KR100644050B1 - Method of inspecting photoresist pattern defect of semiconductor device and method of forming contact hole of semiconductor device using same - Google Patents

Abstract

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for inspecting a photoresist pattern defect of a semiconductor device, which may occur when a contact hole is formed to penetrate an interlayer insulating film so as to connect an interlayer wiring pattern of the semiconductor device. .

According to the present invention, there is provided a method of inspecting a bad photoresist pattern for forming a contact hole in an insulating film on a silicon substrate, by forming a photoresist pattern by applying, exposing and developing a photoresist on the insulating film; Depositing an ARC (Anti Reflective Coating) film on the photoresist; Performing an ashing process to selectively remove the ARC film located on the upper surface of the photosensitive film; Selectively removing the photoresist film from the substrate using a solvent capable of selectively removing only the photoresist film; And a checking step of confirming the presence or absence of the ARC film at the contact hole formation position.

Description

Method for detecting photoresist pattern defect of semiconductor device and method for forming contact hole of semiconductor device using same {Method to detect photo resist pattern defect of Semiconductor and fabricating method of contact hole using the same}

1 is a longitudinal sectional view showing a wafer processing state of a general semiconductor element;

2 and 3 are cross-sectional views illustrating a photoresist patterning process for forming a contact hole in a semiconductor device according to the present invention;

4A to 6A are cross-sectional views illustrating a step of inspecting a photosensitive film wiring pattern hole of a semiconductor device in accordance with the present invention.

4B to 6B are cross-sectional views illustrating a step of checking whether wiring patterns are formed in a semiconductor device according to the present invention which is incompletely formed;

7 to 8 are cross-sectional views illustrating a process of forming a contact hole in a semiconductor device according to the present invention.

<Explanation of symbols for main parts of drawing>

10, 101: substrate 11, 12: wiring layer

102 silicon nitride film 103 silicon oxide film

104: photosensitive film 104a: photosensitive film wiring pattern hole

105: ARC film 105a: ARC film pillar

The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of inspecting a photoresist pattern defect of a semiconductor device for accurate processing of a contact hole formed through an interlayer insulating film so as to connect an interlayer wiring.

In accordance with the trend of high integration and high performance, semiconductor devices have a structure in which the circuit patterns are finely formed and the wirings are laminated in multiple layers.

Accordingly, the wiring pattern layers of the semiconductor device are electrically connected to each other through a metal in the contact hole passing through the interlayer insulating layer stacked between the upper and lower wiring layers.

In the general semiconductor device, as shown in FIG. 1, the metal wiring layers 11 and 12 and the interlayer insulating layer 13 are formed in multiple layers on the substrate 10 on which various elements are formed, and the lower metal wiring layer 11 and the upper metal wiring layer 12 are formed. ), A portion of the interlayer insulating layer 13 is etched to form the contact hole 14, and then metal is deposited inside the contact hole 14.

In this case, a photoresist (not shown) is used as a mask to form the contact hole 14, and the interlayer insulating layer 13 is etched to a predetermined depth through the pattern of the photoresist to form the contact hole 14. .

In the case of a semiconductor device having a multi-layered wiring structure, in the event of an intermediate short circuit or disconnection between wirings due to poor contact hole formation, the electrical characteristics and reliability of the product cannot be secured, so that poor contact hole formation can be reduced. How is it required?

In addition, due to the high integration, the size of the contact hole 14 should be reduced due to the increase in density of the semiconductor device, while the thickness of the interlayer insulating film cannot be reduced to suppress the increase in capacitance between layers. The aspect ratio may be increased to cause a poor etching of the contact hole 14.

In addition, poor contact hole formation may also be caused by poor manufacturing of the wiring pattern hole of the photoresist film, which serves as a mask, and a poor production of the wiring pattern hole of the photosensitive film is caused by uneven thickness of the photoresist film due to the temperature difference between the substrate and the photosensitive agent. If the exposure process fails to uniformly adjust the exposure dose, or if the exposure area has uneven local roughness, the space is wider than the contact hole width, making it difficult to pattern the photoresist film. When the focus and leveling reproducibility generated are poor, when sufficient margin is not secured in the plasma etching process, the photoresist pattern is damaged due to water pressure during the cleaning of the photoresist in the developing process.

In order to find contact hole formation defects that may occur according to various process variables, conventionally, contact holes are formed inside the insulating film, and defect inspection of the contact holes is performed.

Using Darkfield Device and Brightfield Device, which are inspected using transmission and reflection lighting, the contact hole was completely formed inside the device and the electrode was charged therein. The finding of the defect was very difficult.

Moreover, even if a defect is detected, in order to confirm the authenticity of the defect, since the board | substrate must be cut | disconnected and the cross section must be confirmed as shown in FIG. 1, inspection time and cost are high, and semiconductor element productivity fell.

SUMMARY OF THE INVENTION In order to solve the conventional problems, an object of the present invention is to reduce processing defects of contact holes formed in an interlayer insulating film of a semiconductor element, thereby reducing defects of semiconductor elements.

Furthermore, an object of the present invention is to improve the semiconductor process reliability by inspecting the photoresist pattern processing defect used as a mask for forming the contact hole of the insulating layer and improving the cause of the contact hole etching defect.

According to the present invention, there is provided a method of inspecting a bad photoresist pattern for forming a contact hole in an insulating film on a silicon substrate, by forming a photoresist pattern by applying, exposing and developing a photoresist on the insulating film; Depositing an ARC (Anti Reflective Coating) film on the photoresist; Performing an ashing process to selectively remove the ARC film located on the upper surface of the photosensitive film; Selectively removing the photoresist film from the substrate using a solvent capable of selectively removing only the photoresist film; And a checking step of confirming the presence or absence of the ARC film at the contact hole formation position.

In the method for inspecting a contact hole defect of a semiconductor device according to the present invention, the solvent for selectively removing the photosensitive film is a thinner.

In the contact hole defect inspection method of the semiconductor device according to the present invention, the ashing process selectively performs ozone ashing or plasma ashing according to the material of the ARC film.

Hereinafter, a semiconductor device manufacturing process according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, an interlayer insulating film is formed on the substrate 101 on which various elements are formed, and the interlayer insulating film is formed by sequentially depositing the silicon nitride film 102 and the silicon oxide film 103.

In general, the silicon oxide film 103 is formed to be thousands of angstroms thick, and the silicon nitride film 102 is formed to be tens to hundreds of angstroms thick, and the silicon nitride film 102 serves as an etching stopper under an interlayer insulating film. In addition, or when forming a photoresist pattern for patterning a metal wiring layer can be used as an ARC (Anti-Reflection Coating, ARC), when used as an ARC film, further stacked on top of the silicon oxide film.

The photoresist 104 is formed by applying a photoresist on the interlayer insulating films 102 and 103, and the process of patterning the photoresist film is as follows.

Applying a photosensitive agent on the silicon oxide film 103 of the substrate 101, baking at a temperature of less than 150 ℃, and then forming the photosensitive film pattern using optical lithography techniques, as shown in FIG. The exposure mask 20 in which the circuit pattern is drawn is arranged on the photosensitive film 104, and the light emitted from the illumination optical system is incident on the exposure mask 20, and an image is formed on the photosensitive film through the lens 30. As a result, the color of the photosensitive film of the portion not covered by the exposure mask is changed.

Thereafter, when the photosensitive film 104 is developed by applying a developer, the photosensitive film of the exposed portion is removed to form a pattern 104a as shown in FIG. 4A, and the silicon oxide film 103 is formed through the photosensitive film pattern 104a. The top surface is exposed to the outside.

However, as shown in FIG. 4B, when the exposure amount is not uniformly adjusted during the exposure process, when the exposure intensity is unevenly locally, when the difference between the width and the space of the contact hole occurs, the focus generated at the edge of the development facility and Due to poor leveling reproducibility, insufficient margin in the plasma etching process, or the like, the photosensitive film pattern 106 is incompletely formed, whereby the interlayer insulating film at the position where the contact hole is to be formed is not exposed to the outside.

Therefore, as shown in FIG. 4B, when an etching process for etching a portion of the silicon oxide film 103 and the silicon nitride film 102 on the wafer using the incompletely formed photosensitive film pattern 106 is performed, the lower portion of the incomplete photosensitive film pattern is formed. Due to the remaining photoresist, the etchant cannot etch the oxide film 103 and a contact hole cannot be formed.

As described above, when a contact hole is not formed in the interlayer insulating layer due to a poor pattern of the photoresist layer, the corresponding position of the non-formed contact hole may be etched again using a specially manufactured mask. Since the process yield of is reduced, the present invention provides a process for checking whether the etching of the wiring pattern hole of the photosensitive film is completed.

After formation of the photoresist pattern, the wafer is cleaned / dried, and an ARC film (Anti-Reflectance Coating, ARC, 108) is deposited on the photoresist patterns 104 and 106 as shown in FIGS. 5A and 5B.

The ARC film 108 is generally divided into an organic component and an inorganic component. An ARC film of an organic material has components such as C, H, and O, such as a photosensitizer, and has high viscosity. The ARC film of an inorganic material is mainly composed of SiO 2 or carbon (C), and the ARC film 108 is thinner during the process of removing the photoresist patterns 104 and 106 located below. By using the photosensitive film pattern (104, 106) to select a material that does not peel off.

5A and 5B, the ARC film 108 is deposited on top of the photoresist film to a thickness capable of completely filling the photoresist patterns 104 and 106, which is approximately 1000 m to 5000 m, and the deposition time is the photoresist layer. The deposition rate of the ARC film 108 inside the patterns 104 and 106 can be adjusted.

On the other hand, as shown in FIG. 5B, in the case of a substrate on which the incomplete photosensitive film pattern 106 is formed, the photoresist film is present even when the ARC film 108 is filled in the photosensitive film pattern.

After the deposition process of the ARC film 108, the ARC film positioned on the photoresist films 104 and 106 may be selectively removed so that an upper portion of the photoresist film 106 may be formed using a plasma containing oxygen group or oxygen ion. The general ashing process is performed to a predetermined thickness t from which the ARC film 108 located at is removed.

This ashing process is to remove the unnecessarily applied ARC film 108 located on the photoresist patterns 104 and 106, and a portion of the photoresist film may be removed together with the ARC film, which is removed depending on the ashing process conditions. The thickness can be adjusted, and the ashing process must be preceded before the selective removal process of the photosensitive film using a thinner.

The ashing process burns and removes the photoresist pattern 104 and 106 Z and the ARC film made of organic material using reactive active species of oxygen, and it is important to maintain a discharge characteristic having a high radical density.

In a subsequent process, when the photoresist patterns 104 and 106 are selectively removed from the substrate using a thinner, as shown in FIG. 6A, when the photoresist pattern 104 is completely formed, as shown in FIG. Since only 104 is completely peeled off from the substrate by the thinner, the ARC film existing inside the photosensitive film pattern 104 is exposed in the form of the ARC film pillar 109.

That is, since the ARC film 108 existing inside the photosensitive film pattern 104 is deposited on the interlayer insulating film 103, it is not removed by the thinner, so that it protrudes on the interlayer insulating film 103.

By inspecting the number of protrusions of the ARC film pillars 109, it is possible to confirm whether or not the photoresist pattern is poorly formed.

However, as shown in FIG. 5B, when the photoresist pattern 106 is incompletely formed, the photoresist film is peeled off the upper surface of the substrate by the thinner and at the same time, some photoresist positioned under the incompletely formed photoresist pattern 106 also responds to the thinner from the substrate. Since it is removed, as shown in Figure 6b, a portion of the ARC film pillar 110 is inspected in the form of missing contact hole formation position.

That is, as shown in FIG. 6A, when all of the ARC film pillars 109 are present at the positions where the contact holes should be formed, the photoresist pattern etching is accurately performed. As shown in FIG. 6B, the ARC film pillars 110 may be formed. In the case where the number of N is not present, the photoresist pattern etching is incomplete.

The ARC membrane pillars 109 and 110 formed by the method according to the present invention can be easily identified through visual inspection.

When it is determined that the photoresist pattern process is completely formed through this method, the ARC film pillars 109 and 110 existing on the substrate can be completely removed from the upper surface of the substrate by etching using a mask. Since the reliability of the photoresist pattern forming process was confirmed through the method according to the above method, the photoresist pattern forming process was performed under the same conditions to fabricate a contact hole in the interlayer insulating film.

In addition, the substrate on which the etching failure of the photoresist pattern occurs, the ARC film pillar 110 is also removed, the conditions of the photoresist patterning process are rearranged, and the photoresist patterning process is resumed.

In this manner, since the poor photoresist pattern formation is removed to form a fine pattern mask by the photoresist on the interlayer insulating film, a contact hole is formed in the interlayer insulating film using the same, as shown in FIGS. 7 and 8.

As the silicon oxide film 103 and the silicon nitride film 102 exposed through the contact hole pattern of the photosensitive film 104 are sequentially etched through plasma etching, a contact hole 112 is formed, and the contact hole 107 is formed. After removing the reaction product from the bottom of the hole using a plasma containing argon, hydrogen, and oxygen so as to remove the internal deposits, a sputtering process is performed therein, so that a metal ( 114).

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As the contact hole is formed on the insulating film of the semiconductor device by the above method, the present invention has the following effects.

In the method of fabricating a semiconductor device according to the present invention, first, by inspecting the photoresist pattern formation and then etching the interlayer insulating film to form a contact hole of the insulating film, it is possible to improve semiconductor device defects due to poor contact hole formation.

In addition, the semiconductor device manufacturing method according to the present invention can easily inspect the presence or absence of the formation of the photosensitive film pattern, it is possible to shorten the inspection progress time to improve the production yield.

Furthermore, since the cause of the etching failure due to the photoresist pattern formation failure can be identified at an early stage, the process efficiency can be improved by removing the etching failure process variable.

After the photoresist pattern defect inspection, the ARC film pillar formed on the upper portion thereof is removed, and the photoresist pattern is formed again, so that contact holes of the insulating film can be manufactured, thereby reducing process loss.

Claims (5)

In the photosensitive film pattern defect inspection method for forming a contact hole in the insulating film on the silicon substrate, Coating, exposing and developing a photoresist on the insulating film to form a photoresist pattern; Depositing an ARC (Anti Reflective Coating) film on the photoresist; Performing an ashing process to selectively remove the ARC film located on the upper surface of the photosensitive film; Selectively removing the photoresist film from the substrate using a solvent capable of selectively removing only the photoresist film; An inspection step of confirming the presence or absence of the ARC film at the contact hole formation position Photosensitive film pattern defect inspection method of a semiconductor device comprising a. The method of claim 1, And the solvent for selectively removing the photosensitive film is a thinner. The method of claim 1, And the ashing process selectively performs ozone ashing or plasma ashing according to the material of the ARC film. In the method of forming a contact hole in a semiconductor device for forming a contact hole in the insulating film on the silicon substrate, Forming a photoresist pattern formed by coating, exposing and developing a photoresist on the upper surface of the substrate; Depositing an ARC film on the photoresist; Performing an ashing process to selectively remove only the ARC film located on the upper surface of the photosensitive film from the substrate; Selectively removing the photoresist film from the substrate using a solvent capable of selectively removing only the photoresist film; Checking whether the ARC film is present at a contact hole forming position; Adjusting the photoresist pattern forming step according to a test result of the presence or absence of the ARC film to re-form the photoresist pattern on the insulating film; Forming a contact hole in the insulating film of the substrate along the photoresist pattern; Contact hole forming method of a semiconductor device comprising a. The method of claim 4, wherein And the ashing process selectively performs ozone ashing or plasma ashing according to the material of the ARC film.

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