate 100 is exposed 110 is floated from the substrate surface according to the present invention. The open region 110 according to the original design rule is formed between the microstructure pattern including the etching object pattern 104a and the sacrificial layer pattern 102a remaining by the etching process.

5A to 5C illustrate various embodiments of an etching pattern for etching an open area of a pattern in a process of manufacturing a microstructure pattern of the present invention. Etch patterns of the present invention have a regular or irregular pattern form and only one example of the pattern of the regular form in this figure. The shape and the number of the etching patterns may be changed according to the minimum spacing design rule between the microstructure patterns.

Referring to FIG. 5A, an etching pattern 106b added between the etching patterns for the microstructure pattern of the MEMS semiconductor device of the present invention is in the form of a square array pattern 1062. Alternatively, as shown in FIGS. 5B and 5C, the line array patterns 1064 and 1066 may be vertical or horizontal.

As described above, the manufacturing method according to the present invention by using a mask having a plurality of uniform or non-uniform etching pattern in the open area between the etching pattern for the microstructure pattern, leaving a part of the etch structure of the open area and then removing the microstructure It prevents loading phenomenon and footing phenomenon caused by difference in etching rate due to gap between patterns.

Therefore, the present invention has an effect of forming a fine structure having the same mechanical properties as the designer intended by improving the etching profile of the microstructure pattern in the manufacturing process of the MEMS semiconductor device using micromachining.

On the other hand, the present invention is not limited to the above-described embodiment, various modifications are possible by those skilled in the art within the spirit and scope of the present invention described in the claims to be described later.

1A to 1C are process flowcharts illustrating a process of manufacturing a microstructure pattern using micromachining according to the prior art;

2 is a view showing a loading phenomenon occurring during the etching process of the microstructure pattern according to the prior art,

3 is a view showing a footing phenomenon occurring during the etching process of the microstructure pattern according to the prior art,

4A to 4D are process flowcharts illustrating a process of manufacturing a microstructure pattern using micromachining according to the present invention;

5A to 5C illustrate various embodiments of an etching pattern for etching an open region of a pattern in a process of manufacturing a microstructure pattern of the present invention.

<Description of the code | symbol about the principal part of drawing>

100 semiconductor substrate 102 sacrificial layer

104: etching object 106: etching mask

106a: first etching mask 106b: second etching mask

110: open area of the microstructure pattern

Claims (3)

In the method for producing a microstructure pattern of a semiconductor device using a micromachining technique, Etch having a first etching pattern defining the microstructure pattern region and a plurality of fine second etching patterns spaced apart from each other in the open region between the microstructure pattern on the semiconductor substrate on which the sacrificial layer and the etching target are stacked Forming a mask; Patterning an etching object exposed by the etching mask; Patterning a sacrificial layer under the etching target, wherein the sacrificial layer of the first etching pattern is removed to pattern a portion of the sacrificial layer; And And removing the first etching pattern and the etching residue while removing the second etching pattern and the etching object under the sacrificial layer patterning to form a microstructure pattern. The manufacturing method of the microstructure pattern used. The method of claim 1, wherein the second etching pattern is any one of a regular or irregular polygon pattern, a line pattern, and a circular pattern. The method of claim 1, wherein the second etching pattern is adjusted according to a minimum gap between the first etching patterns.