KR20080030803A - Method of fabricating semiconductor integrated circuit device - Google Patents

Abstract

A method of fabricating a semiconductor integrated circuit device is provided to optimize the design of a semiconductor integrated circuit by conducting a mask test and a CD(Critical Dimension) measurement simultaneously, and to reduce the time required for testing a mask, by measuring CD as forming an aerial image. A method of fabricating a semiconductor integrated circuit device comprises the steps of: forming an aerial image by exposing light to a mask, and measuring the CD(Critical Dimension) of a pattern to be formed on a wafer through the mask from the aerial image(S10); forming a CD map by using the measured CD(S20); transferring information obtained from the CD map to a mask database process for correcting a mask manufacturing process(S32,S42); transferring the measured CD value to OPC(Optical Proximity Correction) and ORC(Optical Rule Check) for modeling the OPC and ORC(S34); comparing a simulation aerial image formed by OPC with an aerial image formed by test equipment for modeling the OPC and ORC(S44,S54).

Description

Method of fabricating semiconductor integrated circuit device

1 is a conceptual diagram illustrating a mask inspection apparatus used in a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention.

2 is a flowchart illustrating a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

100: mask inspection equipment 110: light source

120: condenser 130: mask

140: imaging lens 150: imaging unit

The present invention relates to a method for manufacturing a semiconductor integrated circuit device, and more particularly, to a method for manufacturing a semiconductor integrated circuit device for forming an aerial image to inspect a mask.

In manufacturing a semiconductor integrated circuit device, in order to form a pattern on a semiconductor substrate, a mask is fabricated and a pattern is formed on the semiconductor substrate through a photo process.

Specifically, a light shielding pattern for shielding light from a quartz glass substrate is formed to form a mask on which a pattern to be transferred is formed on a wafer. Subsequently, after the photoresist is applied onto the wafer, the mask is exposed to light to be transferred onto the wafer to transfer the pattern formed on the mask onto the wafer. That is, a photoresist pattern having the same shape as the pattern formed on the mask is formed on the wafer. The photoresist pattern may be used as an etching mask to form a desired pattern on the wafer.

When the mask is formed, a light shielding pattern for shielding light from a quartz glass substrate is formed to form a shape of a pattern to be transferred onto a wafer. However, the pattern formed on the mask is not formed the same as the pattern to be formed on the wafer. Therefore, by manufacturing a mask in consideration of the influence of the nature of the light and the process variables in the exposure process, the desired pattern can be formed on the wafer during the process. In order to compensate for this difference, a CD is performed to adjust the CD (Critical Demension) of the pattern to be formed into a wafer.

As a mask inspection method for this purpose, a method of comparing the same repeated shape of the manufactured mask with each other and a method of comparing the design drawing and the manufactured mask with each other may be used. Such a mask inspection method may include a CD of a pattern to be formed on a wafer. It is difficult to consider. As a way to overcome this, there is a mask inspection method using an aerial image using the intensity of light to be transferred which directly affects the wafer CD. However, the mask inspection method using the aerial image currently used only inspects defects of the mask through inspection, and does not check the CD uniformity of the entire wafer area.

Alternatively, there is a method of verifying a design drawing by forming a simulation aerial image using the design drawing to predict the wafer CD. However, because simulation is done with the ideal data for the mask, the exact image is not formed as if the actual pattern was formed with the mask.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method for manufacturing a semiconductor integrated circuit device in which an aerial image is formed to inspect a mask.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In another aspect of the present invention, there is provided a method of manufacturing a semiconductor integrated circuit device by exposing light to a mask to form an aerial image, and in the aerial image, a pattern of a pattern to be formed on a wafer through the mask. It includes measuring CD (Critical Demension).

Other specific details of the invention are included in the detailed description and drawings.

Advantages and features of the present invention, and methods of achieving the same will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Thus, well-known device structures and well-known techniques in some embodiments are not described in detail in order to avoid obscuring the present invention.

Like reference numerals refer to like elements throughout the specification. And / or include each and all combinations of one or more of the items mentioned.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, including and / or comprising the components, steps, operations and / or elements mentioned exclude the presence or addition of one or more other components, steps, operations and / or elements. I never do that.

Hereinafter, a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, a mask inspection apparatus used in a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention will be described with reference to FIG. 1. 1 is a conceptual diagram illustrating a mask inspection apparatus used in a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention.

Referring to FIG. 1, the mask inspection apparatus 100 includes a light source 110, a light collecting unit 120, a mask 130, an imaging lens 140, and an imaging unit 150, and masks using an aerial image. 130 is a test equipment.

The light source 110 generates light. The light source 110 may be, for example, an ultra-high pressure mercury light, an argon fluoride excimer laser, a krypton fluoride excimer laser, an extreme ultraviolet beam or an electron beam. And the like.

The light collecting unit 120 collects the light generated by the light source 110. Light generated by the light source 110 is collected by the light collecting part 120 and is incident to the mask 130.

The mask 130 is a substrate designed to form a desired pattern on the wafer W, and may be, for example, a quartz glass substrate. The mask 130 may include an opaque region in which light is shielded and a region through which the light passes, and may project the shape of the pattern formed on the mask 130 on the wafer W or the CCD camera according to whether light passes. . As the material for shielding the light from the mask 130, chromium (Cr), emulsion, iron oxide, silicon, or the like may be used.

The imaging unit 150 forms an aerial image of a luminance distribution of light passing through the mask 130.

The imaging unit 150 may be, for example, a CCD camera or the like. The imaging unit 150 forms an aerial image of a luminance distribution of light passing through the mask 130. The mask inspection apparatus 100 may measure the CD of the pattern to be formed on the wafer through the mask 130 by analyzing the aerial image formed by the imaging unit 150. In addition, the imaging unit 150 is connected to a mask data process, an optical proximity correction (OPC), and an optical rule check (ORC), and the mask data may be masked by information measured in the aerial image formed by the imaging unit 150. Transfer to processes, OPC, ORC, etc.

Hereinafter, a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 2 is a flowchart illustrating a method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention.

1 and 2, first, the mask inspection apparatus 100 forms an aerial image and measures a CD (S10).

Specifically, the mask 130 is mounted on the mask inspection equipment 100. Subsequently, light generated by the light source 110 is collected by the light collecting unit 120, and the light collected by the light collecting unit 120 is irradiated to the mask 130, and then passes through the imaging lens 140 to the imaging unit 150. Incident. Light incident on the imaging unit 150 forms a luminance image of the light passing through the mask 130 as an aerial image, and when the aerial image is analyzed, a pattern to be formed on the wafer may be estimated.

In addition, when the aerial image is formed on the imaging unit 150, the mask inspection apparatus 100 may measure the CD of the pattern to be formed on the wafer in the aerial image. That is, the overall CD of the pattern to be formed on the wafer can be measured. Forming the aerial image and measuring the CD of the pattern to be formed on the wafer can proceed simultaneously. In this case, the term simultaneously includes a continuous process. That is, forming an aerial image continuously or simultaneously in a piece of equipment and measuring the CD of the pattern to be formed on the wafer. Therefore, a separate process for measuring the CD may not be necessary.

On the other hand, if the overall CD of the pattern to be formed on the wafer is measured, a CD map can be seen at a glance whether the CD is uniformly measured in the aerial image compared to the reference value intended for the operator to form on the wafer. Can be formed (S20). At this time, if the aerial image is formed by the mask inspection apparatus 100, the CD inspection is not necessary because the mask inspection apparatus 100 analyzes the aerial image to measure the CD map. In other words, CD maps can be created more quickly and easily.

The CD map is data that can recognize at a glance the region requiring correction in the manufactured mask 130. Since the CD map is formed using the mask 130 actually manufactured, the CD map provides more accurate information about the pattern to be formed on the wafer. That is, the uniformity and hot spot area of the CD of the pattern to be formed on the wafer may be measured through a mask manufactured through the CD map. Hot spots are areas where process margins are narrow, making it difficult to form patterns on the wafer as desired.

According to the mask inspection method according to the method of manufacturing the semiconductor integrated circuit device according to the embodiment of the present invention, since CD measurement and CD uniformity of the entire pattern to be formed on the wafer can be measured, more accurate data is possible.

On the other hand, the CD and hot spot information measured in the aerial image formed in the imaging unit 150 is transmitted to the mask data process (S32). The mask data process controls the data and process conditions needed to fabricate the mask.

When information about the CD and the hot spot measured in the aerial image formed by the imaging unit 150 is transmitted to the mask data process, the mask data process corrects the mask fabrication process (S42). Thus, the CD of the pattern to be formed on the wafer is adjusted more accurately. As a method of correcting the mask fabrication process, for example, the transmittance of the mask can be adjusted.

Subsequently, the mask is fabricated again by the corrected mask fabrication process (S52). Fabricating the mask with a calibrated mask fabrication process allows for more accurate patterns on the wafer.

On the other hand, the information on the measured CD and hot spot is transmitted to OPC (Optical Proximity Correction) and ORC (Optical Rule Check) (S34).

In addition, the OPC compares a simulated aerial image formed of information on a mask with an aerial image formed of an actually manufactured mask (S44).

Subsequently, the OPC and the ORC are modeled by comparing the data obtained by comparing the simulated aerial image with the aerial image formed by the fabricated mask (S54).

According to the method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention, when the light is exposed to the manufactured mask, the light passing through the mask forms an aerial image in space with the intensity distribution of light to be formed on the wafer, This aerial image is highly related to the CD (Critical Dimension) of the pattern to be formed on the wafer. Therefore, the CD is measured by measuring the intensity distribution of light passing through the mask at the same time as the mask inspection, and it is possible to optimize the design of the semiconductor integrated circuit using the same.

In addition, since the mask inspection apparatus 100 measures the CD while simultaneously forming the aerial image, the time required for inspecting the mask may be shortened.

In addition, according to the method for manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention, an aerial image is formed using a fabricated mask. Thus, more accurate information on the pattern to be formed on the wafer can be obtained.

On the other hand, according to the method of manufacturing a semiconductor integrated circuit device according to an embodiment of the present invention, it is possible to measure the CD uniformity and the hot spot of the entire pattern to be formed on the wafer. Thus, CD correction and data correction can be effectively performed, and a mask capable of forming a pattern on the wafer more accurately can be produced.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the method for manufacturing a semiconductor integrated circuit device as described above, there are one or more of the following effects.

First, CD is measured by measuring the intensity distribution of light passing through the mask at the same time as the mask inspection, and it is possible to optimize the design of the semiconductor integrated circuit by using the same.

Second, since the CD is measured at the same time the aerial equipment forms the aerial image, the time required to inspect the mask can be further shortened.

Third, by forming an aerial image with the mask actually manufactured, more accurate information about the pattern to be formed on a wafer can be obtained.

Fourth, CD uniformity and hot spot of the entire pattern to be formed on the wafer can be measured. Thus, CD correction and data correction can be effectively performed, and a mask capable of forming a pattern on the wafer more accurately can be produced.

Claims (8)

Exposing light to a mask to form an aerial image, and measuring a CD (Critical Demension) of the pattern to be formed on the wafer through the mask in the aerial image. The method of claim 1, Forming the aerial image and measuring the CD of the pattern to be formed on the wafer proceed simultaneously. The method of claim 1, And forming a CD map from the CD measured in the aerial image. The method of claim 1, Transmitting the measured CD value to a mask database process to adjust a mask fabrication process. The method of claim 3, wherein And transmitting the information obtained from the CD map to a mask database process to adjust a mask fabrication process. The method of claim 1, And modeling the OPC and the ORC by transmitting the measured CD values to OPC (Optical Proximity Correction) and ORC (Optical Rule Check). The method of claim 3, wherein And modeling the OPC and the ORC by transmitting the information obtained from the CD map to the OPC and the ORC. The method according to claim 6 or 7, A method for manufacturing a semiconductor integrated circuit device further comprising modeling the OPC and ORC by comparing the simulated aerial image formed in the OPC with the aerial image formed in the inspection equipment.

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