JPS61199655A - Semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate any human reading of code numbers by a method wherein electrode pads independent of an inner functional part are connected to a gate of an MOS type transistor while a source or drain is connected in parallel with multiple electrode pads to form a part of connecting wiring in the state either electrically conductive or non-conductive. CONSTITUTION:A semiconductor device 1 as ROM or gate array impresses an electrode pad 3 with voltage immediately before starting an inspection to make an MOS type transistor 4 conductive. A semiconductor substrate is supplied with OV and then a source of the MOS type transistor 4 is also supplied with OV through a diffused layer 5. When multiple electrode pads 6a-6d are impressed with voltage, each pad is supplied with current or no current conforming to electrically conductive or non-conductive state of a part of wirings 7a-7d. Through these procedures, numbers may be displayed on codes by electrical conductive or non-conduction while any code number may by automatically known immediately before starting an inspection by means of making the numbers correspond to the code numbers. Besides, any increase in chip dimension of a semiconductor device may be reduced by means of providing only one additional pad for code checking.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to semiconductor devices, and particularly to semiconductor devices such as read-only memory semiconductor devices (hereinafter referred to as ROM) and logic semiconductor devices (hereinafter referred to as gate arrays). Regarding.

[Conventional technology]

Conventionally, during the manufacturing process of ROMs and gate arrays #i, they were manufactured with various storage contents and logical contents, and numbers called code numbers were assigned in one-to-one correspondence to each storage contents and logical contents. .

On the other hand, these ROMs and gate l arrays are tested by reading test patterns corresponding to code numbers and l to l into an inspection device. For this reason, it is necessary to identify the code number before testing, and conventionally it was necessary to identify the code number by a person or by reading the code number.
The code number was identified by checking a specially prepared check pattern.

[Problem that the invention seeks to solve]

However, when humans read the code numbers, there are problems such as misreading the numbers and the amount of man-hours required to read the numbers.If you want to read the code numbers by checking a special check pattern, it is necessary to use a chip that creates a special check pattern. This increases the area required, leading to an increase in the chip size of the semiconductor device, and requires a mechanism to be installed in the inspection equipment to check and remove the check pattern, resulting in an increase in the cost of the inspection equipment. .

Therefore, it is an object of the present invention to eliminate the need for such people to read code numbers, to reduce the increase in the chip size of semiconductor devices due to the provision of new dedicated tick patterns, and to enable inspection equipment to check the check patterns. An object of the present invention is to provide a semiconductor device that does not require the provision of a mechanism.

[Means for solving problems]

The semiconductor device of the present invention is provided with an electrode pad that is independent of the internal functional part of the ROM-J take gate/no array, connects the electrode pad to the gate of a MOS transistor, and connects the source or drain of the MOS transistor. is connected to the semiconductor substrate, the other source or drain is connected in parallel to the plurality of electrode pads of the semiconductor device, and a part of the connection wiring is formed to be either electrically conductive or non-conductive. It consists of things.

1. For this reason, just before the inspection starts with the inspection equipment, a voltage is applied to the electrode pad connected to the gate of the MOS transistor, and the MOS transistor is brought into the conductive state KL, and the multiple electrodes of the semiconductor substrate and the semiconductor device are turned on. The code number can be determined by applying source and drain voltages to the pads, measuring the current, checking electrical continuity between the source or drain and the electrode pad, and determining whether the source or drain is electrically conductive or non-conductive. Also, when testing semiconductor devices, by not applying voltage to the gate of the MOS transistor and leaving it in a non-conducting state, all the circuits used to check the code number during the test will be in a non-conducting state. The influence of the number checking circuit can be ignored.

Furthermore, the electrode pads used during examinations in this way.

Since the pad is shared as an electrode pad for code checking, the amount of new electrode pads for code checking can be significantly reduced, and an increase in chip size of the semiconductor device can be suppressed. Furthermore, since the code number can be determined by electrical check from the electrode pad, the code number can be identified using the functions of normal inspection equipment. There is no need to add anything new to the inspection equipment.

〔Example〕

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

FIG. 1 is a schematic plan view showing essential parts of an embodiment of the present invention. In the semiconductor device 1 , an electrode pad 3 independent of the internal functional section 2 is connected to the gate of a MOS transistor 4 . The source of the MOS transistor 4 is connected to the semiconductor substrate through the diffusion layer 5, and the drain is connected in parallel to a plurality of electrode pads 6a to 6d of the semiconductor device. Some of the connection wirings 7a to 7d are formed to be electrically conductive or non-conductive.

FIGS. 2(a) to 2(C) are explanatory diagrams for explaining the method of forming the conductive and non-conductive states. FIG. 2(b) is a diagram showing the formation of conduction and non-conduction states, and FIG. FIG. 2(C) is a diagram illustrating whether a conductive or non-conductive state is formed depending on the presence or absence of the diffusion layer 10.

1 (, the source of the semiconductor device transistor 4 as an OM or gate array is set to □v. A plurality of electrode pads 6a
When a voltage is applied to the wirings 7a to 6d, current may or may not flow depending on whether the wirings 7a to 7d are electrically conductive or nonconductive.

Assuming that the state in which this t flow is flowing is '1' and the state in which it is not flowing is 0#, Fig. 2 (a), (b), and (C) are binary numbers "0110", "0101", and -1010', respectively. It can be expressed as '6#' in decimal number respectively.
``5'' represents ``10''' @ In this way, if you display the number in terms of electrical continuity or non-continuity and set it to correspond to the code number, you can automatically know the code number just before starting the test. In addition, for code checking, it is only necessary to provide one extra pad, which reduces the increase in the chip size of the semiconductor device.Furthermore, the code number can be determined by using the functions of the inspection equipment as is. Since it can be identified, there is no need to newly provide a mechanism for checking the check pattern.

As described above, by sharing the electrode pads used during normal inspection and using the code check bar immediately before the start of the inspection, it is possible to prevent the code check pattern portion from affecting the inspection.

Although the above embodiment deals with a case where there are four electrode bats, the present invention is not limited thereto and is generally applicable to a plurality of electrode bats.

〔Effect of the invention〕

As described above in detail, according to the present invention, the above means eliminates the need to read the code number by 8, and reduces the increase in chip size of a semiconductor device due to the provision of a new dedicated check pattern. Furthermore, it is possible to obtain a semiconductor device in which it is not necessary to provide a mechanism for checking the check pattern in the inspection device.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the main parts of an embodiment of the present invention;
FIGS. 2(a), 2(b), and 2(c) are explanatory diagrams of a method for forming electrical conduction or non-conduction at certain portions of the arrangement. 7a to 7d... Part of wiring, 8... Metal wiring, 9°°゛°°° through hole, 10...
・Diffusion layer. / Living Agent Patent Attorney Uchihara Hl 1゜＼1, (ku) Cb)

Claims (4)

[Claims] (1) In a semiconductor device, an electrode pad is provided independent of the internal functional part, the electrode pad is connected to the gate of a MOS transistor, the source or drain of the MOS transistor is connected to the semiconductor substrate, and the other source is connected to the gate of the MOS transistor. Alternatively, a semiconductor device characterized in that a drain is connected in parallel to a plurality of electrode pads of the semiconductor device, and a part of the connection wiring is formed to be either electrically conductive or non-conductive. (2) Claim No. 1 in which a state of electrical continuity is formed depending on whether a part of the connection wiring between the electrode pad and the source or drain is disconnected or not.
) The semiconductor device described in item 2. (3) Claim (1) in which a part of the connection wiring between the electrode pad and the source or drain is electrically connected depending on the presence or absence of a through hole in the interlayer film. The semiconductor device described. (4) A semiconductor device according to claim (1), wherein a part of the connection wiring between the electrode pad and the source or drain is electrically conductive depending on the presence or absence of a diffusion layer wiring. .