JPS6329818B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing a semiconductor substrate, and more particularly to an automatic method for testing a semiconductor substrate on which a plurality of types of elements are formed.

In the manufacturing process of a semiconductor device, before a semiconductor substrate that has undergone an element formation process is cut and separated into individual elements, all elements formed on the substrate are tested. As is well known, in this board test, the test sample board is placed on the moving table of the test equipment and aligned accurately, and then a prober drawn out from the test equipment is placed on a pad provided on the element surface. The tip of the measuring probe is brought into contact with the device, and various tests are performed according to a test program created in advance to determine the quality of the device. Next, the above operation is repeated for all the elements by moving the movable table, and the test is performed on all the elements.

All of the above operations are performed automatically, but when two or more types of elements are formed on the same board, the test program must be changed depending on the type of element, so the board test is performed as described above. It cannot be done automatically like this. Such situations occur when relatively small orders are received in the production process of mask ROMs that store information requested by users, or during the research and development stage of semiconductor devices.

An object of the present invention is to provide an improved structure of a semiconductor substrate that can automatically identify the types of multiple types of elements created on the same substrate even in such a case, and this purpose is achieved by the present invention. , a determination element is arranged on the surface of the semiconductor substrate together with at least one type of semiconductor element in accordance with the type of the semiconductor element, and the determination element is connected to a power terminal and a source provided on the surface of the semiconductor element. terminal,
and measurement pads are provided at positions corresponding to the arrangement positions of the plurality of output terminals, and measurement pads are provided at the same positions as the above-mentioned power supply terminals and source terminals for identification to identify the type of semiconductor element. An input terminal for supplying a signal and the remaining measurement pads are used as detection terminals, and the input terminals are connected through one of the detection terminals selected according to the type of semiconductor element. This is achieved by making it possible to identify the type of the corresponding semiconductor element from the position of the detection terminal where the identification signal is detected when the identification signal is applied to the input terminal.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a semiconductor substrate according to an embodiment of the present invention, showing an example in which two types of mask ROM are formed, FIG. 2 is a top view showing an example of the pattern configuration of a determination element, and FIG. The figure is a flowchart showing the test procedure of this example.

In this embodiment, as shown in FIG.
the first mask ROM element 2 and the second mask
An example in which the ROM elements 3 are arranged in areas will be explained. In the same figure, 41-4
3 is a determination element 4, 51 corresponding to the first element 2
-58 are the determination elements 5 corresponding to the second element 3. These determining elements 4 and 5 may be provided one each, but it is necessary to arrange them at the leading position of each area with respect to the direction in which the test progresses in the direction of the arrow.

As this determination element, for example, one as shown in FIG. 2 can be used. In the figures a and b, 6 is the Vss (power supply) terminal as the first power supply terminal of the first and second mask ROM elements 2 and 3, and 7 is the arrangement of the Vss (source) terminal as the second power supply terminal. Input terminal provided at the same position as the installation position, 11,
12, 13,... are the same mask ROM elements 2, 3
The detection terminal is located at the same location as the output terminal, and both are measurement pads. mask
A storage device such as a ROM has a number of output terminals corresponding to its number of bits, ie, eight for an 8-bit device. In this embodiment, each determination element has detection terminals 11 and 1 at the same position as the eight output terminals.
2, 13, ..., and the input terminals 6 and 7 are provided at the same positions as the Vcc and Vss terminals.
The two input terminals 6 and 7 were electrically connected through one of the eight detection terminals 11, 12, 13, . . . . These eight detection terminals 11, 12,
Which terminal among 13, . . . should be connected may be determined in accordance with the type of element. FIG. 2A shows an example in which the detection terminal 11 is connected to the detection terminal 11, and FIG.

Next, the test procedure of this example will be explained with reference to FIG. As described above, the substrate to be measured is placed on the moving table, and when the alignment is completed, the measurement probe of the prober comes into contact with each measurement pad of the element at the starting position. Then, prior to the start of the test, according to the program, a signal identifying whether or not this element is a determination element is first sent between the two input terminals 6 and 7, and also sent to the eight detection terminals 11 and 12. ,1
3... detects the presence or absence of a signal.

In this embodiment, as shown in FIG. 1, the determining element 4 shown in FIG. 2a is arranged at the starting position of the substrate 1, so that signals are detected at 11 of the 8 detection terminals. Therefore, it is recognized that this element is a determination element and is in shot mode No. 1. Then, follow the program and switch to shoot mode.
The test program corresponding to No. 1 is called.
Next, the device is tested according to this program. When one program is selected in this manner, subsequent devices are tested according to the selected program, and the program is not changed until another determination device having a short mode is detected.

If the device to be tested is a regular ROM device, any detection terminal 11, 12, 13,
...However, since no signal is detected, in this case it is determined that it is not a determination element, and a test is immediately executed according to the already selected program described above to determine whether it is pass or fail.

When the test progresses and all the elements in the area have been tested and the area is entered, the judgment element shown in Figure 2b is detected, and as soon as it is recognized that this is shot mode No. 2, the test program starts. is replaced with that for shot mode No. 2 and the test for the area is performed.

The above-mentioned test program may be created according to the type of sample to be tested, associated with the short mode, and stored in advance as a subroutine of the main program.

As explained above, even when multiple types of elements are formed on the same substrate, the determination element according to the present invention is placed at the top position of the test in each area, and when the test is executed, By detecting the type of determination element and selecting and using a corresponding test program from pre-stored test programs, it is possible to automatically conduct a board test.

Although it is of course possible to determine the determination element and select the program using hardware, it is easier and more practical to perform the determination using program control as described in the above embodiment.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing an embodiment of the present invention, and FIG. 3 is a plan view showing a semiconductor substrate and a plan view showing a determination element, respectively, and FIG. 3 shows a test procedure using the above embodiment. It is a process diagram. In the figure, 1 is a semiconductor substrate, 2 and 3 are semiconductor elements, 4 and 5 are determination elements, 6 and 7 are input terminals, and 11, 12, 13, . . . are detection terminals.

Claims (1)

[Scope of Claims] 1. At least one type of semiconductor element, and a determination element formed corresponding to the type of the semiconductor element, wherein the determination element is a first type provided on the surface of the semiconductor element. and a second power terminal, and a measuring pad at the same position as the plurality of output terminals, and the measuring pad corresponding to the position of the first and second power terminals is connected to the semiconductor element. an input terminal that supplies an identification signal for identifying the type of the semiconductor element, the remaining measurement pads are used as detection terminals, and a terminal selected from among the detection terminals corresponding to the type of the semiconductor element is connected between the input terminals. and a determination element that is connected to the input terminal through the input terminal, and that when an identification signal is applied to the input terminal, the type of the corresponding semiconductor element can be identified from the position of the detection terminal where the identification signal is detected. A semiconductor substrate characterized by: