Electronic device and manufacturing method thereof

Abstract

An electronic device includes an element group which generates a specific identification number and is composed of a plurality of elements. The specific identification number is set based on irregular deviation in electric characteristic of the elements which is caused due to a random failure in a manufacturing process.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2004-366519 filed in Japan on Dec. 17, 2004, the entire contents of which are hereby incorporated by reference. BACKGROUND ART [0002] The present invention relates to a technology for providing means for assigning a specific identification number to an electronic device. [0003] Assignment of a specific number to an electronic device itself such as a semiconductor chip and the like has been examined in view of manufacturing process management (to record information on when it is manufactured, which wafer or chip it is, and the like). Recently, taking application to IC money, IC tags, ID cards, and the like into consideration, it has been recognized that assignment of a specific number unchangeable from outside to a chip itself is an important key and essential to problem solution. In other words, it is important to provide an artificially u...

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Benefits of technology

[0009] In view of the above problems, the present invention has its object of assigning an identification number specific to an electronic device with high reliability without a new step added to a general manufacture process.

[0010] To attain the above object, the present inventor has contemplated utilizing, as a specific identification number of an electronic device, irregular deviation in electric characteristic which is caused due to a failure (hereinafter referred to as a random failure) of an element (for example, a semiconductor element such as resistor element and the like) which occurs accidentally at a certain probability in an electronic device manufacturing process such as a semiconductor manufacturing process. Specifically, a target element is selected first through, for example, an access transistor, and then, variation in electric characteristic of the selected element is detected by an sense amplifier. This enables setting of a specific identification number based on irregular deviation in electric characteristic of the element which is caused due to a random failure in the manufacturing process. Further, the present inventor has contemplated generating a specific identification number by utilizing, as the irregular deviation in electric characteristic of the element, irregular resistance rise that randomly occurs due to accidental disconnection of, for example, a silicided layer in a silicide wiring (a thin wiring or an active region at least a part of which is silicided) of a semiconductor element.

[0024] In the present invention, the irregular deviation in electric characteristic of an element which is caused due to a random failure in the manufacturing process is utilized as a specific identification number, so that the specific identification number can be set for the device without a new step added to the general manufacturing process. Further, the conventionally utilized variation in physical quantity of an identification element which corresponds to process variation is on a micro scale while the variation in electric characteristic of an element which is caused due to a failure is comparatively large variation, in other words, is irregular deviation. Accordingly, the specific identification number can be recognized with high reliability independent from environment where the element is situated (for example, temperature environment). Further, the specific identification number is impossible to be changed from outside naturally, and therefore an artificially unforgeable semiconductor chips and the like applicable to IC money, IC tags, ID cars, and the like can be obtained.

[0025] As described above, the electronic device and the manufacturing method thereof according to the present invention enable assignment of a specific identification number to an electronic device with high reliability without a new step added to the general manufacturing process.

Problems solved by technology

The former method in which a programmable element is provided, however, requires artificial assignment of the specific number, necessitating an additional step to the general manufacturing process or necessitating an additional step of writing the identification information after the manufacture.

Therefore, it is difficult to indicate an invariable specific number with high reliability over the temperature range where a semiconductor element or the like to be the identification element is used.

Thus, indication of numbers specific to devices with high reliability is difficult through the newly proposed method in the environment in the wide temperature range where the semiconductor element and the like to be the identification element is used actually.

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