JPS6127648A - Failure analysis for integrated circuit - Google Patents

Abstract

PURPOSE:To enable to easily detect a leakage current generating place by a method wherein an electric field or a magnetic field is locally impressed on the surface of a chip and a current to flow on the circuit of the integrated circuit is monitored while the probe electrode is made to shift on the surface of the chip. CONSTITUTION:An electric field is locally impressed vertically on the surface of an integrated circuit chip 1 placed on a metallic stage 2 using a probe electrode 5 and this probe electrode 5 is made to shift on the surface of the chip 1. Probes 3 and 4 are erected on the pads of the chip 1 and a power source 7 and an ammeter 8 are connected. A power source 6 is given to the probe electrode 5 and a power electric field in a degree that the field affects the electric conduction of the surface of the chip 1 is set. When the probe electrode 5 comes to a place where a surface inversion leak exists, a change is generated in the ammeter 8. Even when a magnetic field is used instead of an electric field, the similar effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a failure analysis method for detecting a failure location that causes a leak defect in an integrated circuit.

<Background Art> In recent years, integrated circuits have become increasingly finer and more highly integrated. As a result, device structures are becoming more complex.

For example, there are multiple layers of aluminum wiring and use of polysilicon wiring. This trend is particularly noticeable in MOS and LSI. Such conventional trends inevitably make it difficult to detect failure locations in LSIs. Conventionally, in order to detect failure points, aluminum wiring was cut with a laser beam, a probe needle was placed on top of the aluminum wiring, and
Failure locations were detected while measuring voltage or current. However, in the future, this method has the disadvantage that it will be difficult to set up needles for miniaturization, and it will be extremely difficult to find extremely localized micro-6 leak points, requiring a great deal of time and effort. have.

<Problems to be Solved by the Invention> The purpose of the present invention is to obtain a failure analysis method for integrated circuits that can easily find locations where leakage current is occurring in semiconductor integrated circuits that have been miniaturized and highly integrated. It is in.

<Means for Solving the Problem> According to the present invention, applying an electric field or a magnetic field to the surface of a semiconductor chip changes the electrical conductivity of the semiconductor surface, so that the probe electrode can be locally applied to the surface of the semiconductor chip. We obtain a failure analysis method that applies an electric field or magnetic field and moves this probe electrode to easily detect the location where leakage current occurs.

<Example> The present invention will be explained using FIG. 1. metal stage 2
1 of the integrated circuit chips 1 placed on top.

An electric field is locally applied perpendicularly to the surface of the chip 10 using a probe electrode 5, and the probe electrode 5 is moved on the surface of the chip 10. Probe needles 3 and 4 are set up on the pads of the integrated circuit chip 1, and between these probe needles 3 and 4,
A power source 7 and an ammeter 8 are connected. A power source 6 is applied to the probe electrode 5, and this power source 6 is variable in order to change the electric field. With such a configuration, an appropriate electric field is set by the power source 6 to the extent that it can influence the electrical conduction on the surface of the integrated circuit chip 1. Next, the ammeter 8 is observed while moving the position of the probe electrode. When the probe electrode 5 comes to a location where surface inversion leak exists, a change occurs in the ammeter 8.

If the electric field suppresses conduction type reversal on the surface of the chip 10, the leakage current will be small; on the other hand, if the electric field promotes the reversal, the leakage current will increase. By utilizing this phenomenon of changes in the surface state of the chip 1, it is possible to easily detect minute leakage points that have been difficult to detect in the past.

By configuring the failure analysis device so that the positional movement of the probe electrode 5 and the current change are linked, the failure position detection becomes more efficient. A similar effect can be obtained by using a magnetic field instead of an electric field.

<Effects of the Invention> According to the present invention, the location where a leakage current occurs can be easily detected, and even when integrated circuits become denser and finer, the location of failure can be easily discovered.

[Brief explanation of drawings]

FIG. 1 shows a cross section of an integrated circuit chip during failure analysis and a measurement circuit for detecting a failure location according to an embodiment of the present invention. 1...
...Integrated circuit chip, 2...Metal stage, 3, 4...Probe needle, 5...Probe electrode, 6...For electric field Power supply, 7...
・Power supply for chip, -...Ammeter.

Claims (1)

[Claims] Failure of the integrated circuit is detected by monitoring the circuit current of the integrated circuit while moving a positionally variable probe electrode capable of locally applying an electric or magnetic field to the chip surface of the integrated circuit. A failure analysis method for integrated circuits characterized by detecting locations.