KR20060125210A - Method for forming micropattern in semiconductor device - Google Patents

Abstract

A method for fabricating a fine pattern of a semiconductor device is provided to reduce a process procedure by using a hard mask having a carbon containing silicon or a metal component. A substrate on which a target layer(210) to be etched is formed is provided. An organic layer(211) having a polymer containing a carbon is applied on an upper portion of the target layer. A hard mask(212) having a carbon containing silicon or a metal component is applied on an upper portion of the organic layer. A first etching process(214) using O2 plasma is performed to etch the hard mask. A second etching process using the etched hard mask is performed to etch the organic layer. A third etching process using the etched organic layer and the hard mask is performed to etch the target layer.

Description

METHOD FOR FORMING MICROPATTERN IN SEMICONDUCTOR DEVICE}

1A to 1C are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device according to the prior art.

2A and 2B are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device according to a first embodiment of the present invention;

3 (a) and 3 (b) are SEM photographs of the drawings shown in FIG. 2a.

4 (a) and 4 (b) are SEM images of the drawings shown in FIG. 2b.

5A to 5C are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device in accordance with a second preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

110, 210: etched layer

111, 212: MFHM

112, 213: Photosensitive film pattern

211: organic film

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for forming a fine pattern of a semiconductor device.

The semiconductor device includes a plurality of unit devices therein. As semiconductor devices are highly integrated, semiconductor devices must be formed at a high density on a predetermined cell area, and thus, the size of unit devices, for example, transistors and capacitors, is gradually decreasing. In particular, as a design rule is reduced in a semiconductor memory device such as a DRAM (Dynamic Random Access Memory), the size of semiconductor devices formed in a cell is gradually decreasing. In fact, the latest line width of the DRMA device is less than 0.1㎛. Therefore, many difficulties arise in the manufacturing process of the semiconductor elements forming the cell.

The method of forming a fine pattern of a semiconductor device uses photolithography. As the semiconductor device is highly integrated, the thickness of the photoresist layer must be reduced during the photomask process, and thus, the etching of the lower layer is more difficult with the photoresist layer only during the etching process. In order to solve this problem, a method of forming a fine pattern of a semiconductor device using amorphous carbon as a hard mask has been proposed.

1A to 1C are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device using amorphous carbon as a hard mask according to the prior art.

First, as shown in FIG. 1A, an amorphous carbon film 11, a SiON film 12, and a bottom anti-reflection coating (BARC) film 13 are sequentially formed on the etched layer 10 to be etched. Apply with Then, after the photoresist is coated on the lower anti-reflection film 13, the photoresist pattern 14 is formed by performing exposure and development processes using a photo mask.

Subsequently, as shown in FIG. 1B, an etching process using the photoresist pattern 14 as an etching mask is performed to sequentially etch the lower anti-reflection film 13 and the SiON film 12.

Subsequently, as shown in FIG. 1C, the exposed amorphous carbon film 11 is etched by performing an etching process using an O ₂ plasma. At this time, the uppermost photosensitive film pattern 14 is removed, and the SiON film 12 prevents the amorphous carbon film 11 from being damaged.

Subsequently, although not shown, an etching process using the etched amorphous carbon film 11 as a hard mask is performed to etch the etching target layer 10. As a result, a fine pattern is formed on the etched layer 10.

However, the method of forming a fine pattern of a semiconductor device using the amorphous carbon film according to the related art as a hard mask has the following problems. First, the process is complicated. Second, since the light absorption of the amorphous carbon film is large, an alignment key portion must be formed first for alignment in the exposure apparatus, and thus a process for forming the alignment key is additionally required. Third, the deposition of the amorphous carbon film is carried out by the deposition method rather than the coding method, and thus the deposition is performed on the entire surface of the wafer. Therefore, the bevel etching process, that is, the removal of the amorphous carbon film at the edge of the wafer should be additionally performed. .

Accordingly, an object of the present invention is to provide a method for forming a micropattern of a semiconductor device, which has been devised to solve the above problems of the prior art, which can simplify the process.

According to an aspect of the present invention, there is provided a substrate on which an etched layer is formed, applying a hard mask containing silicon or a metal component to carbon on the etched layer, and O _2. Forming a fine pattern of the semiconductor device, comprising etching the hard mask by performing a first etching process using plasma, and etching the etching target layer by performing a second etching process using the etched hard mask. Provide a method.

According to another aspect of the present invention, there is provided a substrate on which an etched layer is formed, coating an organic film in a polymer form containing carbon on the etched layer, and the organic film Applying a hard mask containing silicon or a metal component on carbon, performing a first etching process using an O ₂ plasma, and etching the hard mask; and a second etching using the etched hard mask. And etching the organic layer by performing a process, and etching the etched layer by performing a third etching process using the etched organic layer and the hard mask.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. In addition, in the drawings, the thicknesses of layers and regions are exaggerated for clarity, and in the case where the layers are said to be "on" another layer or substrate, they may be formed directly on another layer or substrate or Or a third layer may be interposed therebetween. Also, throughout the specification, the same reference numerals denote the same components.

Example 1

2A and 2B are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device according to a first exemplary embodiment of the present invention, and FIG. 3 is a plan view and a cross-sectional view of the SEM shown in FIG. 2A, respectively. (Scanning Electron Microscope) is a photograph, Figure 4 is a SEM photograph showing a plan view and a cross-sectional view shown in Figure 2b, respectively.

First, as shown in FIGS. 2A and 3A and 3B, a multi-functional hard mask (hereinafter referred to as 'MFHM') is formed on the etched layer 110 on which the micropattern is to be formed. 111) is applied. In this case, the MFHM 111 is made of a material containing about 0 to 50% of silicon (Si) in carbon, or 0 to 50% of a metal element such as Ti or Zr in carbon. It is made up of a substance that contains a degree. As such, since the MFHM 111 is made of a film containing silicon or a metal component in carbon, the MFHM 111 may simultaneously function as a BARC film and an etching barrier layer. The carbon component functions as a BARC film, and the silicon component reacts with the O ₂ plasma gas used in the subsequent etching process to be converted into a silicon oxide film, and the thus converted silicon oxide film serves as an etching barrier layer. Of course, the metal component also reacts with the O ₂ plasma gas and is converted into TiO ₂ and ZrO ₂ to function as an etch barrier layer.

Meanwhile, the etched layer 110 may be formed of a silicon nitride film, a silicon oxide film, or a silicon film. In addition, the etched layer 110 may be a nitride film, an oxide film, a metal layer, or a poly layer used in the manufacturing process of the semiconductor device.

Subsequently, after the photoresist film is coated on the MFHM 111, an exposure process and a development process using a photomask are sequentially performed to form a predetermined photoresist pattern 112.

Subsequently, as illustrated in FIGS. 2B and 4A and 4B, the MFHM 111 is etched by performing an etching process 113 using the photoresist pattern 112 as an etching mask. At this time, the etching process 113 is carried out by a dry etching process, using a CF ₄ / O ₂ gas, CF ₄ / O ₂ gas ratio of 1: 2 to 1:50, the process pressure is 10 ~ 300mTorr Process power should be within 50 ~ 2000W. In addition, when the MFHM 111 is made of carbon and a metal component, the etching process 113 is performed by using a gas combination plasma containing chlorine (Cl) and oxygen (Oxygen, O). Meanwhile, the silicon oxide film is formed by reacting carbon contained in the MFHM 111 with the O ₂ plasma used in the etching process 113 by the etching process 113.

Subsequently, although not shown, an etching process using the etched MFHM 111 as an etching mask is performed to etch the etched layer 110. At this time, the etching process is performed by a plasma method. In this case, the MFHM 111 functions as an etching barrier layer because the silicon component of the MFHM 111 is converted into a silicon oxide film by the O ₂ plasma during the etching process 113.

Meanwhile, the etching process of the layer 110 to be etched using the MFHM 111 is performed using CH ₄ / O ₂ , CHF ₃ and Ar. The etching layer 110 is etched by the etching process and the MFHM 111 is simultaneously etched. Is also removed. If the MFHM 111 is not removed and remains, the MFHM 111 is not carried out using a plasma P / R strip, but using a chemical solution containing amine. This is because the silicon present in the MFHM 111 is oxidized in the plasma photosensitive film strip process, so that the removal of the MFHM 111 is difficult.

Example 2

5A through 5C are cross-sectional views illustrating a method of forming a micropattern of a semiconductor device in accordance with a second preferred embodiment of the present invention. The second preferred embodiment of the present invention includes an etched layer 210 and an MFHM 212. The organic substance 211 of a polymer system is interposed in the liver.

First, as shown in FIG. 5A, an organic material 211 of a polymer system containing carbon is coated on an etched layer 210 on which a micropattern is to be formed. In this case, the polymer-based organic film 211 containing carbon may be a photosensitive film or an amorphous carbon film. Meanwhile, the etched layer 210 may be formed of a silicon nitride film, a silicon oxide film, or a silicon film.

Subsequently, the MFHM 212 is applied over the organic film 211. At this time, the MFHM 212 is a film containing carbon and silicon (Si), wherein the content of silicon is in the range of 0 to 50% of the total amount. Alternatively, the carbon containing a metal component, wherein the content of the metal component is in the range of 0 to 50%.

Subsequently, after the photoresist film is coated on the MFHM 212, an exposure and development process using a photo mask is performed to form the photoresist pattern 213.

Subsequently, as illustrated in FIG. 5B, an etching process 214 using the photoresist pattern 213 as an etching mask is performed to etch the MFHM 212. At this time, the etching process 214 uses CF ₄ / O ₂ gas, CF ₄ / O ₂ gas ratio is 2 ~ 50, the process pressure is 10 ~ 300mTorr, process power is carried out within the range of 50 ~ 2000W. In addition, the etching process 214 is performed using a gas combination plasma containing chlorine (Cl) and oxygen (O) when the carbon and the metal component.

Subsequently, as illustrated in FIG. 5C, the organic layer 211 is etched by performing an etching process using the etched MFHM 212 as an etching mask. The etching process of a silicon (or a metal) and O ₂ are reacted with the silicon oxide film in using the gas including the O ₂ because of the bar, the etching O ₂ plasma during the process performed by a plasma method MFHM (212) As a result, the MFHM 212 functions as an etch barrier layer when the lower photoresist layer 211 is etched.

Subsequently, although not shown, an etching process using the MFHM 212 and the organic layer 211 etched in FIGS. 5B and 5C as an etching mask is performed to etch the etching target layer 210. At this time, since the MFHM 212 is applied relatively thin, all of the MFHM 212 is removed during the etching process.

Next, the organic film 211 is removed by performing a strip process. Since the organic layer 211 is formed of an organic material in a polymer form containing carbon, it may be removed by a general strip process.

As described above, in the method of manufacturing the semiconductor device according to the second exemplary embodiment of the present invention, the organic layer 211 is formed between the MFHM 212 and the etched layer 210.

First, when only the MFHM 111 is applied to the etched layer 110 as in Example 1, in order for the MFHM 111 to function as an etch barrier layer, the MFHM 111 must be formed relatively thick. In this case, the MFHM 111 is not removed during the etching process of the etching layer 110, and thus, the MFHM 111 remains on the etching layer 110 and must be separately removed.

As described above, since the silicon contained in the MFHM 111 is converted into a silicon oxide film by O ₂ , it is difficult to remove it by a general photosensitive film strip process, and the process is required because a chemical solution containing amine must be used. Can be complicated.

Thus, as in Example 2, the MFHM 212 is deposited relatively thin enough to be removed through the strip process, and the function as an etch barrier layer deteriorated as the MFHM 212 is deposited thinly is removed through the strip process. Compensation is made by forming an organic film 211 that is easy to use.

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

As described above, according to the present invention, the process can be simplified by using a hard mask containing silicon or a metal component in carbon during the semiconductor manufacturing process for forming the fine pattern.

Claims (20)

Providing a substrate on which an etched layer is formed; Applying a hard mask containing silicon or a metal component to carbon on the etched layer; Etching the hard mask by performing a first etching process using an O ₂ plasma; And Etching the etched layer by performing a second etching process using the etched hard mask; Method of forming a fine pattern of a semiconductor device comprising a. The method of claim 1, The method of forming a fine pattern of a semiconductor device is the content of the silicon or the metal component is 1 to 50% of the total amount of the hard mask. The method according to claim 1 or 2, The metal component is Ti or Zr method of forming a fine pattern of a semiconductor device. The method of claim 1, The first etching process is a method of forming a fine pattern of a semiconductor device using a CF ₄ / O ₂ gas. The method of claim 4, wherein The CF ₄ / O ₂ gas ratio is 1: 2 to 1:50 method of forming a fine pattern of a semiconductor device. The method according to claim 4 or 5, The first etching process is a fine pattern forming method of a semiconductor device performed at a process pressure of 10 ~ 300mTorr and a process power of 50 ~ 2000W. The method according to claim 4 or 5, The first etching process is a method of forming a fine pattern of a semiconductor device using a gas combination plasma containing chlorine and oxygen when the hard mask comprises the carbon and the metal component. The method of claim 1, The hard mask is a method of forming a fine pattern of a semiconductor device is removed during the second etching process. The method of claim 1, The silicon or the metal component of the hard mask reacts with the O ₂ plasma used in the first etching process is converted into an oxide film. The method of claim 1, If the hard mask is not removed during the second etching process and remains on the etched layer, performing a third etching process using a chemical solution containing an amine to remove the remaining hard mask; Method of forming a fine pattern of a semiconductor device. Providing a substrate on which an etched layer is formed; Coating an organic film in a polymer form containing carbon on the etched layer; Applying a hard mask containing silicon or a metal component to carbon on the organic layer; Etching the hard mask by performing a first etching process using an O ₂ plasma; Etching the organic layer by performing a second etching process using the etched hard mask; And Etching the etched layer by performing a third etching process using the etched organic layer and the hard mask; Method of forming a fine pattern of a semiconductor device comprising a. The method of claim 11, The method of forming a fine pattern of a semiconductor device is the content of the silicon or the metal component is 1 to 50% of the total amount of the hard mask. The method according to claim 11 or 12, The metal component is Ti or Zr method of forming a fine pattern of a semiconductor device. The method of claim 11, The second etching process is a method of forming a fine pattern of a semiconductor device using a CF ₄ / O ₂ gas. The method of claim 14, The CF ₄ / O ₂ gas ratio is 1: 2 to 1:50 method of forming a fine pattern of a semiconductor device. The method according to claim 14 or 15, The second etching process is a fine pattern forming method of a semiconductor device performed at a process pressure of 10 ~ 300mTorr and a process power of 50 ~ 2000W. The method according to claim 14 or 15, And the second etching process is performed using a gas combination plasma containing chlorine and oxygen when the hard mask comprises the carbon and the metal component. The method of claim 11, The hard mask is a method of forming a fine pattern of a semiconductor device is removed during the third etching process. The method of claim 11, The silicon or the metal component of the hard mask reacts with the O ₂ plasma used in the second etching process is converted into an oxide film. The method of claim 11, If the hard mask is not removed during the third etching process and remains on the etched layer, performing a third etching process using a chemical solution containing an amine to remove the remaining hard mask; Method of forming a fine pattern of a semiconductor device.

Images