JPH05172896A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To measure the characteristic of a monitor transistor for checking characteristic easily and automatically, in the test for an inside circuit, by measuring the monitor transistor for checking characteristic from outside, by using a common terminal, even after the completion of a semiconductor device. CONSTITUTION:As for an IC, the drain sources of P-channel transistors 6a-6c for switch are connected between a power source pad 1, outside terminal pads 3a-3b, and an inside circuit, and the drain sources of the n-channel transistors 7a-7c for switch are connected between a GND feed side pad 2 and the inside circuit. The drain source of a monitor transistor 5 for checking the P-channel characteristic is connected between the outside pads 3a and 3b, and the drain source of a monitor transistor 4 for checking the n-channel characteristic is connected between the pads 3c and 3d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit,
In particular, the present invention relates to a semiconductor integrated circuit having a characteristic checking monitor transistor whose characteristic can be measured from an external terminal.

[0002]

2. Description of the Related Art Conventionally, a characteristic check monitor transistor built in a semiconductor integrated circuit (IC) chip is an IC.
It is provided separately from the internal circuit inside the chip and is connected to a measurement pad. To measure the characteristics, a probe of an IC tester is applied to the measurement pad for measurement.

[0003]

This conventional monitor transistor for checking the IC characteristics can measure the semiconductor alone as a wafer or a chip, but it cannot be measured as an external terminal in advance after it becomes a finished IC. There is a problem that measurement is impossible unless a check terminal dedicated to the check transistor is prepared.

An object of the present invention is to provide a semiconductor integrated circuit capable of measuring a monitor transistor from an external terminal without a dedicated check terminal.

[0005]

A semiconductor integrated circuit of the present invention has a plurality of power supply and external end pads, a characteristic checking monitor transistor, and an internal circuit connected to the plurality of pads. The semiconductor integrated circuit has switching transistors each having a drain / source inserted between the power supply / external end pad and the internal circuit, and a gate of the monitor transistor is connected to the power supply pad. The source / drain is inserted between the pads for the external end, and the monitor transistor is separated from the internal circuit by inputting a control signal from the power supply pad to the gate of the front switching transistor.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of an embodiment of the present invention. The IC connects the drain and source of P-channel transistors 6a to 6c for switching between the power supply pad 1 and the external terminal pads 3a to 3b and the internal circuit, respectively, and connects the GND and the GND supply terminal pad 2 to the internal circuit, respectively. N for switch
The drains and sources of the channel transistors 7a to 7c are connected, and the P-channel characteristic check monitor transistor 5 and the pads 3c,
The drain and source of the n-channel characteristic checking monitor transistor 4 are connected between 3d.

During normal operation of the internal circuit, the power supply voltage is supplied to the internal circuit from the V _DD supply end pad 1 and the GND supply end pad 2. At this time, the monitor transistors 6a to 6c and the monitor transistors 7a to 7c are switched on, the transistors 5 and 4 are switched off, and the external end pads 3a and 3b and 3c and 3d.
Becomes an independent state from the internal circuit and normal internal circuit operation is performed.

When the characteristic check monitor transistor 4 or 5 is measured, the GND level is applied to the V _DD supply end pad 1.
By supplying the V _DD level to the GND supply terminal pad 2, the P-channel transistors 6a to 6c and the n-channel transistors 7a to 7c are switched off, and the internal wirings 8a to 8f are cut to disconnect the V _DD supply end pad 1 And GND supply end pad 2 and external end pads 3a-3
d is independent of the internal circuit.

For example, the P-channel characteristic checking monitor transistor 5 is measured in the above-described state with the external terminals 3a and 3a.
b, and the measurement of the n-channel characteristic checking monitor transistor 4 is performed independently of the internal circuit using the external terminals 3c and 3d.

[0010]

As described above, the present invention is a semiconductor IC
Since the characteristic check transistor characteristics can be measured using the normal power supply terminal, the GND terminal, and the external terminal, the characteristic check monitor transistor can be externally measured using the normal terminal even after the semiconductor device is completed. It has the effect that it can be done. Further, since the external terminal of the internal circuit is used for the measurement, there is also an effect that the characteristic of the characteristic checking monitor transistor can be easily measured automatically when the internal circuit is tested.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

[Explanation of symbols]

1 V _DD Supply End Pad 2 GND Supply End Pad 3a-3d External End Pad 4 n-Channel Characteristic Check Monitor Transistor 5 P-Channel Characteristic Check Monitor Transistor 6a-6c P-Channel Transistor 7a-7c n-Channel Transistor 8a-8f Internal Wiring

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[Procedure amendment]

[Submission date] November 26, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Semiconductor integrated circuit

Claims (1)

[Claims] 1. A semiconductor integrated circuit having a plurality of power supply pads and external end pads, a characteristic checking monitor transistor, and an internal circuit connected to the plurality of pads, wherein the power supply end and the external end end are provided. A switch transistor having a drain and a source respectively inserted between the pad and the internal circuit; a gate of the monitor transistor is connected to the power supply pad; and a source and a drain between the pad for the external end. And a control signal is input to the gate of the front switching transistor from the power supply pad to disconnect the monitor transistor from the internal circuit.