KR20130028249A

KR20130028249A - Method of forming a fine pattern using multiple etching

Info

Publication number: KR20130028249A
Application number: KR1020110091654A
Authority: KR
Inventors: 김기수; 유동국; 임현태
Original assignee: 삼성테크윈 주식회사
Priority date: 2011-09-09
Filing date: 2011-09-09
Publication date: 2013-03-19

Abstract

The present invention relates to a method for forming a fine pattern using a multi-stage etching, the method of forming a fine pattern on the substrate through the cleaning, photoresist coating, exposure, development, etching, peeling process, the etching process (a) Performing a first etching on the etched layer with an etching solution containing an inorganic additive, (b) cleaning the etched layer, and (c) etching the layer with the etching solution containing no organic or inorganic additives. And performing a second etching, wherein the organic / inorganic additive includes a photoresist softening component so that the photoresist is softened in the first etching process to protect the etched layer. Provided is a method of forming a fine pattern using multi-stage etching capable of securing a sufficient lead top width.

Description

Method of forming fine pattern using multi-stage etching {METHOD OF FORMING A FINE PATTERN USING MULTIPLE ETCHING}

The present invention relates to a method for forming a fine pattern using a multi-stage etching, and in particular, to effectively remove foreign substances generated during the etching process and to secure a sufficient width of the upper end of the lead to form a high quality fine pattern. It relates to a formation method.

In general, etching is a processing method that selectively removes unnecessary portions of an etched layer in the manufacture of semiconductors, such as COF (Chip On Film), PCB (Printed Circuit Board), and FPCB (Flexible Printed Circuit Board). It is applied to most fields forming a. Hereinafter, the COF etching will be described as an example for clearer understanding.

First, COF etching can be divided into general etching and fine pitch etching, depending on the product. Specifically, general etching is a method using an isotropic etching solution without organic / inorganic additives, fine pitch etching using an anisotropic etching solution containing a side cut inhibitor, which is again the organic / inorganic additive It can be distinguished from the case of using an etching solution in which the organic material is coated after development and using an etching solution free of organic / inorganic additives.

In this case, fine pitch etching using organic / inorganic additives is divided into one etching and two etchings according to the number of etchings. Specifically, one-time etching is a method of dispersing a side cut inhibitor (at least one organic / inorganic additive) that interferes with side etching in a solution to implement anisotropic etching, and two-time etching is an exposed type after half etching. A fine pitch is realized by coating an organic material on each surface of the Cu, for example, and then etching back with an etching solution without an organic / inorganic additive. Table 1 below shows the main processes of one-time etching and two-time etching.

division The main process 1 time etching Develop → Etch with Organic / Inorganic Additive → Seed Etch → Peel Off 2 etch Development → Tip coating (1 ~ 2㎛ etch → Tip coating → Dry) → Etch without organic / inorganic additives → Seed etching → Peeling

As shown in Table 1, in the case of one-time etching, Cu is etched about 8 μm with an etching solution containing an organic / inorganic additive. In the case of two times, Cu is etched by 1-2 μm before tip coating. Coating organics that function the same as the etching solution with inorganic additives and then etch back with an etching solution without organic / inorganic additives.

However, the conventional fine pitch etching technique as described above has the following problems.

That is, the fine pitch etching uses a chemical reaction at a low pressure, unlike general etching, in which the etching rate is lower than that of the general etching, and thus, the etching rate is not only exposed to the etching solution for a long time but also uses the inertia of the etching solution at a high pressure. Therefore, the organic / inorganic additives included in the fine pitch etching solution during the etching process, in particular, the single etching process is likely to be agglomerated, and as a result, as shown in FIGS. 1A to 1C, Agglomerates will adhere and cause defects such as shorts 40 and protrusions. For reference, reference numeral 20 in the drawing denotes a photo resist coated on the surface of Cu 10, 30 denotes a foreign material in a liquid formed during the etching process, and 50 denotes a substrate.

Meanwhile, in order to form a fine pattern, a lead top width must be secured to a certain degree. When etching is performed according to the related art as described above, the amount of the etching solution penetrated into the lower portion of the photoresist 20 is described. As a result, the upper portion of the Cu 10 is continuously etched, and thus the width of the upper end of the lead is narrowed, thus making it difficult to implement a fine pattern.

The present invention has been made to solve the above-described problems of the prior art, it is a multi-stage etching that can remove the defects such as short, protrusions, etc. caused by the aggregation of the organic / inorganic additives contained in the etching solution before the etching is completed An object of the present invention is to provide a method for forming a fine pattern.

In addition, another object of the present invention is to provide a fine pattern forming method using a multi-stage etching to prevent the penetration of the etching solution to the top of the etched layer to sufficiently secure the top width of the lead.

As a means for solving the above technical problem,

The present invention relates to a method of forming a fine pattern on a substrate through cleaning, photoresist coating, exposure, development, etching, and peeling process, wherein the etching process comprises (a) an etching solution containing organic and inorganic additives to the etched layer. Performing a first etching, (b) cleaning the etched layer, and (c) performing a second etch on the etched layer with an etching solution free of organic and inorganic additives. Provided is a method for forming a fine pattern using multi-stage etching, wherein the organic and inorganic additives include a photoresist softening component.

In this case, the photoresist softening component is preferably glycols.

In addition, the washing step is preferably made of ultrapure water or chemicals.

According to the present invention, etching is performed in two parts of the first etching and the second etching, and the water treatment or chemical treatment process is added between the first etching and the second etching to complete the etching due to the aggregation of the organic / inorganic additives. By removing before, the quality of the product can be improved.

In addition, by including a component that softens the photoresist as an organic / inorganic additive to inhibit the penetration of the etchant during the etching process it is possible to maximize the lead top width.

1a to 1c is a view showing the etching process and the result according to the prior art,
2 is a process chart of a fine pattern forming method using a multi-stage etching according to a preferred embodiment of the present invention,
3 is a process diagram illustrating a method for forming a fine pattern using multi-stage etching according to a preferred embodiment of the present invention;
Figure 4a is a view showing a cross-sectional shape after the first etching of the fine pattern forming method using a multi-stage etching in accordance with a preferred embodiment of the present invention,
Figure 4b is a view showing the cross-sectional shape after the second etching of the fine pattern forming method using a multi-stage etching in accordance with a preferred embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

2 is a process diagram of a method for forming a fine pattern using a multi-stage etching according to a preferred embodiment of the present invention, Figure 3 is a process diagram illustrating a method for forming a fine pattern using a multi-stage etching according to a preferred embodiment of the present invention, Figure 4a Is a view showing a cross-sectional shape after the first etching of the fine pattern forming method using a multi-stage etching according to a preferred embodiment of the present invention, Figure 4b is a second method of forming a fine pattern using a multi-stage etching according to a preferred embodiment of the present invention It is a figure which shows the cross-sectional shape after etching.

As shown in Figures 2 and 3, the fine pattern forming method using a multi-stage etching according to a preferred embodiment of the present invention in a semiconductor manufacturing process including a cleaning, photoresist coating, exposure, development, etching, peeling process, etc. In particular, the etching process, and comprises a first etching step (S100), a cleaning step (S110) and a second etching step (S120). That is, this invention divides an etching process into two steps, and has the technical feature in adding the washing process in the meantime. Hereinafter, each process will be described in more detail with reference to the accompanying drawings.

First, the first etching step (S100) is an etching process performed after development (FIG. 3A) and half-etches the etching target layer 10 using an etching solution including an organic / inorganic additive. (B) of FIG. For reference, FIG. 4A shows a cross-sectional shape after the first etching is completed. In this case, the present invention is characterized in that the organic / inorganic additive includes a component that softens the photoresist 20.

As described above, when some of the components of the organic / inorganic additive are composed of the photoresist softening component, the photoresist 20 may be formed as shown in FIG. 3B during the process of the first etching step S100. By softening and protecting the etched layer 10, penetration of the etching solution can be suppressed. Accordingly, it is possible to prevent the upper end of the etched layer 10 from being etched by the etching solution in the second etching step (S120), which will be performed later, and as a result, can secure the maximum width of the lead top.

As the photoresist softening component, it is preferable to use a material having excellent water solubility, no volatility, and high boiling point. In the present invention, glycols satisfying such conditions, such as ethylene, propylene, and diethylene, are used. , Dipropylene and the like can be used.

As described above, in the present invention, the photoresist softening phenomenon occurs in the etching process without undergoing a separate process, thereby maintaining the shape of the etched layer 10 as it is, and thus, it is effective in securing the top width of the lead.

Next, the cleaning step (S110) is a process for removing the foreign matter 30 (FIG. 3C) in the liquid formed during the execution of the first etching step S100. The surface of the etched layer 10 is removed. It is done by washing with water. In this case, the foreign material 30 is preferably removed by deionized water (DI) or chemicals, but is not particularly limited.

Specifically, while the first etching step (S100) is in progress, the organic / inorganic additives are agglomerated to interfere with the etching, causing a defect such as a short or a projection, in the present invention to prevent this, the first etching step ( After the implementation of S100) by using a water washing pressure, such as ultrapure water or chemicals, it is to ensure the reliability of the product by removing the foreign matter 30 and other foreign matters in the liquid immediately. As such, when the cleaning step S110 is performed, the foreign matter 30 in the liquid attached to the etched layer 10 is completely removed as shown in FIG. 3D, and in this state, the second etching step is performed. S120 is performed.

Finally, the second etching step (S120) is a process for finally etching the etched layer 10 again to form a fine pattern as shown in FIG. It is carried out using a solution. In the second etching step (S120), the photoresist 20 softened through the first etching step (S100) protects the upper end of the etched layer 10, thereby providing a fine pitch that was not previously expected. Can be implemented. For reference, FIG. 4B shows a cross-sectional shape after the second etching is completed.

In this case, the second etching step (S120) may be performed by various general etching solutions of the known type or the fine pitch etching solution described above, that is, glycols, and is not particularly limited.

When the photoresist 20 is finally peeled off after the second etching step S120 is completed, as shown in FIG. 3 (f), the upper end of the etched layer 10 is not etched to maintain a complete shape. High quality results can be obtained.

Preferred embodiments of the present invention have been described in detail above with reference to the drawings. The description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the scope of the present invention is represented by the following claims rather than the detailed description, and all changes or modifications derived from the meaning, scope, and equivalent concepts of the claims are included in the scope of the present invention. Should be interpreted as

The present invention relates to a method of forming a fine pattern using a multi-stage etching, and can be applied to all fields of forming a circuit using an etching method, for example, manufacturing COF, PCB, FPCB, and the like.

10: etching target layer 20: photoresist
30: foreign matter in liquid 40: short
50: substrate
S100: first etching step S110: cleaning step
S120: second etching step

Claims

In the method of forming a fine pattern on a substrate through a cleaning, photoresist coating, exposure, development, etching, peeling process,
In the etching step,
(a) performing a first etching on the etched layer with an etching solution containing organic and inorganic additives;
(b) cleaning the etched layer; And
(c) performing a second etching on the etched layer with an etching solution containing no organic or inorganic additives;
The organic-inorganic additive is a fine pattern forming method using a multi-stage etching, characterized in that it comprises a photoresist softening component.

The method of claim 1,
The photoresist softening component is a fine pattern forming method using a multi-stage etching, characterized in that the glycol.

The method of claim 1,
The cleaning process is a fine pattern forming method using a multi-stage etching, characterized in that made of ultrapure water or chemicals.