KR20100038014A

KR20100038014A - Checking apparatus and checking method for semiconductor substrate

Info

Publication number: KR20100038014A
Application number: KR1020080097421A
Authority: KR
Inventors: 이성진
Original assignee: 삼성전자주식회사
Priority date: 2008-10-02
Filing date: 2008-10-02
Publication date: 2010-04-12

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate inspection device and method for more accurately measuring defects in a semiconductor substrate using interference of light.

To this end, the present invention divides the light emitted from the light source unit into the first light and the second light by using a beam splitter, and reflects the first light to the inspection area of the semiconductor substrate by reflecting the second light. The present invention provides a method for inspecting a semiconductor substrate that can more accurately measure defects of the semiconductor substrate by increasing the sensitivity of the light by interfering with the light and increase the yield of the semiconductor.

Description

Semiconductor substrate inspection apparatus and its method {CHECKING APPARATUS AND CHECKING METHOD FOR SEMICONDUCTOR SUBSTRATE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate inspection apparatus and a method thereof, and more particularly, to a semiconductor substrate inspection apparatus and a method capable of more accurately measuring a defect of a semiconductor substrate using interference of light.

In general, a semiconductor device includes a fab (FAB) process for forming an electrical circuit on a silicon wafer used as a semiconductor substrate, and an EDS (Electrical Die) for inspecting electrical characteristics of the semiconductor devices formed in the fab process described above. Sorting) process and a package process for encapsulating and individualizing the above-mentioned semiconductor devices with epoxy resin, respectively.

The fab process includes a deposition process for forming a film on a semiconductor substrate, a chemical and mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and an electrical film for the film using the photoresist pattern. An etching process for forming a pattern having a characteristic, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, a cleaning process for removing impurities on the semiconductor substrate, and a semiconductor substrate having films and patterns Inspection process for detecting defects, and the like.

On the other hand, defects in semiconductor substrates, such as foreign matters remaining on the semiconductor substrate, are recognized as an important factor that degrades the operation performance and productivity of the semiconductor device due to the high integration of the semiconductor device, and the importance of an inspection process for detecting such defects This is even more highlighted.

According to an aspect of the present invention to provide a method for more accurately measuring the defect of the semiconductor substrate using the interference of light.

To this end, an inspection apparatus and method for a semiconductor substrate according to an embodiment of the present invention include a semiconductor substrate inspection apparatus for inspecting a defect of a substrate, the light source unit emitting light; and the light as the first light and the second light. And separating the first light from the inspection area of the semiconductor substrate by reflecting the first light, and the second light interfering with the reflected first light.

Preferably, the light source unit includes a laser light source or a lamp light source.

It is preferable to further include a light detector for detecting the interference light and converts it into an electrical signal.

The apparatus may further include a defect determining unit configured to determine a defect of the semiconductor substrate using the electrical signal converted from the photodetector.

On the other hand, the semiconductor substrate inspection method according to an embodiment of the present invention emits light from the light source unit, and separates the light into the first light and the second light, the first light is irradiated to the inspection area of the semiconductor substrate And reflecting the second light interferes with the reflected first light to detect a defect in the substrate.

Preferably, the interfering light is detected and the defect of the substrate is detected using the detected light.

On the other hand, according to one aspect of the present invention it is possible to increase the sensitivity by interfering light reflected on the semiconductor substrate with other light, and the higher the sensitivity of the light reflected from the substrate can be more accurately determine the defects of the semiconductor substrate It can increase the yield and manage the defect well.

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

1 is a perspective view showing an inspection apparatus of a semiconductor substrate according to an embodiment of the present invention.

As shown therein, the inspection apparatus 1 of the semiconductor substrate is for inspecting defects existing on the substrate 4 and supports the support 5, the light source 2, the beam splitter 3, and the light detector 6. ), A defect determining unit 7 and a control unit 8 are provided.

The supporting part 5 functions to support the substrate 4 so that defects can be inspected on the substrate 4, and an electrostatic chuck that can fix the substrate 4 by using electrostatic force is supported by the supporting part ( 5) can be used.

The light source unit 2 emits light to inspect defects present on the substrate 4, and a lamp light source using a lamp or a laser light source using a laser may be used. In addition, the above-described laser may be a krypton fluoride (KrF) excimer laser, an argon fluoride (ArF) excimer laser, an argon (Ar) laser, or the like.

The beam splitter 3 splits the beam irradiated from the light source unit 2 into the first light L1 and the second light L2. The first light is incident on the surface of the substrate 4 at a predetermined angle of incidence, and when the first light is incident on the surface of the substrate 4 and reflected, the first light interferes with the reflected first light to improve the sensitivity of the light. Increase

The light detector 6 detects light reflected from the substrate 4 and interferes with the interference, and is disposed at a position capable of collecting the reflected light. Preferably, the light detector 6 comprises a reflecting mirror (not shown), the reflecting mirror in the first direction and the second facing the light irradiated with respect to the substrate 4 supported by the support 5. A plurality of light sources arranged in the direction or disposed along the circumference of the light source unit 2 are collected and guided to the light detector 6.

On the other hand, the light detector 6 can determine whether the microstructure is defective, the method will be described briefly.

In the regions without defects among the regions on the substrate 4, light is reflected at the same angle as the incident angle. However, light is scattered at an angle different from the incident angle in the defective area among the areas on the substrate 4. Therefore, when almost all light is reflected at the same angle as the incident angle in the substrate 4, it can be predicted that there is no defect in the corresponding area, and when scattered light is detected at a predetermined level or more, it can be predicted that there is a defect in the corresponding area. .

On the other hand, the light detector 6 detects light scattered from the substrate 4 by irradiation of a laser beam, converts the scattered light into an electrical signal, and transmits the light to the defect determination unit 7. As the light detector 6, a charge coupled device sensor or a photo multiplier tube (PMT) may be used. The technology for the CCD sensor is already disclosed in many publications, and a description thereof will be omitted.

The photomultiplier tube 10 collects the light reflected or scattered from the substrate 4 and amplifies it at a predetermined amplification ratio, and the voltage of the photomultiplier tube 10 is 400 to 900V. In addition, since the reflected light or scattered light from the substrate 4 is relatively weak, the photomultiplier tube 10 amplifies the weak light at a predetermined amplification ratio to increase the output signal. In addition, the reflected or scattered light reacts with the photocathode in the photomultiplier tube 10 to produce photoelectrons, and the photoelectrons are sequentially multiplied through multi-stage dynodes to which a high voltage is applied, and corresponding outputs. The pulse is generated.

In addition, the photomultiplier tube 10 can measure up to one photon, has a band of about 0.2 to 1.1 μm, and can measure small dark currents as low as 0.3 pA, which is very useful for defect detection. On the other hand, the photomultiplier tube 10 converts the scattered laser beam into a large and small of the electric signal according to the intensity, and then outputs it as a serial (serial) signal.

The defect determining unit 7 is connected to the light detecting unit, dataizes the laser light detected by the light detecting unit 6, and detects the defect using the electrical signal output from the light detecting unit 6. That is, the defect determination unit 7 detects a defect by analyzing the electrical signal and comparing the preset reference. When the magnitude of the detected electrical signal is greater than or equal to a predetermined level, the defect determination unit 7 determines the defect, or detects the detected electrical signal and the reference electrical. The signal is compared and judged to be a defect if the difference is outside the error range. On the other hand, when the defect of the board | substrate 4 is detected, the position of a defect can also be confirmed, and a kind of defect is a scratch form defect, a particle form defect, the defect by the particle | grains of the lower film formed by a prior process, etc.

The control unit 8 controls the light source unit 2, the light detection unit 6, the defect determination unit 7, and the like so that the laser beam can detect the defect by scanning the inspection area on the substrate 4.

2 is a control flowchart of a semiconductor substrate inspection apparatus according to an embodiment of the present invention.

As shown in FIG. 2, when the inspection of the semiconductor substrate is started, the light source unit 2 emits lamp light or laser light to inspect a defect present in the substrate 4. The above-described laser may be a fluoride krypton aximmer laser, an argon fluoride aximmer laser, a fluorine aximmer laser or an argon laser.

Next, the beam splitter 3 splits the emitted light into lights having two optical axes and irradiates them. Specifically, when the lamp light or the laser light is emitted from the light source unit 2, the beam splitter 3 is decomposed into two lights, the first light is irradiated to the inspection region of the semiconductor substrate, and the second light is reflected from the semiconductor substrate. Interference with the first light coming out (s20).

Next, the light detector 6 detects the first light reflected by the semiconductor substrate and interfered with the second light. At this time, light may be detected using a CCD sensor or a photomultiplier tube. In addition, the determination of the defect of the microstructure can be determined by comparing the incident angle and the reflection angle of the light. In the region without defect among the regions on the substrate 4, the light is reflected at the same angle as the incident angle, but the incident angle in the defective region Defects may be measured based on the principle that light is reflected or scattered at an angle different from (s30).

Next, the defect determination part 7 judges a defect from the information of the detected light. That is, when the first light generated and separated by the light source unit 2 is scanned by the upper surface of the substrate 4 and interferes with the second light to be detected by the photodetector 6 to generate an electrical signal, the defect determination unit ( 7 determines the defect of the substrate 4 by using the electrical signal (s40).

1 is a perspective view showing an inspection apparatus of a semiconductor substrate according to an embodiment of the present invention

Description of the Related Art [0002]

2 light source unit 3 beam splitter

6 light detecting unit 7 defect determining unit

Claims

In the semiconductor substrate inspection apparatus for inspecting a defect of the substrate,

A light source unit emitting light;

A beam splitter which separates the light into first and second lights, reflects the first light by irradiating the inspection area of the semiconductor substrate, and interferes with the reflected first light. Semiconductor substrate inspection apparatus comprising a.

The method of claim 1,

The light source unit includes a laser light source or a lamp light source.

The method of claim 1,

And a light detector for detecting the interference light and converting the light into an electrical signal.

The method of claim 3, wherein

And a defect determining unit which determines a defect of the semiconductor substrate by using the electrical signal.

In the semiconductor substrate inspection method for inspecting the defect of the substrate,

Exit the light,

The light is separated into a first light and a second light, the first light is irradiated to and reflected from the inspection region of the semiconductor substrate, and the second light interferes with the reflected first light to remove defects of the substrate. The semiconductor substrate inspection method characterized by detecting.

The method of claim 5,

Detecting the interference light and detecting a defect of the substrate using the detected light.