KR20060068286A - Method for manufacturing semiconductor device - Google Patents

Abstract

The method of manufacturing a semiconductor device according to the present invention forms a nitride spacer on an upper edge of an isolation layer of a semiconductor substrate to prevent damage to the gapfill oxide layer forming the isolation layer upon contact misalignment. A technique of suppressing a change in device characteristics due to stress and preventing interference of the deuterium heat treatment process caused by the etch stop nitride film is disclosed to improve device reliability.

Description

Manufacturing Method of Semiconductor Device {METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE}

1A and 1B are cross-sectional views illustrating a method of manufacturing a semiconductor device and a problem thereof according to the prior art.

2A and 2B are cross-sectional views illustrating a method of manufacturing a semiconductor device and a problem thereof according to the prior art.

3A to 3I are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention.

4A through 4J are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a second embodiment of the present invention.

<Explanation of Signs of Major Parts of Drawings>

1, 10, 100, 200: semiconductor substrate 2, 20: device isolation film

3, 85, 255: interlayer insulating film 4, 90, 260: contact

30: gate oxide film 40: gate poly

50: LDD oxide film 60: LDD nitride film

70: source / drain region 80: etch stop nitride film

105, 205: pad oxide film 110, 210: pad nitride film

115, 215: photoresist pattern 120, 220: trench                 

125: first gapfill oxide film 130: second gapfill oxide film

135, 245: nitride film 140, 250: nitride film spacer

230: liner nitride film 240: gap fill oxide film

The present invention relates to a method of manufacturing a semiconductor device, to form a nitride spacer in the upper edge of the device isolation layer of the semiconductor substrate to prevent damage to the gap fill oxide film forming the device isolation layer in the case of contact misalignment, the etching stop formed on the front The present invention relates to a method for manufacturing a semiconductor device which suppresses a change in device characteristics due to stress of a nitride film and prevents interference of the deuterium heat treatment process caused by the etch stop nitride film to improve device reliability.

1A and 1B are cross-sectional views illustrating a method of manufacturing a semiconductor device and a problem thereof according to the prior art.

Referring to FIG. 1A, a contact 3 is formed in an active region of a semiconductor substrate 1 on which an isolation layer 2 is formed.

Referring to FIG. 1B, in the process of forming the contact 3 according to the related art, the device isolation layer 2 formed of an oxide film is damaged due to excessive etching (A) while the contact 3 is misaligned.

Recently, in order to prevent damage to the device isolation layer, an etch stop nitride film is formed and a contact is formed on the semiconductor substrate as shown in FIG. 2A.

2A and 2B are cross-sectional views illustrating a method of manufacturing a semiconductor device and a problem thereof according to the prior art.

Referring to FIG. 2A, an isolation layer 20 and a gate electrode are formed on the semiconductor substrate 10. In this case, the gate electrode preferably includes a gate oxide layer 30 and a gate poly 40.

The LDD oxide film 50 and the LDD nitride film 60 are formed on the sidewalls of the gate electrode and etched to form LDD spacers, and then ion implantation is performed to form the source / drain region 70.

Next, an etch stop nitride film 80 is formed on the entire surface of the semiconductor substrate 10 including the gate electrode.

In this case, the etch stop nitride film 80 may be formed to prevent excessive etching of the gapfill oxide film constituting the device isolation layer 20 when misalignment occurs in the forming of the contact.

Referring to FIG. 1B, a contact 70 is formed to be connected to the source / drain region 50.

In the method of manufacturing a semiconductor device according to the related art, the etch stop nitride film formed on an upper portion of a semiconductor substrate changes the mobility of a carrier by applying a strong stress to a lower transistor, thereby changing characteristics of the device and improving reliability of the device. In order to prevent diffusion of the deuterium molecules in the deuterium heat treatment process performed instead of the H ₂ heat treatment process, there is a problem in improving reliability.

In order to solve the above problems, a nitride spacer is formed on the upper edge of the device isolation layer of the semiconductor substrate to prevent damage to the gap fill oxide layer forming the device isolation layer when the contact is misaligned, and due to the stress of the etch stop nitride film formed on the entire surface of the semiconductor substrate. It is an object of the present invention to provide a method for manufacturing a semiconductor device which suppresses a change in device characteristics and prevents interference of the deuterium heat treatment process caused by the etch stop nitride film to improve device reliability.

A method of manufacturing a semiconductor device according to the first embodiment of the present invention

Sequentially forming a pad oxide film and a pad nitride film on the semiconductor substrate;

Etching the pad nitride film, the pad oxide film, and the semiconductor substrate having a predetermined depth to form a trench in the device isolation region;

Forming a first gap fill oxide film on the entire surface and sequentially forming a second gap fill oxide film filling the trench;

Planarization etching until the pad nitride layer is exposed and removing the pad nitride layer;

Partially etching sidewalls of the first and second gapfill oxide layers, wherein the first gapfill oxide layer is further etched;                     

Forming a nitride spacer on sidewalls of the first and second gapfill oxide layers

Characterized in that it comprises a.

A method of manufacturing a semiconductor device according to a second embodiment of the present invention

Sequentially forming a pad oxide film and a pad nitride film on the semiconductor substrate;

Etching the pad nitride film, the pad oxide film, and the semiconductor substrate having a predetermined depth to form a trench in the device isolation region;

Forming a sidewall oxide film on the inner wall of the trench;

Forming a liner nitride film on the entire surface of the semiconductor substrate including the trench;

Forming a gapfill oxide film filling the trench;

Flattening etching until the liner nitride layer is exposed, removing the liner nitride layer and the pad nitride layer, but over-etching the liner nitride layer;

Partially etching sidewalls of the gapfill oxide layer;

Forming a nitride spacer on sidewalls of the gapfill oxide layer

Characterized in that it comprises a.

Hereinafter, with reference to the accompanying drawings a first embodiment of the present invention will be described in detail.

3A to 3I are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention.                     

Referring to FIG. 3A, a photoresist layer pattern 115 including a pad oxide layer 105, a pad nitride layer 110, and an isolation region may be sequentially formed on the semiconductor substrate 100.

Referring to FIG. 3B, the trench 120 is formed by etching the pad nitride layer 110 and the pad oxide layer 102 using the photoresist pattern 115 as a mask.

Referring to FIG. 3C, the trench is formed by sequentially forming the first gapfill oxide film 125 and the second gapfill oxide film 130.

In this case, it is preferable that the first gap fill oxide film 125 is formed to have a thickness of 200 to 1000 GPa using a USG or TEOS film, and the second gap fill oxide film 130 is formed of an HDP oxide film.

Referring to FIG. 3D, the first and second gap fill oxide layers 125 and 130 are planarized and etched until the pad nitride layer 110 is exposed. In the planarization etching process, the first and second gap fill oxide layers 125 and 130 may be etched to a thickness of 100 to 700 Å.

Referring to FIG. 3E, the pad nitride film 110 is removed.

Referring to FIG. 3F, the sidewalls of the first gapfill oxide film 125 and the second gapfill oxide film 130 are partially etched, but the first gapfill oxide film 125 is further etched.

The etching process is performed by a wet etching process using an aqueous solution of HF or BOE, and the first gapfill oxide layer 125 has a high etching selectivity with respect to the second gapfill oxide layer 130, such as 'B'. 125) is more likely to be etched.

Referring to FIG. 3G, a nitride film 135 is formed on the entire surface of the semiconductor substrate 100 including the device isolation region.                     

Here, the nitride film 135 is preferably formed to a thickness of 200 to 800 kPa.

Referring to FIG. 3H, the nitride layer 135 on the active region is etched to form nitride layer spacers 140 on sidewalls of the first gap fill oxide layer 125 and the second gap fill oxide layer 130.

Referring to FIG. 3I, an interlayer insulating layer 145 is formed on the entire surface of the semiconductor substrate, and the interlayer insulating layer 145 is etched to form a contact 150 connecting the active regions.

Hereinafter, with reference to the accompanying drawings a second embodiment of the present invention will be described in detail.

4A through 4J are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a second embodiment of the present invention.

Referring to FIG. 4A, a pad oxide layer 205, a pad nitride layer 210, and a photoresist layer pattern 215 defining element isolation regions are sequentially formed on the semiconductor substrate 200.

Referring to FIG. 4B, a trench 220 is formed by etching the pad nitride layer 210 and the pad oxide layer 205 using the photoresist pattern 215 as a mask.

Referring to FIG. 4C, the sidewall oxide layer 225 is formed on the inner wall of the trench 220.

Referring to FIG. 4D, a liner nitride layer 230 is formed on the entire surface of the semiconductor substrate 200 including the trench 220, and then a gap fill oxide layer 240 filling the trench 220 is formed.

Here, the liner nitride film 230 is preferably formed to a thickness of 200 to 1000 kPa.

Referring to FIG. 4E, the planarization etching process is performed until the liner nitride layer 230 is exposed.

Referring to FIG. 4F, the liner nitride layer 230 and the pad nitride layer 210 are etched and removed, but the liner nitride layer 230 is excessively etched.

At this time, the liner nitride film 230 is excessively etched from the surface of the semiconductor substrate on which the pad oxide film 205 is formed to have a depth of 200 to 100 μs so that a gap is formed between the gap fill oxide film 240 and the sidewall oxide film 225, such as 'C'. It is desirable to do so. The excessive etching process is preferably performed by increasing the etching time with a phosphoric acid solution.

Referring to FIG. 4G, sidewalls of the gap fill oxide layer 240 are partially etched.

When etching the gap fill oxide layer 240, the wet etching is performed using HF or BOE aqueous solution, and the etching is performed to a thickness of 100 to 800 kPa. In this case, the sidewalls of the gap fill oxide layer 240 may be partially etched.

Referring to FIG. 4H, the nitride film 245 is formed on the entire surface of the semiconductor substrate including the device isolation region.

Here, the nitride film 245 is preferably formed to a thickness of 300 to 1000 kPa.

Referring to FIG. 4I, the nitride film 245 is etched to form the nitride film spacer 250 on the sidewall of the gap fill oxide film 240.

Referring to FIG. 4J, an interlayer insulating layer 255 is formed on the semiconductor substrate, and a contact 260 is formed to etch the interlayer insulating layer 255 to connect the active regions.

 The method of manufacturing a semiconductor device according to the present invention forms a nitride spacer on an upper edge of an isolation layer of a semiconductor substrate to prevent damage to the gapfill oxide layer forming the isolation layer upon contact misalignment. By suppressing the change in device characteristics due to stress and preventing the deuteration heat treatment process caused by the etch stop nitride film, there is an effect of improving the reliability of the device.

In addition, the preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and changes are claimed in the following claims It should be seen as belonging to a range.

Claims (12)

Sequentially forming a pad oxide film and a pad nitride film on the semiconductor substrate; Etching the pad nitride film, the pad oxide film, and the semiconductor substrate having a predetermined depth to form a trench in the device isolation region; Forming a first gap fill oxide film on the entire surface and sequentially forming a second gap fill oxide film filling the trench; Planar etching and removing the pad nitride layer until the pad nitride layer is exposed; Partially etching sidewalls of the first and second gapfill oxide layers, wherein the first gapfill oxide layer is further etched; And Forming a nitride spacer on sidewalls of the first and second gapfill oxide layers; Method of manufacturing a semiconductor device comprising a. The method of claim 1, The first gap fill oxide film is a method of manufacturing a semiconductor device, characterized in that formed by USG or TEOS film of 200 to 1000 Å thickness. The method of claim 1, And the second gap fill oxide film is formed of an HDP oxide film. The method of claim 1, The method of claim 1, wherein the first and second gap fill oxide layers are etched in a thickness of 100 to 700 GPa in the planarization etching process. The method of claim 4, wherein The first gap fill oxide layer has a difference in etching selectivity from the second gap fill oxide layer in a wet etching process using an HF or BOE aqueous solution. The method of claim 1, The nitride film is a manufacturing method of a semiconductor device, characterized in that formed in a thickness of 200 to 800Å. Sequentially forming a pad oxide film and a pad nitride film on the semiconductor substrate; Etching the pad nitride film, the pad oxide film, and the semiconductor substrate having a predetermined depth to form a trench in the device isolation region; Forming a sidewall oxide film on the inner wall of the trench; Forming a liner nitride film over an entire surface of the semiconductor substrate including the trench; Forming a gapfill oxide layer filling the trench; Planar etching until the liner nitride layer is exposed, and removing the liner nitride layer and the pad nitride layer, but over-etching the liner nitride layer; Partially etching sidewalls of the gapfill oxide layer; And Forming a nitride spacer on sidewalls of the gapfill oxide layer; Method of manufacturing a semiconductor device comprising a. The method of claim 7, wherein The liner nitride film is a manufacturing method of a semiconductor device, characterized in that formed in a thickness of 200 to 1000Å. The method of claim 7, wherein The liner nitride film is a method of manufacturing a semiconductor device, characterized in that for performing the excessive etching so as to etch a depth of 200 ~ 100Å from the surface of the semiconductor substrate. The method of claim 7, wherein A method of manufacturing a semiconductor device, characterized in that the wet etching is performed using an aqueous HF or BOE solution during the sidewall etching of the gapfill oxide layer. The method of claim 7, wherein The gap fill oxide film is etched to a thickness of 100 to 800 kPa, the manufacturing method of a semiconductor device. The method of claim 7, wherein The nitride film is a semiconductor device manufacturing method, characterized in that formed in a thickness of 300 to 1000 내지.

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