KR-102962675-B1 - EUV PHOTOMASK AND METHOD OF FORMING A MASK PATTERN USING THE SAME

KR102962675B1KR 102962675 B1KR102962675 B1KR 102962675B1KR-102962675-B1

Abstract

An EUV photomask according to the technical concept of the present invention is an EUV photomask that reflects extreme ultraviolet (EUV) light, having a main area and a scribe lane area surrounding the main area, and includes a reflective multilayer film and an absorption pattern formed on the reflective multilayer film, wherein the scribe lane area includes a first lane and a second lane extending from both sides of the main area, and the first lane includes a first sub-lane and a second sub-lane extending in the same direction as the extension direction of the first lane, the first sub-lane includes a first dummy pattern which is part of the absorption pattern, and the second sub-lane includes a second dummy pattern which is part of the absorption pattern, and when EUV light reflected from the reflective multilayer film without being absorbed by the first and second dummy patterns is superimposed on a negative tone photoresist formed on a semiconductor substrate and irradiated at least twice, the amount of light in the negative tone photoresist corresponding to the first lane exceeds the threshold amount.

Inventors

하순목
김재희
윤상호
황찬

Assignees

삼성전자주식회사

Dates

Publication Date: 20260507
Application Date: 20200915

Claims (20)

An EUV photomask having a main region and a scribe lane region surrounding the main region, and reflecting extreme ultraviolet (EUV) light, The above-mentioned scribe lane region includes a reflective multilayer film and an absorption pattern formed on the reflective multilayer film, and The above-mentioned scribe lane area includes a first lane and a second lane extending from both sides of the main area, respectively, and The first lane includes a first sub-lane and a second sub-lane extending in the same direction as the extension direction of the first lane, and The first sub-lane includes a first dummy pattern that is part of the absorption pattern, and The second sub-lane above includes a second dummy pattern that is part of the absorption pattern, and When EUV light reflected from the reflective multilayer film, which is not absorbed by the first and second dummy patterns, is superimposed and irradiated at least twice onto a negative-tone photoresist formed on a semiconductor substrate, the amount of light exceeding the threshold in the negative-tone photoresist corresponding to the first lane, EUV photomask.
In paragraph 1, The second lane includes a third sub-lane and a fourth sub-lane extending in the same direction as the extension direction of the second lane, and The above third sub-lane has a third dummy pattern identical to the above second dummy pattern, and An EUV photomask characterized in that the above-mentioned fourth sub-lane has a fourth dummy pattern identical to the above-mentioned first dummy pattern.
In paragraph 1, An EUV photomask characterized in that the first sub-lane and the second sub-lane have the same width.
In paragraph 1, An EUV photomask characterized in that the first lane further includes a blank area that separates the first sub-lane and the second sub-lane.
In paragraph 4, The above first dummy pattern is a block pattern, and EUV photomask characterized in that the second dummy pattern is a line and space pattern.
In paragraph 1, An EUV photomask characterized in that when EUV light reflected from the reflective multilayer film, which is not absorbed by the first and second dummy patterns, is superimposed on the negative tone photoresist twice, the amount of light irradiated onto the negative tone photoresist corresponding to the scribe lane area is 105% to 150% of the threshold amount of light.
In paragraph 1, Each of the first and second dummy patterns above is a line and space pattern, and The above line and space pattern is characterized by extending in the same direction as the extension direction of the first lane.
In paragraph 1, Each of the first and second dummy patterns above is a line and space pattern, and The above line and space pattern is characterized by extending in a direction perpendicular to the extension direction of the first lane, in an EUV photomask.
In paragraph 1, EUV photomask characterized in that the first and second dummy patterns are different line and space patterns.
In paragraph 1, An EUV photomask characterized in that each of the first and second dummy patterns is a chessboard pattern, a grid-arranged island pattern, or a complementary pattern of the grid-arranged island pattern.
An EUV photomask having a rectangular main area and a scribe lane area surrounding the main area, and reflecting extreme ultraviolet (EUV) light, The above-mentioned scribe lane region includes a reflective multilayer film and an absorption pattern formed on the reflective multilayer film, and The above-mentioned scribe lane area includes first to fourth lanes extending from the edge of the main area, respectively, and The above-mentioned first lane includes first and second sub-lanes, and The above-mentioned second lane includes third and fourth sub-lanes, and The above-mentioned fourth lane includes fifth and sixth sub-lanes, and The above-mentioned fifth lane includes seventh and eighth sub-lanes, and It includes first to eighth dummy patterns corresponding to each of the first to eighth sub-lanes and being part of the absorption pattern, and When EUV light reflected from the reflective multilayer film, which is not absorbed by the first to eighth dummy patterns, is superimposed and irradiated at least twice onto a negative-tone photoresist formed on a semiconductor substrate, the amount of light exceeding the threshold light amount in the negative-tone photoresist corresponding to the first to fourth lanes, EUV photomask.
In Paragraph 11, At least one of the first and second dummy patterns and at least one of the third and fourth dummy patterns is a first line and space pattern, and At least one of the fifth and sixth dummy patterns and at least one of the seventh and eighth dummy patterns is a second line and space pattern, and An EUV photomask characterized in that the extension direction of the first line and space pattern is perpendicular to the extension direction of the second line and space pattern.
In Paragraph 11, The above-mentioned scribe lane area further includes a corner area where the first lane and the third lane meet, and The above corner area is, A first zone where the first sub-lane and the fifth sub-lane intersect; A second zone where the first sub-lane and the sixth sub-lane intersect; A third zone where the second sub-lane and the fifth sub-lane intersect; and A fourth zone where the second sub-lane and the sixth sub-lane intersect; including It includes first to fourth corner dummy patterns that are part of the absorption pattern, corresponding to each of the first to fourth zones, and An EUV photomask characterized by the fact that when EUV light reflected from the reflective multilayer film is superimposed on the negative tone photoresist four times without being absorbed by the first to fourth corner dummy patterns, the threshold amount of light in the negative tone photoresist corresponding to the corner area is exceeded.
In Paragraph 13, An EUV photomask characterized in that the amount of light irradiated onto the negative tone photoresist corresponding to the corner area is 105% to 150% of the threshold amount of light.
In Paragraph 13, The above-mentioned corner region is characterized by further including at least partially a blank region at the boundary of the first to fourth regions.
An EUV photomask having a rectangular main area and a scribe lane area surrounding the main area with a constant width, and reflecting extreme ultraviolet (EUV) light, The above-mentioned scribe lane region includes a reflective multilayer film and an absorption pattern formed on the reflective multilayer film, and The above-mentioned scribe lane area includes first to fourth corner areas adjacent to each of the four corners of the above-mentioned main area, and When reflected EUV light is irradiated once onto a negative-tone photoresist formed on a semiconductor substrate through the first to fourth corner regions, the amount of light exceeding the threshold light amount on the negative-tone photoresist, EUV photomask.
In Paragraph 16, An EUV photomask characterized in that each of the first to fourth corner regions is divided into four zones arranged in a 2 by 2 pattern, and the light reflectances of the four zones are not all the same.
In Paragraph 17, An EUV photomask characterized in that the light reflectances of two diagonally arranged zones among the four zones above are substantially the same as each other.
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In Paragraph 16, The above EUV photomask is characterized by the EUV light having a wavelength of 4 nm to 124 nm.

Description

EUV Photomask and Method of Forming a Mask Pattern Using the Same The technical field of the present invention relates to an EUV photomask and a method for forming a mask pattern using the same, and more specifically, to an EUV photomask that can be designed and manufactured cheaply and quickly and has low defect occurrence, and a method for forming a mask pattern on a semiconductor substrate using the same. To implement semiconductor devices on a semiconductor substrate, photolithography technology including exposure and development processes is used. Due to the downscaling trend of semiconductor devices, extreme ultraviolet (EUV) light is used as the light source of an exposure device when forming a mask pattern on a semiconductor substrate. The EUV photomask used in such an exposure device performs superimposed exposure with respect to the scribe lane, and to this end, it is configured so that EUV light can be reflected through at least a portion of the area corresponding to the scribe lane. However, since the reflected EUV light may be unnecessarily scattered and have an undesirable effect on the main area, a method to control this is required. FIGS. 1a and 1b are schematic diagrams illustrating an EUV exposure apparatus according to an embodiment of the technical concept of the present invention. FIG. 2 is a plan view schematically showing an EUV photomask according to an embodiment of the technical concept of the present invention. Figure 3 is a cross-sectional and planar enlarged view showing part III of Figure 2 enlarged. FIGS. 4 and 5 are conceptual diagrams illustrating a method of exposing a mask pattern on a semiconductor substrate in a step-and-repeat manner using an EUV photomask according to an embodiment of the technical concept of the present invention. FIGS. 6a to 6c are conceptual diagrams conceptually showing the amount of light irradiated when exposed twice in a superposition along the AA' and BB' lines of FIG. 2, and FIG. 6d is a conceptual diagram showing the amount of light irradiated along the DD' line of FIG. 2 and the corresponding mask pattern. FIGS. 7a to 7c are conceptual diagrams showing the formation of a scribe lane pattern when one sub-lane has a block pattern and another sub-lane is in a blank state according to a comparative example, and FIG. 7d is a conceptual diagram showing the distribution of the amount of irradiated light when exposed twice in a superposition according to a comparative example. FIGS. 8a to 8c are conceptual diagrams showing the formation of a scribe lane pattern when a line and space pattern is added to a comparative example without a blank area. FIG. 9a is a conceptual diagram showing dummy patterns on two adjacent sub-lanes in an EUV photomask according to an embodiment of the technical concept of the present invention, and FIG. 9b to 9d are conceptual diagrams showing the formation of a scribe lane pattern when exposed twice in a superposition using the EUV photomask of FIG. 9a. FIG. 10 is a conceptual diagram showing the configuration of a first lane in an EUV photomask according to an embodiment of the technical concept of the present invention. FIG. 11 is a conceptual diagram showing the configuration of a first lane in an EUV photomask according to another embodiment of the technical concept of the present invention. FIG. 12 is a conceptual diagram showing the configuration of a first corner region in an EUV photomask according to an embodiment of the technical concept of the present invention. FIG. 13 is a conceptual diagram showing the arrangement of corner dummy patterns in each corner region of an EUV photomask according to an embodiment of the technical concept of the present invention. FIG. 14 is a conceptual diagram showing the overlapping exposure effect of each corner region in an EUV photomask according to an embodiment of the technical concept of the present invention. FIG. 15 is a conceptual diagram showing the configuration around the first corner region in an EUV photomask according to an embodiment of the technical concept of the present invention. FIG. 16 is a conceptual diagram showing the configuration around the first corner region in an EUV photomask according to another embodiment of the technical concept of the present invention. FIG. 17 is a block diagram illustrating a method for forming a mask pattern according to an embodiment of the technical concept of the present invention. Hereinafter, embodiments of the technical concept of the present invention will be described in detail with reference to the attached drawings. FIGS. 1a and 1b are schematic diagrams illustrating an EUV exposure apparatus according to an embodiment of the technical concept of the present invention. Referring to FIG. 1a and FIG. 1b together, the EUV exposure apparatus (1000) may include an EUV light source (1100), an illumination optical system (1200), a photomask support (1300), a projection optical system (1400), and a substrate stage (1500). T