JPH0316111A - Semiconductor wafer and manufacture thereof and method of selection of semiconductor chip - Google Patents

Abstract

PURPOSE:To discriminate easily individual semiconductor chips which are manufactured in the same wafer by providing reference number patterns in individual semiconductor chips so that the semiconductor chips having the same forms are discriminated individually. CONSTITUTION:Semiconductor chips 2 are formed on a semiconductor wafer 1 and semiconductor chip identification patterns 30 which discriminate kinds of the semiconductor chips and marks of reference number patterns 20 which discriminate individual chips are provided respectively. The formation of the semiconductor chip identification patterns 30 and the reference number patterns 20, for example, allows the reference number patterns and the like to be formed at a mask which exposes the semiconductor wafer at a time and further, its formation is performed by transferring the above patterns onto the semiconductor wafer. Individual semiconductor chips 2 which are manufactured in the same wafer 1 are discriminated easily.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a semiconductor wafer and a method for manufacturing the same.

[Conventional technology]

Conventionally, in the manufacturing process of semiconductor devices, the same type or a plurality of types of semiconductor chips have been simultaneously manufactured on the same semiconductor wafer. Multiple semiconductor chips manufactured on the same semiconductor wafer are tested in the wafer state, and as a result of the pass/fail judgment, defective products are marked with mechanical red marks, ink, etc., and in the subsequent process, Good products were selected and used while referring to this mark.

[Problem to be solved by the invention]

On the above-mentioned conventional semiconductor wafer, semiconductor chips of the same type are manufactured without being particularly distinguished from each other, and chips determined to be non-defective are collectively used as non-defective products without distinction. However, if you want to use the chip in a high frequency band such as microwave, or if you want to use the chip more effectively by distinguishing the chip's purpose based on the value of mutual conductance or drain-source saturation current, or if you want to use the chip more effectively, By controlling and using the withstand voltage value of the transistors in the chip, it is possible to check the inspection results of individual semiconductor chips, especially when using those with high withstand voltage under more severe usage conditions.
Even if it becomes necessary to clearly record the handling history, or if it becomes necessary to comprehensively judge various characteristics and use the ones in order of quality, conventional semiconductor wafers do not distinguish between individual chips. This was practically impossible because there was no such thing. In addition, GaAs has excellent high frequency characteristics.
When testing semiconductor wafers, if mechanical scratches (scratch markers) are used on defective products, good chips may also be scratched under the scratches when they are divided into individual chips (scribe) after the test. There was a drawback that two cracks were generated. In addition, the method of making scratches with laser (laser marker) has problems such as the fact that arsenic in GaAs substrates is often harmful to the human body.
There has been a problem in that gold, which is commonly used as a wiring material in semiconductor wafers, flies off in the form of balls and contaminates other chips and the needles used for testing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor wafer and a method for manufacturing the same that allow easy differentiation of individual semiconductor chips made within the same wafer.

[Means to solve the problem]

In the semiconductor wafer 1 of the present invention, in a semiconductor wafer l1- in which a plurality of semiconductor chips are formed on the same substrate, a mark is provided on each of the address chips so that all of the plurality of semiconductor chips can be individually identified. It is characterized by

Alternatively, the present invention is characterized in that an identification mark is provided on a mask that exposes the entire wafer at once among the masks used in the wafer manufacturing process in order to manufacture the semiconductor wafer S-.

Alternatively, the present invention is characterized in that a desired chip is selected using the relationship between inspection data and identification marks.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of a semiconductor wafer for explaining one embodiment of the present invention. As shown in the figure, a semiconductor chip 2 is formed on a semiconductor wafer 1. In this embodiment, each semiconductor chip 2 is provided with marks such as a semiconductor chip identification pattern 30 for distinguishing the type of semiconductor chip and a reference number pattern 20 for distinguishing between individual chips.

If the semiconductor chip identification pattern 30 or the reference number pattern 20 is formed in the form of such a semiconductor chip identification pattern 30 or the reference number pattern 20, or if the reference number pattern is formed on a mask that exposes the semiconductor wafer at once, it can be easily transferred onto the semiconductor wafer. I can do it.

It is also possible to use a mask dedicated to forming the verification number pattern 20. Furthermore, by preparing masks with different identification numbers corresponding to the number of semiconductor wafers manufactured in the same lot, it becomes possible to individually distinguish and manage not only the semiconductor chips in the same wafer but also all the semiconductor chips in the same lot.

FIG. 2 is a partially enlarged view of FIG. 1. As shown in the figure, a reference number pattern 20 is formed on a protective film or a passivation film provided on each semiconductor chip 2.

With such a structure, semiconductor chips of the same type, such as the semiconductor chip identification pattern A shown in FIGS. 1 and 2, can be easily distinguished. Therefore, for example, in semiconductor devices used at high frequencies such as microwave bands, where differences in individual low-frequency characteristics affect the semiconductor device and overall characteristics, it is possible to identify individual chips, so it is easy to It becomes possible to match the characteristics. Furthermore, it becomes possible to manage the mutual conductance of field effect transistors within a chip and the drain-source saturation current values of each chip, and to select and use those with higher withstand voltages.

FIG. 3 is a plan view of a semiconductor chip for explaining another embodiment of the present invention. As shown in the figure, in this embodiment, since the identification number pattern 20 is formed on the semiconductor material portion 3, there is an advantage that the area that can be used for circuit formation within the semiconductor chip 2 becomes larger. . In this embodiment, in addition to forming the identification number pattern 20 on the semiconductor material itself, the identification number pattern 20 is formed by leaving a protective film, a passivation film, a conductor layer, polyimide, etc. in an appropriate shape on the semiconductor material part 3. It is also possible to form

In recent years, in the production of semiconductor wafers with fine patterns, a method of repeatedly exposing semiconductor wafers partially (
stepper) is used.

On the other hand, in order to electrically connect the semiconductor chips, the protective film or passivation film 4 on the terminal electrode 10 must be removed. The exposure mask used at this time is a method of exposing the entire wafer at once (for example, using a contact mask) because the pattern to be exposed is not minute and the marks used for identification are thick marks for easy visibility. Exposure) can be used. As an example of a manufacturing method, as described above, there is a method in which a mask used for openings in a protective film or a passivation film is used as a contact mask, and a mark is used to individually identify each chip. This method also has the advantage that the mark placed on the chip is located on the top layer, making it easy to see.

Since each chip has an identifiable mark as described above, it is possible to divide the chips into individual chips and then comprehensively judge the test data to select the chip.

In both of the embodiments described above, the mark such as the reference number pattern is represented by characters, but the present invention is not limited thereto, and may be any suitable symbol or a combination of characters and symbols.

〔Effect of the invention〕

As explained above, the present invention provides a reference number pattern on each semiconductor chip that allows semiconductor chips of the same type to be individually distinguished, thereby making it easy to distinguish between individual semiconductor chips manufactured on the same wafer. This makes it possible to manage detailed characteristics of individual semiconductor chips.

Since each chip has a mark that can be identified, it is possible to comprehensively judge the test data and use better chips preferentially after chip division after chip testing. In addition, in the case of mechanically fragile GaAs semiconductor wafers, there is also the effect that there is no need to create scratches on the chip surface, which would cause chip cracking and chipping, including good chips, when dividing the chips.

[Brief explanation of drawings]

FIG. 1 is a plan view of a semiconductor wafer for explaining one embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a plan view of a semiconductor wafer for explaining another embodiment of the present invention. FIG. 3 is a plan view of the chip. l...Semiconductor wafer 2...Semiconductor chip, 3...Semiconductor material part, 4...
Protective film or passivation film, 20...Verification number pattern, 30...Semiconductor chip identification pattern. Chrysanthemum 1

Claims (1)

[Claims] 1. A semiconductor wafer in which a plurality of semiconductor chips are formed on the same substrate, characterized in that a mark is provided on each of the semiconductor chips so that each of the plurality of semiconductor chips can be individually identified. semiconductor wafer. 2. A method for manufacturing a semiconductor wafer, characterized in that marks for identifying individual semiconductor chips are provided in a mask for opening electrode portions of the chips, and manufacturing is performed using the mask. 3. Comprehensive judgment of semiconductor wafer test data,
A semiconductor chip sorting method characterized by using marks for identifying individual semiconductor chips to preferentially select and use chips with better characteristics.