KR20040059260A - shallow trench isolation of semiconductor device and its manufacturing method - Google Patents

Abstract

PURPOSE: An STI(Shallow Trench Isolation) structure and a method for manufacturing the same are provided to grow an isolation layer at low-temperature by using a silicon nozzle. CONSTITUTION: A plurality of trenches(10) are formed in a silicon substrate(2). A plurality of elongated silicon nozzles(12) are formed between the trenches. An isolation layer(14) is grown in the trenches to surround the silicon nozzles. The size of the silicon nozzle is 0.1-0.5 micrometer.

Description

Shallow trench isolation structure of semiconductor device and its manufacturing method

The present invention relates to a structure of a shallow trench separator of a semiconductor device and a method of manufacturing the same. More specifically, no voids are formed when an insulating film is grown inside the trench, and an insulating film can be formed even at low temperatures, thereby improving device characteristics. The present invention relates to a shallow trench separator structure of a semiconductor device and a method of manufacturing the same.

In the semiconductor device, cells of unit devices such as transistors and capacitors exist according to the capacity of the semiconductor device, and these cells need to be electrically separated for operation characteristics independent of each other.

Two separation methods are commonly used for such electrical separation. The first method is Local Oxidation of Silicon (LOCOS) and the second method is Shallow Trench Isolation (STI). Meanwhile, as the size and thickness of semiconductor devices become smaller, they have advantages in active area encroachment, smaller junction edge capacitance, and planar surface topography. STI technology is mainly used, and LOCOS technology is not used well.

However, since the STI technique grows an insulating film inside a relatively wide trench, a large number of voids are likely to occur inside the insulating film, thereby degrading the electrical characteristics of the device. In addition, since the insulating film is grown at a high temperature of 100 ° C. or higher, there is a problem that the electrical characteristics of the device are further deteriorated and the cost is also increased.

SUMMARY OF THE INVENTION The present invention is to overcome the above-mentioned problems, and an object of the present invention is to prevent the formation of voids during the growth of the insulating film inside the trench, and to form the insulating film even at low temperature. A low trench separator structure and a method of manufacturing the same are provided.

1 is a cross-sectional view illustrating a structure of a shallow trench separator of a semiconductor device according to the present invention.

2A to 2E are sequential explanatory diagrams showing a method of manufacturing a shallow trench separator of a semiconductor device according to the present invention.

Description of the main symbols in the drawings

2; Silicon substrate 4; Silicon oxide

6; Silicon nitride film 8; Tetra Ethyl Ortho Silicate (TEOS)

10; Trench 12; Silicone nozzle

14; Insulating film

In order to achieve the above object, the present invention provides a shallow trench isolation structure for electrically separating a plurality of semiconductor devices from a silicon substrate, the trench having a predetermined depth formed in the silicon substrate, and at the bottom of the trench. And a plurality of silicon nozzles extending a predetermined length toward the upper portion, and an insulating film formed to cover the plurality of silicon nozzles inside the trench and grown to a predetermined thickness.

Here, the silicon nozzle is preferably formed within the size of 0.1 ~ 0.5㎛.

In addition, in order to achieve the above object, the method of manufacturing a shallow trench separator of a semiconductor device according to the present invention comprises the steps of sequentially forming a silicon oxide film, a silicon nitride film, and TEOS (Tetra Ethyl Ortho Silicate) on a silicon substrate, and the TEOS After forming the photo pattern thereon, removing the TEOS, the nitride film and the oxide film by a predetermined region by dry etching, and cleaning the surface of the silicon substrate exposed through the oxide film, a plurality of partial regions of the surface is hydrophobic And forming a trench by etching the exposed silicon substrate using the oxide film as a mask, and forming a plurality of silicon nozzles extending from the bottom of the trench to the top. An insulating film is formed to surround the plurality of silicon nozzles inside the trench. That consisting of the steps of such features.

Here, the insulating film growth is preferably performed in the range of 50 ~ 100 ℃.

As described above, according to the shallow trench isolation structure of the semiconductor device and the manufacturing method thereof, the voids can be essentially removed during the growth of the insulating film, and the insulating film can be grown at a low temperature to provide the electrical properties of the semiconductor device. There is an advantage that can significantly improve the characteristics.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings such that those skilled in the art may easily implement the present invention.

Referring to Fig. 1, a shallow trench isolation structure of a semiconductor device according to the present invention is shown.

As shown, a substantially plate-shaped silicon substrate 2 is provided, and the trench 10 is formed at a predetermined depth to electrically separate a plurality of semiconductor devices (not shown). It is. A plurality of silicon nozzles 12 extending a predetermined length from the bottom surface of the trench 10 toward the top is formed, the silicon nozzle 12 is preferably formed within 0.1 ~ 0.5㎛ size. In addition, the insulating layer 14 is grown to a predetermined thickness in the upper part of the trench 10 while surrounding the plurality of silicon nozzles 12.

As described above, according to the present invention, a plurality of silicon nozzles 12 are formed in the trench 10, and the insulating film 14 is formed around the silicon nozzle 12, thereby essentially forming the insulating film 14. The voids are not formed, and thus the electrical characteristics of the semiconductor device are improved.

2A to 2E, a method of manufacturing a shallow trench separator of a semiconductor device according to the present invention is shown in sequence.

First, as shown in FIG. 2A, a silicon oxide film 4, a silicon nitride film 6, and a TEOS 8 (Tetra Ethyl Ortho Silicate) are sequentially formed on the silicon substrate 2.

Subsequently, as shown in FIG. 2B, after forming a photo pattern (not shown) on the TEOS 8, the TEOS 8, the nitride film 6, and the oxide film 4 are dried by a predetermined area by dry etching. It is removed so that the surface of the silicon substrate 2 is exposed outward.

Then, as shown in Fig. 2C, the surface of the silicon substrate 2 exposed through the plurality of films is wetted so that a plurality of partial regions of the surface turn hydrophobic.

Subsequently, as shown in FIG. 2D, the exposed silicon substrate 2 is etched using the plurality of films as a mask to form a trench 10 having a predetermined depth, and the bottom surface of the trench 10. Extending from above, a number of silicon nozzles 12 are formed.

That is, a predetermined region of the surface of the silicon substrate 2 is changed to hydrophobicity by the cleaning process, and the hydrophobicly changed portion remains without being etched by the etching process, so that the silicon nozzle 12 having a predetermined length naturally occurs. It is formed.

Subsequently, as illustrated in FIG. 2E, the insulating layer 14 is grown while surrounding the plurality of silicon nozzles 12 inside the trench 10.

At this time, since a plurality of silicon nozzles 12 are already formed inside the trench 10, the insulating film 14 is grown very uniformly. In fact, the growth of the insulating film 14 may be performed in a range of approximately 50 to 100 ° C. to minimize the thermal effect on the semiconductor device. In this case, no voids may be formed inside the insulating film 14. do.

As described above, the shallow trench isolation structure of the semiconductor device and the manufacturing method thereof according to the present invention can fundamentally remove voids during the growth of the insulating film, and also enable the insulating film to be grown at low temperature, thereby reducing the electrical conductivity of the semiconductor device. There is an effect that can significantly improve the characteristics.

What has been described above is just one embodiment for carrying out the structure of the shallow trench isolation structure and the manufacturing method of the semiconductor device according to the present invention, the present invention is not limited to the above-described embodiment, in the claims As claimed, any person having ordinary skill in the art without departing from the gist of the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (4)

In a shallow trench separator structure for electrically separating a plurality of semiconductor devices from a silicon substrate, Trenches of predetermined depth formed in said silicon substrate; A plurality of silicon nozzles extending a predetermined length from the bottom of the trench to the top; And, A shallow trench isolation structure of a semiconductor device including an insulating film formed to cover the plurality of silicon nozzles inside the trench and grown to a predetermined thickness. The shallow trench isolation structure of claim 1, wherein the silicon nozzle is formed within a size of about 0.1 μm to about 0.5 μm. Sequentially forming a silicon oxide film, a silicon nitride film, and TEOS (Tetra Ethyl Ortho Silicate) on the silicon substrate; Forming a photo pattern on the TEOS, and then removing the TEOS, the nitride layer, and the oxide layer by a predetermined region by dry etching; Cleaning the surface of the silicon substrate exposed through the oxide film to cause a plurality of partial regions of the surface to become hydrophobic; Etching the exposed silicon substrate to form a trench using the oxide film as a mask, and forming a plurality of silicon nozzles extending from the bottom of the trench to an upper portion thereof; And, And covering the plurality of silicon nozzles inside the trench to allow an insulating film to be grown. The method of claim 3, wherein the insulating film growth is performed in a range of 50 ° C. to 100 ° C. 5.