JPH0680672B2 - IC element processing equipment - Google Patents

Description

The present invention relates to an IC device processing apparatus for processing a fine wiring pattern or the like of a highly integrated device.

[Conventional technology]

In semiconductor integrated circuits, CaAs devices, magnetic valve memories, Josephson devices, etc., pattern widths and wiring widths are becoming finer. That is, devices with a width of 3μ to 2μ have been realized, and devices with wiring widths of 1.5μ, 1μ and submicron are being developed. For these devices, conventionally, wiring cutting for debugging at the device development stage, and cutting of a part of the device for relief, writing, resistance value, capacitance, adjustment at the defective part production stage,
Means such as connection have been taken.

The cutting of Al wiring for debugging will be described below as a typical example. It is clear that the following can also be applied to wiring such as Au and Poli Silicon.

In a semiconductor integrated circuit (hereinafter referred to as “IC”), a prototype chip often does not operate as it is because of a design defect or a process defect in the design and development process. In this case, in order to determine the defective portion, it is necessary to cut the wiring around the defective portion and perform an operation test or the like. For a pattern of 5 μm or more, a method of observing the device with a microscope and scratching it with a thin metal needle attached to the manipulator was used as a means for this purpose.
However, this method has a low success rate and requires skill, so it cannot be used for ICs with a 3 μ pattern or less. FIG. 1 shows a device for cutting the wiring of an IC with a laser. A laser beam 1a emitted from a laser oscillator 1 is reflected by a mirror 2 and then expanded in beam diameter by a beam expander 3 composed of a combination of lenses 3a and 3b.
The reduced projection image of the rectangular pattern is formed by the lens 7 on the sample 8 placed on the stage 9. In this case, the light from the reference light lamp 2a is reflected by the concave mirror 2b, is made into a parallel beam by the lens 2c, and forms an image on the wiring through the same path as the laser beam. Etc. are possible. Ie the second
In FIG. 3A, the Al wiring portion 11 is adjacent to the wiring-free portion 10. That is, the cross section is as shown in FIG. 2B, and the Al wiring 15 is formed on the Si substrate 13 via the insulating layer 14 of SiO ₂ . Slit by reference beam 2d in Fig. 1
Although images 5 and 6 are projected, the width of the slit is adjusted by the micrometers 5a and 6a to match the width of the wiring 11 to be cut. After that, when the laser is irradiated, the laser light forms an image at exactly the same position 12 and this portion is removed. In this case, there were the following problems. That is, the portion melted by the laser scatters to the periphery and adheres to the adjacent portion, which deteriorates the characteristics and causes a short circuit. Further, it causes damage to the lower Si, and a part of the Si melts and rises to cause a short circuit with the Al wiring. In addition, the side of the wiring is also likely to affect the adjacent portion where there is no Al wiring, damage the lower Si, and cause the same Al-Si short circuit as described above.
This is mainly because it is difficult to position the laser irradiation area and a part of the laser light is irradiated to a portion without Al wiring, or the adjacent Si portion is damaged during heat conduction and Al scattering.

Especially when the passivation film 18 is coated on the Al wiring 15 as shown in FIG. 5, these films 18 are generally made of Si.
Since it is made of O ₂ , Si ₃ N _4, etc. and is transparent to laser light, it is not directly processed by laser and the lower Al wiring 15 absorbs the laser and receives thermal energy, so that the upper passivation film is removed. It will break and jump out. Therefore, in this case, the scattered Al particles have much higher energy than when there is no passivation film, and as shown in FIG. 6, the lower part and the periphery are easily damaged, and the passivation film itself is also damaged. It may cause cracks. In addition, the cut part has a hole 20 in the passivation film.
However, there is a problem that the characteristics are deteriorated because there is no method for easily filling this.

Further, as a fundamental problem, the wiring cutting method by laser processing has a limit to the tendency that the wiring width is narrowed from 2μ to 1.5,1μ and submicron due to the miniaturization and high integration of ICs. That is, according to the image projection method shown in FIG. 1 as well, even when the beam is narrowed down by the lens 21 as shown in FIG. It is difficult to obtain a spot diameter (0.5μ in visible light). Furthermore, in the laser processing method, it is impossible to avoid the influence of the surroundings due to heat conduction and melting jet because the material absorbs the laser light and changes into heat and then blows it away. However, the heat affected zone was always larger than the spot diameter. That is, the practical minimum processing size is about 1 μm, and thus it is difficult to apply the laser processing method to a wiring pattern of 1 μm or less. Further, as conventional techniques, JP 56-80131 A, JP 56-94630 A, Applied, Physics, and Letter `` A High Intensity Scanning Ion Probe with Submicrometer Spot Size (Appl.Phys.
Lett.34 (5), “A highintesity scanning ionprobe
with submicrometer spot size ") P310-311, 1979 Mar.
Published on Jan. 1st, The Institute of Applied Physics, The Institute of Applied Physics, Japan Society for Applied Physics, Japan Society for the Promotion of Applied Electronic Properties, Japan Society for the Promotion of Science, Application of charged particle beam to industry, 132nd Committee, 13th Symposium "Ion Implantation and Submicron Machining" February 3, 1982
Sun-5, pages 19-22, "Fine Focusing Device Using Liquid Metal Ion Source" is known. In any of the conventional techniques, only a sputter etching processing technique using a focused ion beam is described. The SIM observation device merely observes the sputter-etched state.

[Problems to be solved by the invention]

The object of the present invention is to complete VLSKI, ULSI, etc. having a step-like protective film on an ultrafine wiring of 1 μm or less without the drawbacks of the conventional wiring cutting method of an IC by the laser processing and its device. For the IC element, sputter processing is performed with a uniform depth over the width of the wiring up to the wiring existing in the lower layer of the protective film at the point where the wiring is to be cut, and the wiring in the lower and peripheral areas and the substrate are processed. Prevents damage or short-circuiting, or the possibility of causing it, and at the same time disconnects the wiring without affecting its characteristics, performs wiring analysis in a short time, analyzes and corrects defects, and significantly shortens the development period. , It is to provide a processing device of an IC element capable of improving the yield at the time of development.

Further, an object of the present invention is to cut a wiring existing in a lower layer of a protective film for a completed IC element such as VLSKI or ULSI having a step-like protective film on an ultrafine wiring of 1 μm or less, and further An IC that can perform a short circuit in the development period, improve the yield at the time of development, etc. by performing local film forming processing on the insulating film etc. to analyze and correct defective parts
An object is to provide a device processing device.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a liquid metal ion source that emits a high-intensity ion beam and an aperture that extracts near the central portion with high energy density from the high-intensity ion beam emitted from the liquid metal ion source. Means and a charged particle optical system for focusing the high-brightness ion beam extracted by the aperture means to an ion beam spot diameter significantly narrower than the width of the wiring, and irradiation / stop of the ion beam focused by the charged particle optical system. A barrel having a blanking electrode and a deflecting electrode for scanning an ion beam spot focused by the charged particle optical system, and an IC element coated with a step-like protective film on the wiring are installed on the wiring. Secondary electrons generated from the surface of the protective film of the IC element by the ion beam spot focused by the sample stage and the charged particle optical system, Is a processing device of an IC element configured to form a vacuum chamber with a sample chamber provided with a secondary charged particle detector for detecting secondary ions, and controlling the deflection electrode to provide the ion beam spot. And scan the irradiation area on the surface of the protective film in the vicinity of the portion where the wiring of the IC element is to be cut, and control the deflection electrode based on the secondary electrons or secondary ions detected by the secondary charged particle detector. A scanning ion microscope that displays a magnified SIM image of the observation region and magnifies and observes the deflection signal to control the scanning region by the deflection electrode based on the magnified SIM image magnified and observed by the scanning ion microscope. Then, the protective film is formed by scanning and irradiating an ion beam spot that is significantly narrower than the width of the wiring with energy of 10 KeV or more only in the region across the width of the wiring in the portion where the wiring is to be cut. Of at least the wiring width of the wiring and the uniform cutting sputter processing over the width of the wiring in the lower layer while performing the sputter processing of the wiring, detecting the end point of the wiring cutting and controlling the blanking electrode. It is a processing device for an IC element, which is provided with a control means for stopping irradiation of an ion beam spot. In order to achieve the above-mentioned other object, the present invention provides a liquid metal ion source that emits a high-intensity ion beam and a high-intensity ion beam emitted from the liquid metal ion source, in the vicinity of a central portion having a high energy density. Aperture means for extracting, a charged particle optical system for focusing the high-intensity ion beam extracted by the aperture means to an ion beam spot diameter significantly narrower than the width of the wiring, and irradiation of an ion beam focused by the charged particle optical system. .A lens barrel having a blanking electrode for stopping and a deflection electrode for scanning the ion beam spot focused by the charged particle optical system, and an IC covered with a step-like protective film on the wiring The IC is provided by a sample stage on which an element is installed and an ion beam spot focused by the charged particle optical system.
A processing device for an IC device, which comprises a sample chamber provided with a secondary charged particle detector for detecting secondary electrons or secondary ions generated from the surface of a protective film of the device, and a sample chamber configured to form a vacuum container, Secondary electrons detected by the secondary charged particle detector by scanning and irradiating the observation area on the surface of the protective film in the vicinity of the portion where the wiring of the IC element is to be cut by controlling the deflection electrode A scanning ion microscope that receives a deflection signal that controls the deflection electrode based on secondary ions and displays an enlarged SIM image of the observation region for enlarged observation, and a gas that introduces a gas near the surface of the IC element in the sample chamber. Controlling the scanning area by the deflection electrode based on the magnified SIM image magnified and observed by the scanning ion microscope with the introduction means, and of the area across the width of the wiring in the portion where the wiring is to be cut. The energy to 10 KeV or more to scan and irradiate an ion beam spot that is significantly narrower than the width of the wiring to form a uniform hole sputter processing over at least the width of the wiring on the protective film and the width of the wiring in the underlying layer. Uniform cutting sputter processing to detect the end point of wiring cutting and control the blanking electrode to stop the irradiation of the ion beam spot, and to obtain a magnified SIM image magnified and observed by the scanning ion microscope. Based on said I
An IC element characterized by comprising a control means for controlling a scanning region of an ion beam spot by the deflection electrode at a desired position of the C element to locally form a film by a reaction with a gas introduced by the gas introducing means. Processing equipment. Further, the present invention is, in the processing device of the IC element, provided with a sample exchange chamber connected to the sample chamber through a gate valve,
It is characterized in that the IC element can be mounted on the sample table in the sample chamber from the sample exchange chamber through the gate valve. Further, the present invention is characterized in that, in the IC device processing apparatus, an electronic shower is provided in the sample chamber in order to prevent disturbance of an ion beam spot with which the IC device is irradiated.

[Action]

Particularly in the case of the present invention, a spot diameter of 0.3 to 0.1 μ or less can be obtained, and since the processing process is sputtering processing by collision and scattering of ions and target atoms, there is almost no influence on the periphery due to thermal diffusion. Since it does not exist, it can be processed with dimensions of 0.3μ or less, and 1μ
Protective film (passivation film) in the vicinity of the part where the ion beam having a spot diameter of 0.3 μm or less, which is significantly narrower than the wiring having a width of m or less, is to be cut
A secondary charged particle detector detects and scans secondary electrons or secondary ions generated from the observation region of the surface of the protective film which is projected by scanning and projected, and projected onto the observation region of the surface for irradiation. An enlarged SIM image of the observation region is displayed on an ion microscope and enlarged observation is performed, and the scanning region by the deflection electrode is controlled based on the enlarged SIM image observed by the enlargement to control the scanning region by the deflection electrode, as shown in FIG. 9B. Ion beam projected with an energy of 10 KeV or more and an ion beam spot diameter of 0.3 μm or less, which is much smaller than the width of the wiring, by the charged particle optical system only in the region across the width of the wiring where the wiring is to be cut As shown in FIG. 12 by performing scanning irradiation with a hole, sputter processing over the width of the wiring to the protective film and cutting sputter processing over the width of the wiring in the underlying layer are performed. Unlike the processing shown in Fig. 12 (b), as shown in Fig. 12 (b), it is possible to carry out sputter processing with the same depth as the wiring cross section, that is, in a short time for practical use. Therefore, it is possible to prevent damage to the lower layer and its periphery and to easily and highly accurately cut the wiring of 1 μm or less. Further, according to the present invention, it is possible to carry out local film formation such that the hole portion of the passivation film after cutting is filled by using microdeposition with a focused ion beam.

〔Example〕

 Hereinafter, the present invention will be described with reference to the drawings.

FIG. 6 shows an embodiment of the wiring cutting device according to the present invention.

The apparatus shown in FIG. 6 includes a pedestal 37, a lens barrel 39 forming a vacuum container, a sample chamber 40, and a sample exchange chamber connected to the sample chamber 40.
41, vacuum exhaust system, sample stage 55 for sample, liquid metal ion source 65, control (bias) electrode 66, ion beam extraction electrode 67, aperture 69, electrostatic lens 7
0,71,72, brushing electrode 73, aperture 74, deflection electrodes 75,76, filament power supply 77, control electrode power supply 78, extraction electrode power supply 79, electrostatic lens electrodes 80,8
1, high-voltage power supply 82, blanking electrode power supply 83, deflection electrode power supply 84, power supply control device 85, secondary charged particle detector 86 inserted in the sample chamber 40, SIM (scanning ion microscope) observation device 87, and means 89 for preventing spot disturbance due to the electric charge of the ion beam.

The pedestal 37 is earthquake-proofed by an air support 38.

The sample chamber 40 and the sample exchange chamber 41 are installed on the pedestal 37, and the lens barrel 39 is installed on the sample chamber 40.

The sample chamber 40 and the lens barrel 39 are partitioned by a gate valve 43, and the sample 40 and the sample exchange chamber 41 are separated by another gate valve.
It is separated by 43.

The vacuum exhaust system includes an oil rotary pump 47, an oil trap 48, an ion pump 49, a turbo molecular pump 50, and valves 51, 52, 53, 54. The vacuum exhaust system is connected to the lens barrel 39, the sample chamber 40, and the sample exchange chamber 41 via vacuum pipes 44, 45, and 46, and the lens barrel 39, the sample chamber 40, and the sample exchange chamber 41 are vacuum pipes. It is connected via the 44, 45 and 46, these barrels 39, sample chamber 40, the specimen-exchange chamber 41 ^10-5
It is designed so that a vacuum below torr can be achieved.

The above-described object table 55 is provided with X, Y, through rotation introduction terminals 61, 62, 63.
The moving micrometers 56, 57, 58 in the Z direction are attached, and the moving ring 59 in the θ direction is provided, and the stage 55 uses the moving micrometers 56, 57, 58 and the moving ring 59 for X, The fine movements in the Y and Z directions and the rotation angle in the horizontal plane are adjusted.

A sample table 60 is installed on the above-described table 55, and the sample table 60 is installed.
The sample is placed on the 60. And
The sample table 60 is connected to the sample chamber 40 and the sample exchange chamber by the sample drawing tool 64.
It is possible to move between 41.When exchanging a sample, the gate valve 43 is opened, the sample table 60 is pulled out to the sample chamber 40, the gate valve 43 is closed, the door of the sample exchange chamber 41 is opened, and the sample is exchanged. Place it, close the door, and pre-evacuate the sample exchange chamber 41, then open the gate valve 43 and move the sample table 60 to the sample chamber 40.
It is designed to be put in. The sample is indicated by reference numeral 90 in FIG.

The liquid metal ion source 65 is provided in the sample chamber 40 at the head of the lens barrel 39.
It is provided to face. The liquid metal ion source 65 shown in FIG. 7 includes a base 650 made of an insulator, filaments 651 and 652 attached to the Vess 650 in a U shape, and made of tungsten or the like between the tip portions of both filaments 651 and 652. Sharp needle 65 attached by spot welding to the
3, a metal 65 attached to the needle 653 as an ion source
It has four and. As the metal 654 serving as an ion source, Ca, In, Au, Bi, Sn, Cu or the like is used. The filaments 651 and 652 are connected to the filament power source 77 connected to the high voltage power source 82 through the electrodes 651 'and 652', as shown in FIG.

The control electrode 66 is installed under the liquid metal ion source 65 and is connected to a concrete electrode power supply 78 connected to a high voltage power supply 82.
A low positive and negative voltage is applied to the installation position of 66 to control the current which is an ion beam.

The ion beam extraction electrode 67 is a control electrode.
It is connected to an extraction electrode power supply 79 which is installed below 66 and is connected to a high voltage power supply 82. Then, an electric current is supplied to the filaments 651 and 652 of the liquid metal ion source 65,
When a negative voltage of tens of KV is applied to the extraction electrode 67 after heating and melting in a vacuum of 0 ^-5 torr or less, the ion beam is extracted from the extremely narrow region at the tip of the needle 653 of the liquid metal ion source 65. To be done. The ion beam in FIG. 6 is indicated by reference numeral 68, and the spot is indicated by reference numeral 68 '.

The aperture 69 is installed below the extraction electrode 67 and extracts only the vicinity of the central portion of the ion beam extracted by the extraction electrode 67.

The pair of electrostatic lenses 70, 71, 72 is arranged under the aperture 69 and is connected to a high-voltage power supply 82.
It is connected to 0,81. These electrostatic lenses 70,71,72
Is designed to focus the ion beam extracted by the aperture 69.

The blanking electrode 73 is installed under the electrostatic lens 72 and is connected to a blanking electrode power source 83 connected to a control device 85. This blanking electrode 73 is
Scan the ion beam at a very high speed in the direction orthogonal to the direction toward the sample, remove the aperture 74 installed below the blanking electrode 73, and stop the irradiation of the ion beam to the IC element at high speed. It has become.

The aperture 74 is the spot of the ion beam focused by the electrostatic lenses 70, 71 and 72, as shown in FIG. 4 or FIG.
The image is projected and imaged on the IC element shown in (3) with a spot diameter of 0.3 to 0.1 μm or less.

The pair of deflection electrodes 75 and 76 is connected to a deflection electrode power supply 84 which is installed under the aperture 74 and is connected to a control device 85. The deflecting electrodes 75 and 76 are used to focus the spots of the ion beams focused by the electrostatic lenses 70, 71 and 72 in X and Y directions.
It can be deflected in the direction, and can be connected on the IC element shown in FIG. 4 or FIG. 16 (a) with a spot diameter of 0.3 to 0.1 μm or less.

A high voltage power supply 82 for applying a voltage to the filament power supply 77, the control electrode power supply 78, the ion beam extraction electrode power supply 79, and the lens power supplies 80 and 81 of the liquid metal ion source 65.
Is used for several tens of KV.

The controller 85 controls the blanking electrode 73 and the deflecting electrodes 75 and 76 through a blanking electrode power source 83 and a deflecting electrode power source 84 so as to operate according to a certain pattern.

The secondary charged particle detector 86 is installed in the sample chamber 40 toward the sample, which is an IC element, and is controlled by a control signal from the control device 85 via the blanking electrode power source 83 to deflect the blanking electrode 73 and the deflection. The deflection electrodes 75 and 76 are controlled via the electrode power source 84, and I shown in FIG. 4 or FIG.
Passivation film (protective film) with stepped C element 18
When the observation region of the surface of the is irradiated with an ion beam spot having a spot diameter of 0.3 to 0.1 μm or less, it receives secondary electrons or secondary ions emitted from the surface of the passivation film 18 having steps. The intensity corresponding to the step is converted into the intensity of the current, and the signal is converted to SIM observation device 87
It is designed to be sent to.

The SIM observation device 97 includes a cathode ray tube 88. Then, the SIM observing device 87 receives a signal relating to the deflection amount of the ion beam in the X and Y directions from the deflection electrode power supply 84 in order to observe the observation region, and synchronizes with this to obtain a cathode ray tube.
By scanning the bright spots of 88 and changing the brightness of the bright spots in accordance with the current intensity signal sent from the secondary charged particle detector 86, the passivation film 18 having a step is formed on the surface of the passivation film 18. The SIM that can obtain a step image corresponding to the secondary electron emission capability at each point, that is, the function of the scanning ion microscope, enables magnified observation of the IC surface.

The means 89 for preventing the spot disturbance due to the electric charge of the ion beam is provided between the deflection electrode 76 and the IC element. The means 89 for preventing the spot disturbance is shown in FIG. 8 in which the electron shower 890,
891 is a counter device, each electronic shower 890,891 is a cup-shaped main body 892, a filament 893 provided therein,
The main body 892 includes a grid-shaped extraction electrode 894 provided in the opening. And each electronic shower 890,89
1 draws the electron stream 895 from the filament 893 with an accelerating voltage of about 100 V by the extraction electrode 894, discharges the electron stream 895 into the space through which the ion beam passes, and imparts a negative charge to the ion beam to neutralize it. ing. In FIG. 8, reference numeral 68 is an ion beam, 75 and 76 are deflection electrodes, and 90 is a sample which is an IC element.

Next, with reference to FIGS. 6 to 9 (a) and (b), the operation of the element correcting apparatus of the above-described embodiment and an embodiment mode of the element correcting method of the present invention will be described. Sample 90 which is an IC element
Is placed on the sample table 60 in the sample exchange chamber 41, and then the sample exchange chamber 41 is sealed, and after preliminary evacuation by the vacuum exhaust system, the sample is put into the sample chamber 40 via the sample withdrawing tool 64 and placed. Place it on the stand 55.

Then, the interior of the lens barrel 39 and the sample chamber 40 is ^moved to 10 ^-6 to
Evacuate to about rr and maintain that vacuum state.

Next, in the apparatus shown in FIG. 6, the IC chip or wafer shown in FIG. 4 or FIG.
The method of installing on 90 and cutting the wiring will be described.
First, the high voltage power source 82 operates the filament power source 77, the control electrode power source 78, and the extraction electrode power source 79 to extract the high-intensity ion beam from the aperture 69 of the liquid metal ion source, and the lens power sources 80 and 81. Activated and electrostatic lens 70, 71, 72 and aperture 70 to 0.3-0.1
Focusing on a spot system of μm or less and setting the ion beam irradiation condition to a low energy beam, a control device
By controlling the blanking electrode 73 and the deflecting electrodes 75, 76 via the blanking electrode power source 83 and the deflecting electrode power source 84 by the control signal from the 85, the observation area on the surface of the passivation film 18 of the IC chip or the wafer is controlled. , An ion beam spot having a spot diameter of 0.3 to 0.1 μm or smaller is scanned and irradiated, and secondary electrons or secondary electrons output from the secondary charged particle detector 86 at each point on the surface of the passivation film 18 having a step are detected. An enlarged image of the step surface of the passivation film 18 due to the secondary ions is observed by the cathode ray tube 88 of the SIM observation device 87, and based on the step information of the passivation film 18 obtained from the observed enlarged image, as shown in FIG. The range (cutting point) is set to cut the wiring of 1 μm or less shown. Also in the local film formation described later, it is clear that the range of the local film formation is set based on the step information of the passivation film 18 obtained from the enlarged image observed by the cathode ray tube 88 of the SIM observation device 87. Then, the energy is set to 10 KeV or more so that the in-beam irradiation condition can be processed by sputtering, and the spot diameter of 0.3 to 0.1 μm or less is focused on the portion to be cut of the wiring set by the control signal from the control device 85. The irradiated ion beam spot is scanned and irradiated to form a hole in the passivation film 18 as shown in FIG. 12 (a) or 16 (b), and further, FIG. 12 (b) or 16 (b). As shown in, the wiring located under the hole is sputtered to remove and cut. In this case, it is necessary to match the scanning width with the wiring width, which can be performed with high precision by the control system of the deflection voltage.

9 (a) and 9 (b) show the case where the wiring is cut by the sputtering method in this case. In FIG. 9A, it is assumed that the rectangular portion indicated by 12 in the Al wiring on the IC chip or wafer covered with the passivation film 18 is the area to be cut and removed. At this time, the focused ion beams 200a, 200b, 200d, 200c, ..., As shown in FIG. 9 (b) for the 12 portions set based on the step position information of the passivation film 18 observed as the SIM image. While scanning with the deflection electrodes 75 and 76 in the order of 200 z, focused irradiation is performed to open a hole in the passivation film 18 of the irradiation portion and to remove the wiring of the irradiation portion to perform cutting.

FIG. 10 is a reference diagram which is not an embodiment of the present invention, and shows a configuration in which the configuration of the ion beam optical system in the apparatus of FIG. 6 is changed to an aperture projection system.
That is, the ion beam emitted from the high-brightness ion source 210 becomes a parallel beam by the electrostatic lenses 201, 202, 203 and enters the apertures 204, 205, 206, 207. This ion beam optical system has the same configuration as that of the laser optical system shown in FIG. 1, and is for projecting an aperture image on the sample 210 in a reduced image by lenses 208 and 209. Here, 211 indicates the projected image. For example, if the lenses 208 and 209 are 40 × magnification lenses, the micrometer head will be used in the aperture section.
If 204a, 205a, 206a, and 207a are adjusted and a 40μ rectangle is set with an accuracy of ± 2μ, a 1μ rectangular ion beam image is set with an accuracy of ± 0.05μ on the sample surface when aberration is ignored. It will be. Therefore, highly accurate positioning can be easily performed, which is advantageous. In this case, the aperture 11 is set so that the rectangular beam 12 is irradiated with the ion beam in FIG. 9A, and the ion beam is irradiated to cut the wiring 11.

As shown in FIG. 2 (b) using the ion beam optical system as shown in FIG. 6, even when the wiring of an IC having no passivation film, which is not the object of the present invention, is cut by ion beam sputtering. Only the Al wiring 15 can be removed with high accuracy and without damage to the surroundings, and a cross section as shown in FIG. 11 can be obtained.

Next, when the wiring having the passivation coat as shown in FIG. 4 is cut, since the passivation film on the surface is sequentially processed by the ion beam processing, first, as shown in FIG. The passivation film 18 is processed to the surface of the wiring 15, and then the Al wiring 15 is processed to obtain a cross section as shown in FIG. 12 (b). Also in this case, unlike the case of laser processing, no damage to the periphery, cracks in the passivation film, and damage to the lower portion and the adjacent portion are observed at all.

FIG. 13 shows a main sectional view of an apparatus according to another embodiment of the present invention. Here, the vacuum exhaust system, the secondary electron image display, the sample exchange chamber, the pedestal and the like are the same as those in FIG. 6 and are omitted.

The liquid metal ion source 65 is assumed to be an alloy ion source such as Al-Si and Au-Si. The ion beam extracted by the extraction electrode 66 and controlled by the control electrode 67 is the lens 7
An electric field applied by the power control unit 115 of the EXB mass filter 102 when passing through the EXB mass filter (mass separation device) 102 after being made into a parallel beam by 0, 71, 72 and part of which is taken out by the aperture 101. E, adjusting the magnetic field B, only ions of a specific mass go straight through the lower aperture 103, ions of other masses are bent like a beam 104, kicked by the aperture 103, and moved downward. Can be prevented from reaching. The ions that have proceeded straight are focused by focusing lenses 104, 105, and 106, and the blanking electrode 7
3. The sample surface 90 is reached via the deflection electrodes 75 and 76.

The sample chamber 102 is exhausted from the passage 119 by an exhaust pump. A gas introduction nozzle 107 from a gas cylinder 109 for N ₂ gas, O ₂ gas, etc. is installed in the sample chamber 120, and the valve of the cylinder is controlled by a controller 117. The vacuum gauge 110 installed in the sample chamber 120 monitors the degree of vacuum inside the sample chamber 120, and the controller 117 controls the valve 108 so that the gas concentration becomes constant. In the sample chamber, in addition to the secondary electron detector 86, there is a secondary ion mass spectrometer 111 such as a quadrupole mass spectrometer tube.
The system for performing mass analysis of secondary ions which is formed when the ion beam is irradiated at 0 is controlled by one controller 118, and is a controller 1 of the secondary ion mass spectrometer 111.
12 signals go into this. Further, 113 is an ion source power supply control unit, which is a current of the heater 65 of the ion source, a voltage of the extraction electrode 66,
The voltage of the control electrode 67 is controlled. 114 is a power control unit for the first lens 70,
It controls 71 and 72. 115 is a power supply control unit, EXB
The power source of the mass filter 102 is controlled. A power supply control unit 116 controls the power supply of the second lenses 104, 105, 106.

A control device 118 controls all of the ion source power supply control unit 113, the first lens power supply control unit 114, the EXB mass filter power supply control unit 115, the second lens power supply control unit 116, and the like. In addition, although not shown in the drawing, the power supply control units of the blanking electrode 73 and the deflection electrodes 75 and 76 are also controlled by the control device 118.

FIG. 14 (a) shows the output of the secondary ion mass spectrometer tube. When the sample having an Al thin film on Si is processed by an ion beam as shown in FIG. 14 (b), the secondary ion current is initially Al only (as shown in FIG. 14 (a)). Solid line). However, when the boundary between Al and Si becomes closer, Si (dotted line) becomes visible, and this changes at the boundary, and when processing continues, Al does not come out.
Only Si. In this way, the time point t ₁ when the processing reaches the boundary can be detected. If this signal is used,
The control device 118 shown in the figure can control the ion beam irradiation to be stopped at a time t ₁ when only Al is processed.

According to FIG. 13, the holes of the passivation film can be filled after cutting the Al wiring except for the passivation film on the upper side, as shown in FIG. That is, the ion source
As 65, for example, using an Au-Si alloy ion source, only the Au ions are extracted and processed by the EXB mass separator 102,
After processing the passivation film and the Al wiring as shown in FIG. 12 (b), the electric field and magnetic field applied to the EXB mass separator are changed so that only Si ions are extracted. Further, the valve 108 of the gas cylinder 109 is opened, O ₂ gas is introduced into the sample chamber 120, the pressure is measured by a vacuum gauge, and the controller 117 controls the opening and closing of the valve 108 so that the pressure becomes constant.

In addition, the voltage applied to the first lens and the second lens is changed by the power supply control units 114 and 116 so that the ion beam is applied to the sample unit from several KeV to several KeV.
The energy is set to 10 eV, and the light is made to enter while being finely focused. (When processing, the energy is 10 KeV or more.) With such low energy, the ion beam adheres to the sample surface and deposition is performed.

As described above, the Si ion beam is irradiated in the O ₂ atmosphere to the opening of the passivation film 18 shown in FIG.
As a result, the SiO ₂ film 111 can be deposited as shown in FIG.

If N ₂ is used instead of O ₂ as a gas to be introduced, a Si ₃ N ₄ film can be deposited. As a result, the passivation film on the cut portion of the Al wiring can be filled with the passivation film, and the passivation film can be recoated, so that deterioration of the device can be prevented and electrical characteristics can be stabilized.

FIGS. 16 (a) to 16 (e) are new embodiments of the apparatus shown in FIG. That is, a method is shown in which the Al wiring runs in two layers above and below and the lower layer portion is cut by an ion beam at the intersection.

In FIG. 16A, the Al wiring 302 runs left and right on the Si 301 via the SiO ₂ insulating film 309, and the Al wiring 304 runs on the Si 301 in the direction perpendicular to the paper surface via the SiO ₂ insulating film 303. . Further, a passivation film 305 of SiO ₂ is formed on it. In this case, a method of cutting only the lower Al wiring 309 will be shown below. As the ion source 65 in the apparatus shown in FIG.
-Al alloy by EXB mass separator 102 using -Si alloy ion source
Only the ion beam is separated and taken out downward, and the sample in Fig. 16 (a) is irradiated and the lower Al wiring is processed.
Obtain a cross section as shown in FIG. Next EXB mass separator 1
By changing the electric field and magnetic field of 02, only the Si ion balm is taken out downward, and O ₂ is introduced from the gas cylinder 109 into the sample chamber 102. In addition, the voltage of the lens is controlled so that the Si ion beam is focused on the sample with energy of several KeV or less. In this manner, the SiO ₂ film is vapor-deposited on the processed portion up to the original height of the lower Al wiring by the method described in detail above to obtain a cross section as shown in FIG. 16 (c). After that, the sample chamber was made an oxygen-free atmosphere in which O ₂ gas was stopped and exhausted, and only Al was taken out by the EXB mass separator 102, and Al vapor deposition such as 307 in FIG. 16 (d) was performed with energy of several KeV or less. Obtain the layer and recreate the original top Al wiring.
Further, a SiO ₂ film 308 is vapor-deposited thereon to form a passivation layer by the same method as described above. By the following, only the lower Al wiring could be cut at the intersection of the Al wiring.

The above Fig. 13 shows a method of taking out one kind of metal with an EXB mass separator using an alloy ion source, but if there is no suitable alloy ion source, prepare several kinds of ion sources and switch. Need to FIG. 17 (a) shows an example of such a device, and FIG. 17 (b) shows its cross section. In FIG. 17A, the lens barrel portion 403 includes elements such as the lens 413 deflector 414. The ion source section is a container for a plurality of different element ion sources 406a, 406b, 406.
.. are attached to a cylindrical rotating body 415, and are housed in a vacuum container 416 connected to the lens barrel portion. These ion source containers are ion source parts 407a, 407b, 407c, ... Extraction electrodes 408a, 408b, 408c, ... Control electrodes 409a, 409ba, 409,
Contains ... The heater current, the extraction voltage, the control voltage, etc. are introduced into each ion source by branch cables 410a, 410b, 410c, ... Through an introduction terminal 411 which also serves as a terminal by a high voltage cable 412. In FIG. 17 (a), the ion source 407a is used by being connected to the optical system, but the rotating body 415 is rotated about the axis 405 to provide the ion source 40a.
It can be used by switching to 7b, 407c, .... In this apparatus, an angle deflection mechanism, a fine adjustment mechanism, and a fixing mechanism are attached to the axis of the optical system with high accuracy, but they are omitted in the figure.

If this device is used, the wiring repair process described above can be performed by combining not only the metal ion species forming a specific alloy as in the case of FIG. 13 but also any liquid metal ion source (or other type of ion source). Is possible.

〔The invention's effect〕

According to the present invention, for a completed IC element such as VLSI or ULSI in which a wiring having a wiring width of 1 μm or less is covered with a protective film,
Unlike the processing shown in FIG. 4 (b), as shown in FIG. 12 (b), it is possible to perform the sputtering processing as shown in FIG. The present invention has an effect of preventing damage to the periphery and the like and cutting the wiring having a wiring width of 1 μm or less in a short time for practical use.

In this case, unlike the conventional laser processing method, there is almost no damage or influence on the surroundings.

Further, according to the present invention, the fine cutting process having a passivation coat on the upper portion, which is difficult to perform well by the conventional laser processing method, is used to perform wiring cutting and local film correction processing. The effect that can be realized by the high-intensity focused ion beam processing apparatus using the liquid metal ion source is obtained.

That is, the present invention is desirable in a state in which a function as an IC element can be formed for almost any type of IC element which is further miniaturized in the future, including VLSI and ULSI, and a protective film is almost completed. Precisely cutting and local film forming can be performed on the extremely fine wiring part of 1 μm or less in a high-intensity focused ion beam processing apparatus using a single liquid metal ion source, and as a result, analysis of defective points It is possible to make corrections and the like, and it is possible to greatly shorten the development period and improve the yield at the time of development, and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is a block diagram showing a conventional wiring cutting device by a laser, and FIG. 2 (a) is an IC showing a cutting method of an Al wiring by it.
FIG. 2 (b) is a plan view of the Al wiring part of FIG.
FIG. 3 is a plan view showing the influence on the periphery when cutting Al wiring with a laser, FIGS. 4 (a) and 4 (b) are cross-sectional views of the respective samples, and FIG. 5 is a conventional wiring cutting apparatus with a laser. FIG. 6 is a configuration diagram of an ion beam wiring cutting device according to the present invention, FIG. 7 is a diagram showing a liquid metal ion source, and FIG. 8 is a diagram showing beam neutralization by an electron shower. 9 (a) and 9 (b) are front views showing wiring cutting by scanning with an ion beam, and FIG. 10 is a projection type ion beam wiring cutting device configuration which is not an embodiment of the present invention. Fig. 11 is a sectional view of the sample, Figs. 12 (a) and 12 (b) are sectional views of the sample, respectively, and Fig. 13 is a configuration diagram of an ion beam wiring repair apparatus equipped with the same gold ion source and mass spectrometer. , Fig. 14 (a) is a diagram showing the output of the mass spectrometer, and Fig. 14 (b) is a sample cross section. , FIG. 15 sample cross section,
FIGS. 16 (a) to 16 (e) are cross-sectional views showing a method for cutting the lower wiring, and FIG. 17 (a) is a view showing a wiring cutting device by an ion beam having many ion mirrors, FIG. (B)
Is a sectional view thereof. 37 ... Stand, 40 ... Sample chamber 41 ... Sample exchange chamber, 55 ... Loading stage 65 ... Liquid metal ion source 85 ... Secondary charged particle detector

Front Page Continuation (72) Inventor Mikio Hongo 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Pref., Institute of Industrial Science, Hitachi, Ltd. (56) Reference JP-A-56-80131 (JP, A) JP-A-56 -94630 (JP, A) JP 57-132653 (JP, A) JP 57-87124 (JP, A) JP 58-2202 (JP, A)

Claims (6)

[Claims] 1. A liquid metal ion source which emits a high-intensity ion beam and an high-intensity ion beam emitted from the liquid metal ion source are extracted by an aperture unit and an aperture unit for extracting the vicinity of a central portion having a high energy density. The charged particle optical system for focusing the focused high-intensity ion beam to an ion beam spot diameter much smaller than the width of the wiring, the blanking electrode for irradiating and stopping the ion beam focused by the charged particle optical system, and the charging. The lens barrel having a deflection electrode for scanning an ion beam spot focused by a particle optical system, a sample stage on which an IC element coated with a step-like protective film following the wiring is provided on the wiring, and the charged particle optics. Detect secondary electrons or secondary ions generated from the surface of the protective film of the IC element by the ion beam spot focused by the system 2 A device for processing an IC device configured to form a vacuum chamber with a sample chamber equipped with a secondary charged particle detector, wherein the deflection electrode is controlled to disconnect the ion beam spot from the IC device. The observation region on the surface of the protective film near the point to be scanned is irradiated with scanning light, and the observation is performed by receiving a deflection signal for controlling the deflection electrode based on secondary electrons or secondary ions detected by the secondary charged particle detector. An attempt is made to control the scanning area by the deflection electrode based on the enlarged SIM image magnified and observed by the scanning ion microscope, and to cut the wiring by providing a scanning ion microscope for displaying the enlarged SIM image of the area and magnifying and observing. At least the width of the wiring to the protective film by scanning and irradiating an ion beam spot that is significantly narrower than the width of the wiring by setting the energy to 10 KeV or more only in the region across the width of the wiring at the location. While performing uniform hole sputter processing and uniform cutting sputter processing across the width of the wiring in the lower layer, the end point of wiring cutting is detected and the blanking electrode is controlled to irradiate the ion beam spot. A device for processing an IC element, comprising a control means for stopping. 2. A sample exchange chamber connected to the sample chamber via a gate valve is provided so that the IC element can be placed on the sample table in the sample chamber from the sample exchange chamber via the gate valve. The processing device for an IC element according to claim 1, wherein the processing device is configured. 3. The IC device processing apparatus according to claim 1, wherein an electronic shower is provided in the sample chamber in order to prevent the disturbance of the ion beam spot with which the IC device is irradiated. 4. A liquid metal ion source that emits a high-intensity ion beam and an high-intensity ion beam emitted from the liquid metal ion source are extracted by an aperture unit and an aperture unit for extracting the vicinity of a central portion having a high energy density. The charged particle optical system for focusing the focused high-intensity ion beam to an ion beam spot diameter much smaller than the width of the wiring, the blanking electrode for irradiating and stopping the ion beam focused by the charged particle optical system, and the charging. A lens barrel having a deflection electrode for scanning an ion beam spot focused by a particle optical system, a sample stage on which an IC element coated with a step-like protective film on the wiring, which covers the wiring, and the charged particles are installed. Secondary electrons or 2 generated from the surface of the protective film of the IC element by the ion beam spot focused by the optical system
An apparatus for processing an IC element, which is configured to form a vacuum chamber with a sample chamber provided with a secondary charged particle detector for detecting a secondary ion, wherein the deflection electrode is controlled to control the ion beam spot to the ion beam spot. Deflection for controlling the deflection electrode based on secondary electrons or secondary ions detected by the secondary charged particle detector by scanning and irradiating the observation region on the surface of the protective film near the portion where the wiring of the IC element is to be cut. Magnification observation with the scanning ion microscope equipped with a scanning ion microscope for receiving a signal and displaying an enlarged SIM image of the observation region for magnifying observation and a gas introducing means for introducing gas near the surface of the IC element in the sample chamber Based on the magnified SIM image obtained, the scanning area by the deflection electrode is controlled so that the energy is 10 KeV only in the area across the width of the wiring in the portion where the wiring is to be cut.
As described above, the ion beam spot, which is much narrower than the width of the wiring, is irradiated by scanning to form a uniform hole-sputtering process on the protective film at least over the width of the wiring and a uniform width over the width of the wiring in the lower layer. Cutting spattering and detecting the end point of wiring cutting to control the blanking electrode to stop the irradiation of the ion beam spot, and further the IC based on the magnified SIM image magnified and observed by the scanning ion microscope. An IC device characterized by comprising control means for controlling a scanning region of an ion beam spot by the deflection electrode at a desired portion of the device to locally form a film by a reaction with a gas introduced by the gas introducing device. Processing equipment. 5. A sample exchange chamber connected to the sample chamber via a gate valve is provided so that the IC element can be placed on the sample table in the sample chamber from the sample exchange chamber via the gate valve. The processing device for an IC element according to claim 4, which is configured. 6. An apparatus for processing an IC element according to claim 4, wherein an electronic shower is provided in the sample chamber to prevent the ion beam spot irradiated on the IC element from being disturbed.