JPS61260649A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To rate the performance of a chip only by visually inspecting it from outside by a method wherein the performance of the chip is measured in a wafer check process wherein some or all of the markings, built into the chip simultaneously with the formation of a pattern within the chip, are erased dependently upon the result of the measurement. CONSTITUTION:Simultaneously with the formation of a wiring pattern 1 made for example of Al in a region in each of the chips surrounded by a scribe region 3 in a semiconductor wafer, English letters A, B and C are built of aluminum film into an otherwise useless portion 2 in the chip. In a wafer checking process following the final step of manufacture, the performance is measured of each of the chips. Th performance is categorized for example into A, B, and C. In case of a chip rated to be on the performance level A, the letter A is retained while the letters B and C are erased by laser. In case of a chip rated to be on the performance level B, the letter B is retained and the other two letters are erased, and in case of a chip on the level C, the letter C only is retained. By using this method, the performance of given chip is easily rated on the basis of retained markings.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a semiconductor integrated circuit that classifies chip performance, etc. when checking a wafer after the final process, and displays the results on the chip for selection. Regarding things.

[Conventional technology]

In the conventional technology, after the wafer is divided into chips, it is impossible to determine the performance of each chip based on its appearance, and the I
After assembling it as C, it was necessary to sort it again using a sorting machine.

[The problem that the invention attempts to solve]

In the conventional chip sorting method described above, after the dicing process,
This was impossible until it was assembled as an IC, and it had the disadvantage that it would be cumbersome unless other chips than those exhibiting the desired performance were assembled.

[Means for solving problems]

The present invention measures the performance of a chip when checking a wafer, erases some or all of the multiple marks that were simultaneously printed on the chip during patterning, depending on the measurement results, and removes only the external appearance. It has a display that allows you to judge the performance of the chip.

〔Example〕

Next, the present invention will be explained using examples.

1A and 1A are plan views for explaining the chip performance discrimination method according to an embodiment of the present invention. First, as shown in FIG. 1W and FIG. In each chip area surrounded by area 3,
For example, at the same time as forming the wiring pattern l using aluminum,
A, L (, C
Write down the English letters. Then, in the wafer check after the final process, the performance of each chip is measured and the performance is classified.

When classifying into three stages, B and C, for those in the performance stage A, as shown in Figure 1b), of the aluminum labels A, H, and C, leave A and the remaining IJ and C. ``'C is erased by a laser. If the chip's performance classification is B (Bf, CQ), leave the C acupuncture,
Delete the others. Therefore, the performance of each chip can be easily determined based on the marks left behind.

Fig. 2 ta+ is a plan view of an example in which four square gadots 5 are formed in the unnecessary part 2 in the chip as a performance discrimination mark, and as shown in Fig. 2 Tbl, the remaining Depending on the dot 50 position, the performance classification of the chip is displayed.

Figure 3 ial, (blVi, as a performance indicator,
An example using three numbers 1, 2°3 is shown. Figure 2 1blO
YoV (numbers left by laser etc. remain as they are,
This results in a performance of class 3.

In the above example, the mark is made of an aluminum layer, but this is not limited to aluminum and can be easily erased physically or chemically, making it easy to identify what is left behind and preventing it from contaminating the chip. You can use it as long as it's not a thing. Also, it is erased by laser.

It is also possible to erase by a method other than laser, and the performance can also be displayed by chemical etching.

〔Effect of the invention〕

As explained above, (1) the present invention makes it possible to improve the performance of the chip at the chip stage by erasing part, the casing, or all of the markings that have been punctured depending on the performance classification of the chip during the Ueno check. It is possible to distinguish between categories, and when selecting products with performance that meets market costs, it is very effective because it can be handled quickly and without waste. When checking the wafer (1'/W),
) can also be indicated by a needle wound, and is suitable for LSIKI & D/A, which require relative precision.

[Brief explanation of the drawing]

FIG. 1(a) and (+)l are plan views showing an example of chip performance display according to the present invention cii>one embodiment; FIG. 2(a)
), (b) is a plan view showing an example of chip performance display using square dot indicators, and FIG. 3 is a plan view showing an example of chip performance display using numerical indicators. 1...Wiring pattern, 2...Unnecessary portion, 3...Scribe area, 5...Dot mark. Second time. (bnogo diagram

Claims (1)

[Claims] In the manufacturing process of semiconductor devices, a plurality of marks for indicating the performance of the chips are formed in each chip in the wafer at the same time as patterning, and each chip is measured when checking the wafer before the dicing process. A method for manufacturing a semiconductor device, characterized in that the performance of each chip is displayed and selected by erasing some or all of the plurality of marks of each chip depending on the result.