KR20030089628A - Monitoring patterns of a semiconductor device - Google Patents

Abstract

PURPOSE: A monitoring pattern of a semiconductor device is provided to measure best focus in an exposure process using conventional illumination and oblique angle illumination by using a monitoring pattern composed of a chess board pattern and a bar pattern. CONSTITUTION: The bar pattern is prepared. The chess board pattern in which pillars and contact holes are repeatedly disposed is prepared, separated from the bar pattern by a predetermined interval. The bar pattern is 1-50 micrometer in length and 1-10000 micrometer in width. The width and length of the pillar and the contact hole is 0.05-5 micrometer. The monitoring patterns are repeatedly disposed at an interval of 1-100 micrometer.

Description

Monitoring patterns of a semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring pattern of a semiconductor device. More specifically, a bar pattern and a chess board pattern capable of measuring the best focus of the X-axis and the Y-axis using conventional lighting and powerful incident lighting. It relates to a monitoring pattern of a semiconductor device formed of a board pattern).

As semiconductor devices are highly integrated, efforts are being made to form fine patterns using optical lithography, and for this purpose, high-resolution exposure equipment is required.

The resolution R of the exposure apparatus may be expressed as follows.

R = K1 × λ / NA (K1 is the process variable, λ is the wavelength of the light source, NA is the numerical aperture of the lens)

In order to increase the resolution of the exposure apparatus, the wavelength of the light source must be shortened and the numerical aperture of the lens must be large. However, this method requires a new investment in the exposure apparatus and thus presents a problem in relative competitiveness.

Therefore, the method of increasing the resolution using the wavelength of the given light source and the numerical aperture of the lens without the investment of new exposure equipment is to lower the process variable K1.

For this purpose, the application of an alternating phase shift mask, the application of a thin resist, the application of off-axis illumination (hereinafter referred to as OAI) are used.

Among them, the evaluation of dipole illumination, thin annular illumination and crosspole illumination using extreme OAI is being made and will be applied in future processes.

However, powerful OAI increases resolution and depth of focus (DOV) in dense patterns, but there are many differences in island-dense bias compared to conventional OAI and dipole illumination. The disadvantage is that the resolution depends on the pattern orientation.

In addition, the best focus measurement in the exposure equipment before the lithography process is very important. Conventionally, the best focus was measured by drawing a Gaussian distribution using an exposure-focus matrix using a line / space pattern.

However, in dipole illumination, the CD (critical dimension) of the pattern decreases and then increases again as the line / space pattern is defocused, and thus the Gaussian distribution is not drawn, and thus the best focus cannot be measured.

Therefore, there is a need for a new shape monitoring pattern that can measure the best focus in dipole lighting as well as conventional OAI.

Hereinafter, a test pattern forming method of a semiconductor device according to the prior art will be described with reference to the accompanying drawings.

1 is a schematic diagram illustrating a method of measuring best focus in an exposure process, and illustrates a method of measuring best focus using a monitoring pattern composed of a line / space pattern called chop. Here, the normal profile appears in case of best focus as in ⓐ, but the profile of 촙 is deformed or lost in case of defocus as in ⓑ and ⓒ.

2 is a plan view illustrating a monitoring pattern of a semiconductor device according to the prior art, and FIGS. 3A and 3B illustrate a center value according to a profile change of a monitoring pattern by conventional lighting in the monitoring pattern of a semiconductor device according to the prior art. The graph which shows the simulation result by the HOST (hynix OPC simulation tool) which measures a best focus by an offset change is demonstrated in association with each other.

The monitoring pattern shown in FIG. 2 indicates that a plurality of chops, which are a bar pattern and a line / space pattern, are repeatedly formed.

Here, the monitoring pattern is formed of a pad having a bar pattern of 5.5 μm (A), and 15 pieces having a width of 0.25 μm (E) on one side of the pad are 0.25 μm apart from each other to form a 7.5 μm (B) length. Then, the bar pattern and the pattern as described above is formed in a structure that is repeatedly arranged spaced 3.0㎛ (C).

When the monitoring pattern formed as described above is used horizontally, the best focus of the X-axis can be measured, and when it is used vertically, the best focus of the Y-axis can be measured.

When the best focus is measured by using the monitoring pattern, the best focus may be measured by finding a peak value of a Gaussian distribution that describes the offset change of the center value due to the profile change of the line / space pattern.

However, the best focus is measured in conventional illumination as in FIG. 3A, but the best focus is not measured because two peak values appear in dipole illumination as in FIG. 3B.

As described above, the monitoring pattern of the semiconductor device according to the related art needs to change the position of the monitoring pattern during the best focus measurement of the X-axis and the Y-axis. In this case, a change in CD (critical dimension) decreases and then grows again, which makes it impossible to measure the best focus, thereby degrading the reproducibility of the pattern and thus lowering the yield and reliability of the semiconductor device.

The present invention is to solve the problems of the prior art, by using the monitoring pattern consisting of a chess board pattern and a bar pattern formed of pillars and contact holes to measure the best focus during the exposure process using conventional lighting and powerful incident lighting The purpose of the present invention is to provide a monitoring pattern of a semiconductor device, which improves the reproducibility of the pattern and thereby advantageously enables high integration of the semiconductor device.

1 is a schematic diagram illustrating a method of measuring best focus in an exposure process;

2 is a plan view showing a monitoring pattern of a semiconductor device according to the prior art.

3A is a graph illustrating a HOST simulation result of measuring a best focus by a change in offset of a center value according to a profile change of a monitoring pattern by conventional illumination in a monitoring pattern of a semiconductor device according to the related art.

3B is a graph illustrating a HOST simulation result of measuring a best focus by a change in offset of a center value according to a profile change of a monitoring pattern by dipole illumination in a monitoring pattern of a semiconductor device according to the related art.

4 is a plan view showing a monitoring pattern of a semiconductor device according to the present invention.

5A is a graph illustrating a HOST simulation result of measuring a best focus by a change in offset of a center value according to a profile change of a monitoring pattern by conventional illumination in a monitoring pattern of a semiconductor device according to the present invention;

5B is a graph illustrating a HOST simulation result of measuring a best focus by a change in offset of a center value according to a profile change of a monitoring pattern by dipole illumination in a monitoring pattern of a semiconductor device according to the present invention;

In order to achieve the above object, the monitoring pattern of the semiconductor device according to the present invention,

Bar Pattern,

A chess board pattern in which pillars and contact holes are repeatedly arranged to be spaced apart from the bar pattern by a predetermined distance,

The bar pattern has a length of 1 to 50 µm and a width of 1 to 10000 µm,

The pillar and the contact hole has a width and length of 0.05 to 5㎛,

The monitoring pattern is repeated to be spaced apart from 1 to 100㎛,

The monitoring pattern is formed of Novolac type I-line resist, positive chemically amplified, negative chemically amplified and chemically amplified resist reacting to ArF, E-beam, X-ray light source,

The resist is formed to a thickness of 10 to 30000 kPa,

The monitoring pattern may include measuring the best focus using conventional illumination, annular illumination, dipole illumination, crosspole illumination or quadropole illumination,

The monitoring pattern may be formed by a photo process using a binary mask, an integrated phase inversion mask, or an alternating phase inversion mask as an exposure mask.

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

4 is a diagram illustrating a monitoring pattern of a semiconductor device according to the present invention, and FIGS. 5A and 5B are diagrams illustrating a center value according to a profile change of a monitoring pattern by conventional lighting in a monitoring pattern of a semiconductor device according to the present invention. The graph which shows the simulation result by the HOST (hynix OPC simulation tool) which measures a best focus by an offset change is demonstrated in association with each other.

The monitoring pattern includes a bar pattern and a chess board pattern in which pillars and contact holes are repeatedly arranged to be spaced apart from the bar pattern by a predetermined distance.

Here, the bar pattern is formed with a length of 1 to 50 μm (A) and a width of 1 to 10000 μm (D), and the chess board pattern has a width (E) and a length (F) of 0.05 to 5 μm. Phosphor pillars and contact holes are repeatedly formed.

In addition, the monitoring pattern formed of the bar pattern and the chess board pattern is formed by repeatedly spaced apart by 1 ~ 100㎛ (C).

The monitoring pattern is formed using a novolac type I-line resist, a positive chemically amplified type, a negative chemically amplified type, and a chemically amplified resist reacting to an ArF, E-beam, or X-ray light source. Has a thickness of 10 to 30000 kPa.

In addition, when the best focus is measured using the monitoring pattern, it may be performed using conventional illumination, annular illumination, dipole illumination, crosspole illumination or quadrupole illumination. .

An exposure mask for forming the monitoring pattern may be a binary mask, an attenuated phase shift mask, or an alternating phase shift mask.

5A and 5B, when the best focus is measured by conventional lighting and dipole lighting using a monitoring pattern according to the present invention, a Gaussian drawing a change in the offset of the center value due to the profile change of the chess board pattern. We can find peak value of distribution and can measure best focus.

As described above, the monitoring pattern of the semiconductor device according to the present invention is best used in the exposure process using the conventional lighting and the strong incident light using the monitoring pattern consisting of a chess board pattern and a bar pattern formed by repeating pillars and contact holes. By measuring the focus, there is an advantage in that the reproducibility of the pattern is improved and thus the high integration of the semiconductor device is advantageous.

Claims (8)

Bar Pattern, And a chess board pattern in which pillars and contact holes are repeatedly arranged to be spaced apart from the bar pattern by a predetermined distance. The method of claim 1, The bar pattern is a monitoring pattern of the semiconductor device, characterized in that the length of 1 to 50㎛ and 1 to 10000㎛ width. The method of claim 1, The pillar and the contact hole has a width and length of 0.05 to 5㎛ monitoring pattern of the semiconductor device. The method of claim 1, The monitoring pattern is a monitoring pattern of a semiconductor device, characterized in that arranged repeatedly spaced from 1 to 100㎛. The method of claim 1, The monitoring pattern is formed of a novolac I-line resist, positive chemically amplified, negative chemically amplified, and a semiconductor, characterized in that formed with a chemically amplified resist in response to ArF, E-beam, X-ray light source Monitoring pattern of the device. The method of claim 5, The resist is a monitoring pattern of a semiconductor device, characterized in that formed in a thickness of 10 ~ 30000Å. The method of claim 1, The monitoring pattern is a monitoring pattern of a semiconductor device, characterized in that to measure the best focus using conventional lighting, annular (annular), dipole, crosspole (crosspole) or quadrupole (quadrupole) illumination. The method of claim 1, The monitoring pattern is a monitoring pattern of a semiconductor device, characterized in that formed by a photo process using a binary mask, an integrated phase inversion mask or an alternating phase inversion mask as an exposure mask.