JP2011023615A - Distinguishing mark - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To distinguish an recognition mark accurately even when there is a remaining film. <P>SOLUTION: Since the end face length of a dot constituting a distinguishing mark which is desired to be recognized is made long or a surface area which is a reflection surface of light can be increased by arranging minute dots 2 at the periphery of the dot 1 or in such a manner that it has an overlapping portion, the reflecting section of radiated light is increased, recognition rate can be increased, and traceability can be assured. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recognition mark such as an ID (abbreviation of Identification) used for individual recognition of a product or the like.

  In recent years, in the manufacture of products, it is important to ensure traceability by reading identification marks such as IDs. For example, even in the semiconductor wafer manufacturing management method, an ID is imprinted on the surface of the wafer with a two-dimensional code (hereinafter referred to as a 2D code), and ID confirmation is performed at a necessary timing, so that the wafer processing history is definitely recorded. It is recorded and managed. These are essential techniques for acquiring data necessary for improving the yield of wafers.

  The 2D code and alphanumeric characters are engraved with an array of dots having a diameter of 100 μm, as can be seen from standards such as SEMI-T7 (standard number of SEMI standard) and SEMI-M12. These codes and alphanumeric characters confirm the ID by recognizing each dot.

  In conventional dot recognition, as shown in Patent Document 1, a dot having a concave shape is formed, and the periphery of the dot is imaged by applying oblique illumination or vertical illumination to recognize the dot. At this time, whether to use oblique illumination or vertical illumination is performed by switching the conditions depending on the type of deposited film on the wafer surface, for example. Furthermore, efforts have been made to further improve the dot recognition rate by adopting not only concave dots but also convex dots.

The principle of dot recognition will be briefly described with reference to FIG.
FIG. 16 is a cross-sectional view for explaining a conventional dot recognition method.
In FIG. 16, 5 is a light source, and 6 is an ID reading camera. Reference numeral 51 denotes a conventional dot, which has a concave cross section and is, for example, a hole having a diameter of 100 μm. When the light source 5 irradiates light from the upper part of the dot 51, for example, in a wafer formed of silicon, reflection of light should occur at the dot 51 and its periphery. There are two types of illumination methods for dot recognition, a dark field method and a bright field method. For example, in the dark field method, the object is irradiated with light from the light source 5 at an inclined position that is not coaxial with the optical axis of the camera, and a part of the light reflected by, for example, unevenness on the object enters the camera 6. This is a method for recognizing the contrast formed on the object. For example, the light that hits the hole of the dot 51 and the light that hits the flat surface of the target object in this case are not reflected and returned to the camera 6. Further, a part of the light hitting the end of the dot 51 reflects the light of the light source 5 to the camera 6 at somewhere on the reflecting surface continuous from the object surface to the concave surface, for example, the end surface of the concave hole. Since there is a reflecting surface, it is strongly incident on the camera 6, and only a part of the light hitting the periphery of the camera 6 is incident on the camera 6. Therefore, only dots are recognized as bright circles. The dot arrangement thus shined is recognized by the camera 6 to recognize 2D codes and alphanumeric characters.

  On the other hand, in the bright field method, the object is irradiated with light from the light source 5 that is coaxial with the optical axis of the camera. For example, the light reflected from the uneven part on the object is reflected on the camera. This is a method of recognizing from contrast formed on a darkened object in incident light.

JP 2005-209918 A

  However, due to the advancement of the difficulty of processing techniques accompanying the miniaturization of semiconductor wafers and the diversification of materials used, a residual film may be generated due to the process result in the ID forming portion on the wafer surface. For this reason, with conventional dots, even if an attempt is made to read the ID, the dots under the remaining film cannot be easily read. Therefore, there is a problem that a situation in which traceability cannot be ensured occurs.

The dot reading defect will be briefly described with reference to FIG.
FIG. 17 is a diagram for explaining a conventional dot reading defect.
In FIG. 17, the dots 51 form the number 1 and 4 indicates the remaining film. For example, when the remaining film 4 is present on a part of the dots 51 of the number 1, even if an attempt is made to recognize the dots 51 by irradiating light, the number 1 cannot be completely recognized in the camera recognition screen image. In this case, the number formed with dots cannot be read, that is, NG determination is made.

Therefore, in addition to the development of technology for removing the remaining film, development of a technology that can read a recognition mark such as a dot even if there is a remaining film has been awaited.
The present invention has been made to solve the above-described problems, and an object of the present invention is to accurately identify a recognition mark even if there is a remaining film.

  In order to achieve the above object, a semiconductor device according to the present invention is an identification mark that is recognized by reading reflected light of irradiated light, and is formed in the vicinity of the first mark and the first mark. One or a plurality of second marks, the first mark and the one or more second marks as one element, and formed by one or a plurality of the elements. To do.

  Further, the identification mark is recognized by reading the reflected light of the irradiated light, and is formed in a plurality of first marks arranged in a matrix and one or more formed in the vicinity of each of the first marks. The first mark and the second mark arranged in a matrix form one element, and are formed by a plurality of the elements.

In addition, it is preferable that the corresponding first mark and the second mark partially overlap each other.
The first mark and the second mark are preferably dots.

In addition, it is preferable that the second mark has a smaller planar view area than the first mark.
Further, it is preferable that the first mark and the second mark are circular or square.

In addition, it is preferable that the diameter or the opposite side length of the second mark is 1/8 or more and 1/2 or less the diameter or the opposite side length of the first mark.
Preferably, the first mark and the second mark are circular, and the center of the second mark exists on the circumference of the first mark.

Preferably, the first mark and the second mark are square, and a diagonal line of the second mark exists on the side of the first mark.
Moreover, it is preferable that the row | line | column space | interval of a said 1st mark is 3 times or less of the width | variety parallel to the row direction of a said 1st mark.

A plurality of second marks provided corresponding to the first marks may be provided.
The first mark and the second mark are preferably formed in a concave shape.

The first mark and the second mark are preferably formed in a convex shape.
As described above, even if there is a remaining film, the recognition mark can be accurately identified.

  As described above, by arranging an auxiliary identification mark around or overlapping the identification mark, the end face length of the identification mark to be recognized is increased, or the surface area that is the light reflecting surface is increased. Therefore, the reflection part of the irradiated light increases, and the recognition rate can be increased to ensure traceability.

The figure explaining the shape of the identification mark in 1st Embodiment The figure explaining the control method of the reflectance of a dot in a 1st embodiment. The figure explaining the formation position of the minute dot in a 1st embodiment. The figure explaining the crossing angle of the micro dot and light reflective surface in 1st Embodiment The top view which shows reflection of the minute dot in 1st Embodiment The top view which shows the relationship between the recognition mark and 1st film in 1st Embodiment The side view which shows the light source position in 1st Embodiment The figure explaining the pixel arrangement which recognized the dot of the dot reading in the conventional 4x4 pixel area The figure explaining the pixel arrangement which recognized the dot of the dot reading in the conventional 3x3 pixel area The figure explaining the pixel arrangement in the conventional pixel area, and the pixel arrangement which recognized the dot The figure explaining the pixel arrangement | sequence which recognized the dot by the minute dot in 1st Embodiment The figure explaining the pixel arrangement | sequence which recognized the magnitude | size of the minute dot and dot recognition in 1st Embodiment The figure which shows the structure of the recognition mark in 2nd Embodiment. The figure which shows a mode that light is irradiated with respect to the recognition mark of 2nd Embodiment. The figure which shows the mode of the reflected light in the recognition mark of 2nd Embodiment. Sectional drawing explaining the conventional dot recognition method Diagram explaining conventional dot reading failure

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
Hereinafter, the identification mark according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 12, taking a semiconductor device in which dots are formed as an example. In the following drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a diagram for explaining the shape of an identification mark in the first embodiment. FIG. 1 is an enlarged view of a portion of a semiconductor device where dots are formed. FIG. 1 (a) is a circle, and FIG. Shows square dots with rounded corners. 2 to 4 are cross-sectional views illustrating a dot reflectance control method according to the first embodiment, FIG. 5 is a plan view illustrating reflection of a minute dot according to the first embodiment, and FIG. 6 is a first embodiment. FIG. 7 is a side view showing a light source position in the first embodiment. FIG. 7 is a plan view showing the relationship between the recognition mark and the remaining film in the embodiment.

  In FIG. 1, a concave dot 1 provided on the wafer surface and a concave minute dot 2 which is an auxiliary dot provided on the wafer surface are formed, and the minute dot 2 partially overlaps the dot 1. Has been processed. 7 represents the diameter of the minute dots 2 (in the case of FIG. 1A), and 8 represents the opposite side length (in the case of FIG. 1B). The shape of the dot is not limited to the concave shape as described above, and may be a convex shape. The minute dots 2 do not necessarily overlap with the dots 1 and can be formed in the vicinity of the dots 1.

  In FIG. 1A, the broken line represents a portion where a part of the outer periphery of the dot 1 is cut out by the minute dot 2. A one-dot chain line is a line including a diameter of a circle passing through the outer periphery of the dot 1, and the two lines are orthogonal to each other. The intersection of these two one-dot chain lines indicates the center of the dot 1. In FIG. 1B, the broken line represents a portion where a part of the outer periphery of the dot 1 is cut out by the minute dot 2. The alternate long and short dash line is a line including a square diagonal line passing through the outer periphery of the dot 1, and the two lines are orthogonal to each other. The intersection of these two one-dot chain lines indicates the center of gravity of the dot 1. A double line and a two-dot chain line indicate an area occupied by dots.

  Here, the semiconductor device is, for example, a large scale integrated circuit (LSI) formed on a silicon wafer (silicon substrate), and a portion where dots are formed is formed at one end of the semiconductor device. .

  The processing method of the dots 1 and the minute dots 2 on the silicon wafer is performed by, for example, processing by melting or partial evaporation of silicon by laser irradiation. In the case of FIG. 1A, the depth of the hole is formed to be substantially the same as the radius of the hole. In other words, since the radius of the hole to be processed in dot 1 and minute dot 2 is r1 (dot 1)> r2 (minute dot 2), the depth is different, and minute dot 2 is shallower than dot 1 It will be a thing. Also in the case of FIG. 1B, the minute dots 2 are formed so as to be shallower than the dots 1. In this way, by forming the minute dot 2 shallower than the dot 1, the dot end length or the peripheral length of the simple circular or square shape of the dot 1 can be set within the dot occupying region indicated by the double-line and two-dot chain line. The ends of the plurality of minute dots 2 can be added continuously, and the end length can be increased. Incidentally, the purpose of defining the dot occupation area is that the dot setting area in the camera recognition is set in a simple circular shape or a simple square shape.

  Specific sizes of dots studied in this embodiment will be exemplified below. In the dots shown in FIG. 1A, the radius of the dot 1 is 60 μm, and the radius of the minute dot 2 is 10 μm. Further, in the dot shown in FIG. 1A, the depth of the dot 1 is 60 μm, and the depth of the minute dot 2 is 10 μm.

  In the dot shown in FIG. 1B, the length of one side of the dot 1 is 120 μm, and the length of one side of the minute dot 2 is 40 μm. The rounded corner is an arc having a radius of 20 μm. In the dot shown in FIG. 1B, the depth of the dot 1 is 60 μm, and the depth of the minute dot 2 is 20 μm.

  In the semiconductor device having dots shown in FIGS. 1A and 1B, the opening area of the entire dot or the peripheral length of the opening without increasing the area of the dot 1 due to the presence of the minute dots 2. Therefore, it is possible to improve the reflectance of the entire dot, which is an identification mark, and to improve the recognizability of the dot 1.

Next, using the cross-sectional views shown in FIGS. 2 to 4, it will be described that the dot reflectance can be controlled by the overlapping state of the dots 1 and the minute dots 2.
3 and 4 show the overlap between the dot 1 and the minute dots 2a, 2b, and 2c and the difference in cross-sectional shape. Here, an example will be described in which dots having a circular planar shape as shown in FIG. 1A are formed into a spherical partial concave shape.

  In FIG. 2, the portion where the perpendicular drawn from the outer periphery of the minute dot 2 a intersects with the one-dot chain line of the dot 1 is the center position of the laser beam irradiation when the minute dot 2 is formed. Further, the depth of the step formed at the end of the dot 1 by the minute dot 2 formed at that time is defined as an intersection depth 10. Further, when the minute dots 2 are formed, the angle at which the tangent line (two-dot chain line) of the minute dots 2 on the surface of the light reflecting object intersects the surface of the light reflecting object is defined as an intersection angle 11.

  In each figure of FIG. 3, a description will be given with respect to a position where a line passing through the center of the dot 1 (indicated by a one-dot chain line) and a tangent line (indicated by a broken line) of the minute dots 2a, 2b, 2c intersect To do. 3A shows a case where the center of the minute dot 2a substantially overlaps the circumference of the dot 1, and FIG. 3B shows a case where the center of the minute dot 2b is inside the circumference of the dot 1 (that is, the circumference of the dot 1). 3C shows a case where the center of the minute dot 2c comes outside the circumference of the dot 1 (that is, the outside as seen from the circumference of the dot 1).

  Corresponding to these FIGS. 3A to 3C, in FIG. 4, FIG. 4A shows a case where the crossing angle 11a is approximately 90 degrees. FIG. 4B shows a case where the crossing angle 11b is 45 degrees to 90 degrees. FIG. 4C illustrates a case where the crossing angle 11c is 0 degree to 45 degrees.

  These angles indicate that when the light is irradiated from above the dots 1, the reflectance and the amount of reflection to the camera (not shown) provided at the position where the semiconductor device is photographed can be adjusted by the minute dots 2. As the crossing angle 11 decreases, the amount of reflected light increases. Therefore, it is shown that the reflectance and the amount of reflection to the camera (not shown) provided at the position where the semiconductor device is copied can be adjusted by the minute dot 2 according to the marking position of the minute dot 2.

  Furthermore, the reflectance and the amount of reflection of the dot 1 can be adjusted by changing the arrangement and number of the minute dots 2 with respect to the dot 1, and the recognition of the dot 1 can be facilitated by increasing the amount of reflection.

In order to show that the dot 1 can be easily recognized, the case where the dot shown in FIG. 1 is irradiated with light from above the dot will be described with reference to FIG.
FIG. 5 shows a state in which the light from the upper part of the dot 1 can be largely reflected, and 3 is the reflection part. In this way, by forming dots that reflect greatly, the amount of reflection increases and the reflected light can pass through the remaining film, so that the dot 1 can be easily recognized. In addition, since the reflectance of a dot can be raised more by adjusting the overlapping condition of the dot 1 and the dot 2 as shown in FIGS. 2-4, the recognizability of the dot 1 improves further.

  When the dot 1 and the minute dot 2 shown in FIG. 1 are used, that is, when a recognition mark composed of a plurality of elements is formed on the semiconductor device as one element of the recognition mark by a pair of one dot 1 and one minute dot 2 FIG. 6 shows how the recognition mark is recognized. FIG. 6 shows that the reflecting portion 3 can be confirmed by the action of the large reflectance of the minute dots 2 even if the remaining film 4 shown in FIG. FIG. 6 shows that the number 1 can be recognized.

  Here, the remaining film 4 will be described. For example, in a laminated film formed by a semiconductor process, there is a film having a material and a film thickness that does not transmit light at all, and a film having a small film thickness and partially transmitting light. Here, a remarkable effect is shown in a film such as a TEOS film (a compound of glass Si and O) that transmits light. Of course, the present invention is not limited to the TEOS film.

  FIG. 7 shows an adjustment region of the light source 5 for largely reflecting light from the upper part of the dot 1 shown in FIG. Here, in order to avoid complication, the minute dots 2 are not shown. The light source 5 is positioned so that the optical axis of the radiated light hits the target dot 1. The position of the light source 5 can be strongly illuminated by arranging the light source 5 within the range of 10 to 70 degrees information from the wafer surface. This is because even if a hole is machined into a concave shape by laser irradiation or cutting, its end cannot be machined at 90 degrees. In the case of laser machining, the end is melted or in the case of machining. This is because the crossing angle always occurs on the chamfered surface made of chamfered chips and burrs.

The results shown in FIGS. 5 to 7 will be considered below.
When a residual film is generated due to the process processing result in the ID forming portion on the wafer surface, the conventional recognition mark as shown in FIG. 17 is read by reflected light from only the end portion of the dot 1 when the dot 1 is concave. Therefore, one or a plurality of dots 1 under the remaining film 4 cannot be read. On the other hand, the end face length (that is, the length of the edge) of the concave dot 1 to be recognized is increased by arranging one or more fine dots 2 so as to overlap the dots 1 as in the present invention. (In the case of the convex dot 1, the surface area can be increased), the number of reflected portions of the irradiated light is increased, the recognition rate can be increased, and traceability can be ensured. Furthermore, the recognition rate can be improved by appropriately controlling the incident angle of the light source 5 with respect to the dots.

  Next, the relational dimensions of dots in this embodiment will be described. By making the diameter 7 or the opposite side length 8 of the minute dot 2 be 1/8 or more and 1/2 or less of the diameter or the opposite side length of the recognition dot 1, the light reflection can be maximized, which is preferable. In the example shown in FIG. 1, the minute dots 2 are provided with a diameter of 1/6.

  Here, when the diameter 7 or the opposite side length 8 of the minute dot 2 is set to 1/8 or more and 1/2 or less of the diameter or the opposite side length of the recognition dot 1, the light reflection can be maximized as follows. Because of the reason.

This will be described in detail with reference to FIGS.
FIG. 8 shows a region where there is no reflected light in dot recognition with a dark field or no reflected light in dot recognition with a bright field. A square surrounded by a one-dot chain line represents one of the pixels of the camera. Each one senses the presence or absence of dots by sensing the brightness of the reflected light, for example. First, in the case where a dot is recognized within a 4 × 4 16-pixel region (FIG. 8A), the presence or absence of a dot is determined by 12 pixels (FIG. 8B), 11 depending on the position of the dot in the camera. It can be seen that recognition is performed with various pixel arrangements such as pixels (FIG. 8C) and 9 pixels (FIG. 8D). Here, it can also be seen that a 2 × 3 6-pixel region is always included even in the 12-pixel, 11-pixel, and 9-pixel recognition.

  For reference, a case where dot recognition is performed in a 3 × 3 9 pixel region (FIG. 9A) will be described with reference to FIG. It can be seen that the presence or absence of a dot is recognized by various pixel arrangements of 5 pixels (FIG. 9B) and 4 pixels (FIGS. 9C and 9D) depending on the position of the dot in the camera. Here, it can be seen that even if each of the five-pixel and four-pixel recognitions is used, a three-pixel region is always included, but it can also be seen that the arrangement is an arrangement bent in a square shape. In particular, in the case of FIG. 9C, there is a possibility that two pixels will be recognized depending on the variation in the detection of the brightness of the dots, and there is a high possibility that the number of recognized pixels will be insufficient for stable dot recognition. . Incidentally, the number of pixels for recognizing dots is determined by the relationship between the magnification ratio of the camera lens and the number of image sensors of a CCD (charge coupled device image sensor).

  In FIG. 10, dots are recognized as 4 × 4 16 pixel regions (FIG. 10A), 8 × 8 64 pixel regions are recognized (FIG. 10B), and 16 × 16 256 pixel regions are recognized (FIG. 10B). c)) is shown, it can be easily understood that the dot can be recognized more accurately as the number of recognized pixels increases. This time, there is a demand for further improvement of the recognition rate in a system with a low magnification and a small number of pixels, such as 4 × 4 16 pixel region recognition, and the size of a minute dot that improves the recognition rate will be described.

  FIG. 11 is a diagram for comparing pixel area recognition in the prior art (FIG. 11 (a)) and the present invention (FIG. 11 (b)), in which micro dots are arranged on conventional dots in 4 × 4 16 pixel area recognition. Thus, it can be seen that, for example, the light non-reflective dot shape in the bright field is recognized by the 12 pixel recognition of the 4 × 4 16 pixel region, but is recognized by the 16 pixel region of the entire dot. The minute dots at this time are shown when the minute dots are formed with a radius of 1/4 of the dot. Thus, it can be seen that dot recognition can be performed stably as the number of dot recognition increases. However, since a plurality of adjacent dots must be recognized as letters, numbers, or symbols only after being arranged in the shape of letters, numbers, or symbols, the maximum size for each dot that can be recognized as a dot There is a size.

  In FIG. 12, the minute dot size in the case of character recognition according to the current character standard (for example, SEMI font) will be described more specifically. FIG. 12A shows an example in which the radius of the minute dots combined with the dots is halved, and four are arranged on the outer periphery of the dots. In the past, recognition was performed with 11 pixels shown in the left figure, but it was possible to increase up to 19 pixels in the pixel portion indicated by hatching. When the area occupied by the dots is defined by a rectangle, it has been found that it is effective to improve the number of pixel recognition by a maximum of ½ of the dot radius. At this time, the overlapping amount and arrangement are not limited to the case where the four shown in FIG. FIG. 12B shows a case where the radius of the minute dot combined with the dot is 1/8. By setting the radius of the minute dots to a minimum of 1/8, it was possible to increase the number of pixels in the shaded area up to 16 pixels, which was conventionally recognized with 12 pixels shown in the left figure. In particular, it has been proved by dot arrangement verification and experiments that the effect can be sufficiently achieved at 1/8 or more depending on the positional relationship between dots and pixels. The overlapping amount and arrangement at this time are not limited to those shown in FIG.

By the way, although the explanation is given with the example of the bright field, it is known that there is an increase in the number of recognized pixels due to the minute dots even when the dark field dots shine.
In this description, the action is shown using a circular shape, but the shape is not limited to a circular shape, and a square shape may be used. Further, the dots and the minute dots are arranged so as to be in contact with each other, but the way of contacting and overlapping is not limited to this arrangement.

That is, if the dot 1 is set to 1/8 or more of the diameter or the opposite side length of the dot 1, the area of the dot 2 having a high reflectance can be increased, and the amount of light from the dot 1 and the dot 2 can be increased. It can be taken big. Further, if the minute dot 2 is set to be 1/2 or less of the diameter or the opposite side length of the dot 1, the end face length of the dot 1 and the minute dot 2 can be increased. From these facts, the light reflection can be maximized by setting the diameter or the opposite side length of the minute dot 2 to 1/8 or more and 1/2 or less of the diameter or the opposite side length of the recognition dot 1.
(Second Embodiment)
An identification mark according to the second embodiment of the present invention will be described with reference to FIGS. 13 to 15 by taking a semiconductor device in which dots are formed as an example.

  FIG. 13 is a diagram showing a configuration of a recognition mark in the second embodiment, FIG. 14 is a diagram showing a state of irradiating light to the recognition mark of the second embodiment, and FIG. 15 is a recognition of the second embodiment. It is a figure which shows the mode of the reflected light in a mark.

  In the first embodiment, the dot 1 and the minute dot 2 (see FIG. 1 and the like) are used as one element, and the recognition mark is formed by a plurality of elements. However, in this embodiment, as shown in the first embodiment. A single dot is formed by arranging a plurality of pairs of simple dots 1 and minute dots (not shown) so that the distance between columns is constant, and a recognition mark is formed by a plurality of elements. To do. FIG. 13 shows the case where the distance between the centers of the dots 1 is 1 time (FIG. 13A) and 1.5 times the width of the dot 1 (FIG. 13B).

  For example, the dot 1 is circular and has a radius of 20 μm and a depth of 20 μm. The size of the dot 1 is about 1/3 of the size of the dot 1 shown in the first embodiment. Further, the size of the minute dots can be about ½ of the size of the dots 1 shown in the second embodiment. Further, the form of the dots 1 may be circular or square as in the first embodiment, and may be concave or convex.

  As a single dot, three dots 1 are arranged so as to be in contact with each other from the top to the bottom on the paper surface of FIG. 13, and are arranged in two rows at regular intervals. That is, one single dot is constituted by a dot arrangement of 2 columns and 3 rows (hereinafter referred to as 2 × 3 columns). In FIG. 13, the solid line is the interval between the dots, the broken line is the area where the dots are formed, the center of the set of dots in which the alternate long and short dash line is arranged in 2 × 3 rows, and the circumference of the dot 1 shown in the first embodiment. It shows.

  FIG. 14 is a diagram showing a state in which a single dot for recognition is formed by the 2 × 3 rows of dots 1 shown in FIG. FIG. 14A is a diagram illustrating the present embodiment, and FIG. 14B is a diagram illustrating the case of the dot 1 according to the first embodiment. FIG. 15 is a diagram illustrating a state of light reflection between the 2 × 3 rows of dots 1 illustrated in FIG. 13 and the dots 1 illustrated in the first embodiment. FIG. 15A is a diagram illustrating the present embodiment, and FIG. 15B is a diagram illustrating the case of the dot 1 according to the first embodiment. In FIG. 14 and FIG. 15, the description of minute dots is omitted to avoid complexity.

  As shown in FIG. 14, by forming a single dot by arranging a plurality of dots in a row, conventionally, the presence or absence of a dot is determined by a single reflector 3, but a plurality of, for example, 2 × 3 Thus, the presence or absence of dots can be determined by the six reflecting portions 3, and the amount of reflected light is improved and the recognition rate is improved in the six reflecting portions 3 compared to the conventional one reflecting portion 3.

  Further, in FIG. 15, the state where the dot arrangement interval is reflected on the camera of the reflected light is examined, and the dot arrangement interval is adjusted to x1 to x1.5 so as to be adjacent to each other and can be recognized as one lump. showed that.

As shown in FIG. 15, when a plurality of small reflecting portions are gathered, the total amount of reflected light can be increased, and the reading rate can be improved.
The 2 × 3 rows of dots shown in FIG. 13 are regarded as one single dot (ie, one element), and characters such as those shown in FIG. 6 are written to increase the length or surface area of the end and increase the amount of reflected light. Therefore, the character reading rate is further improved as compared with the case of the first embodiment.

  For example, according to the semiconductor device in which dots are formed according to the present embodiment, a plurality of dots are arranged in response to a phenomenon in which the remaining film 4 that makes it difficult to recognize the dots 1 is generated in the ID forming portion on the wafer surface. In this case, the amount of reflected light of a single dot to be recognized can be increased, the recognition rate can be further increased as compared with the case of the first embodiment, the ID reading rate can be increased, and traceability can be secured.

  In the second embodiment, the distance between the columns (in the horizontal direction in FIG. 13) is not more than three times the length of one side when the dot 1 is a circle and the diameter when the dot 1 is a square. It is preferable. This is because if the interval between columns is three times or less, a set of dots can be recognized as one element (one element).

  In the second embodiment, the arrangement of dots is not limited to 2 × 3 columns, but may be m × n columns (m and n are natural numbers). For example, it may be 1 × 2 columns or 3 × 4 columns. Further, the dot arrangement is not limited to m × n columns. For example, the dots may be arranged radially from the center.

  In the first and second embodiments, the planar shapes of the dots 1 and the minute dots 2 are not limited to a circle or a rectangle, but may be a polygon such as an ellipse, a pentagon, or a hexagon. The shapes of the dots 1 and the minute dots 2 may be different from each other, and the shapes may be different between the plurality of dots 1 or between the plurality of minute dots 2.

  In the first and second embodiments, the semiconductor device is not limited to an LSI formed on a silicon substrate. For example, semiconductor laser elements and field effect transistor (FET) elements formed on GaAs substrates, light-emitting diode (LED) elements and semiconductor laser elements formed on sapphire substrates and GaN substrates, and glass substrates. It may be like an electronic device. The present invention can also be applied to devices such as solar cells and organic electroluminescence elements. The present invention is also applicable to a package on which a semiconductor element is mounted. Furthermore, it can also be used for identification marks of products other than semiconductor devices.

  In the first and second embodiments, the dots and minute dots can be processed by applying lithography or the like other than silicon melting or partial evaporation by laser irradiation. . Examples of the laser light source used for laser irradiation include YAG laser, nitrogen laser, and excimer laser. Moreover, the processing means of a dot and a micro dot can be suitably selected with the board | substrate and material to be used.

  In the first and second embodiments, the dots and the minute dots are not limited to the concave shape, and may be a convex shape or a combination of the concave shape and the convex shape. Moreover, when providing convex shape, the material which forms convex shape may differ from the material which comprises board | substrates, such as a wafer.

  The identification marks of the first and second embodiments have been described with reference to characters. However, the identification marks that are imprinted or drawn with dots and minute dots are not limited to characters but may be patterns.

  In the first and second embodiments described above, the size (radius or length of one side) of the dots and the minute dots is described as about 1 to 10 μm. Any size that can be identified is acceptable.

Furthermore, in the first and second embodiments, the concave shape or convex shape of the dot can be any shape such as a part of a sphere, a cone, a pyramid, a cylinder, or a prism.
In each of the embodiments described above, the case where the identification mark is formed with dots has been described. However, the present invention is not limited to the case where the identification mark is formed with one or a plurality of dots, and characters and symbols are directly formed as identification marks. Also, by forming an auxiliary mark adjacent or overlapping so that the length or surface area of the end portion increases, the amount of reflected light increases and the recognition mark can be identified with high accuracy.

  The present invention can accurately identify a recognition mark even if there is a residual film, and is useful for a recognition mark used for individual recognition or the like.

1 dot 2 minute dot 2a minute dot 2b minute dot 2c minute dot 3 reflector 4 remaining film 5 light source 6 camera 7 diameter 8 opposite side length 10 intersection depth 11 intersection angle 11a intersection angle 11b intersection angle 11c intersection angle 51 conventional dot

Claims (13)

An identification mark that is recognized by reading reflected light of the irradiated light,
The first mark,
One or a plurality of second marks formed in the vicinity of the first mark, the first mark and the one or more second marks as one element An identification mark formed by an element. An identification mark that is recognized by reading reflected light of the irradiated light,
A plurality of first marks arranged in a matrix;
One or a plurality of second marks formed in the vicinity of each first mark, the first mark and the second mark arranged in a matrix as one element, An identification mark formed by an element.   The identification mark according to claim 1, wherein the first mark and the second mark corresponding to each other partially overlap each other.   The identification mark according to claim 1, wherein the first mark and the second mark are dots.   The identification mark according to claim 1, wherein the second mark has a smaller area in plan view than the first mark.   5. The identification mark according to claim 4, wherein the first mark and the second mark are circular or square.   7. The identification mark according to claim 6, wherein the diameter or the opposite side length of the second mark is 1/8 or more and 1/2 or less the diameter or the opposite side length of the first mark.   The identification mark according to claim 4, wherein the first mark and the second mark are circular, and the center of the second mark exists on the circumference of the first mark.   The identification mark according to claim 4, wherein the first mark and the second mark are square, and a diagonal line of the second mark exists on a side of the first mark.   3. The identification mark according to claim 2, wherein the column interval of the first mark is not more than three times the width parallel to the row direction of the first mark.   The identification mark according to any one of claims 1 to 10, wherein a plurality of the second marks provided corresponding to the first marks are provided.   The identification mark according to any one of claims 1 to 11, wherein the first mark and the second mark are formed in a concave shape.   The identification mark according to claim 1, wherein the first mark and the second mark are formed in a convex shape.

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