JPS61263235A - Inspecting device - Google Patents

Abstract

PURPOSE:To inspect an element to be inspected with reproducibility at a rapid speed by using an infrared ray camera for inspecting the element, i.e., a semiconductor integrated circuit to discover a defective portion upon heating of the element. CONSTITUTION:An external light ray to be emitted to a pellet 3 is interrupted by an interrupting film 10, and the prescribed operation signal is input through leads 5 led to a testing circuit to the pellet 3 to become an operating state. Then, defective portions with heating such as gate damage or a latchup in a semiconductor integrated circuit formed on the pellet 3 is observed by an infrared ray camera 8 for recognizing the image of the pellet 3 by detecting the temperature distribution of the pellet 3 to rapidly specify the defective portion of the pellet 3, thereby accelerating the inspecting work in the operating state of the pellet 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inspection technique, and particularly to a technique effective when applied to failure analysis inspection in the manufacture of semiconductor devices.

[Background Art] For example, when inspecting the operating state of a semiconductor integrated circuit device such as a pellet, the following methods can be considered in order to discover failures such as gate breakage and latch amplifiers inside the device from the outside.

In other words, a liquid crystal whose color changes depending on the temperature is applied to the surface of the pellet exposed to the outside, and when a predetermined operating signal is applied to the pellet, the electrostatic charge inside the pellet is applied. The malfunctioning part of the pellet can be identified by detecting the heat generated by abnormal current at the malfunctioning part, such as a breakage or latch-up part, as a change in the color of the liquid crystal coated on the pellet surface.

However, the above method has drawbacks such as the pellet being contaminated by the applied liquid crystal, which may change the electrical characteristics of the pellet, and the test results not being reproducible due to changes in the properties of the liquid crystal over time. The inventor has discovered that there is.

Another inspection method is to install a pellet in a designated dark room and operate it, and use a predetermined amount of weak light that is generated due to heat generation at failure points such as electrostatic damage or latch-up parts inside the pellet. However, the present inventors have found that the light beam is weak, so it takes a long time to find the failure location, and the inspection efficiency is low.

The literature explaining the inspection of semiconductor integrated circuit devices is Kogyo Kenkyukai Co., Ltd., November 1982.
"Electronic Materials" 1984 special issue, published on the 15th of May, P213~
There is P220.

[Object of the Invention] An object of the present invention is to provide an inspection technique that allows rapid and reproducible inspection.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, by using an infrared camera to inspect the inspected object, for example, it is possible to easily find a faulty part of the inspected object due to heat generation, and to enable rapid and reproducible inspection of the inspected object. .

[Example] FIG. 1 is an explanatory diagram of an inspection apparatus that is an example of the present invention.

A socket board 2 is placed on a horizontally provided inspection stage 1.

Furthermore, a package base 4 made of ceramics or the like is placed on the socket board 2, on which a pellet 3 (test object), which is a semiconductor integrated circuit element, is mounted.

The plurality of leads 5 fixed to the package base 4 are electrically connected to the pellet 3 by bonding wires 6, and the leads 5 are further inserted into predetermined contact holes (not shown) of the socket board 2 to form a predetermined contact hole (not shown) in the socket board 2. The test circuit section (not shown) is connected to the test circuit section (not shown).

Furthermore, an optical lens 7 and an infrared camera 8 are provided above the socket board 2 so that their axes are substantially perpendicular to the socket board 2, and are mounted on a buff cage base 4 positioned above the socket board 2. beret 3
The image in the operating state is magnified by the input signal from the test circuit section, etc., and is incident on the infrared camera 8, and the intensity of the infrared rays emitted from each part of the bellet 3 and the temperature distribution of each part of the bellet 3 are measured. Based on Beret 3
The image of

The image of the pellet 3 constructed as described above is then observed on a display section 9 connected to an infrared camera 8 and constructed of, for example, a cathode ray tube.

In addition, light is shielded so as to partially surround the socket board 2 and the optical lens 7 and infrared camera 8 provided above the socket board 2. 10 is provided to prevent external light from being applied to the pellet 3 mounted on the package base 4 placed on the socket board 2, and the pellet is inspected in an operating state. This avoids malfunctions caused by the irradiation of the light beam in step 3.

The operation of this embodiment will be explained below.

First, a package base 4 on which a pellet 3 is mounted is fixed to the package base 4, and a wire 5 is electrically connected to the pellet 3 by a bonding wire 6 and inserted into a predetermined contact hole of the socket board 2. It is set by

Next, the external light irradiated to the pellet 3 is blocked by the light shielding curtain 10, and a predetermined operating signal is manually applied to the pellet 3 via the lead 5 which is electrically connected to the test circuit section, so that the pellet 3 is brought into an operating state. .

At this time, if a part of the semiconductor integrated circuit formed on the pellet 3 has a faulty part such as gate destruction or latch-up, heat due to abnormal current is generated at these faulty parts, and the pellet 3 The temperature is raised above other normal parts of the body.

In this embodiment, the bellet 3 in the above operating state is
The image is magnified to a predetermined magnification by an optical lens 7, and then observed by an infrared camera 8 that recognizes the image of the pellet 3 based on the temperature distribution of the subject, the pellet 3, and a display unit 9 connected to the infrared camera 8. , the failure location of the semiconductor integrated circuit formed in the pellet 3 can be quickly identified from the temperature distribution in the pellet 3.

In this way, failures such as gate breakdown and heat generation in the semiconductor integrated circuit formed in the pellet 3, such as in the latch amplifier, can be observed by the infrared camera 8, which recognizes the image of the pellet 3 by detecting the temperature distribution of the pellet 3. Therefore, the failure location of the pellet 3 can be quickly identified, and inspection work on the operating state of the pellet 3 can be speeded up.

In addition, since it is not necessary to apply a foreign substance such as liquid crystal to the pellet 3, the electrical characteristics of the pellet 3 may change due to changes over time of the applied foreign substance, and the pellet 3 This prevents the reproducibility of the inspection of the failed location from being reduced, and it is possible to obtain inspection results with good reproducibility.

Then, pellet 3 was quickly identified as described above.
A more detailed inspection is performed on the failure location using an optical microscope (not shown) to determine the cause of the failure.

Effect C (1): Since an infrared camera is used to inspect the object to be inspected, a faulty part that causes heat generation in the object to be inspected can be quickly found, and the inspection of the object to be inspected can be speeded up.

(2) As a result of (11) above, it is not necessary to apply a foreign substance such as liquid crystal to the object to be inspected, so the electrical characteristics of the object to be inspected may change over time. It is possible to avoid deterioration in the reproducibility of the inspection of a faulty part of the object to be inspected due to changes, and it is possible to obtain inspection results with good reproducibility.

(3), above fl), (As a result of (21), failure analysis of semiconductor devices can be speeded up, the research and development period for semiconductor devices can be shortened, and productivity in manufacturing semiconductor devices can be improved.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the object to be inspected is not limited to pellets, but the present invention can also be applied to inspections in which semiconductor circuit elements formed on wafers are brought into an operating state with a prober.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to the field of application of the invention, which is the inspection of semiconductor integrated circuit devices, but the invention is not limited to this. It can be widely applied to the inspection of objects to be inspected whose parts generate heat.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an inspection apparatus that is an embodiment of the present invention. 1... Inspection stage, 2... Socket board, 3.
... Pellet (test object), 4... Buff cage base, 5... Lead, 6... Bonding wire, 7...
...Optical lens, 8...Infrared camera, 9...Display section, 10...Shading curtain. Figure 1

Claims (1)

[Scope of Claims] 1. An inspection device characterized in that an infrared camera is used to inspect an object to be inspected. 2. The inspection apparatus according to claim 1, wherein the object to be inspected is a semiconductor integrated circuit element in an operating state.