JPS63182655A - mask - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique that is effective when applied to masks used in manufacturing semiconductor devices.

[Conventional technology]

In the so-called wafer 1 process, which is a semiconductor device manufacturing process, impurity ions are implanted to form various circuit elements on a semiconductor substrate such as silicon (Sl) single crystal, and other processes are performed before the semiconductor wafer is completed. Many resist patterns are formed in order to form wiring made of aluminum (A1) or the like used for electrical connection of circuit elements and the like. This resist pattern is created by applying a resist film to the entire main surface of the semiconductor wafer for circuit formation.
It is formed by transferring the pattern onto the resist film using a mask. Regarding masks, there is an explanation in "Electronic Materials J 1982 Special Edition, p. 119, published by Kogyo Research Association Co., Ltd., November 15, 1982.

Incidentally, in the production of semiconductor devices, it is common practice to simultaneously form, for example, approximately 100 pellets on one semiconductor wafer.

Further, until the semiconductor wafer 1 is completed, for example, ten masks are sequentially used to form a desired cyst pattern. Therefore, the mask for forming the resist pattern has a pattern corresponding to more than 100 pellets (hereinafter referred to as pellet formation area).

) is formed. In a mask in which so many pellet forming regions are formed, it is desirable that all the patterns are perfect, but it is extremely difficult to create such a mask.

Therefore, in actual work, a tolerance range is determined, and if the number of defects in the pellet forming area falls within the tolerance range as a result of the visual inspection, that mask is used in the wafer process. There is.

As a measure in this case, it is conceivable to attach a recording means, such as a recording paper, in which the results of the visual inspection of the mask are written, when the mask is shipped.

[Problems to be Solved by the Invention] However, when an information means containing information about the results of the visual inspection is attached to a mask as described above, it is difficult to manage the information means and it is easy to lose. There is a problem in that it is difficult to make full use of test results. Yoshiba, even if the semiconductor wafer is not lost, there is no record of the semiconductor wafer itself, so even if you look at the completed semiconductor wafer, it is difficult to tell whether there are defective pellets on the wafer due to defects in the mask used. It is not easy to determine whether there are only Therefore, in order to identify defective pellets without going through a so-called probe inspection, it is necessary to check the recording means attached to all the masks used until the completion of the semiconductor wafer, which is extremely complicated. The inventor has also discovered that there is a problem in that the lateral sole cannot be put to practical use.

An object of the present invention is to provide a technology that allows one to easily grasp and recognize information regarding the masks used to complete a semiconductor wafer just by looking at the completed semiconductor wafer.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

-3= [Means for solving the problem] A brief summary of typical inventions disclosed in this application is as follows.

That is, an information recording area is formed in a part of the transfer area of the mask.

[Effect]

According to the above-mentioned means, it is possible to record information on all the masks used until the completion of the semiconductor wafer on a part of the completed semiconductor wafer, and from the recording of the information, defects caused by the masks can be detected. Various information such as the position of the pellet can be easily read.

〔Example〕

FIG. 1(a) is a schematic explanatory diagram showing a mask according to an embodiment of the present invention, and FIG. 1(b) is a schematic explanatory diagram showing an enlarged target formation area for overlapping the masks. be. Furthermore, FIG. 2(a) is a schematic explanatory diagram showing a semiconductor wafer on which a pattern has been created by applying the mask of this example, and FIG. FIG. 4 is a schematic explanatory diagram showing an enlarged view of a target region for overlay formed on the semiconductor wafer corresponding to Pair 4;

The mask of this embodiment is made up of a rectangular plate-shaped quartz glass 1 on which a light shielding part 2 made of chromium (Cr) is adhered. A large number of pellet forming areas 3 are formed in the light shielding part 2 by partitioning the light shielding part 2 at predetermined intervals vertically and horizontally. Therefore, when creating a pattern on a semiconductor wafer using the above mask, a pellet area (pattern) 5 is formed on the semiconductor wafer 4 shown in FIG. 2 corresponding to the above pellet forming area (pattern) 3. become.

After a series of steps are completed, semiconductor pellets (not shown) are manufactured by dividing the pellet into individual pellet regions by guising along the scribe line 6, which is the boundary line of the pellet region 5. It is something that

By the way, patterning of semiconductor wafers involves many steps, such as implanting impurity ions into the semiconductor substrate to form circuit elements, etc., and forming wiring for electrical connection of the formed circuit elements. This is achieved for the first time. In each step, a resist pattern is formed using a mask depending on the purpose. Therefore, in order to ensure the integrity of the pellet area 5 formed on the semiconductor wafer, it is required that the series of masks used always be precisely aligned with the predetermined positions on the semiconductor wafer. Therefore, in general, a mark for overlapping each mask is formed on a part of the mask.

The mark is formed in the overlay target formation area (part of the transfer area) 7 shown in FIG. 1(a).
It is.

In the mask of this embodiment, the overlapping target formation area 7 has a target 8 formed with an X mark formed in a part thereof, as shown in FIG. Defect information of the pellet area 5 included in the mask itself is recorded at a predetermined position. The records are A (1, 2), (4, 2), which means that the mask of this example is used in the A process, and as a result of the visual inspection, this mask has ( ], , 2) and (4°2) indicate that pellet forming regions 3a and 3b with defects in the light-shielding film pattern of the mask itself were found. That is, as long as the mask of this embodiment is used, the completed semiconductor wafer 4 will have the above (1, 2)
) and (4,2), defective pellet areas 5a and 5b will inevitably occur. Note that the above coordinates mean the XY coordinates when the overlapping target formation region 7a located on the left side of the figure is set as the origin (0, 0). It goes without saying that the overlapping target forming regions 7 and 7a are transferred to the semiconductor wafer 4 at corresponding positions as the overlapping target regions 9 and 9a, and the latter 9a is This is the origin (0,0) of the wafer 4.

FIG. 2(b) shows an enlarged view of the target area 9 for overlaying a semiconductor wafer 4 patterned using the mask of this embodiment as one of a series of masks used.

In the target area 9 for overlaying, there is a target area (also made of X marks) which is the target 8 of the mask.
8a is transferred and formed, and in the blank area of this target area for overlay, in addition to information A (1, 2), (4, 2) from the mask of this example, B process, Defect information from a series of masks (not shown) used in each of the steps C and D is also recorded in recognizable predetermined locations. Therefore, by observing the overlapping target area 9 on the semiconductor wafer 4 after the pattern is completed, it is possible to easily grasp the pellet area that should be rejected as a defective pellet due to the mask used for its creation. It is something that can be done.

In order to write information into the target formation area 7 for overlaying, after the mask is created, the appearance of the mask is inspected, and information based on the inspection is written in the blank area of the area 7 using, for example, a laser beam. This can be achieved by scattering the chromium film by irradiation.

As described above, according to this embodiment, the following effects can be obtained.

(1) Target formation area 7 for overlapping masks
By providing an information recording area in the margin of the semiconductor wafer 4, information regarding the defect position of the pellet forming area (pattern) 3 existing in each of a series of masks used in multiple steps when creating the pattern of the semiconductor wafer 4 can be recorded. can be recorded in a location allocated for each mask, so the overlay target area formed on a part of the semiconductor wafer on which the pattern has been completed can be recorded with respect to all the masks used up to the completion of the pattern. Information on defect locations can be recorded.

(2) According to (1) above, just by looking at the semiconductor wafer 4 on which the pattern has been completed, it is possible to determine from the above information recorded on the semiconductor wafer 4 that the pattern is inevitably generated due to the mask used in its creation. Since the position of the defective pellet that occurs can be easily read; b<b<, the defective pellet can be eliminated without performing a so-called probe test.

(3) According to [1] above, information on defects in the pellet forming area (pattern) existing in the mask attached to the mask when it is delivered does not have to be verified for each mask used. By simply reading the record in the information recording area, it is possible to identify defective pellet areas 5a, 5b, etc. present in the semiconductor wafer 4 on which the pattern has been completed, so the identification work can be carried out extremely accurately and quickly. can.

(4) By detecting defects in the pellet forming area through visual inspection, taking a mask for wiring formation as an example, it is possible to detect defects that may not be discovered during probe inspection but may develop into defects such as wire breakage in the future. Since patterns such as highly abnormal fine lines can be eliminated in advance, defective pellets can be eliminated more completely than in probe inspection, and the reliability of semiconductor devices can be improved.

(5) Regarding a series of masks used in multiple steps when creating patterns on semiconductor wafers, when preparing multiple masks to be applied to each step, each mask has its own pellet in the information recording area. By recording the defect positions in the formation area, the records can be aggregated and when a series of masks is applied, the masks can be combined so that the defect positions existing in each mask overlap as much as possible. It is possible to design a semiconductor wafer patterning process that minimizes the number of defective pellets that inevitably occur due to the mask used.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, in the above embodiment, only the defect position in the pellet forming area 3 is shown as the information recorded on the mask, but it is not limited to this. Any information may be used as long as it can be effectively used by recording it on the semiconductor wafer 4 as information. In addition, as for the information recording area, although the case where the blank space of the target formation area 7 for overlaying is used is shown, a specific area inside the transfer area 10 shown by the two-dot chain line in FIG. It goes without saying that a portion may be used as an area exclusively for recording information.

In the above explanation, we have mainly explained the case where the invention made by the present inventor is applied to masks, which is the field of application that formed the background of the invention. This also includes all exposure masks, regardless of the type of exposure means.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

In other words, by forming an information recording area in a part of the transfer area of the mask, it is possible to record information about all the masks used until the pattern is completed on a part of the semiconductor wafer on which the pattern has been completed. Therefore, various information such as the position of defective pellets caused by the mask can be easily read from the recorded information. Therefore, even if a large number of masks are used to create the semiconductor wafer described above, there is no need to check the information held by each mask for all masks. Various information such as the location of defective pellet areas can be easily grasped.

[Brief explanation of the drawing]

FIG. 1(a) is a schematic explanatory diagram showing a mask according to an embodiment of the present invention, and FIG. ) is a schematic explanatory diagram showing a semiconductor wafer on which a pattern has been created by applying the mask of this example, and FIG. FIG. 2 is a schematic explanatory diagram showing an enlarged target area for use in the present invention. DESCRIPTION OF SYMBOLS 1... Quartz glass, 2... Light shielding part, 3... Pellet formation region, 3a, 3b... Defected pellet formation region, 4... Semiconductor wafer, 5... Pellet region,
5a, 5b... Defective bullet area, 6... Scribe line, 7, 7a... Target formation area for overlay (part of transfer area), 8, 8a... Target, 9°9a ... Target, 10... Transcription region. Figure 1

Claims (1)

[Claims] 1. A mask in which an information recording area is formed in a part of the transfer area. 2. The mask according to claim 1, wherein the information recording area is a blank space of a target formation area for overlay. 3. Claim 1, wherein the information recording area is used for recording characteristics of the mask itself.
Mask as described in section. 4. The mask according to claim 3, wherein information is recorded in different locations in the information recording area for a series of masks used in a wafer process.