JPH01262636A - Convergent ion beam system - Google Patents

Abstract

PURPOSE:To shorten the time required in wiring correction work, and to improve accuracy by observing a picture image based on the information of secondary electrons generated from wiring structure, etc., and reflected electrons and the like and the waveform of an actuating signal and the like. CONSTITUTION:Operating power, an actuating signal, etc., are applied to a semiconductor device 4 from an electric-signal applying means 12, and fine holes 46a, 46c formed by ion beams 7 and the region of a conductor thin-film 9a are scanned. Secondary electrons 13 generated from the thin-film 9a are detected 14, the strength change of electrons 13 is made to correspond to the brightness of a picture plane by a picture processing section 15, and synchronized with the scanning of beams 7, and the waveform of the actuating signal is shaped on the basis of the quantity of electrons 13, and displayed 16. The quantity of electrons 13 is increased under the state in which the holes 46a, 46c are incomplete and wiring structure 45a, 45c and a thin-film 4a are not connected perfectly by the protective film 46 of residual one part, only the structure 45a or 45c at high potential is observed dark, the thin-film 9a at low potential and the structure 45a or 45c are observed bright, and the waveform of the actuating signal corresponding to the potential fluctuation of the thin-film 9a is also brought to an abnormal state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to focused ion beam technology, and in particular, by modifying the wiring structure of a part of a completed semiconductor device.
It relates to techniques that are effective when applied to techniques for evaluating semiconductor devices and analyzing failures.

[Conventional technology]

For example, during the development stage of a semiconductor device, by modifying the wiring structure of the completed semiconductor device from the outside,
! ! It is known to perform evaluations of manufacturing processes, failure analysis, and even logic changes, and an example of wiring modification technology used for such purposes is the one published by Press Journal Co., Ltd., August 20, 1987. , “Monthly Semiconductor World J September 1987 issue, P27~
There is a technique described in P.30.

The outline of the process is to irradiate a focused ion beam onto the target part of a semiconductor device, and use the sputtering action of the ion beam to make minute holes in the protective film or wiring structure to expose or cut the wiring, and as needed. By supplying organometallic compound gas to the ion beam irradiation site and forming a thin film of conductor that is connected to a part of the wiring structure through a chemical vapor deposition reaction caused by the energy of the ion beam, multiple wiring structures can be fabricated. This process involves making connections and forming probing pads to which probes for measuring potential changes in the wiring structure are connected.

[Problem to be solved by the invention]

However, in the above-mentioned conventional technology, for example, the confirmation of the completion of the wiring structure exposure and cutting work, which is performed by drilling microholes in the protective oxide film on the surface, is performed by sputtering using ion beam irradiation. Since this is done by detecting secondary ions, an insulating oxide film may remain on the surface of the wiring structure, resulting in a poor connection with the blowing pad, or the wiring structure may be incompletely cut. There is a problem in that the accuracy of correction work decreases.

Therefore, it is a good idea to check the connection between the blowing pad and the intended wiring structure by measuring the potential of the blowing pad while actually operating the semiconductor device using a separately provided electron beam tester. However, in each case, complicated work such as transferring semiconductor devices between the focused ion beam equipment and the electron beam tester is required, and the time required for logic correction and failure analysis due to wiring correction is longer than necessary. This creates a new problem in that it becomes longer.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a focused ion beam technique that can shorten the time required for wiring correction work of a semiconductor device.

Another object of the present invention is to provide focused ion beam technology that can improve accuracy in wiring correction work for semiconductor devices.

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.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, it is a focused ion beam device that performs wiring repair work on semiconductor devices by irradiating an ion beam, and includes a detection means for detecting charged particles generated from the ion beam irradiation site of the semiconductor device, and a detection means for detecting charged particles from the detection means. It is equipped with a display section that displays at least one of an image of the semiconductor device and an operating signal waveform based on the information, and an electric signal applying means that puts the semiconductor device into an operating state, and allows the semiconductor device to be put into an operating state at any time for wiring correction work. I issued a 1 to carry out the following.

[Effect]

According to the above-mentioned means, for example, during or after wiring correction work, the semiconductor device is brought into operation, and images and images based on information such as secondary electrons and backscattered electrons generated from the target wiring structure, etc. By observing operating signal waveforms, etc., it is possible to immediately and accurately determine whether or not wiring correction work is possible without performing complicated work such as transferring semiconductor devices, thereby shortening the time required for wiring correction work. At the same time, it is possible to improve the accuracy of wiring correction work.

〔Example〕

FIG. 1 is a block diagram showing the configuration of a focused ion beam apparatus which is an embodiment of the present invention, and FIGS. 2(a) and 2(a) are explanatory diagrams showing an example of wiring correction work.

Inside the sealed sample chamber l, an X-Y table 2 that is movable in a horizontal plane is provided.
A socket 3 is placed on the table 2.

In the socket 3, for example, a semiconductor device 4 consisting of a package base 4b mounting a semiconductor pellet 4a with an integrated circuit formed therein, and a plurality of connection terminals 4c connected to the semiconductor pellet 4a is connected to the connection terminal 4c. The upper surface of the semiconductor pellet 4a is exposed to the outside.

A lens barrel 5 is vertically connected to the sample chamber 1 directly above the X-Y table 2, and an ion beam 7 made of, for example, Ga" is connected vertically to the sample chamber 1 directly above the X-Y table 2.
-Ion # emitted toward Y table 2! 6 is provided.

An ion optical system 8 consisting of an electron lens and the like is arranged in the path of the ion beam 7 inside the lens barrel 5.
The ion beam 7 emitted from the ion source 6 is focused, and the irradiation position of the focused ion beam 7 on the semiconductor device 4 fixed to the socket 3 provided on the X-Y table 2 is controlled. It is configured.

In the sample chamber 1, a reaction gas 9 made of a metal compound such as hexacarbonical tungsten (W(CO)6) is constantly applied to the ion beam 7 irradiation area of the semiconductor device 4 fixed in the socket 3. A gas supply means 10 is provided.

Then, a conductive thin film 9a made of tungsten (W) or the like contained in the reaction gas 9 is deposited on the irradiation area of the ion beam 7 on the semiconductor pellet 4a at any time by a chemical vapor deposition reaction using the energy of the ion beam 7. is to be carried out.

Ion source6. Ion optical system8. The gas supply means 10 and the like are collectively controlled by a control section 11.

In this case, the socket 3 on which the semiconductor device 4 is mounted is
An electrical signal applying means 12 for supplying power, electrical signals, etc. to bring the semiconductor device 4 into a normal operating state is connected, and the semiconductor device 4 is configured to be brought into the operating state at any time.

Further, a detector 14 is provided near the semiconductor device 4 to which the ion beam 7 is irradiated, for example, to detect the amount of secondary electrons 13 generated from the semiconductor device 4 by the ion beam 7 irradiation. Information regarding the secondary electrons 13 detected by this detector 14 is transmitted to the image processing unit 1
5.

The image processing unit 15 configures an image of the scanning area of the ion beam 7 based on, for example, the scanning position of the ion beam 7 with respect to the semiconductor device 4 obtained from the ion optical system 8 and the amount of secondary electrons 13, and Secondary electrons 13 that fluctuate according to potential changes in the wiring structure of the semiconductor device 4, etc.
A display unit 161 consisting of a cathode ray tube or the like in the subsequent stage is configured to configure an operating signal waveform based on the amount of the signal and display the signal.

Furthermore, the sample chamber 1 is equipped with a mass spectrometer (not shown), and the sample chamber 1 is equipped with a mass analyzer (not shown).
Secondary ions 7a generated from 4a can be detected.

Further, an exhaust pipe 17 connected to an exhaust mechanism (not shown) such as a vacuum pump is connected to the sample chamber 1, so that the inside of the sample chamber 1 and the lens barrel 5 can be evacuated to a desired degree of vacuum. ing.

Hereinafter, an example of wiring correction work using the focused ion beam apparatus in this embodiment will be described with reference to the drawings.

First, as shown in FIG. 2(a), the semiconductor pellet 4a of the semiconductor device 4 in this embodiment is formed by forming a plurality of wiring layers 43 on a substrate 41 via insulating layers 42 and 44 such as an oxide film. ．． It has a multilayer structure in which wiring layers 45 are laminated, and the upper wiring layer 45 is hidden by an insulating protective film 46.

In this embodiment, as an example of wiring correction work, a plurality of wiring structures 45a and 45b constituting the upper wiring layer 45 are
, 45c, a case where a part of the wiring structures 45a and 45C are exposed and connected to each other will be described.

First, by evacuation through the exhaust pipe 17, the inside of the sample chamber 1 and the lens barrel 5 are made to a desired degree of vacuum, and by moving the X-Y table 2 appropriately, the wiring structure in the semiconductor pellet 4a is created. The right upper part of 45a is positioned so as to coincide with the optical axis of the ion optical system 8.

Thereafter, as shown in FIG. 2(a), irradiation of the semiconductor pellet 4a with the ion beam 7 is started, and the ion optical system 8 is appropriately controlled to scan the ion beam 7 within a predetermined range. A microhole 46a is formed in a portion of the protective film 46 directly above the wiring structure 45a by sputtering or the like.

At this time, secondary ions 7a generated from the irradiation site of the ion beam 7 are constantly observed using a mass spectrometer (not shown), and, for example, the secondary ions 7a are made of a material constituting the protective film 46 or a material constituting the wiring structure 45a. By stopping the drilling of the microhole 46a by the ion beam 7 when the change occurs, a part of the wiring structure 45a is exposed to the outside through the microhole 46a.

Further, by the same operation as above, a microhole 46c is also formed in the protective film 46 directly above the other wiring structure 45c.

Next, while scanning the ion beam 7 across the micro holes 46a and 46C formed directly above each of the wiring structures 45a and 45c, the gas supply means 1
0, by supplying a reaction gas 9 made of, for example, a metal compound and promoting a chemical vapor deposition reaction in the scanning region of the ion beam 7, the micropores 46a and 46c are formed.
A conductor thin film 9a is formed to a predetermined thickness so as to connect the wiring structures 45a and 45C exposed from the conductive film 9a (see FIG. 2, etc.).
As shown in FIG. 2, wiring structures 45a and 45C are electrically connected.

Thereafter, in this embodiment, the electric signal applying means 12 is connected to the socket 3. While applying operating power, an operating signal, etc. to the semiconductor device 4 through the connection terminal 40, etc., and putting the semiconductor device 4 into an operating state, the microhole formed by the above-mentioned series of operations is performed using the ion beam 7 with relatively low energy. 46a, 46C and the areas of the conductive thin film 9a are scanned.

Then, the secondary electrons 13 generated from the conductive thin film 9a are detected by the detector 14, and the image processing object 15 makes the intensity change of the secondary electrons 130 correspond to the brightness of the screen, and the ion beam 7 is detected by the ion optical system 8. By synchronizing with the scanning, an image of the scanning area of the ion beam 7 is constructed, and an operating signal waveform is generated based on the amount of secondary electrons 13, which varies according to the potential of the conductive thin film 9a, which varies depending on the operating signal of the semiconductor device 4. is configured and displayed on the display unit 16 at any time.

Here, if the drilling work of the micro holes 46a and 46c is performed accurately and the wiring structures 45a and 45c are completely exposed without any part of the protective film 46 remaining, the operation of the semiconductor device 4 is confirmed. As an operating current flows through the conductive thin film 9a, some of the secondary electrons 13 generated by the irradiation with the ion beam 7 are lost together with the operating current, and the detector 1
4 decreases the amount of secondary electrons 13 captured by the conductor thin film 9.
The image a is observed darkly along with the wiring structures 45a and 45c, and at this time a normal operating signal waveform is obtained.

On the other hand, if the drilling work of the micro holes 46a and 46c is incomplete and the wiring structures 45a and 45C and the conductive thin film 9a are in a poor connection due to the remaining part of the protective film 46, the detected secondary electrons 13 1 increases, only the high-potential wiring structure 45a or 45C is observed darkly, and the low-potential conductive thin film 9a and wiring structure 45a or 45C are observed brightly, and the operation signal corresponding to the potential change of the conductive thin film 9a The waveform also becomes abnormal.

In this manner, in the case of this embodiment, the quality of the wiring repair work by irradiation with the ion beam 7 can be immediately and accurately determined without involving complicated work such as transferring the semiconductor device 4.

As a result, it is possible to shorten the time required for wiring correction work in the semiconductor device 4 and improve accuracy.

Note that it goes without saying that the above-described inspection with the semiconductor device 4 in an operating state may be performed immediately after the drilling of the microholes 46a and 46C, or at the same time as the drilling operation.

On the other hand, although not particularly shown, the wiring structure 45a may be cut by setting the diameter and depth of the microhole 46a drilled by the ion beam 7 to be larger than the width and depth of the wiring structure 45a. , the semiconductor device 4 is put into operation, and the secondary electrons 13 at the cutting site and its vicinity are
By observing images based on , it is possible to accurately and quickly determine the quality of the cutting work.

That is, if the cutting operation is complete, the potentials of the wiring structure 45a before and after the cutting part will be different.
There will be a difference in brightness and darkness of the image depending on the potential, and if the cutting is incomplete, the front and back of the cut will be at the same potential, and the wiring structure 4
5a has the same brightness or darkness before and after the cut portion.

From this, it is possible to accurately and quickly determine the quality of the cutting work of the wiring structure 45a.

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 form of a semiconductor device is not limited to one mounted on a package base as in the above-mentioned embodiment, but for example, wiring correction work is performed on a semiconductor wafer before dicing, and individual semiconductor devices are pumped. The semiconductor device may be brought into operation at any time by contacting a needle-shaped electrode with a pad or the like and applying operating power, an operating signal, or the like.

In the above description, the invention made by the present inventor has been mainly applied to the wiring correction technology of semiconductor devices, which is the background field of application, but the invention is not limited thereto. Widely applicable to general evaluation techniques.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

That is, the focused ion beam apparatus performs wiring correction work on a semiconductor device by irradiation with an ion beam, and includes a detection means for detecting charged particles generated from a portion of the semiconductor device irradiated with the ion beam, and a detection means for detecting charged particles generated from the ion beam irradiation site of the semiconductor device; A display section that displays at least one of an image and an operating signal waveform of the semiconductor device based on information about the charged particles, and an electric signal applying means that puts the semiconductor device into an operating state, and the display section that operates the semiconductor device at any time Since the wiring correction work is performed while the semiconductor device is in the operating state, for example, during and after the wiring correction work, secondary electrons and reflected electrons generated from the target wiring structure, etc. By observing images and operating signal waveforms based on information such as
It is possible to accurately determine whether or not the wiring correction work can be performed without performing any additional work, and the time required for the wiring correction work can be shortened, and the accuracy of the wiring correction work can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a focused ion beam apparatus which is an embodiment of the present invention, and FIGS. 2(a) and 2(a) are explanatory diagrams showing an example of wiring correction work. DESCRIPTION OF SYMBOLS 1... Sample chamber, 2... X-Y table, 3... Socket, 4... Semiconductor device, 4a... Semiconductor heret, 4b... Package base, 4c... Connection terminal, 5... Lens barrel, 6... Ion source, 7... Ion beam, 7a... Secondary ion, 8... Ion optical system,
9... Reactive gas, 9a... Conductor thin film, 10... Gas supply means, 11... Control unit, 12... Electric signal application means, 13... Secondary electrons (charged particles), 14...
Detector, 15... Image processing section, 16... Display section, 1
7... Exhaust pipe, 41... Substrate, 42.44... Insulating film, 43.45... Wiring 1.45a, 45b, 45
cm...Wiring structure, 46...Protective film, 46a, 46c
...Minor pores. Agent Patent Attorney Daiwa Tsutsui

Claims (1)

[Scope of Claims] 1. A focused ion beam device that performs wiring repair work on a semiconductor device by irradiation with an ion beam, the device comprising: a detection means for detecting charged particles generated from a portion of the semiconductor device irradiated with the ion beam; , comprising a display section that displays at least one of an image of the semiconductor device and an operating signal waveform based on information about the charged particles from the detection means, and an electric signal applying means for putting the semiconductor device into an operating state, and at any time. . A focused ion beam apparatus, characterized in that the wiring correction work is carried out with the semiconductor device in an operating state. 2. During or after the wiring correction work, the semiconductor device is put into an operating state, and at least one of the image and the operating signal waveform of the semiconductor device in the operating state is converted into the 2. The focused ion beam apparatus according to claim 1, wherein whether or not the wiring correction work is possible is determined by observing through a display unit. 3. The focused ion beam device according to claim 1, wherein the charged particles are secondary electrons.