KR100214551B1 - Method for fabrication sample of semiconductor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fabricating a specimen of a semiconductor. In the related art, when fabricating a specimen for analysis of a transmission electron microscope that analyzes a defect of a specific region in a semiconductor integrated circuit, it is not easy to mill a large region as easy as analysis. There is a problem that the processing time takes a lot, the present invention uses a laser cutter to produce a specimen of a semiconductor for use in a transmission electron microscope for analyzing defects in a specific area in a semiconductor integrated circuit, to produce a specimen of a transmission electron microscope The time can be shortened, and the tilting angle is increased when analyzing the specimen with a transmission electron microscope, so that various parts can be observed due to various angles.

Description

Semiconductor Specimen Fabrication Method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fabricating a semiconductor specimen, and more particularly, to a method for fabricating a semiconductor specimen that can shorten the fabrication time and improve the structure of the specimen.

In general, as the cell size of a semiconductor device decreases, a transmission electron microscope (TEM) occupies an important position as a device for analyzing defects in a specific area in a semiconductor integrated circuit.

Not only can the cross-sectional structure of the wafer be observed using the transmission electron microscope, but also the high magnification observation, qualitative and quantitative analysis of a specific area within the wafer structure, which is very difficult with other analysis equipment.

However, there is a difficulty in processing very thin enough that electrons can penetrate the sample.

In general, ion milling is used to fabricate the specimen, which is to grind or polish the sample up to 100 μm, thin the area of interest to 5 μm, and finally use argon ions next to the area of interest. It is a way to get a very thin area by making holes.

However, the ion milling method as described above is difficult to fabricate the specimen in a specific region because the specimen cannot be fabricated while observing the region of interest accurately.

Therefore, recently, a method of fabricating a specimen using a focused ion beam (hereinafter referred to as FIB) is used.

In the method using the FIB, as shown in FIGS. 1A to 1D, a specific region in the wafer 10 is cut into a specimen 20 of 50 μm × 3 mm (FIG. 1B), and both sides of the observation site are centered. The part is milled to 20 μm × 20 μm using FIB to produce a specimen 30a (FIG. 1c), and the thickness of the region of interest is finally processed into a thin specimen 40a of 0.1 μm (FIG. 1d).

However, the conventional method for fabricating a specimen of a semiconductor using FIB takes about 2 hours to process by milling to 20 μm × 20 μm and has difficulty in processing a large area.

If a large area is not secured, X-rays are difficult to detect when analyzing the wafer 10 with an energy dispersive spectroscopy (EDS) within the transmission electron microscope, and the tilting angle is limited, making the transmission electron microscope analysis difficult. There has been a demand for a supplement.

Accordingly, the present invention has been made in view of the above problems, and by fabricating a specimen using a laser cutter, it is easy to process a large area in a short time, thereby improving the structure and manufacturing time of the specimen in a specific region in a semiconductor integrated circuit. It is an object of the present invention to provide a method for manufacturing a semiconductor specimen that can be shortened.

1A to 1D illustrate a method for fabricating a specimen of a conventional semiconductor.

Figure 1e is a diagram showing the tilt angle of the specimen by a conventional method for producing a specimen of a semiconductor.

FIG. 1F is a diagram showing an increase in sensitivity of an energy dispersive spectroscopy (EDS) of a specimen by a conventional method for fabricating a semiconductor.

2A to 2D illustrate a method of fabricating a specimen of a semiconductor of the present invention.

Figure 2e is a diagram showing the tilting angle of the specimen by the method for manufacturing a specimen of the semiconductor of the present invention.

Figure 2f is a diagram showing the increase in the energy dispersive spectroscopy (EDS) sensitivity of the specimen by the method for fabricating the semiconductor of the present invention.

* Explanation of symbols for main parts of the drawings

10: wafer 20: 50μm × 3000μm specimen

30: The specimen which milled both observation parts using the laser cutter

40: specimen milled to a thickness of 0.1 μm using a laser cutter

In order to achieve the above object, the present invention provides a method for manufacturing a semiconductor specimen, characterized in that for producing a specimen of the semiconductor used in the transmission electron microscope to analyze the defect of a specific region in the semiconductor integrated circuit using a laser cutter. do.

Hereinafter, with reference to the accompanying drawings a method for producing a test piece of a semiconductor of the present invention will be described in detail.

In the method for fabricating a semiconductor specimen of the present invention, as shown in FIGS. 2A to 2D, the cut portion in the wafer 10 is cut into a specimen 20 of 50 µm × 3000 µm (FIG. 2D).

Then, both parts of the specimen 30 are milled using a laser cutter around the observation site. (FIG. 2C)

The specimen is milled using a laser cutter to obtain a specimen 40 having a final thickness of 0.1 μm (FIG. 2d).

The laser cutter makes it easy to process 50μm x 50μm in the air, making it easy to process large areas and shorten uptime.

2d shows the final specimen 40 where a large area is milled.

The semiconductor specimen of the present invention has a wide tilting angle since a wide area is milled, as shown in FIG. 2E.

Therefore, when analyzing the specimen using a transmission electron microscope, it is possible to reduce the probability of electrons hitting the wall and obstruct the specimen observation, and to observe various parts due to various angles.

Figure 2f shows that by milling a large area using a laser cutter, the ability to detect x-rays generated at the site of interest improves the analysis of wafers with energy dispersive spectroscopy (EDS). Giving.

Narrow milled areas reduce the accuracy of the analysis because the x-rays generated in the sample can hit the silicon walls and regenerate the silicon x-rays.

According to the method for fabricating a semiconductor specimen of the present invention, it is possible to shorten the time for fabricating a specimen of a transmission electron microscope that analyzes a specific region of the semiconductor wafer, and to increase the tilting angle when analyzing the specimen with the transmission electron microscope. It is effective to observe several parts.

Claims (1)

A method for fabricating a semiconductor specimen, comprising fabricating a specimen of a semiconductor for use in a transmission electron microscope for analyzing defects in a specific region in a semiconductor integrated circuit using a laser cutter.