KR100569567B1 - A align key of the semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment key of a semiconductor device, and to align the semiconductor substrate to a predetermined thickness to respond to a predetermined light source in order to omit the key open mask process to simplify the process and thereby reduce the production cost of the semiconductor device. A trench alignment key is formed in the key region, and a polysilicon layer, a tungsten silicide layer, a hard mask layer, an interlayer insulating film, and a photoresist layer are formed on the semiconductor substrate including the trench alignment key, and a tungsten silicide layer. By forming an alignment key of a semiconductor device having a predetermined thickness so as to respond to the predetermined light source, it is a technology capable of improving productivity due to process simplification and thereby improving characteristics and reliability of the semiconductor device.

Description

A align key of the semiconductor device

1 is a cross-sectional view showing an alignment key formed in accordance with the present invention.

FIG. 2 is a graph illustrating the degree of alignment change according to the thickness of tungsten silicide as the gate electrode material layer. FIG.

3A and 3B are graphs illustrating a change in alignment according to the depth of device isolation layers.

<Description of Symbols for Main Parts of Drawings>

11 semiconductor substrate 13 trench type alignment key

15 polysilicon layer 17 tungsten silicide layer

19: hard mask layer 21: interlayer insulating film

23: photosensitive film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment key of a semiconductor device. In particular, an element isolation film and a gate electrode material of an alignment key region are omitted in order to omit a key open mask process of an alignment key for a subsequent process after a device isolation film forming process. The present invention relates to a technique for controlling the thickness of a layer and measuring alignment keys using a predetermined light source.

In general, the manufacturing process of a semiconductor device provides a semiconductor device with predetermined characteristics by forming each device formed in a subsequent process using an alignment key formed on a wafer.

Although not shown, a method of forming an alignment key of a semiconductor device according to the related art is as follows.

First, an isolation layer defining an active region is formed on a semiconductor substrate.

Here, the device isolation layer is formed in a trench type. In this case, the device isolation layer of the alignment key region, which is the region where the alignment key is to be formed, serves as the alignment key in the subsequent process.

At this time, the upper structure of the semiconductor substrate is formed in a flattened form.

Then, an alignment key is formed by a key open mask process to form the alignment key on the entire surface.

Then, the subsequent process is performed using the alignment key formed by the key open mask process.

However, in the case where the key open mask process is omitted, it is difficult to align the subsequent process so that a structure necessary for a predetermined position cannot be formed.

As described above, the alignment key and the alignment key measuring method of the semiconductor device according to the related art are formed so that the alignment keys necessary for the manufacturing process of the semiconductor device having the multilayer structure are formed as the reference for each layer. There is a problem that the production cost increases. In addition, when the alignment key forming process is omitted, it is difficult to proceed with the subsequent process.

The present invention provides a semiconductor substrate including an element isolation film by forming an element isolation film for an alignment key in an alignment key region of a semiconductor substrate and using the device isolation film as an alignment key without an alignment key open process in a subsequent process. Forming a gate electrode material layer on the upper side, by adjusting the thickness to form an alignment mark and to provide an alignment key of the semiconductor device to easily measure the alignment key by measuring the degree of alignment using a predetermined light source. The purpose is.

In order to achieve the above object, the alignment key of the semiconductor device according to the present invention,
A gate electrode material including a trench alignment key formed in an alignment key region of a semiconductor substrate and a stacked structure of a polysilicon layer, a tungsten silicide layer, a hard mask layer, an interlayer insulating film, and a photoresist film formed on the semiconductor substrate including the trench alignment key. Including a layer, in order to omit the key open mask process, the trench-type alignment key is formed to a predetermined thickness to respond to a predetermined light source, and the tungsten silicide layer is formed to a predetermined thickness to react to a predetermined light source. Here, it is preferable that a predetermined light source uses a red laser having a wavelength of 633 nm. In addition, it is preferable that the trench type alignment key responding to a predetermined light source is formed to a thickness of 1 to 450 mW, and the tungsten silicide layer is formed to a thickness of 1000 mW or less.

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

1 is a cross-sectional view showing an alignment key of a semiconductor device formed in accordance with the present invention.

First, the trench type alignment key 13 is formed in the alignment key region of the semiconductor substrate 11, and is formed to have a thickness in response to a predetermined light source.

At this time, the trench type alignment key 13 is formed to a thickness of 1 to 450 kHz.

In addition, a red laser having a wavelength of 633 nm is used as the predetermined light source.

Subsequently, the trench alignment key 13 is read using a red laser having a wavelength of 633 nm in a subsequent process, and an alignment process using the same is performed.

In addition, a polysilicon layer 15, a tungsten silicide layer 17, a hard mask layer 19, and an interlayer insulating layer 21, which are a gate electrode material layer, is formed on the semiconductor substrate 11 including the trench type alignment key 13. And the photosensitive film 23 is formed.

At this time, the tungsten silicide layer 17 is formed to a thickness in response to a red laser having a wavelength of 633 nm, the thickness is formed to 1000 kHz or less.

FIG. 2 is a graph illustrating a change in alignment accuracy with respect to a change in thickness of the tungsten silicide layer 17. As the thickness of the tungsten silicide layer 17 decreases, the accuracy increases.

At this time, it can be seen that the alignment accuracy is high in the tungsten silicide layer 17 having a predetermined thickness when using a red laser having a wavelength of 633 nm.

3A and 3B are graphs showing a change in accuracy of alignment according to a change in thickness of the trench-type alignment key 13, and having a predetermined thickness without using a key open mask process when using a red laser having a wavelength of 633 nm. It can be seen that the accuracy of the alignment is high in the trench type alignment key 13.

 As described above, the alignment mark of the semiconductor device according to the present invention can improve the accuracy of alignment by using a specific laser without performing a separate key open mask process on the semiconductor substrate on which the trench type alignment key is formed. The key open mask process can be omitted, thus simplifying the process and improving the productivity, properties and reliability.

Claims (4)

A trench type alignment key formed in the alignment key region of the semiconductor substrate; And A gate electrode material layer including a polysilicon layer, a tungsten silicide layer, a hard mask layer, an interlayer insulating layer, and a photosensitive layer formed on the semiconductor substrate including the trench type alignment key is included. In order to omit a key open mask process, the trench type alignment key is formed to have a predetermined thickness to respond to a predetermined light source, and the tungsten silicide layer is formed to have a predetermined thickness to react to the predetermined light source. . The method of claim 1, And the predetermined light source uses a red laser having a wavelength of 633 nm. The method of claim 1, The trench type alignment key is a semiconductor device, characterized in that formed in a thickness of 1 to 450Å. The method of claim 1, And the tungsten silicide layer is formed to a thickness of 1000 Å or less.

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