阅读说明：本技术 一种监控光刻机遮光片开口精度的标记及其使用方法 (Mark for monitoring opening precision of photoetching machine shading sheet and use method thereof ) 是由 常欢 陆捷 于 2020-12-21 设计创作，主要内容包括：本发明提供一种监控光刻机遮光片开口精度的标记及其使用方法,设有图形区域和遮光带的光罩；遮光带环绕于图形区域的四周；设置于遮光带内外边缘的标记；光刻机上的遮光片,遮光片将图形区域束缚其中用于控制光罩透光开口的大小；遮光带外边缘与图形区域的距离为光刻机台的精度规格L；精度规则L的范围为：M≤L≤N；位于遮光带的内边缘的标记与图形区域之间的距离为M/2；位于遮光带的所述外边缘的所述标记与图形区域之间的距离为N+100μm。本发明通过在遮光带上增加套刻精度标记,可以在线时时监控,节省了人力和机时；有效地防止了遮光片开口过大或者过小导致的产品漏光或者过遮光情况；通过系统量测抓取,实现了自动化处理。(The invention provides a mark for monitoring the opening precision of a photoetching machine shading sheet and a using method thereof, wherein the mark is provided with a pattern area and a photomask with a shading belt; the shading band surrounds the periphery of the graphic area; the mark is arranged on the inner edge and the outer edge of the shading belt; a light shielding sheet on the photoetching machine, wherein the light shielding sheet is used for restraining the pattern area therein and controlling the size of the light-transmitting opening of the photomask; the distance between the outer edge of the shading belt and the pattern area is the precision specification L of the photoetching machine; the range of the accuracy rule L is: l is more than or equal to M and less than or equal to N; the distance between the mark at the inner edge of the shading band and the pattern area is M/2; the distance between the mark located at the outer edge of the light-shielding tape and the pattern region is N +100 μm. According to the invention, the alignment precision mark is added on the shading belt, so that online real-time monitoring can be realized, and manpower and machine time are saved; the light leakage or over-shading of the product caused by too large or too small opening of the shading sheet is effectively prevented; and automatic processing is realized by measuring and grabbing the system.)

1. A mark for monitoring the opening accuracy of a light shield of a lithography machine is characterized by at least comprising:

a light shield provided with a pattern area and a shading band; the pattern area is a rectangular area positioned in the center of the photomask; the shading belt surrounds the periphery of the graphic area;

the marks are respectively arranged at the inner edge and the outer edge of the shading belt; wherein the inner edge is an edge of the light-shielding tape close to the graphic region, and the outer edge is an edge of the light-shielding tape far away from the graphic region;

two L-shaped light-shielding sheets which are matched with each other to form a rectangular frame are arranged on the photoetching machine table, and the light-shielding sheets are used for restraining the graphic area therein and controlling the size of the light-transmitting opening of the photomask; the distance between the outer edge of the shading belt and the pattern area is L mum of the precision specification of the photoetching machine; the range of the accuracy rule L is as follows: l is more than or equal to M and less than or equal to N, wherein M, N is a positive integer;

the distance between the mark located at the inner edge of the light-shielding tape and the graphic region is M/2 μ M; the distance between the mark located at the outer edge of the light-shielding tape and the pattern region is N +100 μm.

2. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the shading belt is composed of rectangles which are respectively positioned at four positions of the upper part, the lower part, the left part and the right part of the graph area.

3. The mark for on-line monitoring of the opening accuracy of a light shield of a lithography machine according to claim 1, wherein: the width of the shading belt is 1.5 mm.

4. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the distance between the outer edge of the shading belt and the pattern area is 600 mu m of the precision specification of the photoetching machine.

5. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the range of the precision rule L is 400-800 mu m.

6. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the distance between the mark located at the inner edge of the light blocking tape and the pattern region is 200 μm.

7. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the distance between the mark located at the inner edge of the light blocking tape and the pattern region is 900 μm.

8. The mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 1, wherein: the width of the L-shaped shading sheet is 10 cm.

9. A method for using a mark for monitoring the opening accuracy of a mask of a lithography machine according to any one of claims 1 to 9, wherein: at least comprises the following steps:

providing the photomask and a photoetching machine table provided with an L-shaped shading sheet;

step two, the shading sheet is bound around the graphic area for exposure;

step three, measuring the alignment precision of the mark; and judging whether the marks positioned at the inner and outer edges of the shading belt are exposed: when the marks positioned at the inner edge and the outer edge of the shading belt are not exposed, the shading sheet is shielded; when the marks on the inner edge and the outer edge of the shading belt are exposed, the shading sheet generates light leakage; when the marks at the inner edge of the light shielding belt are exposed and the marks at the outer edge of the light shielding belt are not exposed, the light shielding sheet normally controls the size of the light-transmitting opening of the photomask.

10. The method for using the mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 9, is characterized in that: when the overlay precision measurement is performed on the marks in the third step, the marks located at the inner edge of the shading band are measured first, and then the marks located at the outer edge of the shading band are measured.

11. The method for using the mark for monitoring the opening accuracy of the light shield of the lithography machine according to claim 9, is characterized in that: and step three, judging whether the marks positioned at the inner edge and the outer edge of the shading belt are exposed or not through PCB programming setting: 1 for the exposed mark; and 0 for unexposed marks.

Technical Field

The invention relates to the technical field of semiconductors, in particular to a mark and a method for monitoring the opening precision of a photoetching machine shading sheet on line.

Background

The Nikon lithography machine determines a light transmission area of a pattern on a photomask (Reticle) by controlling the size of an opening of the Reticle blade (ARB).

The opening of ARB passes through the precision and monitors under the normal condition, but this kind of method one needs off-line (the offline) to borrow the machine platform to go the operation, then to the outward appearance machine on the naked eye watch, it is more time-consuming and laboursome, two is exactly that the precision monitoring is put the project of annual maintenance, can appear the time delay effect, in case the ARB true problem can't be grabbed in the very first time to cause the product to scrap.

There is also a method that the current factory FAB uses a lot, i.e. manual looking on the machine, but this also has a big disadvantage that the online personnel does not have time and experience to see each card; second, most products will skip over the stations, so one hundred percent of confirmation is not possible, and every card doing so will certainly result in a serious stockpile on the line. In addition, if the ARB has large errors to cause shading or light leakage, thereby affecting the whole cutting track or even a pattern area, the overlay accuracy (OVL) measurement is generally tenable, but for small-amplitude deviation of the ARB, such as only affecting a part of the cutting track, the OVL mark on the cutting track can still be exposed, and the ARB accuracy jumps for a plurality of times, although the pattern area is not affected, 2/3 of the cutting track is blocked, so that the mark is not exposed, thereby affecting the back layer and WAT test.

Therefore, a new method is needed to solve the above problems.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a mark and a method for on-line monitoring of the opening accuracy of a mask of a lithography machine, so as to solve the problem in the prior art that a scribe line or a WAT test point is affected due to over-masking or light leakage of the mask of the lithography machine.

To achieve the above and other related objects, the present invention provides a mark for monitoring the opening accuracy of a mask of a lithography machine, comprising:

a light shield provided with a pattern area and a shading band; the pattern area is a rectangular area positioned in the center of the photomask; the shading belt surrounds the periphery of the graphic area;

the marks are respectively arranged at the inner edge and the outer edge of the shading belt; wherein the inner edge is an edge of the light-shielding tape close to the graphic region, and the outer edge is an edge of the light-shielding tape far away from the graphic region;

two L-shaped light-shielding sheets which are matched with each other to form a rectangular frame are arranged on the photoetching machine table, and the light-shielding sheets are used for restraining the graphic area therein and controlling the size of the light-transmitting opening of the photomask; the distance between the outer edge of the shading belt and the pattern area is L mum of the precision specification of the photoetching machine; the range of the accuracy rule L is as follows: l is more than or equal to M and less than or equal to N, wherein M, N is a positive integer;

the distance between the mark located at the inner edge of the light-shielding tape and the graphic region is M/2 μ M; the distance between the mark located at the outer edge of the light-shielding tape and the pattern region is N +100 μm.

Preferably, the shading band is composed of rectangles respectively located at four positions of the upper, lower, left and right of the graphic area.

Preferably, the width of the light-shielding tape is 1.5 mm.

Preferably, the distance between the outer edge of the shading band and the pattern area is 600 μm of the precision specification of the photoetching machine.

Preferably, the range of the precision rule L is 400-800 μm.

Preferably, the distance between the mark located at the inner edge of the light-shielding tape and the pattern region is 200 μm.

Preferably, the distance between the mark located at the inner edge of the light-shielding tape and the pattern region is 900 μm.

Preferably, the width of the L-shaped shading sheet is 10 cm.

The invention also provides a use method of the mark for monitoring the opening precision of the photoetching machine gobo, which at least comprises the following steps:

providing the photomask and a photoetching machine table provided with an L-shaped shading sheet;

step two, the shading sheet is bound around the graphic area for exposure;

step three, measuring the alignment precision of the mark; and judging whether the marks positioned at the inner and outer edges of the shading belt are exposed: when the marks positioned at the inner edge and the outer edge of the shading belt are not exposed, the shading sheet is shielded; when the marks on the inner edge and the outer edge of the shading belt are exposed, the shading sheet generates light leakage; when the marks at the inner edge of the light shielding belt are exposed and the marks at the outer edge of the light shielding belt are not exposed, the light shielding sheet normally controls the size of the light-transmitting opening of the photomask.

Preferably, when the overlay precision measurement is performed on the mark in the third step, the mark located at the inner edge of the light-shielding strip is measured first, and then the mark located at the outer edge of the light-shielding strip is measured.

Preferably, in the third step, whether the mark located at the inner and outer edges of the shading belt is exposed is judged through PCB programming setting: 1 for the exposed mark; and 0 for unexposed marks.

As mentioned above, the mark and the method for monitoring the opening precision of the photoetching machine gobo on line have the following beneficial effects: according to the invention, the alignment precision mark is added on the shading belt, so that shading or light leakage caused by abnormal precision of the photoetching machine is prevented. The online real-time monitoring can be realized, so that the manpower and the machine time are saved; the light leakage or over-shading of the product caused by too large or too small opening of the shading sheet is effectively prevented; and automatic processing is realized by measuring and grabbing the system.

Drawings

FIG. 1 is a schematic view showing the position relationship among a light-shielding tape, a pattern region and a light-shielding sheet during normal exposure according to the present invention;

FIG. 2 is a schematic view showing a structure of a shade band according to the present invention with marks;

FIG. 3 is a schematic structural view showing the inner and outer edge marks of the light-shielding belt being shielded by the light-shielding sheet according to the present invention;

FIG. 4 is a schematic view showing a structure in which marks on the inner and outer edges of a light shielding tape are exposed;

fig. 5 is a schematic structural view showing a structure in which the light-shielding sheet is tilted to expose the edge mark of the light-shielding band and the outer edge mark is shielded.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 1 to 5. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

The invention provides a mark for monitoring the opening precision of a photoetching machine shading sheet, which at least comprises: a light shield provided with a pattern area and a shading band; the pattern area is a rectangular area positioned in the center of the photomask; the shading belt surrounds the periphery of the graphic area; the marks are respectively arranged at the inner edge and the outer edge of the shading belt; wherein the inner edge is an edge of the light-shielding tape close to the graphic region, and the outer edge is an edge of the light-shielding tape far away from the graphic region; two L-shaped light-shielding sheets which are matched with each other to form a rectangular frame are arranged on the photoetching machine table, and the light-shielding sheets are used for restraining the graphic area therein and controlling the size of the light-transmitting opening of the photomask; the distance between the outer edge of the shading belt and the pattern area is L mum of the precision specification of the photoetching machine; the range of the accuracy rule L is as follows: l is more than or equal to M and less than or equal to N, wherein M, N is a positive integer; the distance between the mark located at the inner edge of the light-shielding tape and the graphic region is M/2 μ M; the distance between the mark located at the outer edge of the light-shielding tape and the pattern region is N +100 μm.

As shown in fig. 1, fig. 1 is a schematic diagram illustrating a positional relationship among a light-shielding tape, a pattern area and a light-shielding sheet during normal exposure according to the present invention. The photomask is provided with the pattern area 03 and a shading belt 02, the pattern area 03 is a rectangular area located in the center of the photomask, and the pattern area is used for arranging a pattern transferred to a wafer; the pattern of the pattern area is transferred to the wafer after exposure, so that the pattern area on the photomask is positioned in the mask frame of the photoetching machine during exposure.

The shading band 02 surrounds the periphery of the pattern area 03.

Further, the light-shielding tape 02 in this embodiment is composed of rectangles respectively located at four positions, i.e., the upper, the lower, the left, and the right of the graphic area. In fig. 1, the light-shielding tape is shown as an integral structure at four positions, i.e., the upper, lower, left, and right positions of the graphic area.

Under the condition of normal exposure of a light shielding sheet of a lithography machine, as shown in fig. 1, the inner edge of the light shielding sheet 01 needs to fall within the light shielding belt 02, that is, the light shielding sheet is partially overlapped with the light shielding belt on the photomask, and if the light shielding sheet covers the light shielding belt completely, an over-light shielding condition occurs; if the light-shielding sheet and the light-shielding band are not overlapped at all, light leakage occurs.

As shown in fig. 2, fig. 2 is a schematic structural view of the light-shielding tape of the present invention with marks; the invention also includes: marks respectively arranged at the inner edge and the outer edge of the shading band 02; wherein the inner edge is an edge of the light-shielding tape close to the graphic region, and the outer edge is an edge of the light-shielding tape far away from the graphic region. For example, the light shielding tape of the rectangle above the pattern area in fig. 2 has two long sides, wherein the long side far away from the pattern area is the outer edge, and the long side near the pattern area is the inner edge. And the marks are located at the edges inside the two long sides respectively.

As shown in fig. 1, two L-shaped light-shielding sheets 01 that are matched with each other to form a rectangular frame are disposed on a photolithography machine, and the pattern area 03 is bound by the light-shielding sheets 02 for controlling the size of the light-transmitting opening of the photomask; the distance between the outer edge of the shading belt 02 and the pattern area 03 is L mum of the precision specification of the photoetching machine; the range of the accuracy rule L is as follows: l is more than or equal to M and less than or equal to N, wherein M, N is a positive integer; that is, the distance between the outer edge of the light-shielding tape 02 and the pattern region 03 is defined as the accuracy specification, which floats within a certain range, and the unit of the accuracy specification is micrometers (μm).

Further, the distance between the outer edge of the shading band and the pattern area is 600 μm of the precision specification of the lithography machine.

The distance between the mark located at the inner edge of the light-shielding tape and the graphic region is M/2 μ M; the distance between the mark located at the outer edge of the light-shielding tape and the pattern region is N +100 μm. Further, the range of the accuracy rule L in this embodiment is 400 to 800 μm. Still further, the distance between the mark located at the inner edge of the light-shielding tape and the pattern region is 200 μm. Further, the distance between the mark located at the inner edge of the light-shielding tape and the pattern region is 900 μm.

Further, the width of the L-shaped light-shielding sheet of this embodiment is 10 cm.

The invention also provides a use method of the mark for monitoring the opening precision of the photoetching machine gobo, which at least comprises the following steps:

providing the photomask and a photoetching machine table provided with an L-shaped shading sheet; wherein the photomask is provided with a pattern area and a shading band. The light shielding sheet is used for restraining the pattern area therein for controlling the size of the light-transmitting opening of the photomask.

Step two, the shading sheet is bound around the graphic area for exposure;

step three, measuring the alignment precision of the mark; and judging whether the marks positioned at the inner and outer edges of the shading belt are exposed:

(1) when the marks positioned at the inner edge and the outer edge of the shading belt are not exposed, the shading sheet is shielded; further, when performing overlay precision measurement on the marks in the third step of this embodiment, the marks located at the inner edge of the light-shielding tape are measured first, and then the marks located at the outer edge of the light-shielding tape are measured. Still further, in the third step, whether the mark located at the inner and outer edges of the shading belt is exposed is judged through the PCB programming setting: 1 for the exposed mark; and 0 for unexposed marks.

As shown in fig. 3, fig. 3 is a schematic structural view showing that the marks on the inner and outer edges of the light-shielding belt are shielded by the light-shielding sheet according to the present invention. As can be seen from fig. 3, the mark 05 located at the inner edge of the light-shielding tape and the mark 04 located at the outer edge of the light-shielding tape are both shielded by the light-shielding sheet and thus are not exposed. Therefore, in this case of the present embodiment, the case where the mark on the inner edge of the light-shielding band is not exposed is written as 0; the case where the mark on the outer edge of the light shielding tape is not exposed is recorded as 0.

(2) When the marks on the inner edge and the outer edge of the shading belt are exposed, the shading sheet generates light leakage; as shown in fig. 4, fig. 4 is a schematic structural view showing that the marks on the inner and outer edges of the light shielding tape are exposed. As can be seen from fig. 4, the mark 05 located at the inner edge of the light-shielding tape and the mark 04 located at the outer edge of the light-shielding tape are exposed without being shielded by the light-shielding sheet. Therefore, in this case of the present embodiment, the case where the mark on the edge of the light-shielding band is exposed is denoted as 1; the case where the mark on the outer edge of the light shielding tape is exposed is denoted as 1.

(3) When the marks at the inner edge of the light shielding belt are exposed and the marks at the outer edge of the light shielding belt are not exposed, the light shielding sheet normally controls the size of the light-transmitting opening of the photomask. As shown in fig. 5, fig. 5 is a schematic structural view illustrating the structure of the light-shielding sheet of the present invention tilted to expose the edge mark of the light-shielding tape and shield the outer edge mark. As can be seen from fig. 5, the mark 05 located at the inner edge of the light-shielding tape and the mark 04 located at the outer edge of the light-shielding tape are exposed without being shielded by the light-shielding sheet. Therefore, in this case of the present embodiment, the case where the mark on the edge of the light-shielding band is exposed is denoted as 1; the case where the mark on the outer edge of the light shielding tape is exposed is denoted as 1.

In summary, the alignment precision mark is added on the shading belt, so that shading or light leakage caused by abnormal precision of the photoetching machine is prevented. The online real-time monitoring can be realized, so that the manpower and the machine time are saved; the light leakage or over-shading of the product caused by too large or too small opening of the shading sheet is effectively prevented; and automatic processing is realized by measuring and grabbing the system. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.