KR20080061588A

KR20080061588A - Method for mesuring pattern in semiconductor manufacturing process

Info

Publication number: KR20080061588A
Application number: KR1020060136496A
Authority: KR
Inventors: 강재현
Original assignee: 동부일렉트로닉스 주식회사
Priority date: 2006-12-28
Filing date: 2006-12-28
Publication date: 2008-07-03

Abstract

The present invention relates to a method for measuring a pattern in a semiconductor manufacturing process. When measuring a pattern model formed on a semiconductor substrate, the short wavelength light source is regularly scanned at multiple angles on the pattern to detect scattered light, thereby measuring horizontal and vertical dimensions of the pattern. By measuring simultaneously, the short wavelength light source uses a helium-neon laser, and the scan angle is performed at -47 ° to 47 °.

As described above, the present invention not only shortens the time by adopting the measurement using the OCD, but also obtains a large amount of CD data in a short time, and enables accurate OPC modeling based on a large amount of CD data.

Description

Pattern measurement method in semiconductor manufacturing process {METHOD FOR MESURING PATTERN IN SEMICONDUCTOR MANUFACTURING PROCESS}

1 is a conceptual view of the principle of OCD for applying to OPC according to the present invention.

The present invention relates to a method for measuring a pattern in a semiconductor manufacturing process. More specifically, by using an optical critical dimension (OCD) in measuring a pattern model, high accuracy OPC modeling can be realized and generation of OPC errors can be avoided. It relates to a pattern measuring method of a semiconductor manufacturing process to reduce.

The importance of photolithography related processes in semiconductor manufacturing is well known in the art. The photolithography process requires more precision as the integration of the device increases. As the integration of the device increases, the size of the pattern becomes smaller. In order to resolve such a small pattern, a process that requires precision is required. Because. Resolution Enhancement Technology (RET) is a technology that is developed to improve resolution and pattern fidelity for such small patterns because the technology of the photolithography equipment is not supported. Among these techniques, the description of the present invention is optical proximity compensation (OPC).

In general, in the semiconductor manufacturing process, OPC below 0.13um is a resolution enhancement technology that is common to almost all devices. Therefore, OPC based on the model is to correct the pattern to realize the image suitable for the target by using the OPC simulation model. As these design rules become smaller, they are increasingly used.

However, in the related art, it is difficult to satisfy all of the logic patterns in terms of accuracy. In other words, the accuracy of the model is due to the amount of data and the stability of the process. In particular, when using a photoresist using an ArF light source, some problems may occur. The photoresist of an ArF light source (193 nm) causes shrinkage when measuring critical dimensions (CD), thereby improving reliability of data. In addition to dropping, problems such as critical dimension uniformity (CDU), line edge roughness (LER), and CD variation due to the number of measurements in the ArF photoresist pattern occur.

Table 1 shows the amount of change in the measured CD data. When using the CD-SEM device, it is not only time-consuming to obtain 3 shots of CD data but also a large amount of change. This directly adversely affects model accuracy, which increases the chance of error after OPC. In Table 1, L, C, and R represent critical dimension uniformity (CDU), line edge roughness (LER), and ArF photoresist pattern, and 3sigam is a standard of data distribution commonly used in statistics. Indicates a deviation.

Table 1

As described above, the conventional measurement method generally uses a CD-SEM device. The disadvantage of the CD-SEM device is that only information on the surface can be obtained, the measurement time is long, and the measurement error is large.

In addition, when the measured pattern is measured again, a decrease (contraction) of the resist occurs, and the difference between the first measured CD value and 5 nm or more is shown. Therefore, it is difficult to secure reproducibility.

An object of the present invention is to implement OPC modeling with high accuracy by using an optical critical dimension (OCD), and to reduce the occurrence of OPC errors.

In the present invention for achieving the above object, in the measurement of the data of the test pattern for OPC modeling, by scanning a short wavelength light source on the pattern at regular angles to detect the scattered light to measure the horizontal and vertical dimensions of the pattern at the same time It is characterized by.

The short wavelength light source is preferably a helium-neon laser.

The scan angle is preferably -47 ° to 47 °.

As such, the present invention adopts measurements using OCD using the Scatterometry method, which supplements the problems of the prior art.

Measuring CDs using OCD not only shortens the time, but also obtains a large amount of CD data in a short time, and enables accurate OPC modeling based on a large amount of CD data.

Hereinafter, preferred embodiments of the present invention as described above will be described in more detail with reference to the accompanying drawings.

1 is a conceptual diagram of an OCD for implementing an OPC according to the present invention, in which a short wavelength light source (generally a He-Ne laser (632.8 nm)) is arranged in a regularly arranged pattern 110 using the scanning optical equipment 100. The photo detector 120 obtains the polarized beams scattered in the S and P directions by scanning at angles (−47 ° to 47 °).

Thereafter, horizontal and vertical dimensions are obtained by comparison with a library of film information.

The scan optical device 100 may use a scatterometer, but is not limited thereto.

As described above, when the OCD measuring device according to the present invention can measure horizontal and vertical dimensions simultaneously, the line critical dimension (Line CD) and the space critical dimension (Space CD) can be simultaneously obtained, as well as the LER. This is because the measurement is made by the light source.

In addition, a large amount of data can be obtained at a time, and it is possible to secure the reproducibility of the measurement because it does not damage the resist.

As described above, the present invention has the effect of securing a large amount of photos of CD data without damaging the resist.

In addition, CD data can be reproduced, OPC modeling accuracy can be improved, OPC error can be reduced, mask re-creation cost due to OPC error points can be reduced, and OPC modeling time can be shortened. .

Claims

In measuring the data of the test pattern for OPC modeling,

The pattern measuring method of the semiconductor manufacturing process, characterized in that by scanning a short wavelength light source on the pattern regularly from multiple angles to detect the scattered light to measure the horizontal and vertical dimensions of the pattern at the same time.

The method of claim 1,

The short wavelength light source uses a helium-neon laser pattern measuring method of a semiconductor manufacturing process.

The method of claim 1,

The scanning angle is a pattern measuring method of the semiconductor manufacturing process, characterized in that -47 ° ~ 47 °.

The method of claim 1,

A pattern measuring method of a semiconductor manufacturing process, characterized in that a scatterometer is used to scan a short wavelength light source for the pattern.