KR20060079476A - Stain treatment chemical capable of confirming easily aluminum compound formation - Google Patents

Abstract

The present invention relates to a stain treatment liquid and a stain treatment method, wherein in the stain treatment liquid, the stain treatment liquid includes a mixture containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O). And a mixed composition ratio of ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) is 1: 4: X, and is a composition ratio (X) of deionized water (H ₂ O). It is characterized by adjusting the concentration of the mixture. According to this, it is possible to easily determine whether the aluminum compound is formed by maximizing the difference in the degree of stain between the pure aluminum and the aluminum compound as a stain treatment liquid to implement an electron microscope image.

ALUMINUM COMPOUND, STAIN TREATMENT

Description

Stain Treatment Chemical Capable of Confirming Easily Aluminum Compound Formation

1 to 3 are cross-sectional views for each process for explaining a stain treatment method using a stain treatment liquid according to an embodiment of the present invention.

4 and 5 are electron micrographs of the specimen using the stain treatment method according to an embodiment of the present invention.

<Description of Major Symbols in Drawing>

100; A first insulating film 120; Aluminum film

130; A second insulating film 140; Via Hole

150; Tungsten plug

The present invention relates to a stain treatment liquid and a stain treatment method, and more particularly, to a stain treatment liquid and a stain treatment method capable of easily confirming the formation of an aluminum compound.                         

In the case of manufacturing a conventional semiconductor device, when pure aluminum is formed as a conductive film between silicon oxide films and tungsten is formed as an interconnection, an unwanted aluminum compound (eg, Al _x F _y ) is formed between pure aluminum and a tungsten plug. It was often created.

It is known that aluminum compound (Al _x F _y ) generation is caused by injection of fluorine (F) or oxygen (O ₂ ). These unwanted aluminum compounds (Al _x F _y ) do not act as conductors because of their high resistance. Accordingly, when an unwanted aluminum compound (Al _x F _y ) is formed between aluminum and tungsten, there is a problem of causing electrical failure of the semiconductor device by increasing contact resistance.

Accordingly, the present invention has been made to solve the above-described problems in the prior art, an object of the present invention is to provide a stain treatment solution and a stain treatment method that can easily determine whether or not the formation of aluminum compounds that cause electrical failure of the semiconductor device In providing.

The stain treatment liquid according to the present invention is characterized in that it can cause a difference in stain of the aluminum compound with respect to pure aluminum.

In the stain treatment liquid according to the embodiment of the present invention, in the stain treatment liquid, the stain treatment liquid is a mixture containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) , The mixed composition ratio of ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) is 1: 4: X, the composition ratio (X) of the deionized water (H ₂ O) It is characterized by adjusting the concentration of the mixture.

According to another aspect of the present invention, there is provided a stain processing method comprising: providing a first insulating film having an aluminum film formed thereon as a metal wiring; Forming a second insulating film on the first insulating film; Selectively removing the second insulating film to form a via hole for opening the aluminum film; Preparing a specimen by filling the via hole with tungsten to form a tungsten plug electrically connected to the aluminum film; And treating the specimen with a stain treatment solution containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH), and deionized water (H ₂ O) for a predetermined time to obtain an aluminum compound between the aluminum film and the tungsten plug. Characterized in that it comprises the step of confirming the formation.

In the present invention, the aluminum film and the resultant tungsten plug formed is treated with a stain treatment solution containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) for a predetermined time to the aluminum The step of confirming whether the aluminum compound is formed between the film and the tungsten plug, the fluoride in a stain treatment solution containing the ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) The mixing composition ratio of ammonium (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) is 1: 4: 3.2, the predetermined time is 20 to 30 seconds, preferably 25 seconds do.

According to the present invention, it is possible to easily determine whether the aluminum compound is formed by maximizing the difference in the degree of stain between the pure aluminum and the aluminum compound with the stain treatment liquid and implementing the electron microscope image.

Hereinafter, a stain treatment liquid and a stain treatment method according to the present invention will be described in detail with reference to the accompanying drawings.

Embodiment

1 to 3 are cross-sectional views of processes for explaining a stain treatment method using a stain treatment liquid according to an embodiment of the present invention.

Referring to FIG. 1, a first insulating film 100 on which an aluminum film 120 is deposited is prepared as a metal wire. As the first insulating film 100, silicon oxide (SiO ₂ ) is formed by chemical vapor deposition (CVD). Although not shown in the drawing, a transistor may be formed under the first insulating layer 100 in which a plug connected to the aluminum layer 120 and a junction region contacting the plug are formed.

Referring to FIG. 2, a second insulating film 130 is formed on the first insulating film 100 on which the aluminum film 120 is formed to electrically insulate the aluminum film 120, which is a metal wiring. Then, the second insulating layer 130 is selectively etched to expose the aluminum layer 120 to form a via hole 140 connecting the metal wires. If the second insulating film 130 remains on the surface of the aluminum film 120 exposed by the via hole 140, an operation error occurs because electrons cannot move through the via hole 140. However, it is difficult to confirm whether the via hole 140 is completely opened after the via hole 140 is etched during the process. Therefore, in order to completely open the via hole 140, it is preferable to allow part of the surface of the aluminum film 120 to be over etched.

Referring to FIG. 3, the via hole 140 is filled with tungsten to form a tungsten plug 150 to prepare a specimen. At this time, in the process of filling the via hole 140 with tungsten, WF ₆ gas is used, and the WF ₆ gas is chemically reacted with the aluminum film 120 exposed to the outside to form an aluminum compound (Al _X F _Y ), for example, AlF _3. Causes formation. Since the AlF ₃ resistance is high, it cannot serve as a conductor. Therefore, the contact resistance between the aluminum film 120 and the tungsten plug 150 is greatly increased, resulting in a defect of the semiconductor chip. Therefore, it is necessary to confirm whether or not such an unwanted aluminum compound is formed.

To this end, it is preferable to image the specimen by using a scanning electron microscope (SEM) to determine whether the aluminum compound is formed using a treatment liquid that may cause a difference in staining of the aluminum compound with respect to pure aluminum.

As such, staining the specimen with a treatment solution containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH), and deionized water (H ₂ O) to induce stain differences of the aluminum compound with respect to pure aluminum may occur. desirable. Specifically, the mixed composition ratio of each component constituting the stain treatment liquid is ammonium fluoride (NH ₄ F): acetic acid (CH ₃ COOH) = 1: 4, and the concentration of the etchant is adjusted by the composition ratio of deionized water (H ₂ O). .

If the ammonium fluoride (NH ₄ F): acetic acid (CH ₃ COOH): deionized water (H ₂ O) = 1: 4: 3.2, the stain treatment time is about 20 to 30 seconds, preferably 25 seconds do. When stained with the stain treatment liquid of the present embodiment it can be easily seen through the scanning electron microscope (SEM) image whether the aluminum compound (Al _X F _Y ).

4 and 5 are scanning electron microscope (SEM) photographs of the specimens using the stain treatment method according to an embodiment of the present invention.

Staining the specimens subjected to a series of processes with the stain treatment solution of this embodiment causes a difference in the staining of the aluminum compounds with respect to pure aluminum, thus causing undesired aluminum compounds (Al) between the aluminum film 120 and the tungsten plug 150. _It is easy to know whether _X F _Y ) is formed.

Specifically, Figure 4, the aluminum film 120 and the tungsten-aluminum compound (Al _X F _Y) between the plug (150) when formed, so that the stain gap between the aluminum and the aluminum compound caused the aluminum compound (Al _X F _Y ) Is clearly shown in scanning electron microscopy (SEM) images. However, referring to FIG. 5, if the aluminum compound (Al _X F _Y ) is not formed between the aluminum film 120 and the tungsten plug 150, the aluminum compound (Al _X F _Y ) is a scanning electron microscope (SEM). You can't see it in the picture.

That is, the present embodiment the scanning electron micrograph (Figure 4) and Any aluminum compound which stains the treatment solution of an aluminum compound to the specimen unwanted after the stain treatment (Al _X F _Y) is formed (Al _X F _Y) is which is not formed By comparing the normal scanning electron micrograph (Fig. 5) with each other it is possible to monitor the occurrence of defects (aluminum compound).

Although specific embodiments of the present invention have been described with reference to the drawings, this is intended to be easily understood by those skilled in the art and is not intended to limit the technical scope of the present invention. Therefore, the technical scope of the present invention is determined by the matters described in the claims, and the embodiments described with reference to the drawings may be modified or modified as much as possible within the technical spirit and scope of the present invention.

As described above in detail, according to the stain treatment liquid and the stain treatment method according to the present invention, the electron microscope image formed with an aluminum compound can be realized by electron microscope image by maximizing the difference in the degree of stain between pure aluminum and aluminum compound as a stain treatment liquid Normal scanning electron micrographs can be compared to monitor for defects (aluminum compounds). Therefore, the stain treatment with the stain treatment liquid of the present invention has an effect that can easily know whether or not the aluminum compound is generated. In addition, since the aluminum compound can be easily identified, the risk of producing a defective device can be prevented in advance, thereby improving the yield.

Claims (3)

In the stain treatment liquid, The stain treatment liquid is a mixture containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O), The mixed composition ratio of ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) is 1: 4: X, And a concentration of the mixture by adjusting the composition ratio (X) of the deionized water (H ₂ O). Providing a first insulating film having an aluminum film formed thereon as a metal wiring; Forming a second insulating film on the first insulating film; Selectively removing the second insulating film to form a via hole for opening the aluminum film; Preparing a specimen by filling the via hole with tungsten to form a tungsten plug electrically connected to the aluminum film; And The specimen was treated with a stain treatment solution containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) for a predetermined time to form an aluminum compound between the aluminum film and the tungsten plug. Confirming whether or not; Stain treatment method comprising a. The method of claim 2, The aluminum film and the resultant product on which the tungsten plug is formed are treated with a stain treatment solution containing ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH), and deionized water (H ₂ O) for a predetermined period of time. Determining whether the aluminum compound is formed between the tungsten plug, the ammonium fluoride (NH) in a stain treatment solution containing the ammonium fluoride (NH ₄ F), acetic acid (CH ₃ COOH) and deionized water (H ₂ O) ₄ F) and the mixed composition ratio of acetic acid (CH ₃ COOH) and deionized water (H ₂ O) is 1: 4: 3.2, the predetermined time is 20 to 30 seconds.

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