KR100272656B1 - Reticle structure of semiconductor - Google Patents

Abstract

PURPOSE: A reticle structure of a semiconductor device is provided to prevent a ghost image from being generated in a portion where a reticle is formed, by forming an interception pattern on a phase shift mask wherein the interception pattern have a width greater than that of the phase shift mask. CONSTITUTION: The first interception pattern(12) is formed on a quartz plate(11), having a predetermined type. A phase shift mask(13) is formed on the first interception pattern. The second interception pattern(14) is formed on the phase shift mask, wherein the edge portion of the phase shift mask is exposed.

Description

Reticle Structure of Semiconductor Devices

TECHNICAL FIELD The present invention relates to a reticle structure of a semiconductor device, and more particularly, to a reticle structure of a semiconductor device including a phase inversion mask.

In general, the photolithography process represents a series of processes of applying a photoresist film, a selective exposure process of the photoresist film by a reticle, and a developing process such that the exposed photoresist film is removed.

Here, the reticle structure used as the mask of the photoresist film, as shown in Figure 1 (a), the phase shift mask (phase shift mask) on the blocking pattern so that the edge portion of the blocking pattern is the phase "0" Is formed.

That is, referring to the drawing, a blocking pattern 2 arranged in a predetermined shape is formed on the quartz plate 1. The blocking pattern 2 is formed of an opaque metal, for example, a metal film such as chromium, and a phase inversion mask 3 for inverting the phase of incident light is formed on the blocking pattern 2. Here, the phase inversion mask 3 is formed of a transparent film.

Then, the waveform on the wafer has a standing wave shape as shown in FIG. 1 (b), while the waveform applied to the photoresist by the phase inversion mask 3 is equal to or less than "0" as shown in FIG. 1 (c). The value is reversed. Therefore, the light intensity is high in the opening portion A between the reticles, and the light intensity is "0" in the edge portion of the phase reversal mask 3. Thus, the light contrast is increased, and the resolution and depth of focus (DOF) are improved.

However, when the phase inversion mask is formed in the above-described form, the wavelength of “0” or less is inverted between the blocking patterns, thereby having a certain intensity.

This results in ghosts on the wafer that are not on the reticle layout, resulting in defects such as sidelobes that form a predetermined photoresist pattern.

Accordingly, an object of the present invention is to provide a reticle structure of a semiconductor device capable of eliminating a ghost image generated through interposition of a phase reversal mask and preventing pattern defects.

1 (a) to 1 (c) are views for explaining a reticle structure of a conventional semiconductor device.

2 is a plan view of a reticle structure according to the present invention.

Figure 3 (a) is a cross-sectional view taken along the line III-III 'of FIG.

FIG. 3 (b) is a graph showing the light intensity of the portion where the reticle of FIG.

* Explanation of symbols for main parts of the drawings

11: quartz plate 12: first blocking pattern

13: phase reversal mask 14: second blocking pattern

In order to achieve the above object of the present invention, the present invention, the first blocking pattern is formed on a quartz plate arranged and formed in a predetermined form; And a second blocking pattern formed on the first blocking pattern, and a second blocking pattern formed on the phase inversion mask and exposed to an edge portion of the phase inversion mask.

According to the present invention, in the structure of forming the phase inversion mask in the same shape as the shape of the reticle, a blocking pattern having a width smaller than the width of the phase inversion mask is formed on the phase inversion mask, and the reticle and This prevents the occurrence of ghost phase.

EXAMPLE

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

FIG. 2 is a plan view of the reticle structure according to the present invention. FIG. 3 (a) is a cross-sectional view taken along line III-III ′ of FIG. 2, and FIG. 3 (b) is a view of FIG. This graph shows the light intensity of the part where the reticle is present and the part that is open.

First, referring to FIG. 2, the reticle structure of the present invention is arranged, for example, on a quartz plate (not shown) in a lattice form. At this time, a first blocking pattern (not shown) is disposed under the phase inversion mask 13 in the same size and shape as the phase inversion mask 13. In order to remove the ghost image formed on the portion where the phase inversion mask 13 is formed, irrespective of the mask design, a second blocking pattern 14 is formed on the phase inversion mask 13. In this case, the second blocking pattern 14 is formed to be narrower than the width of the phase inversion mask 13 so that the edge portion of the phase inversion mask 13 is exposed. Here, the first and second blocking patterns are opaque films, preferably a chromium film.

FIG. 3 (a) is a cross-sectional view of FIG. 2 taken along line III-III ', and the first blocking pattern 12 is formed on the quartz plate 11 substantially in the form of a reticle. A phase inversion mask pattern made of a transparent film is formed on the first blocking pattern 12 to increase the resolution of a photoresist film (not shown) by giving a phase difference to light passing through the first blocking pattern 12. (13) is formed. Subsequently, an opaque film is deposited on the phase reversal mask pattern 13, and then patterned to expose the opening between the edge of the phase reversal mask pattern 13 and the first blocking pattern 12 to expose the second blocking pattern 14. ) Is formed. Here, forming the second blocking pattern 12 smaller than the width of the phase inversion mask 13 causes the edge portion of the phase inversion mask 13 to be exposed, so that the light intensity of the edge portion of the phase inversion mask 13 is exposed. Is to increase the contrast ratio.

Accordingly, the waveform applied to the photoresist is minimized by the second blocking pattern 14, as shown in FIG. 3 (b), to minimize the light intensity on the ghost between the first blocking patterns 11. In addition, the light intensity becomes "0" at the edge portion of the phase inversion mask 13.

As described in detail above, according to the present invention, in the structure of forming the phase inversion mask in the same shape as the shape of the reticle, by forming a blocking pattern having a width smaller than the width of the phase inversion mask on the phase inversion mask In this case, the phenomenon in which the ghost phase is generated regardless of the reticle is prevented in the portion where the reticle is formed.

In addition, this invention can be implemented in various changes within the range which does not deviate from the summary.

Claims (3)

A first blocking pattern formed on the quartz plate and disposed and formed in a predetermined shape; A phase inversion mask formed on the first blocking pattern; And a second blocking pattern formed on the phase inversion mask and formed to expose an edge portion of the phase inversion mask. The reticle structure of a semiconductor device according to claim 1, wherein the first and second blocking patterns are opaque films. The reticle structure of a semiconductor device according to claim 2, wherein the opaque film is a chromium film.

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