JPH11163068A - Detecting device for defective part of semiconductor element - Google Patents

Abstract

(57) [Problem] Conventionally, since a high-sensitivity camera and a lens unit are not separated, it is necessary to readjust an optical axis and the like at the time of disassembling and assembling, so that disassembling and assembling operations are not easy. SOLUTION: A zoom lens unit 4 provided with a light shielding cover 1 at one end and having a plurality of zoom lenses and a means for controlling a distance between the zoom lenses, and the zoom lens unit 4 can be moved in XYZ directions. And the optical fiber 8 that connects the weak light detector and the zoom lens unit 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a defective portion of a semiconductor device, and more particularly to a device for detecting a defective portion of a semiconductor device by using a work microscope.

[0002]

2. Description of the Related Art In a semiconductor device, semiconductor elements such as transistors are formed in an extremely fine pattern in a minute semiconductor substrate area, and these semiconductor elements are electrically connected to each other by wiring to perform a desired circuit function. obtain.

[0003] With the advance of semiconductor technology, further miniaturization and lower current consumption have been attempted. However, with such high integration, leakage due to defects has been caused by miniaturization and lower current consumption of semiconductor devices. As a method for detecting a leak current with high sensitivity and high accuracy due to a small current, a method using an emission microscope for detecting minute light generated from a failure location has been conventionally used. Furthermore, in order to analyze defects that are reproduced only during the operation of the semiconductor device,
In addition to constant voltage sources and pattern generators as signal sources,
A method using an LSI tester as described in JP-A-5-335394 has been adopted.

A conventional emission microscope (K. Van)
Doorslaer, U.S.A. Swerts, L.A. Van
Den Bumpt, “Broadening th
eUse of Emission Microsco
py ”, Proceedings of ISTFA '
95, pp. 58, 1995), as shown in FIG. 9, a light-shielding cover 21 for covering the entire socket including the lens tip and the sample for blocking extraneous light, and a high-sensitivity camera 22 for detecting weak light. A video lens 24 for observing the semiconductor element S to be measured, an illuminating device 25 for the video lens 24, a fixing stand 26 for adjusting the position of the semiconductor element S to be measured, and operating the semiconductor element S A socket 27 for supplying power and a control signal for controlling the high-sensitivity camera 22, a detector control controller 31 for controlling the high-sensitivity camera 22, and a measurement control for controlling the detector control controller 31. Monitor 32
And a measurement image display monitor 33, a data processing measurement control computer 34, and an operation panel 35. In FIG. 9, reference numeral 23 denotes a tester head.

[0005]

The conventional minute light emission detecting device has the advantages that it can be manufactured at low cost and requires a short set-up time. However, when a light shielding cover is provided at the front end of the lens, a single light emitting device can be used. Since a video lens is used, the magnification that can be enlarged by zooming in is limited to a relatively low magnification (observation magnification of about 300). In addition, the high-sensitivity camera and the lens unit are not separated, so they must be disassembled.
Assembly work was not easy.

SUMMARY OF THE INVENTION An object of the present invention is to use a plurality of zoom lenses in an emission microscope while maintaining the advantages of the conventional micro-emission detection device, and to achieve a high magnification with a light-shielding cover provided at the lens tip. Observation magnification 500
(Up to 1000 times or more) Enables observation of semiconductor devices, separates optical system and camera unit, facilitates transportation of emission microscope, and detects minute light emission without limiting LSI driving device To improve the accuracy of detection and improve product reliability.

[0007]

According to a first aspect of the present invention, there is provided a defective portion detecting apparatus comprising: a light emission detecting unit; a plurality of zoom lenses each having a light shielding cover provided at one end; and a unit for controlling a distance between the zoom lenses. A zoom lens unit, a position setting unit capable of moving the zoom lens unit in the XYZ directions, and a connection unit capable of separately controlling the position of the light emission detector and the zoom lens unit, and electrically connecting the light emission detector and the zoom lens unit. It is characterized by having.

That is, the apparatus for detecting a defective portion of a semiconductor element according to the present invention detects an optical system (zoom lens unit) including a zoom lens that can be observed from low magnification to high magnification, and detects weak light generated from a leaked portion. Sensitivity camera (emission detection means) for the camera and XY of the zoom lens unit
It comprises a positioner (position setting means) for moving in the Z direction, and a light-shielding cover provided at the lens tip for blocking extraneous light, and uses a plurality of zoom lenses for zooming. It is characterized in that a lens unit is formed, and the optical system and the high-sensitivity camera are connected by an optical fiber (connection means).

In the micro-emission analysis apparatus of the present invention having such a structure, by forming a zoom lens unit using a plurality of zoom lenses, it is possible to increase the magnification up to a high magnification (500 to 1000 times) with the light-shielding cover provided at the tip of the lens. Up to the above) Observation of the semiconductor device can be performed, and by coupling the optical system and the high-sensitivity camera with an optical fiber, the small emission analyzer can be easily transported, and LS
Measurement becomes possible without limiting the driving device of I. That is,
The accuracy of detection is increased and the reliability of the product is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail using an embodiment.

FIG. 1 is a structural view of a semiconductor element defect detecting device according to an embodiment of the present invention, FIG. 2 is a sectional view of a zoom lens unit used in the semiconductor element defect detecting device of the present invention, and FIG. FIG. 4 is an external view showing a method of installing a first light-shielding cover used in the semiconductor element defect detection device of the present invention. FIG. 4 is an external view showing a second light-shielding cover installation method used in the semiconductor element defect detection device of the present invention. FIGS. 5 and 5 are external views showing a method for installing a third light-shielding cover used in the semiconductor element defect detection device of the present invention. FIG. 6A is a light-shielding cover used in the semiconductor element defect detection device of the present invention. FIG. 7B is a cross-sectional view of the light-shielding cover when a synthetic resin is used, FIG. 7B is a top view of the light-shielding cover, and FIG. Use a soft material other than synthetic resin for the cover. Sectional view of the shielding cover when you were,
8B is a top view of the light-shielding cover, and FIG. 8 is a diagram provided for describing an operation method of the semiconductor element defect detection device according to the present invention. 1 to 8, S is a semiconductor element, 1 is a light-shielding cover, 2 is an optical fiber interface, 3
Is a tester head, 4 is a zoom lens unit, 5 is a zoom ring, 6 is a positioner, 7 is a socket, 8 is an optical fiber, 9 is an optical fiber interface, 1
0 is a weak light detector, 11 is a controller for detection control, 1
Reference numeral 2 denotes a measurement control monitor, 13 denotes a measurement image display monitor, and 14 denotes a data processing measurement control computer.

A zoom lens unit 4 having a plurality of zoom rings 5 is supported by a positioner 6 movable in XYZ directions, and is installed so that the zoom lens unit 4 comes directly above the semiconductor element S. Semiconductor element S
Is fixed by a socket 7 installed on the tester head 3.

A light-shielding cover 1 for blocking extraneous light is provided between the zoom lens unit 4 and the semiconductor element S. The zoom lens unit 4 and the weak light detector 10 are connected by an optical fiber interface 2, an optical fiber 8, and an optical fiber interface. A detector control controller 11 for controlling the weak light detector 10 is connected to the weak light detector 10,
The output signal is transmitted to the monitor 12 for measurement control, the monitor 13 for displaying a measurement image, and the computer 14 for data processing and measurement control.
4 has an operation panel 15.

As shown in FIG. 2, it is assumed that the zoom lens unit 4 has a structure in which a plurality of ordinary zoom lenses that are variable in the optical axis direction when zooming in and out are connected. Therefore, the zoom lens unit 4
It is also assumed that the zoom lens itself is variable in the optical axis direction when zooming in and zooming out. When zooming in, zoom rings 5a, 5
By rotating one or more of b, 5c, one or more of the corresponding lens barrels (movable parts) 4b, 4d, 4f are lowered. Accordingly, the variable distance between lenses D
l, D3 and D5 become longer and the image is reduced. Note that the fixed distances D2, D4, and D6 between the lenses remain constant during zooming in and zooming out.

The light shielding cover 1 has a package S2 of PGA, SOP, FPT, LCC, PLCC, QFP,
VSOP, VQFP, MSP, CSP, TCP, MCM
-D, MCM-C, MCM-L, MCM-Si, MCM
-Opened plastic mold package with pins arranged in four directions such as D / C or LGA, PGA, B
In the case of an opened plastic mold package in which pins are arranged in a lattice, such as GA, μBGA, mini-BGA, etc., the negative part of the package S2 including the entire semiconductor chip Sl is covered as shown in FIG.

The package S2 is composed of PGA, SOP,
FPT, LCC, PLCC, QFP, VSOP, VQF
P, MSP, CSP, TCP, MCM-D, MCM-
Ceramic package with pins arranged in four directions, such as C, MCM-L, MCM-Si, MCM-D / C, or ceramic package with pins arranged in a grid such as LGA, PGA, BGA, μBGA, miniBGA In some cases, as shown in FIG. 4, the entire package S2 including the entire semiconductor chip Sl is covered.

Further, the package S is made of DIP, SHRIN
K DIP, SKINNY DIP, QUIP, SI
P, ZIP, QFJ, SOJ, SON, SOP, SHR
Package with pins arranged in two directions such as INKSOP, TSOP, VSOP, SVP, BLP, or CO
In the case B, the package S2 including the semiconductor chip S1 and the entire socket 7 are covered as shown in FIG.

The light-shielding cover 1 covers a part of the package S2 including the entire semiconductor chip S1 or the semiconductor chip Sl.
Whether to cover the entire package S2 including the whole or the entire package S2 including the semiconductor chip S1 and the socket 7 depends on the size and shape of the package S2, or whether the package is a ceramic package or a mold package. change. For example, it is desirable to cover the entire package S2 and socket 7 as much as possible, but if the package S2 is rectangular,
Needs to be adjusted to the length of the long side of the package S2, so that a part of the package S2 included in the entire semiconductor chip S1 may be covered.

Since the ceramic package has an opening larger than the size of the chip, it is difficult to cover a part of the package as shown in FIG. 3. However, the opening of the mold package is about the same size as the chip. Therefore, it is easy to cover a part of the package as shown in FIG.

The color of the surface of the light-shielding cover 1 is black or a color close to black so that external light is easily absorbed by the surface, or silver or a color close to silver so that the external light is easily reflected by the surface. Shall be. The color of the back surface of the light-shielding cover 1 is set to black or a color close to black irrespective of the color of the surface so that reflection due to minute light emission does not occur.

The material of the light-shielding cover 1 is such that the semiconductor element S is kept in a state of being shielded from external light even if the zoom lens unit 4 moves in any of the X, Y and Z directions. (Silicone rubber, fluorine rubber, urethane rubber, acrylic rubber, nitrile rubber, natural rubber, polysulfide rubber, crystal rubber, neoprene, etc. with a thickness of 5 mm or less), leather (cowhide, sheep leather, synthetic with a thickness of 5 mm or less) Leather, etc.), cloths (cotton, hemp, etc.), synthetic fibers (polyamide (nylon) fibers, polyester fibers, acrylic fibers, etc.), synthetic resins (polyethylene, polyvinyl chloride, polysterene with a thickness of 1 mm or less) , Polypropylene, methacrylic resin, polycarbonate, polyamide, polyacetal, fluororesin, urea resin, phenolic resin, unsaturated Riesuteru resin, polyurethane, alkyd resins, epoxy resins, melamine resins, etc.), sponges (fluororubber sponge, silicone rubber sponge, neoprene sponge, such vinyl acetate sponge) or other soft materials (such as Kalrez)
Shall be used. The shape of the light-shielding cover 1 is relatively hard when the material of the light-shielding cover 1 is a synthetic resin.
As shown in FIG. 6, the front and back surfaces are made uneven and have a highly elastic shape so that the semiconductor element S is kept shielded from external light regardless of the direction of movement in the Z direction. Fig. 7 when the material of No. 1 is other than synthetic resin granules
And a hemispherical shape as shown in FIG.

The optical fiber interface 2 is detachable from the zoom lens unit 4, and the optical fiber interface 9 is detachable from the weak light detector 10. The optical fiber 8 between the optical fiber interface 2 and the optical fiber interface 9 is a single mode optical fiber (core: quartz glass, clad: quartz glass),
Graded index type optical fiber (core: quartz glass, clad: silica glass) or step index type optical fiber (core: quartz glass, clad: quartz glass or core: multi-component glass, clad: multi-component glass or core: plastic, clad: (Plastic) or the like.

Next, the procedure for transporting the apparatus of the present invention shown in FIG. 1 will be described.

First, after turning off the power of all the electric systems, the optical fiber interface 2 is removed from the zoom lens unit 4 and the optical fiber interface 9 is removed from the weak light detector 10, and the optical fiber interface between the optical fiber interface 2 and the optical fiber interface 9 is removed. The optical fiber 8 is removed from between the zoom lens unit 4 and the weak light detector 10 while the cable 8 remains connected.

Next, the light-shielding cover 1 is pulled up, and the zoom lens unit 4 provided with the focus ring 5 is removed together with the positioner 6 from the tester head 3 so as not to damage the semiconductor element S. 7 is also removed from the tester head 3.

Next, with the weak light detector 10 and the detector control controller 11 still connected, the detector control controller 11 is disconnected from the data processing / measurement control computer 14, and the measurement control monitor 12, The measurement image display monitor 13 and the operation panel 15 are also removed from the data processing measurement control computer 14. The optical fiber interface 2 and the optical fiber interface 9 removed as described above, the optical fiber 8 between them, the zoom lens unit 4 including the focus ring 5, the light shielding cover 1, the positioner 6, the measurement control monitor 12, and the measurement image display monitor 13 The computer 14 for data processing and measurement, the operation controller 1S, the weak light detector 10 and the controller 11 for detector control are mounted on a trolley or the like, or used for manually operating the semiconductor element S to be measured. Signal sources (e.g., verification testers for analysis and verification, prototypes, logic testers used for mass production testing, memory testers, logic analog testers, CCD testers, LCD driver testers, etc., or simple testers, Pattern generator It does carefully transported to a place where are located the constant voltage source, etc.).

When the signal source is reached, the minute light emitting device of the present invention is installed in the signal source by the reverse procedure of the removal.

Next, an example of a method for detecting a defective portion of a semiconductor element using the apparatus of the present invention shown in FIG. 1 will be described (see FIG. 8).

(1) Put the semiconductor element S on the socket 7
The semiconductor element S is set so as to be energized by the tester head 3 and to be directly below the zoom lens unit 4.

(2) Initial setup is performed (step (a)), and the optical system of the zoom lens unit 4 is set to the minimum magnification (step (b)).

(3) After turning on the light source of the zoom lens unit 4 (step (c)) and adjusting the focus of the image by the positioner 6 (step (d)), a pattern image of the semiconductor element S is photographed (step (e)). )) And stores the image data in the first memory of the computer 14 (step (f)).

(4) The light source of the zoom lens unit 4 is turned off (step (g)), and a tester for mass-produced products (logic tester, memory tester, logic analog tester, CCD tester, A signal generated by a liquid crystal driver tester or the like, a simple tester, a pattern generator, a constant voltage source, or the like) is applied (step (h)).

(5) Since light is emitted from the defective portion of the semi-dedicated element S, this image is taken by the high sensitivity camera 10 (step (i)) and stored in the second memory of the computer 14 (step (j)). I do.

(6) An image of the first memory (a pattern image of the semiconductor element) and an image of the second memory (an emission image from the semiconductor element)
Are displayed (step (k)) in an overlapping manner, so that a defective portion can be detected (Y in step (l)).
ES).

(7) The magnification to be observed by the zoom lens of the zoom lens unit 4 is increased (step (n)).

(8) The above (3) to (7) are repeated.

(9) When a defective part cannot be specified by the above (1) to (8) (NO in step (1))
Transports the apparatus of the present invention to a tester for analysis (such as a verification tester) according to the above-mentioned procedure (steps (o), (p), (q)) in order to perform a more detailed analysis.

(10) A defective portion is detected in the same procedure as in the above (1) to (8). (11) Next, in order to specify a defective portion in another semiconductor element S '(step (r)), the apparatus of the present invention is used in another tester (a logic tester, a memory tester, and a logic analog used for testing mass-produced products). Tester, CC
D tester, LCD driver tester, etc. or simple tester, pattern generator or constant voltage source)
Transport to

(12) With respect to another semiconductor element S ', a defective portion is detected in the same manner as in the steps (1) to (10) for the semiconductor element S.

By the above operation, it is possible to detect a defective portion due to a leak current generated in the semiconductor element S and another semiconductor element S ′. The above procedures (5) and (6)
In the second memory means that the semiconductor element S
When a constant voltage is supplied to the device, a light emission image obtained only once from the defective portion of the semiconductor element S or a light emission image obtained from the defective portion of the semiconductor device S is obtained twice, and the result of performing the comparison operation process is obtained. Image data (JP-A-5-1524)
No. 08).

When a test logic pattern is supplied from the signal source to the semiconductor element S at a constant voltage, the image of the second memory is defined as one light emission at the time when light emission occurs from a defective portion of the semiconductor element S. Image obtained only once (Japanese Patent Application Laid-Open No. 5-3353)
No. 9), or image data obtained as a result of obtaining light emission generated from a defective portion of the semiconductor element S twice and performing a comparison operation process.

[0042]

As described above in detail, by using the present invention, a plurality of zoom lenses are employed in a zoom lens unit in an emission microscope, so that a light-shielding cover is attached to a lens tip. , It is possible to acquire a light emission image of the semiconductor device up to a relatively high magnification (500 to 1000 times or more), and to transport the minute light emission analyzer by coupling an optical fiber between the optical system and the high sensitivity camera. Becomes easier and LSI
The measurement can be performed without limiting the driving device. Thereby, the accuracy of detection is improved, and the reliability of the product is improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus for detecting a defect of a semiconductor element according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the configuration of a zoom lens unit used in the semiconductor element defect detection device of the present invention.

FIG. 3 is an external view showing a method of installing a first light-shielding cover used in the semiconductor element defect detection device of the present invention.

FIG. 4 is an external view showing a method of installing a second light-shielding cover used in the semiconductor element defect detection device of the present invention.

FIG. 5 is an external view showing a method of installing a third light-shielding cover used in the semiconductor element defect detection device of the present invention.

FIG. 6A is a cross-sectional view of a light-shielding cover when a synthetic resin is used for the light-shielding cover used in the semiconductor element defect detection device of the present invention, and FIG. 6B is a top view of the light-shielding cover. FIG.

FIG. 7A is a cross-sectional view of a light-shielding cover when a soft material other than synthetic resins is used for the light-shielding cover used in the semiconductor element defect detection device of the present invention, and FIG. It is a top view of the cover for use.

FIG. 8 is a diagram for explaining an operation method of the semiconductor element defect detection device of the present invention.

FIG. 9 is a schematic configuration diagram of a conventional emission microscope.

[Explanation of symbols]

 S Semiconductor element 1 Light shielding cover 2 Optical fiber interface 3 Tester head 4 Zoom lens unit 5 Zoom ring 6 Positioner 7 Socket 8 Optical fiber 9 Optical fiber interface 10 Weak light detector 11 Detection control controller 12 Measurement control monitor 13 Measurement image display Monitor 14 Computer for data processing and measurement control 15 Operation panel

Claims (2)

[Claims] 1. A zoom lens unit having light emission detection means, a plurality of zoom lenses provided with a light-shielding cover at one end, and means for controlling a distance between the zoom lenses, and a zoom lens unit in XYZ directions. Defective position of a semiconductor element, comprising: a position setting means that can be moved to a predetermined position; and a connection means that can separately control the position of the light emission detector and the zoom lens unit and electrically connect the light emission detector and the zoom lens unit. Detection device. 2. An apparatus according to claim 1, wherein said connecting means is an optical fiber.