JP2518162B2 - Semiconductor integrated circuit failure inspection equipment - Google Patents

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 failure inspection apparatus, and more particularly to a semiconductor integrated circuit failure inspection apparatus for inspecting various elements in a semiconductor integrated circuit chip for failure using a laser beam.

[0002]

2. Description of the Related Art There is a conventional semiconductor integrated circuit failure inspection device of this type using an electron beam. This is done by irradiating the surface of the semiconductor chip with an electron beam and irradiating it.
By utilizing the fact that the amount of secondary electrons is related to the voltage on the surface of the chip, the voltage inside the semiconductor integrated circuit is measured and the failure is inspected. However, with this method using an electron beam, it is difficult to measure the voltage with high accuracy, and it is possible to measure only the voltage of the wiring part on the chip surface, and in the case of multilayer wiring, the potential of the wiring inside the chip cannot be measured. There were difficulties such as. Furthermore, there is a difficult problem in identifying the actual physical failure position from the observed potential.

On the other hand, in the method based on Japanese Patent Application No. 5-85817 "Inspection method and apparatus for internal interconnection of semiconductor integrated circuit", it is possible to inspect internal defects of interconnections on the surface of a semiconductor chip. This is because the temperature of the irradiated part is changed by irradiating the surface of the semiconductor chip with a laser beam, and the thermal conduction state varies depending on the presence or absence of defects inside the wiring, resulting in a difference in the temperature fluctuation range. The position of the defect is specified by using the difference in the fluctuation of the resistance value. However, with this method, it is impossible to detect a defect in a non-wiring portion such as a transistor.

[0004]

In this conventional semiconductor integrated circuit failure inspection apparatus, it takes a lot of time to identify the actual physical failure position from the observed potential in the circuit. It will be impossible. Also, if the target wiring does not exist on the surface due to multilayer wiring, etc.,
The potential of the part cannot be measured. On the other hand, the latter method has an advantage that the failure position can be immediately specified, but has a problem that only the failure in the wiring portion is targeted and other failures cannot be dealt with.

[0005]

In order to solve the above problems, a semiconductor integrated circuit failure inspection apparatus according to the present invention is
Focusing on the difference in the input / output characteristics of the semiconductor integrated circuit device due to the fact that the semiconductor chip surface is irradiated with a laser beam and the temperature characteristics of the semiconductor element based on the temperature change of the irradiation part differ between the defective element and the normal element. To do.

The semiconductor integrated circuit failure inspection apparatus of the present invention comprises:
In a failure detection / diagnosis device for a semiconductor integrated circuit chip,
A laser generator for generating a beam that locally raises the temperature of the semiconductor integrated circuit chip surface, and a laser beam for receiving a laser beam from the laser generator and irradiating a non-defective chip and an inspected chip. A laser distributor that divides the laser beam into two parts, a first laser scanning unit that receives a laser beam for irradiating a non-defective chip from the laser distributor, scans and irradiates a non-defective chip, and a laser beam from the laser distributor. A second laser scanning unit for receiving a laser beam for irradiating an inspection chip to scan and irradiate the chip to be inspected, a non-defective device, and a circuit characteristic of each device to be inspected are measured.
Determined the power supply and supplying the input signal power / input signal generating unit, and the good devices, the capture of the output signal from the device under test, the circuit characteristics of both for each element
Output signal detection / comparison processing section for comparing circuit characteristic variations due to differences in temperature characteristics, laser beam irradiation position information from the first and second laser scanning sections, and output signal detection / comparison processing section. It is characterized by comprising an image processing unit for creating an image indicating a defective element in the device chip to be inspected based on the result of 1. and an image display device for displaying the image.

[0007]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, a laser generator 1 generates a laser beam with which a semiconductor integrated circuit chip is irradiated. Laser distributor 2
Receives the laser beam generated by the laser generator 1, divides the laser beam into two for irradiating the chip 13 of the device under test 11 and the chip 12 of the non-defective device 10 for reference, and guides them to their respective optical paths. The laser scanning units 3 and 4 shape the laser beam received from the laser distributor 2, respectively, and refer to the chip 12 of the reference good device and the chip 1 of the device under test 11.
Irradiate while scanning to 3. At this time, the laser scanning units 3 and 4 perform beam scanning in synchronization with each other.

The temperature controller 5 keeps the temperature of the non-defective device 10 and the device under test 11 constant and reduces noise during measurement.

The power supply / input signal generator 6 supplies power to the non-defective device 10 and the device under test 12 and inputs a test signal.

The irradiation of the laser beam locally raises the temperature of the irradiation portion. By the way, the temperature characteristics of semiconductor elements such as transistors formed on a chip are extremely sensitive, and when the semiconductor element section is irradiated with a laser beam, the output characteristics of the semiconductor device greatly change due to the temperature change. . Here, the temperature characteristic differs between the semiconductor element having a failure and the normal semiconductor element, and the difference in the temperature characteristic is also reflected in the output characteristic of the semiconductor device. Therefore, the laser beam is used by the laser scanning units 3 and 4 to refer to the non-defective chip 12 and the inspected chip 13.
While scanning and irradiating the top, the output is detected / output signal
By observing by the comparison processing unit 9 and observing the change in the output characteristics of each semiconductor device due to the irradiation of the laser beam, and performing the comparison processing, the change in the specific output characteristics when the faulty element is irradiated with the laser is observed. Can be detected.

The image processing unit 8 receives the result of the output signal detection / comparison processing unit 9, receives the laser beam irradiation position information from the laser scanning units 3 and 4, and outputs the result on the image display device 7. . As a result, the defective element of the semiconductor chip can be immediately identified.

The wavelength and power of the laser beam are determined by counting the scanning speed and the type of device.

[0013]

As described above, the semiconductor integrated circuit failure inspection apparatus according to the present invention utilizes the fact that the variation of the characteristics of the semiconductor element due to the temperature change is different between the normal element and the defective element, thereby identifying the failure position. Therefore, the physical failure position of the semiconductor integrated circuit chip can be pointed out immediately, and the failure of the element inside the chip which cannot be observed from the surface of the chip can be pointed out.

[Brief description of drawings]

FIG. 1 is a device configuration diagram showing an embodiment of a semiconductor integrated circuit failure inspection device according to the present invention.

[Explanation of symbols]

 1 Laser Generator 2 Laser Distributor 3 Laser Scanner for Irradiating Good Semiconductor Device 4 Laser Scanner for Irradiating Semiconductor Device to be Inspected 5 Semiconductor Device Temperature Controller for Inspection 6 Power Supply / Input Signal Generator 7 Image Display Device 8 Image Processor 9 Output signal detection / comparison processing unit 10 Good semiconductor device 11 Inspected semiconductor device 12 Good semiconductor chip 13 Inspected semiconductor chip

Claims (1)

(57) [Claims] 1. A failure detection / diagnosis apparatus for a semiconductor integrated circuit chip, comprising: a laser generator that generates a beam that locally raises the temperature of the surface of the semiconductor integrated circuit chip; A laser distributor that receives a laser beam and divides it into a laser beam for irradiating good chips and a laser beam for irradiating chips to be inspected, and a laser beam for irradiating good chips from the laser distributor, scans and irradiates good chips. A first laser scanning unit for scanning, a second laser scanning unit for receiving a laser beam for irradiating a chip to be inspected from the laser distributor, scanning and irradiating the chip to be inspected, a non-defective device, and Circuit characteristics of each inspection device
Power supply for measuring
The output signals from the input signal generator, the non-defective device, and the device under test are fetched, the circuit characteristics of both are obtained, and the temperature characteristics of each element are determined.
Output signal detection / comparison processing section for comparing variations in circuit characteristics due to differences in characteristics, laser beam irradiation position information from the first and second laser scanning sections, and results from the output signal detection / comparison processing section A semiconductor integrated circuit failure inspection apparatus, comprising: an image processing unit that creates an image indicating a defective element in a device chip to be inspected based on the above; and an image display device that displays the image.