JP2000357640A - Production of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a production method of semiconductor element which can be applied even to a logic having different pattern by identifying the position of a pellet on a wafer. SOLUTION: The production method of semiconductor element comprises a step for performing exposure again using an exposing reticle having a pattern for passing UV-rays or infrared rays only partially before photoresist is developed with developer when a plurality of pellets 1, 2, 3, 4 are produced from a sheet of semiconductor wafer 5. The mask used for re-exposure only has an opening for generating an identification pattern of a single pellet and it is stepped in X and Y directions by a step width different from the dimension of the pellet. That dimension is equal to the pellet width ±α, where αcorresponds to the interval of the identification pattern and the stepping direction 6 is shown by a dot line on the drawing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device for identifying a portion where a wafer is located.

[0002]

2. Description of the Related Art In recent years, the complexity of characteristics has been increased due to the miniaturization and high density of semiconductors and the combination of digital and analog devices, and the price per wafer has become higher due to the increase in diameter.
In addition, since the life of the product has been shortened, it is necessary to manufacture many good products having the same characteristics from the wafer. However, in the case of digital / analog mixed mounting, delicate characteristics are often measured after resin sealing is finally performed,
If a defect occurs at that time, it is important to know where the wafer was located.

As one example of a conventional method of manufacturing a semiconductor device, there is a method of manufacturing a semiconductor device described in Japanese Patent Application Laid-Open No. H10-055939. This manufacturing method is capable of indicating unique identification information of an electronic device, and at this time, a method of manufacturing a semiconductor device capable of setting identification information without duplication for a plurality of electronic devices. This is an electronic device system that can prevent signal interference when transmitting / receiving a signal and enhance the security of transmitted / received data.

FIG. 8 and FIG. 9 are views showing the above-mentioned conventional example. 8A and 8B are views showing an example of a conventional method for manufacturing a semiconductor device, in which FIG. 8A shows a semiconductor wafer, and FIG. 8B is an enlarged view of a part of FIG. FIG. 9 (A),
(B) is a figure which shows the exposure location of an adjacent pellet. First, four ICs 61, 71, 31, and 41 are formed on a portion 60 of the semiconductor wafer shown in FIG. Here, 62 indicates the same location of 61, and 72 indicates the same location of 71. 100, 101, 200 and 201 are transistors, 110 and 210 are contact holes, 12
0, 121, 220, 221 are word lines, 130, 13
1, 230 and 231 indicate bit lines. In this method, as shown in FIG. 8, a mask in which the width Xb in the X direction is shorter than the width Xa in the X direction of the pellet by a length x in the exposure process at the time of forming the contact hole of the mask ROM is formed.
Exposure is performed by sequentially moving the semiconductor wafer 5 in the x direction on the semiconductor wafer 5 by b. In this way, as shown in FIG. 8, by exposing a mask which is shorter by the length x by the width Xb sequentially in the x-direction, as shown in FIG. The positions are sequentially shifted, and the formation positions of the contact holes are different for each adjacent pellet, such as 110 and 210. Thereby, a different pattern is formed for each pellet.

[0005]

However, in the above-mentioned conventional example, a pattern for identifying each position is not formed on the pellet. Therefore, this method is difficult to apply only to the case of a ROM pattern having the same pattern repeated, and cannot be applied to the case of a logic having a different pattern.

[0006] In addition, although it is said that it has different identification information, it actually has different characteristics of products, which means that all products have different characteristics. Therefore, there is a problem that it is not possible to create a pattern for identifying products having the same characteristics when they are made in the same wafer, and it is not possible to identify a position on the wafer.

Therefore, the object of the present invention can be applied to the case of a logic having a different pattern in order to solve the above-mentioned problem, and a semiconductor device which can identify a position on a wafer which is located there. It is to provide a manufacturing method of.

[0008]

In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention is to manufacture a plurality of semiconductor devices (pellets) having the same electrical characteristics from a single semiconductor wafer. In a method of manufacturing a semiconductor device, different identification information is added to each of the plurality of semiconductor devices so as to identify which part of the semiconductor wafer was located.

Further, after forming a semiconductor element on a single semiconductor wafer, a step of growing a metal film to be a wiring material over the entire surface, a step of applying a photoresist to the surface of the metal film, and a step of exposing the wiring by exposure. Optionally forming a step,
Before developing the photoresist with a developer, exposing again using a reticle for exposure having a pattern that transmits light rays such as ultraviolet rays or infrared rays only partially,
It is preferable that the mask (reticle) for re-exposure has only an opening for creating a pattern for identification.

Further, when re-exposure, when stepping in the X and Y directions, it is preferable to move in the X and Y directions with a step width different from the size of the pellet.

[0011] Furthermore, the dimension to move is the pellet width ±
In the dimension of α, the value of α is preferably a dimension corresponding to the interval of the identification pattern.

In the identification pattern, a plurality of resistance elements connected by metal wiring are arranged, and the number of pellets in the X direction is at least equal to or greater than the number of pellets in the X direction.
Preferably, the number of pellets in the direction is equal to or more than the number of pellets, and it is preferable that each resistance value in the X direction and the Y direction can be known by drawing the resistance value to an external pad.

Further, the pad is not dedicated to the identification pattern, but is constituted by at least three or more pads, one of which is used in common for X and Y, and the other two are provided with a power supply having the same potential. It is preferable to use the same pad.

Although the method of manufacturing a semiconductor device according to the present invention has been described above, even if all the pellets in a wafer formed by the above-described manufacturing method have the same electrical characteristics,
By making different identification elements one by one, even if the inside is not visually visible due to resin sealing etc., each pellet is examined by examining the electrical characteristics such as the resistance value between the pads exposed to the outside. It becomes possible to identify which position was located.

As described above, in the method of manufacturing a semiconductor device according to the present invention, all of the semiconductor devices (hereinafter referred to as pellets) for manufacturing a plurality of products having the same electrical characteristics from one semiconductor wafer are manufactured. Have different identification information.

[0016]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an embodiment of a method of manufacturing a semiconductor device according to the present invention. This figure also shows an embodiment of the method for manufacturing a semiconductor device of the present invention and an example of an identification pattern to be manufactured. First, in the case of manufacturing a semiconductor device, usually, after applying a positive type photoresist, exposure is performed by stepping a photomask (referred to as a reticle) at regular intervals by a stepper. The image is shown in FIG. The wafer 5 is exposed in a stepping direction 6 by a predetermined route (for example, a route such as A → B). In this case, 3 × 3 = 9 can be exposed in one exposure. This is called one shot 7. After manufacturing the semiconductor element, the entire surface is covered with metal to process the wiring. Next, the entire surface is covered with a photoresist.

As described above, in the method of manufacturing a semiconductor device according to the present invention, in particular, all the pellets in the same wafer 5 have the same electrical characteristics.
Is manufactured, it is possible to identify which part of the wafer 5 was located.

[0019]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a schematic diagram showing the configuration of the embodiment of the present invention. First, exposure is performed with a reticle for forming a wiring pattern. Next, exposure is performed using another re-exposure reticle 10 without developing. Thereafter, development is performed. The re-exposure reticle 10 used at the time of this re-exposure has a re-exposure pattern 11.

FIG. 3 is a schematic diagram showing a re-exposure pattern. The re-exposure pattern 11 is a pattern for arranging a part of the identification symbol 12 in a space other than the wiring that determines the characteristics of the product as shown in FIG. 3 and exposing a part of the identification pattern.

FIG. 4 is a schematic diagram showing an example of the identification pattern. In this case, several resistance elements 13 are arranged in parallel in the Y direction and the X direction, respectively. The resistance element 13 is A
The two ends are connected to bonding pads 16, 17, 18. For example, the resistance value between the bonding pad A16 and the bonding pad B17 and the resistance value between the bonding pad B17 and the bonding pad C18 are unique values in the X and Y directions of the pellet.

In the case of exposure with a stepper at the time of re-exposure, this re-exposure reticle has only one pellet pattern and exposes each individual pellet in the stepping direction 6 (FIG. 1). In this case, when stepping in the X direction and the Y direction, it moves in the X and Y directions with a step width different from the size of the pellet.

The dimensions are pellet width ± α15 (FIG. 5).
Where the value of α is a dimension corresponding to the interval α15 between the identification patterns. For example, in the case of re-exposure, assuming that the upper left of FIG. 1 is the coordinate (1, 1), if the position is shifted by + α when moving forward by one, in the case of the pellet (1, 4) 2, as shown in FIG. The position is shifted by 3α16 in the Y direction, and the exposure is performed as in the X direction exposure position 19 and the Y direction exposure position 20.

Further, as shown in FIG.
2) Similarly, in the case of 3, exposure is performed by 3α18 shift in the X direction and α17 shift in the Y direction. In the case of the pellet (final), exposure is performed as shown in FIG. Is connected to the wiring, and in the Y direction, wiring other than one is cut.

That is, when the exposed portion of the positive type resist is irradiated with light, developed and etched, the wirings at the X-direction exposure portion 19 and the Y-direction exposure portion 20 are cut off, and the resistance is opened. As a result, even if each pellet is a product having the same characteristics, it can have a different identification pattern regardless of that, and by measuring the resistance value between the pads, the coordinates of X and Y can be relatively set. It becomes possible to know. In the first embodiment, when the resistance values arranged in parallel are arranged in parallel, the discrimination resistance value of each pellet has a difference in resistance value that is equal to or more than the variation range in consideration of the variation in the formation of the resistance value. To make it work. Therefore, the length of each resistance element in FIG. 4 is different.

Next, another embodiment of the present invention will be described in detail.

First, a second embodiment of the present invention will be described. In the above-described first embodiment, when the resistance values arranged in parallel are made parallel, the resistance element 13 is made to have a difference in resistance value larger than the variation in consideration of the variation of the resistance value when the resistance value is made. However, in the second embodiment, in order to make the lengths of the resistive elements the same and to make the resistive elements have variations, the use of resistive elements having different layer resistances is mentioned. This second embodiment is not particularly shown.

[0029]

As described above, according to the present invention,
What identifies the location can be formed on the pellet. Therefore, since all the pellets having the same characteristic in the same wafer have different identification characteristics, it is possible to identify the position on the wafer where the pellet was located.

In addition, it is possible to easily identify a product by forming a pattern for the identification in each product, and to provide early feedback to a process of making the product to reduce a loss.

[Brief description of the drawings]

FIG. 1 is a plan view showing a configuration of an embodiment of the present invention, showing an image of exposure by a stepper.

FIG. 2 is a schematic diagram showing an image of re-exposure.

FIG. 3 is a schematic view showing a partial arrangement of a pellet and an identification element in a wafer.

FIG. 4 is a schematic diagram showing an example of an identification pattern.

FIG. 5 is a schematic view showing an exposure location in the case of a pellet (1, 4).

FIG. 6 is a schematic view showing an exposure location in the case of a pellet (4, 2).

FIG. 7 is a schematic view showing an exposure location in the case of a pellet (final).

FIG. 8 is a schematic view showing a conventional example. (A) shows a semiconductor wafer, and (B) is an enlarged view of a part of (A).

FIG. 9 is a schematic diagram showing an exposed portion of adjacent pellets during exposure. (A) and (B) are adjacent pellets.

[Explanation of symbols]

 Reference Signs List 1 pellet 1a pellet A 1b pellet B 1c pellet C2 pellet (1,4) 3 pellet (4,2) 4 pellet (final) 5 wafer 6 stepping direction 7 shot 8 scribe width 9 shot 10 re-exposure reticle 11 re-exposure pattern 12 Identification pattern position 13 Resistance element 14 AL wiring 15 α 16 Bonding pad A 17 Bonding pad B 18 Bonding pad C 19 X direction exposure location 20 Y direction exposure location 60 Part of semiconductor wafer 61, 71, 31, 41 IC 62 61 Same location 72 71 Same location 50 Semiconductor wafer 100, 101, 200, 201 Transistor 110, 210 Contact hole 120, 121, 220, 221 Word line 130, 131, 230, 231 Bit line

Claims (6)

[Claims] 1. A method of manufacturing a plurality of semiconductor devices (pellets) having the same electrical characteristics from one semiconductor wafer, wherein each of the plurality of semiconductor devices includes a semiconductor wafer. A method of manufacturing a semiconductor device, wherein different identification information for identifying whether a part is present is provided. 2. A step of growing a metal film to be a wiring material over the entire surface after forming a semiconductor element on one semiconductor wafer; a step of applying a photoresist on the surface of the metal film; Arbitrarily forming a step, and before developing the photoresist with a developer, exposing again using a reticle for exposure having a pattern that transmits only a portion of light such as ultraviolet light or infrared light, 2. The method according to claim 1, wherein the reticle for re-exposure has only an opening for creating an identification pattern. 3. The method according to claim 2, wherein the step of moving in the X and Y directions at a step width different from the dimension of the pellet when stepping in the X direction and the Y direction when the exposure is performed again. A method for manufacturing a semiconductor device. 4. The manufacturing method of a semiconductor device according to claim 3, wherein said moving dimension is a dimension of a pellet width ± α, and said value of α is a dimension corresponding to an interval between identification patterns. Method. 5. The identification pattern includes a plurality of resistance elements connected by the metal wiring, wherein at least the number of pellets in the X direction is equal to or greater than the number of pellets in the X direction, and the number of pellets in the Y direction is equal to the Y direction. More than the number of pellets are lined up,
5. The method of manufacturing a semiconductor device according to claim 4, wherein each of the resistance values in the directions can be known by drawing the resistance value to an external pad. 6. The pad is not dedicated to the identification pattern, but is composed of at least three or more pads, one of which is X,
6. The method of manufacturing a semiconductor device according to claim 5, wherein Y is used in common, and the remaining two are shared with a power supply pad if there is a power supply having the same potential.