JPH05159960A - Manufacture of magnetized film - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for easily producing a patterned fine magnetized film, and a device to which the magnetized film produced by the method is applied. [Structure] Install a magnetizing coil near the sample substrate and
The magnetic film is deposited by D and magnetized. Since the diameter of the ion beam can be set to 1 μm or less, a desired pattern can be obtained by direct drawing by deflecting the ion beam. [Effect] A fine magnetized film can be easily formed, and the time and cost required for manufacturing can be reduced. Further, it contributes to high performance of the integrated circuit to which the fine magnetized film is applied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic film, a method of manufacturing a high-density magnetic recording medium, and a method of repairing an integrated circuit, which are used for manufacturing an integrated circuit using a magnetic field generated by a locally deposited magnetic film. The present invention relates to a method and a manufacturing method of a micromachine.

[0002]

2. Description of the Related Art Regarding the film deposition of iron, which is a ferromagnetic film, by the electron beam induced deposition method, R. R. Kunz et al., Journal of Vacuum Science and Technology B6 (1988) pp. 1557-156.
Page 4 (J. Vac. Sci. Technol. B6 (1988) 1557
-1564). Further, when the deposited ferromagnetic film is patterned, a method of performing patterning by lithography after forming the film has been usually performed.

[0003]

In the above-mentioned known example of Kunz et al., A method of depositing a ferromagnetic film by a focused ion beam induced deposition method (FIBID) has been shown. The application of the fine magnetic film was not discussed. It is an object of the present invention to form a magnetic film on the surface of a substrate in a patterned state from the beginning. Further, as a result, fine magnetic recording, high performance of the semiconductor circuit, and manufacture of a semiconductor circuit to which a minute magnetic field is applied are performed.

[0004]

A focused ion beam (FIB) having a diameter of 1 μm or less is used, and while scanning this on a substrate, a reactive gas containing a ferromagnetic metal is blown onto the substrate to scan the beam. A film is formed by FIBID that forms a ferromagnetic film only in the pattern region, and a magnetic field is applied to the formed film to form a patterned magnetized film on the substrate.

[0005]

Since the diameter of the FIB can be reduced to 1 μm or less, deposition is performed in a gas atmosphere containing a ferromagnetic metal while scanning the substrate with the beam. By using FIBID, a ferromagnetic film having a desired pattern shape can be obtained by direct writing. At this time, a magnetic field is generated by a coil, electromagnet, permanent magnet, etc. installed near the sample table,
By placing the deposited film in a magnetic field, the ferromagnetic film can be magnetized. Since the direction of this magnetization does not change unless a strong magnetic field is applied thereafter, it has the magnetization of the desired direction,
In addition, a patterned thin film can be formed.

[0006]

<Embodiment 1> FIG. 1 is a sectional view of a magnetic film manufacturing apparatus using FIBID as one embodiment of the present invention. Ions emitted from the liquid metal ion source 1 are focused by the electrostatic lens 2 to form a beam having a diameter of 1 μm or less on the substrate 4. 1 for the ion source and the focusing lens system
It is housed in a vacuum chamber 8 in which a degree of vacuum of about 0 −6 torr or more is maintained, but a gas of a compound containing a metal serving as a ferromagnetic material is supplied to a sample surface by a nozzle 9. Therefore, the sample surface is locally in a high-pressure gas atmosphere. Ions accelerated to an energy number of 10 keV are scanned in a desired pattern by the deflector 3 to decompose the gas adsorbed on the sample surface and deposit the metal in the gas. A coil 6 is wound around the sample stage 5 of the focused ion beam apparatus so that the substrate exists in a uniform magnetic field. However,
When the deposition and the magnetization are performed at the same time, the direction of the magnetic field and the vector of the particle velocity do not completely coincide with each other due to the deflection, and therefore the Lorentz force is exerted, and the trajectory of the ion is deflected. The magnetic field strength must be adjusted depending on the ion mass and acceleration energy. That is, in the case of light ions, the deflection is largely received, and therefore the magnetic field is weak, and in the case of heavy ions, the deflection is difficult, so that the magnetic field may be increased.

<Embodiment 2> FIG. 2 shows an electron wave interference circuit manufactured according to the present invention. This circuit was made of an aluminum conductor wire having a line width of about 1 μm. The circuits 14, 15 and 16 are formed on a SiO ₂ substrate 11 which is an insulator, and a SiO ₂ film 12 which is a protective film is further formed thereon by chemical vapor deposition to a thickness of about 1 μm.
It is formed to a thickness of. The operation of the circuit is carried out at an extremely low temperature to prevent the scattering of electrons in the aluminum wiring. The electron wave interference circuit is an electronic device that utilizes the fact that the signal on the output side changes like 1, 0 when the phases of the electron waves coming through the two paths are the same or opposite. Magnetized film 1
FIG. 3 shows an output result before forming No. 3. When the magnetic flux does not exist in the circuit, the phases of the electron waves passing through the wiring 17 and the wiring 18 (FIG. 4) in each circuit are the same, and the output generated by the interference 20 is 1 in any circuit. .. However, it is known as the AB effect that the phase of the electron wave differs depending on the presence or absence of magnetic flux in the circuit. By depositing the minute magnetic film 13, the phases of the electron waves of the conductors 17 and 18 in the circuit 15 are changed, the phases of the electron waves passing through the wiring 17 and the wiring 18 are reversed, and the mutual interference causes the output. Becomes 0.
FIG. 5 shows the output when the "writing" by the magnetic film is performed on the circuit shown in FIG. It can be seen that the output of the circuit 15 that has performed the "writing" is close to zero. The reason why it does not completely become 0 is that the adjustment of the magnetization intensity is insufficient and the phases are not completely reversed. There is an optimum value for the magnitude of the magnetic flux generated in the circuit, and it is necessary to adjust the magnitude of the film and the strength of magnetization at the time of depositing the magnetized film. Further, when forming circuits very close to each other, the magnetic flux may leak to adjacent circuits, so that the distance between the circuits is limited.

<Embodiment 3> The present invention relates to an induced reaction using an ion beam, but almost the same can be achieved by using an electron beam. However, in the usual case, the ion beam induced reaction has a higher reaction efficiency, that is, the number of reaction molecules decomposed per incident particle. When an electron beam is used, the reaction efficiency is poor, but it has advantages that it is easier to focus finely compared with ions and that a large current is easily obtained. However, in the case of the electron beam, the mass is smaller than that of the ion beam, so that the electron beam is deflected in the magnetic field to perform the cyclotron motion. Therefore, the micro beam is deflected in the magnetic field and the
It is difficult to form a fine magnetized film pattern of sub-μ or so and magnetize at the same time. Therefore, it is necessary to perform film formation and magnetization of the generated film separately. However, this method is effective in forming a macroscopic film instead of a local film. For example, a high current electron source 21 as shown in FIG.
If a structure is adopted in which the coil 24 is irradiated to cause a reaction, and the coil 24 simultaneously magnetizes, a large-area magnetized film can be formed.

<Embodiment 4> FIG. 7 shows a method of forming a high-density magnetic recording medium on a substrate using FIBID.
Is. Coil 2 installed near the ion beam irradiation point
By changing the direction of the current of No. 7, the direction of the magnetic field near the deposited film is reversed. The direction of the current was reversed and the direction of the magnetic field was changed to deposit the magnetic film 29 in a line shape. As a result, it was possible to deposit a magnetic film having a partially different magnetization direction. Width is reduced to 0 by connecting the patterns.
It was possible to form a magnetic recording medium having 1-bit information in an area of 1 μm and a length of 0.2 μm. Further coil 27
The direction of magnetization can be freely changed with respect to the surface of the substrate to perform recording by making the direction of (1) movable or disposing a plurality of coils.

FIG. 8 shows a magnetic recording medium formed by the same device as in Example 1 without using a local magnetic field generated by a fine coil. In this example, the direction of magnetization is constant, and the presence or absence of the magnetic film 32 represents information of 1 and 0. Since the locality of the magnetic field of the magnetizing coil is not required, the recording density in this case is almost determined by the beam diameter. In normal magnetic recording, the upper limit of the recording density is limited by the size of the write head, but this method can improve the recording density as compared with the conventional method. For example, when an ion beam is used, a beam diameter of about 10 nanometers can be realized, and the recording density can be increased accordingly. In this example, the recording area of 1 bit is 20 nm × 40
nm.

It is difficult to read information from the above magnetic recording medium with a conventional magnetic head due to the problem of position resolution. However, it is possible if the deflection of the electron beam by the magnetic field is used. When an electron beam is incident parallel to the substrate, its deflection angle is the integral of the deflection angles received at all points where the electron has passed, so most commonly, the substrate on which the magnetic recording medium is present is parallel to the beam. Only by rotating to obtain the deflection angle information at all angles of incidence, the distribution of the magnetic field strength on the substrate is calculated, ie the recorded information is obtained. However, usually, magnetic recording is not completely two-dimensional, and the recording direction is also clearly limited. Therefore, the substrate is rotated in this way to obtain information on the deflection angle with respect to all incident angles. There is no need. For example, as shown in FIG. 7, in the case of recording in only one direction, an electron beam is incident perpendicularly to the recording direction (direction in which a magnetic film is attached), and when the deflection angle is small (electrons reach up to the adjacent magnetic film). The electron beam is deflected in a constant direction determined by the magnetization direction of the film (to the extent that it is not deflected), and the deflection angle is 0 when there is no film. Therefore, it is only necessary to arrange the deflected electron detector only in this direction, and it is easy to read information. In the case of a two-dimensional array as shown in FIG. 8, reading cannot be performed by such a simple method, but it is also recorded by measuring the deflection angle of incident electrons from a predetermined number of directions. You can get all information. When the magnetization direction of the film used for recording is not perpendicular to the substrate, the electrons are also deflected in the direction perpendicular to the substrate. In this case, if the electrons are set so as to receive a force in a direction away from the substrate, they are less likely to be deflected by another magnetic film after being deflected once,
It is deflected only at the incident point of the electron beam. This method is effective for high-density recording because the information at each point is directly obtained instead of the information integrated about the electron orbit.

<Embodiment 5> Although the magnetic field strength of the magnetized film is weak,
It is sufficient to support very small mechanical parts such as gears and cams used in micromechanics. Here, an example using a magnetized film is shown as a method of supporting and carrying such a component. FIG. 9 shows a case where the gear 34 cut out by performing fine processing by FIB is being carried. Gear diameter is about 30μ, thickness is about 10μ
The material is silicon. The gear was cut out using FIB-induced etching with chlorine gas. After cutting out,
The gas was switched to iron carbonyl Fe (CO) ₅ and a thin film 35 of iron Fe having a thickness of about 1 μ was deposited on the surface of the gear. Further magnetization was performed to make this thin film into a minute magnet. As a result, without using a special supporting method, for example, a device such as minute vacuum tweezers, if the thin rod 33 made of iron, nickel or the like as shown in FIG. Gears can be easily transported. The deposition of the metal film also prevents the micro-mechanical components from being charged, and prevents repulsion and suction between the components and between the jig and the components, which facilitates handling. Contrary to this example, the component can be supported and transported by depositing a ferromagnetic film on the component and using an electromagnet or the like in the transport jig. The method can also be used to align and collect the direction of fine parts. It is also suitable for manufacturing a part using a magnet such as a micromotor from a material such as silicon.

<Embodiment 6> This magnetized film can also be used for detecting the magnetism of a fine magnetized film to detect the position with high accuracy. FIG. 10 shows a method of detecting a defective portion in the wafer scale integrated circuit when the circuit is repaired. In the case of a highly integrated circuit such as a wafer-scale integrated circuit, it is inevitable that a defect exists on the wafer, and even if a defect is found, it is difficult to completely repair it on the spot. Therefore, repair is usually performed through several processes. At that time, it is important that the defect location can be easily detected. Usually, the operation inspection of the integrated circuit is performed by using the signal detection by the electron beam tester and the sputter processing by the FIB together. In this example, the circuit in which the malfunction is detected is removed by etching, and a non-defective circuit is embedded in the groove 38. However, after the embedding, when rewiring with the peripheral circuit is performed, a direct electron beam is applied. It uses lithography by drawing. In this case, if the positions of many defects on the wafer can be quickly determined, the repair can be easily performed. In order to do this, after the sputter processing by FIB and inspection, a minute magnetic film 39 is deposited on the defective portion by FIBID. Next, in drawing an electron beam, first, an electron beam was scanned in parallel with the surface of the wafer 37 in close proximity to the surface of the wafer 37, and the location of deflection on the wafer surface was specified. Since the electron beam is deflected by a weak magnetic field and is greatly deflected by the magnetic field generated by the magnetized film, the defect position can be easily determined using this method, and a wiring pattern for repair is drawn on the specified part. did. LSI after protective film formation
The surface is insulative and easily accumulates electric charges, which makes it difficult to align with a scanning electron microscope or the like, but according to this method, alignment and drawing can be performed without using marks on the wafer. Further, as shown in FIG. 10, by changing the shape of the magnetized film, information such as the type of the replacement module can be written, so that the electron beam drawing pattern can be changed accordingly.

In the case of a normal logic circuit, memory circuit, etc.,
It is not necessary to remove the magnetic film even after repair because it does not cause a malfunction in a weak magnetic field of about a minute magnetic film, but it can be removed by dry etching, ion beam sputtering, etc. Marks can be easily erased.

Metals exhibiting ferromagnetism such as iron, nickel and cobalt form impurity levels in semiconductors such as silicon and deteriorate the performance of semiconductor devices. Therefore, they are not usually used in semiconductor integrated circuits. However, FIBID is performed on a semiconductor circuit after forming a protective film, and the surface of the integrated circuit is protected by an insulating film such as SiO ₂ , so that contamination of the substrate and deterioration of device characteristics can be prevented. This protective film is effective except for special cases such as elements that diffuse very quickly in silicon oxide. Further, since the FIB is formed with an accelerating voltage of about several tens of kV to several hundreds of kV, a protective film having a thickness of about 1 μ, such as phosphorus glass
If a film such as SiO _{2 is used} as a protective film, ions will not reach the substrate.

In the present embodiment, the case of performing electron beam drawing has been described, but the same method can be used for detecting the location, for example, also when performing wiring repair using FIBID. Further, it is also possible to detect the magnetic field of the magnetized film to specify the location when observing and analyzing a large sample such as a wafer with an electron microscope, an Auger analyzer or the like.

[0017]

According to the present invention, an integrated circuit using a fine magnetized film can be formed, and high performance of the circuit can be realized. It is possible to realize a magnetic recording medium having a dramatically high recording density. In addition, it is possible to provide new processes such as position detection using a magnetized film and supporting and carrying of micro mechanical parts.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a focused ion beam magnetized film manufacturing apparatus according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the present invention in which information is written by depositing a magnetized film on an electron wave circuit.

3 is an explanatory diagram showing an output before writing by a magnetized film of the electron wave circuit of FIG. 2. FIG.

FIG. 4 is an explanatory diagram showing a structure of an electron wave circuit.

5 is an explanatory diagram of an output after writing by a magnetized film of the electron wave circuit of FIG. 2.

FIG. 6 is a sectional view showing a structure of a magnetized film manufacturing apparatus using an electron beam.

FIG. 7 is an explanatory diagram showing a state where writing is performed on a magnetic recording medium that records information by locally changing a magnetization direction by using a focused ion beam induced deposition method.

FIG. 8 is an explanatory diagram showing a state where writing is performed on a magnetic recording medium that records information with or without a magnetic film by using a focused ion beam induced deposition method.

FIG. 9 is an explanatory view showing a state in which a magnetized film is deposited on a minute gear and the magnet is used to convey the gear.

FIG. 10 is an explanatory diagram showing a state in which a defective portion of a wafer scale integrated circuit is marked by using a focused ion beam induced deposition method.

[Explanation of symbols]

6, 24, 27 ... Magnetizing coil, 14, 15, 16 ... Electron wave interference circuit, 13, 29, 32, 35 ... Magnetizing film, 34 ...
Micro mechanical components, 37 ... Wafer scale integrated circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 21/265 21/268 A 8617-4M 21/66 A 8406-4M

Claims (9)

[Claims] 1. A method of manufacturing a magnetized film, which uses a focused ion beam induced deposition method. 2. The method for producing a magnetic film according to claim 1, wherein the substrate on which the film is to be formed is placed in a magnetic field, and film deposition and film magnetization are performed simultaneously. 3. A semiconductor integrated circuit using the magnetism of a magnetized film according to claim 1. 4. A magnetic recording medium using the magnetic film according to claim 1. 5. The gas used in claim 1,
Carbonyl compounds of iron, nickel, cobalt and iron,
A method for manufacturing a magnetized film using an organometallic complex containing nickel and cobalt. 6. A semiconductor integrated circuit according to claim 3, wherein a magnetized film according to this manufacturing method is used for phase modulation of an electron wave. 7. A magnetic recording medium according to claim 4, wherein the direction of magnetization in the film is locally controlled by changing the direction of the magnetic field during film formation. 8. The method for manufacturing a micromachine according to claim 1, wherein the magnetized film is used for transporting the micromachine part. 9. A method for repairing a semiconductor integrated circuit using marking with a magnetized film formed by the manufacturing method according to claim 1.