KR20070053831A - Method of inspecting a substrate - Google Patents

Abstract

In a substrate surface inspection method for shortening a process time, first, a photo map is obtained based on a substrate on which a pattern is formed in shot units, a center coordinate of the photo map is detected, and a plurality of alignments are based on the center coordinates. Set the coordinates. In addition, the inspection process recipe is set by registering intersection coordinates of the dividing lines for dividing the plurality of shots. Subsequently, the semiconductor substrate is loaded onto an inspection stage and the position of the substrate is recognized using the center coordinates, alignment coordinates and intersection coordinates. The measurement position of the substrate is detected using the alignment coordinates and the intersection coordinates to measure the thickness of the film or pattern corresponding to the measurement position. Here, the process recipe setting time can be shortened by setting a process recipe by a photo map without a sample semiconductor substrate as mentioned above.

Description

Method of inspecting a substrate

1 is a schematic cross-sectional view for explaining a substrate inspection method according to an exemplary embodiment of the present invention.

2 is a schematic partial cross-sectional view for explaining a photo map.

Explanation of symbols on the main parts of the drawings

100: shot 102: chip

104: alignment coordinate 106: intersection coordinate

The present invention relates to a substrate surface inspection method. More specifically, the present invention relates to a substrate surface inspection method for measuring the thickness of a film or pattern formed on a substrate.

In general, a semiconductor device includes a fabrication (FAB) process for forming an electrical circuit on a silicon semiconductor wafer used as a semiconductor substrate, a process for inspecting electrical characteristics of the semiconductor devices formed in the fab process, and The semiconductor substrates are each manufactured through a package assembly process for encapsulating and individualizing epoxy resins.

The fab process includes a deposition process for forming a film on a semiconductor substrate, a chemical mechanical polishing process for planarizing the film, a photolithography process for forming a photoresist pattern on the film, and the photoresist pattern. An etching process for forming the film into a pattern having electrical characteristics, an ion implantation process for implanting specific ions into a predetermined region of the semiconductor substrate, a cleaning process for removing impurities on the semiconductor substrate, and the film or pattern Inspection process for inspecting the surface of the formed semiconductor substrate;

After performing the unit processes as described above, a substrate surface inspection process of measuring the thickness of the film or pattern should be performed to confirm whether the film formed on the semiconductor substrate is laminated to a desired thickness and the film is etched to a desired portion. .

In the process for inspecting the thickness of the film or pattern formed on the semiconductor substrate, first, a process recipe for the semiconductor substrate to be measured is set, and the thickness of the position to be measured is measured using the process recipe.

In more detail, the process recipe includes a class representing a name of a product or a version of a product, an identification of wafer (IDW) for a map of the semiconductor substrate, Information between a reference position and a measurement position of the semiconductor substrate (IDP) and a catalog procedure.

In this case, the information between the reference position and the measurement position, the size of the semiconductor substrate, the number of shots (shot) formed on the semiconductor substrate, the shot (shot pitch), the number of chips in the shot (chip) The chip may be obtained from a chip pitch, a scribe line size, and the like.

Conventionally, after loading a sample semiconductor substrate to an inspection stage to set the process recipe, information necessary for the process recipe was detected from the semiconductor substrate.

In the case of using the sample semiconductor substrate as described above, the semiconductor substrate should be moved to the inspection stage of the corresponding process. Therefore, waiting time is required while the semiconductor substrate arrives at the corresponding process step, thereby causing a problem of a large amount of manpower and overall process time.

An object of the present invention for solving the above problems is to provide a substrate surface inspection method for reducing the time to form the inspection process recipe.

According to an aspect of the present invention for achieving the above object, a photo map is obtained based on a substrate on which a pattern is formed in shot units. The center coordinates of the photo map are detected. A plurality of alignment coordinates are set based on the center coordinates. Register intersection coordinates of the dividing lines to distinguish the plurality of shots. The substrate is loaded onto the inspection stage. The center coordinates, alignment coordinates, and intersection coordinates are used to recognize the position of the substrate. The alignment coordinates and intersection coordinates are used to detect the measurement position of the substrate. The thickness of the film or pattern corresponding to the measurement position is measured.

According to an embodiment of the present invention, some of the alignment coordinates may be the same as the intersection coordinates. The center coordinates of the photo map may be detected by the size of the substrate, the shot quantity and the size of the substrate.

According to the present invention as described above, by setting the inspection process recipe using a photo map without a sample semiconductor substrate, it is possible to set the inspection process recipe faster than before by suppressing the time loss occurring while the sample semiconductor substrate is moved to the inspection stage. have.

Hereinafter, a method for inspecting a substrate according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view for describing a substrate inspection method according to an exemplary embodiment of the present invention, and FIG. 2 is a schematic partial cross-sectional view for explaining a photo map.

Referring to FIG. 1, first, a photo map is obtained by scanning a surface of a semiconductor substrate on which a pattern is formed.

The pattern is formed by repeatedly exposing using a reticle as an exposure mask on a semiconductor substrate on which a film is formed, and developing the exposed film. In this case, the one shot by the reticle during the exposure process is referred to as a shot 100, and the pattern is formed in shot units. Also, referring to FIG. 2, each shot 100 includes a plurality of chips 102 and a scribe line that distinguishes between the chips 102. One or more chips 102 may be included in the shot 100.

The wafer size, the shot pitch, the chip pitch, and the size of the scribe line are checked.

Next, the center coordinates of the photo map are detected (S110). The center coordinates may be detected using the size of the semiconductor substrate, the size of the shot 100, the size of the chip 102, the size of the scribe line, and the like. Can be. In more detail, the center coordinate is a point where the left / right and up / down of the photo map are symmetrical, and thus the plurality of shots 100 are left / right and up / down symmetrical by the coordinates.

In this case, the center coordinates of the photo map are substantially the same as the center coordinates of the stage where the semiconductor substrate is to be loaded later. In addition, the center coordinates of the semiconductor substrate are substantially the same for all semiconductor substrates. That is, the center coordinates are substantially the same in all semiconductor substrates regardless of the size of the semiconductor substrate.

However, the center coordinates may vary depending on the quantity of the shots 100. In more detail, when the number of shots 100 formed in the horizontal and vertical directions is an even number, the center coordinates are formed at the edge of the shot 100. Alternatively, when the number of shots 100 formed in the vertical direction and the horizontal direction is an odd number, the center coordinates are formed at the center of the shot 100. As such, although the center coordinates may appear different depending on the quantity of the shot 100, the center coordinates of the actual semiconductor substrates are the same.

Here, the stages provided in the facility may be different for each facility, and thus, the center coordinates of the stage may be different from the center coordinates of the photo map. In this case, the center coordinates of the stage may be shifted by the difference value. The center coordinates and the center coordinates of the photo map can be corrected in the same manner.

For example, when the X coordinate of the stage center coordinate is 100000 μm, the Y coordinate is 100000 μm, the X coordinate of the center coordinate of the photo map is 100500 μm, and the Y coordinate is 99500 μm, the center coordinate of the stage It can be seen that the center coordinates of the photo map deviate by +500 µm on the X axis and -500 µm on the Y axis. Accordingly, in order to correct the center coordinates of the stage to be the same as the center coordinates of the photo map, the center coordinates of the stage are moved by +500 μm on the X axis and −500 μm on the Y axis.

Subsequently, a plurality of alignment coordinates 104 are set based on the center coordinates of the photo map. (S120) The alignment coordinates 104 are configured to store a semiconductor substrate loaded onto the stage. Used to sort by.

In addition, the cross coordinates 106 of the dividing lines for dividing the plurality of shots 100 are registered. (S130) The cross coordinates 106 are horizontal dividing lines as points for dividing the plurality of shots 100. These are the intersections of the vertical dividing lines.

Referring to FIG. 2, each shot 100 has a quadrangular shape, and a plurality of shots 100 having the quadrangular shape are arranged in a horizontal and vertical direction on a semiconductor substrate. In this case, a divider line is generated to distinguish the shots 100 among the shots 100, and a point at which the horizontal divider line and the horizontal divider line intersect is generated. At this time, the intersection point is four in one shot 100, and the intersection point of the lower left side is the origin point of the shot 100. Therefore, the measurement position designated in the shot 100 can be more easily detected using the cross coordinates 106.

In this case, the alignment coordinates 104 may be selected coordinates among intersection points generated by the shot 100. Accordingly, the plurality of alignment coordinates 104 may be measured using the center coordinates and the size of the shot 100.

On the other hand, the alignment coordinates 104 may be differently designated and set as arbitrary coordinates.

As described above, a process recipe for performing a substrate inspection process using a photo map of a semiconductor substrate without a sample semiconductor substrate is set. Thereby, the waiting time loss which occurred conventionally by setting a process recipe using a sample semiconductor substrate can be suppressed, and the process recipe setting time can be reduced.

Looking at the experimental data in more detail, by setting the process recipe in the above manner, the process recipe setting time, which was conventionally 4 hours in one process step, was reduced to about 1 hour.

Hereinafter, the thickness of the film or pattern formed on the semiconductor substrate is measured using the process recipe.

The semiconductor substrate is loaded onto the inspection stage (S140). The semiconductor substrate is then loaded onto the inspection stage by a transfer robot from an accommodating device such as a cassette for accommodating the semiconductor substrates.

Subsequently, the position of the semiconductor substrate loaded onto the inspection stage is recognized using the center coordinates, the plurality of alignment coordinates 104, and the intersection coordinates 106 (S150).

As described above, the center coordinates of the semiconductor substrate are automatically identified because all the semiconductor substrates are substantially the same.

Accordingly, the alignment coordinates 104 and the intersection coordinates 106 are also identified by checking the center coordinates, and the position to be examined is detected based on the center coordinates, the alignment coordinates 104 and the intersection coordinates 106. (S160)

The thickness of the film or pattern is measured using light at the detected position on the semiconductor substrate. In brief, the light is emitted to the measuring position, the emitted light is reflected from the measuring position, and the sensor of the measuring device detects the reflected light to detect the thickness of the measuring position. (S170)

In performing the inspection process as described above, it can be seen that the time required for the semiconductor substrate to move to the inspection stage and wait is improved by about 34.3% from 27.47 minutes to 18.05 minutes per day. This is because the time for setting the process recipe is shortened.

As described above, according to a preferred embodiment of the present invention, by setting the inspection process recipe using the photo map without the sample semiconductor substrate, it is possible to suppress the time loss that occurs while the sample semiconductor substrate moves to the inspection stage, thereby making it faster than before. Inspection process recipes can be set.

Thus, the overall inspection process time can be reduced.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (3)

Obtaining a photo map based on a substrate on which a pattern is formed in shot units; Detecting center coordinates of the photo map; Setting a plurality of alignment coordinates based on the center coordinates; Registering intersection coordinates of the dividing lines for dividing the plurality of shots; Loading the substrate onto the inspection stage; Recognizing a position of the substrate using the center coordinates, alignment coordinates, and intersection coordinates; Detecting a measurement position of the substrate using the alignment coordinates and the intersection coordinates; And Measuring the thickness of the film or pattern corresponding to the measurement position. The method of claim 1, wherein some of the alignment coordinates are the same as the intersection coordinates. The method of claim 1, wherein the center coordinates of the photo map are detected by the size of the substrate, the shot quantity, and the size of the substrate.

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