JPH04130649A - Method of producing and testing integrated circuit - Google Patents

Abstract

PURPOSE:To shorten a developing period from the designing to the production by providing wiring whose energizing path is cut by a cut part provided through a mask layer and is mainly constituted by a protecting element. CONSTITUTION:Wiring 4, whose energizing path is cut by a cut part 6 provided through a mask layer and is mainly constituted by a protecting element 3, is provided. Since the cut of the energizing path of the wiring 4 is carried out only through the mask layer, the final selection of the protecting element can be well performed by the final step at which the characteristic of an internal circuit is confirmed and the internal circuits and circuit parts can be independently tested. Since the mask layer for the wiring cut is a simple layer which can be produced easily in a short time, a period required for the development from the designing to the product delivery is permitted to be short.

Description

[Detailed description of the invention] [overview] Regarding integrated circuits.

The purpose is to shorten the time required from circuit design to commercialization and maintain reliability.

The current-carrying path is interrupted by a cut portion made through the mask layer, and the wiring portion is mainly composed of a protection element.

Alternatively, it is configured to include a plurality of circuit parts that are mainly composed of a protection element or a protection element bypass path, and at least one of which is selectively cut off from the current-carrying path by a cut portion made through a mask layer. .

[Industrial Application Field 1] The present invention relates to an integrated circuit, and its manufacturing method and testing method. In particular, this integrated circuit, its manufacturing method, and testing method are applicable to the selection of protection elements for internal circuits in input/output terminal sections. suitable.

In integrated circuits, circuit elements and wiring are generally

Each chip is arranged according to a mask pattern transferred onto a wafer through a mask, thereby manufacturing a desired integrated circuit. The line width of the mask pattern has become extremely narrow due to the recent reduction in chip area, and its production requires a great deal of labor and time.

[Prior Art] When developing a new integrated circuit, it may not be possible to determine everything from the beginning at the design stage. Examples of such a resistor include a resistor used as a protection element for protecting an internal circuit from static electricity or the like in an input/output terminal section, a diode, or a transistor used for the same purpose as a diode. For example, the protection element cannot be determined at the input/output terminal section.

The type and rating of the protection element are determined by the relationship with the characteristics of the internal circuit to be protected, but since the internal circuit itself is composed of many circuit elements and wiring sections,
This is because its characteristics cannot be clearly defined at the design stage.

For the above reasons, protection elements are often selected empirically at the design stage, and integrated circuits with protection elements selected in this way are not actually completed as prototypes through the manufacturing process. The electrostatic withstand voltage value of the integrated circuit is measured by an electrostatic withstand voltage test that is commonly performed on integrated circuits. If this electrostatic withstand voltage value does not reach the initial expected value, the design is returned to and the protection element selection is reviewed, and the mask pattern is fabricated again using the integrated circuit equipped with the reselected protection element. A manufacturing process is carried out. In this way, trial and review is repeated until the desired performance is achieved.

[Problems to be solved by the invention] With the shortening of product life cycles in recent years, there is an increasing need for speed in the development of new products. There is a growing need for a more effective response. However, if the conventional trial-and-review method is used to select an a-container element, the process of manufacturing a mask pattern, etc., which takes a long time, will be repeated, and there is a problem in that it is not possible to meet the demands for promptness and flexible response. .

In addition, in order to obtain design data for future commercialization of other integrated circuits, there may be cases where it is desired to measure the characteristics of internal circuits and protection elements individually. It would be convenient if all the elements could be shut off, but in the case of conventional integrated circuits, this kind of consideration is not taken into consideration in the product, so there is a problem in that each element must be manufactured separately.

The present invention solves the above-mentioned problems regarding the selection of protection elements in integrated circuits, and provides integrated circuits that can shorten the development period from design to commercialization, are highly reliable, and are highly mass-producible. purpose.

A further object of the present invention is to provide a method for manufacturing and testing an integrated circuit, which is also capable of shortening the development period for new products, has high reliability, and is highly mass-producible.

[Means for Solving the Problems] FIG. 1 is a diagram showing the principle of an integrated circuit according to the present invention. In the figure, 2 is an internal circuit of this integrated circuit, 3 is a protection element, 4 is a wiring portion whose current path is cut off, 6 is a cut portion, and 6A is a portion that can be used as a cut portion.

In order to achieve the above-mentioned object, the integrated circuit of the present invention is configured to include a wiring portion 4 mainly composed of a protection element 3, in which a current-carrying path is interrupted by a cut portion 6 made through a mask layer.

In the case of the integrated circuit shown in this principle diagram, 2.
The test is conducted by cutting off the energizing path using a laser or the like at either the cut portion 6 or the portion 6A that can be used as the cut portion, or by testing the entire portion without the cut portion. In order to manufacture an integrated circuit that has been confirmed to be good as a result of the test, a cut portion 6 is made through a mask pattern that is added at the time of manufacturing the final product to interrupt the current-carrying path. Therefore, the protection element 3 that is no longer needed as a circuit element is left without being connected to the internal circuit.

In addition to the above purpose, these test data are left as data for commercializing another integrated circuit. In this case, there is no need to separately fabricate internal circuits or protection elements for the data collection.

As shown in the embodiment of the integrated circuit of the present invention in FIG. 2, in the integrated circuit testing method of the present invention, two internal circuits (2) having a predetermined function are used.

A circuit part for connecting with the internal circuit (2) to protect the internal circuit (2), including a protection element or a protection element bypass path, and connected in parallel to each other by nine current-carrying paths, each having a different performance. circuit part (41-44.81-83
) to form an integrated circuit consisting of

By selectively cutting off the energizing path, a suitability test for the internal circuit (2) of the circuit portion is performed.

Furthermore, in the integrated circuit manufacturing method of the present invention, an internal circuit (2) having a predetermined function.

The internal circuit (2) is connected to the internal circuit (2) by a current-carrying path.
2), which includes a protection element or a protection element bypass path (41 to 44.8
1 to 83).

The method is configured to include a step of interrupting the current-carrying path by a cut portion made through a mask.

Conventionally, when wiring is changed to eliminate defects found during testing, etc., an example of redundant wiring is known, such as separating unnecessary wiring from other circuit parts using a laser or the like when the final product is completed. However, in the integrated circuit and manufacturing method thereof of the present invention.

At the design stage, we test wiring parts that will selectively interrupt current-carrying paths in advance), and at the product stage, we cut unnecessary wiring parts to cut off current-carrying paths through the mask layer. Unlike the example of a redundant circuit, it uses a configuration that shuts off the circuit.

There are no problems such as lack of reliability as a product, and there is no lack of mass production. Note that it is preferable that the cut portion through the mask layer (or its specific portion even if no cut is made) be provided in a region or layer that can be easily masked.

[Function] In the integrated circuit of the present invention, the current-carrying path is interrupted by the cut portion 6 made through the mask layer, and the protective element 3 is
Since the current-carrying path of the wiring portion 4 can be cut off simply through the mask layer, the final selection of the protective element should be made at the final stage when the characteristics of the internal circuit can be determined. Or each internal circuit and circuit part can be tested individually, and the mask layer for cutting wiring can be simple and can be manufactured in a short time and easily, so it can be easily manufactured from design to product shipment. The development period required is short.

Further, in the integrated circuit manufacturing method of the present invention, the mask pattern added in the manufacturing process after testing the prototype in order to interrupt the current-carrying path in the final product is only a simple mask pattern for cutting wiring.

Since other masks can be used as is, there is no need to repeat trial and review when selecting a protective element, and the period from design to product shipment can be shortened.

Furthermore, in the integrated circuit testing method of the present invention, prior to testing a large number of integrated circuits manufactured as the same product, the conductive paths of unnecessary wiring portions are only selectively cut off (or cut off as necessary). It is possible to perform circuit tests in parallel for all cases of protection elements assumed at the design stage (including cases where protection elements are not applied), and the test period can be shortened because there is no need to repeat trial and review.

Also, when one integrated circuit includes a large number of internal circuits and a corresponding protection element is provided for each one.

The advantages of the invention become even more pronounced. An internal circuit (21
), and each protection element (32...2n) belonging to some other internal circuits (22...2n).
・3. ), etc., the same thing holds true.

[Example] The present invention will be further explained based on the drawings. FIG. 2 is a schematic circuit diagram of an integrated circuit according to a first embodiment of the present invention and an integrated circuit manufactured or tested by the method for manufacturing and testing an integrated circuit according to the first embodiment of the present invention. In the figure, this integrated circuit 20 has four circuit parts 4 each including protection elements 31 to 34 of different types or different rated values.
1 to 44. The four circuit portions are connected in parallel to each other or can be selectively disconnected via any of the cut portions 61 to 68, so that each circuit portion 41
.about.44 are arranged in the integrated circuit so as to be connected in parallel to the internal circuit 2 or selectively disconnected via any of the cut portions 61 to 68. In some cases, all the protection elements are deemed unnecessary and are separated from the internal circuit 2 via the cut portion.

The circuit portions 41 to 44 are cut in the respective cut portions 61 to B8.
In this case, it is taken into consideration at the design stage that it can be separated from the internal circuit 2 of the integrated circuit. That is, this cut scheduled portion 61
The wiring containing -H or the wiring adjacent thereto can be easily interrupted or separated by placing it in the uppermost layer, for example, as a wiring layer.

Normally, in an integrated circuit as a product, one of the four circuit parts 41 to 44 containing a pre-imagined protection element is one circuit part that actually contains the protection element most suitable for electrostatic protection of the internal circuit 2. Only.

It remains connected to the wiring 5.5' of the input/output circuit. The other three circuit parts are configured as wiring parts whose current-carrying paths are cut off by cuts made through one simple cutting mask layer added during the manufacture of the final product. The types or rated values of the protective elements 31 to 34 to be selected for protecting the internal circuit 2 are determined, for example, from the measurement results of an electrostatic withstand voltage test at a testing stage before the final product is manufactured.

During the testing stage of the prototype, the planned cut parts 61 to 68, which can become cut parts in the final product, are manufactured as part of normal wiring, so for each integrated circuit made as the exact same prototype, If necessary, the protective elements are selected by actually separating the wiring at different cut areas 61 to 68 using a laser or the like, and the withstand voltage value of each is measured through an electrostatic withstand voltage test.

Figure 84 is a schematic diagram of the electrostatic withstand voltage test circuit. In the same figure, the test circuit includes a battery V, a capacitor C, and a switch S.
1. After closing switch S1 and charging a capacitor C having a predetermined capacity to a predetermined voltage, switch S1 is opened and switch S2 is closed, and the capacitor voltage is applied to the integrated circuit to check the withstand voltage. be. Once the most suitable protection element for the internal circuit 2 is selected through this measurement, a cutting mask layer is added to the final product to create a cut section for disconnecting unnecessary wiring. will be newly manufactured.

Therefore, in the final product, the circuit portions 41 to 44 are separated at one or more pairs of cut portions made through the cutting mask layer at any one of the planned cut portions 81 to BB. The wiring section separated by this method is different from the separation using a laser etc. used in conventional redundant circuits, and there is no risk of damaging the internal circuit section with a laser etc.
The reliability of the disconnection is extremely high because there is no risk that the disconnected portion will be connected to the internal circuit again due to the influence of heat or other adverse effects after the product is manufactured.

An example of the structure of the portion to be cut is shown in the schematic perspective view of FIG. In the same figure, electric circuits 51 to 54 connected to input/output terminals (not shown) are arranged in the lower white portion of the wiring layer of the integrated circuit. 44, planned cut portion 81.63.85.
The portion adjacent to 67 is arranged in the upper layer portion. Each of the circuit sections 41 to 44 is again disposed in the lower layer on the right side of the drawing and is connected to a respective protection element (not shown). Electric circuit 51
54 and the circuit portions 41 to 44, only one contact hole 63 has a contact mounted therein, and the other contact hole portions 61, 65 . Contacts are removed from BY at the stage of commercialization. In this case, the contact hole portions 61.85.87 serving as cut portions are
The mask layer for wiring cutting can be made of a mask layer for removing unnecessary portions of contacts made with a contact mask.

In the integrated circuit 20 of the present embodiment, a protection element 31 is arranged near the input/output terminal 1 and serves as the circuit portions 41 to 44 whose energizing path is selectively cut off to protect the internal circuit 2.
A circuit portion including .about.34 is shown. The positions where the input/output terminal 1 and the ground terminal of the integrated circuit are arranged are relatively spacious, so there are disadvantages in the arrangement that result from having circuit parts that are partially unnecessary in the product. is not very large and does not pose a particular problem even in the case of ffi products. However, the protection element of the integrated circuit according to the present invention is not limited to one provided at the input/output terminal section, but may be one for protecting elements in other parts of the internal circuit.

FIG. 3 shows a second embodiment of the invention. The integrated circuit of the embodiment shown in FIG. 3 differs from the embodiment shown in FIG. . The circuit portion 81 consists of a protection element bypass path, and one circuit portion 82.83
is mainly composed of protective resistors r2+r2.

Since the internal circuit 2 is configured as a complex circuit including many types of circuit elements and wiring, characteristics such as the equivalent resistance value are often not clear until it is actually manufactured. Therefore, the internal circuit 2.

In the completed state as a prototype, the isomuscular resistance value is measured using the test circuit shown in FIG. In other words, the 2 equivalent resistance value is
In FIG. 6, the capacitor C charged to a constant voltage V by closing the switch S1 is then connected to the reactor connected in series with the capacitor C and the internal circuit 2 by the switch S2, which is closed after opening the switch S1. LCR between
This is done to form a discharge circuit. The time constant of the entire circuit as an LCR discharge circuit is set to υ1, and the equivalent resistance value R is calculated from the known values of inductance and capacitance.

If the equivalent resistance value R is too low compared to the requirements at the time of design, reduce the output current of the previous stage circuit to protect the previous stage circuit of this integrated circuit, or reduce the current of the internal circuit 2 of this integrated circuit. of the circuit part 82.83 in order to adjust the overall circuit resistance via a protective resistor Z r 2 or r, which is selected according to the measured equivalent resistance value R, etc., for the purpose of protecting the internal circuitry by One is selected. When the equivalent resistance of the internal circuit 2 is appropriate, the protection element bypass path 81 is selected.

In each of the above embodiments, the circuit portions 41 to 44 including the protection elements 31 to 34 inserted in parallel with the internal circuit 2. and a protection element bypass path 81 and a protection resistor r2. which are inserted in series. In any of the circuit portions 82.83 including r2, one of the cut portions 61-68, 71-75 is adjacent to the input/output terminal 1, and the input/output terminal 1 and the circuit portions 41-44.111 are adjacent to the input/output terminal 1. It is inserted between 83 and 83.

In FIG. 3, only the cut portion of the protection element bypass path 81 is shown as a single cut portion, but in some cases, it may be necessary to completely separate other circuit portions from the internal circuit via a pair of cut portions. It is sufficient to interrupt the current-carrying path through one cut.

In addition, in the integrated circuit of the present invention, its manufacturing method, and testing method, the current-carrying path is cut off in a circuit portion consisting of a protection element or a protection element bypass path. It can be extended to circuit parts including all circuit elements and wiring connected to the circuit.

[Effects of the Invention] As explained above, according to the integrated circuit of the present invention and its manufacturing method and testing method, it is possible to respond quickly and flexibly in the period from the start of designing a new integrated circuit to the completion of the product. , the time required from development to product shipment can be shortened, and without compromising reliability and mass production, we can meet market needs. Figure 1 is a diagram of the principle of the present invention, Figure 2 is a circuit diagram of Embodiment 1, FIG. 3 is a circuit diagram of the second embodiment, and FIG. 4 is a circuit diagram of the second embodiment.

General electrostatic withstand voltage test circuit diagram for integrated circuits, Part 5
The figure is a schematic perspective view for explaining the structure of the portion to be cut, and FIG. 6 is an equivalent resistance measurement circuit diagram.

In FIG. 1, 1 is an input/output terminal, 2 is an internal circuit, 3 is a protection element, 4 is a wiring part, 6 is a cut part, and 6A is a part that can be used as a cut part.

No. figure One Example 1 @Figure 2 Example 2 Figure 3 Cut part (4^4ba1 Figure 5

Claims (1)

[Claims] 1) A wiring portion (4) whose current carrying path is interrupted by a cut portion (6) made through a mask layer and which is mainly composed of a protective element (3) is provided. integrated circuit. 2) A plurality of circuit parts (41 to 44, 81) that are mainly composed of a protection element or a protection element bypass path, and at least one of which is selectively cut off from the current-carrying path by a cut made through a mask layer. ~83). 3) An internal circuit (2) having a predetermined function, and a circuit portion connected to the internal circuit (2) to protect the internal circuit (2), including a protection element or a protection element bypass path. , forming an integrated circuit having a plurality of circuit parts (41 to 44, 81 to 83) having different performances connected in parallel to each other by current carrying paths. By selectively cutting off the current carrying paths, the circuit parts are A method for testing an integrated circuit, characterized by conducting an aptitude test for an internal circuit (2). 4) An internal circuit (2) having a predetermined function, and a circuit part that is connected to the internal circuit (2) by a current-carrying path to protect the internal circuit (2), and includes a protection element or a protection element bypass. Circuit parts including routes (41-44, 81-83)
1. A method of manufacturing an integrated circuit, the method comprising the step of: cutting off the current-carrying path by a cut portion made through a mask after forming the current-carrying path; 5) After forming a plurality of circuit portions (41 to 44, 81 to 83) having different performances, which are connected in parallel to each other by an energizing path, the energizing path is selectively cut off. A method of manufacturing integrated circuits.