JP2810137B2 - Ion beam processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a fine component used for manufacturing a microelectronic device, a micromechanical device, or the like, and particularly to a method of cutting out a fine component using a focused beam narrowed down.

[Prior art]

As prior art in this field, for example, the 4th International Conference on Solid-State Sensors and Actuators (The 4th International Conference on Solid-State S)
ensors and Actuators (1987) pp. 853-856). In this report, the diameter 30
0μm gear is photolithography and reactive
It is formed by ion etching. In addition, in the Electrotechnical Research Institute News No. 380, pages 1 to 6 (1981), an example is shown in which characters are punched out from a nickel mesh by sputtering using focused ion beam irradiation.

[Problems to be solved by the invention]

The former prior art has an advantage that a large number of fine parts can be manufactured at low cost. However, by the time the parts are completed, (1) preparation of a photomask, (2) application of resist, (3) exposure,
(4) Development and (5) etching and many steps are required, and a lot of time is spent after designing the component shape until the component is actually formed. The use of the technique of direct writing on a resist by an electron beam lithography apparatus greatly reduces the photomask preparation process time of (1), but the following steps are also required. Therefore, this technique is not suitable for trial production of parts or small-lot production of parts in which the shape of the parts is modified. In addition, the latter conventional technique can be evaluated in that it shows that direct fine processing can be performed using a focused beam. However, it is only necessary to process the character pattern portion, and it is not enough to process the contour of the required component shape and obtain the desired component shape. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for processing a fine component in which the effects of electrostatic attraction force and surface tension are not negligible in a single apparatus, and for processing a detailed fine component at high speed and with high accuracy.

[Means for Solving the Problems]

The above object is achieved by irradiating a focused ion beam to a thin-film base material supported by a transport manipulator, and forming a part to be a part of the thin-film base material with the component in a state where the thin-film base material supports the part. Removing a peripheral portion of the portion to be formed,
Next, the step of transferring the thin film base material using the transport manipulator so that the part to be the part of the thin film base material is positioned on the part in the bonding relationship, and after the step, the part This is achieved by providing an ion beam processing method, comprising a step of irradiating the ion beam between a portion to be formed and the base material to separate them.

[Function] When the target component becomes finer, the mass becomes smaller, so that the electrostatic attraction force and the surface tension become more dominant than the weight. When such a component is moved and attached by picking it with, for example, tweezers, it is difficult to move or construct the component due to the influence of electrostatic attraction. In the present invention, the part is formed in a state where the part is supported by the base material by an ion beam that enables extremely fine processing,
Since it is supported by the thin-film base material until it is transported and placed to the enforcement location, it is necessary to suppress the influence of the movement of fine parts formed from the thin-film base material and the effect of electrostatic attraction during construction. In addition, fine and thin parts are not deformed or distorted during processing and transport by the ion beam.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a basic configuration diagram of a focused ion beam (hereinafter, referred to as FIB) device used in the embodiment. The ions emitted from the liquid metal ion source 100 are focused by the condenser lens 101 and the objective lens 102, and
Thus, the light is irradiated onto the workpiece 2. Between both lenses,
An aperture 104, an aligner / stigma 105, a blanker 106, and a deflector 107 are provided. Workpiece 2 is 2
It is fixed on a stage 103 that can move in the axis (X, Y) direction. Secondary electrons e generated from the sample by FIB1 irradiation
Is detected by the secondary electron detector 108 and synchronized with the deflection control of the FIB1 to display the SIM on the computer CRT.
(Scanning Ion Microscope) image is displayed. The current flowing into the workpiece or the stage is measured by the current detector 109. Beam deflection, signal detection,
The control of the stage and the like is controlled by a computer via a system bus. FIG. 1 is an embodiment that best illustrates the present invention. Submicron FI with an acceleration voltage of 25 kV and a beam current of 5 nA for the thin film base material 2
B was deflected, and the base material was cut out using the sputtering phenomenon to produce fine parts 3a and 3b. As the material of the thin film base material, stainless steel and silicon having a thickness of 2 μm were used, and a favorable processed shape was obtained in both cases. The stainless thin film is obtained by thinning a plate material having a thickness of 10 μm by etching, and the silicon thin film is formed by thinning a silicon substrate for semiconductor by back etching. In the present embodiment, sputter etching using FIB was used. However, other techniques that can process fine shapes are as follows: 1) FIB assisted etching by FIB irradiation in an etching gas atmosphere 2) Focused electron beam in an etching gas atmosphere FEB assisted etching by irradiation (hereinafter, referred to as FEB) 3) There is FLB assisted etching by irradiation of a focused laser beam (hereinafter, referred to as FLB) in an etching gas atmosphere. FLB has excellent processing speed, and FEB has excellent convergence.
FIB has a good balance between processing speed and convergence. Means for aligning the processed part and observing the shape after processing include: 1) Observing an image using a secondary electron signal generated from a thin film or the like in synchronization with FEB deflection scanning. FEB is suitable for image observation because FEB causes less damage to the sample and has good focusing characteristics. 2) Image observation is performed using secondary charged particles generated from a thin film or the like in synchronization with the deflection scanning of the FIB. Since the sample to be observed is sputtered by FIB irradiation, it is necessary to reduce the beam current amount and sweep at a high speed during observation to reduce damage to the sample. 3) Observe the image with an optical microscope. The device configuration is simple and inexpensive. However, it is possible. For example, observe the image with FEB and process with F
By using a hybrid system such as IB, it is possible to construct a system that can perform fine processing without damage. Further, when the observation and the processing are performed in the same FIB as in the present embodiment, there is an advantage that the hardware configuration can be simplified. In this embodiment, the cutout is performed so that the thin arm 4 remains between the fine parts 3a and 3b and the thin film base material 2. This is intended to carry the fine parts 3a and 3b while holding the thin film base material 2. After transport, the arm 4 is removed by local irradiation of the focused beam 1 or by mechanical breakage. In mechanical parts such as gears, it is particularly important to secure mechanical strength, and in a homogeneous part cut out from a uniform thin film, a functional problem may occur. To solve this problem: 1) Ion implantation is performed by high-acceleration FIB irradiation to modify a part or the whole of a fine component. 2) Irradiate FLB or FEB to a part or the whole of the micro component, and modify the material by the annealing effect. Can be used. In addition, CVD (Chemical Vapor Depositi) such as W (CO) ₆
When the focused beam is locally irradiated while the gas for on) is introduced, 1) repair of a part that has been cut too much by mistake 2) It is possible to realize a part shape that cannot be achieved only by cutting out. FIG. 3 to FIG. 5 show a method of detecting the end point of the cutting process. FIG. 3 is a diagram in which particles 9 secondary generated by FIB irradiation are detected by a secondary particle detector 20, and the progress of processing of the beam irradiation unit is monitored by an output signal of the detector. In this embodiment, the thin film material was set to the ground potential, a positive voltage was applied to the lattice at the tip of the detector 20, secondary electrons were induced, and the signal was amplified by a scintillator and a photomultiplier to create a monitor signal. When it is desired to detect secondary ions, a negative voltage is applied to the lattice, and an amplifier is arranged at the subsequent stage. FIG. 4 monitors the progress of the processing by the current flowing into the peritoneum 2. In order to detect the current, an ammeter 21 was inserted between the thin film and the ground potential.
The current value detected by the ammeter is the sum of the beam current of the FIB incident on the thin film and the current generated by the secondary charged particles emitted from the thin film. The end point of the cutting process is the time when the current value becomes extremely small. FIG. 5 is a diagram for monitoring the progress of processing by measuring the intensity of a beam penetrating the thin film 2 and arranging a current detecting plate 22 below the thin film, which is larger than the beam deflection area, to detect the flowing beam current. Detected by a total of 21. Current detection plate with material with low secondary electron yield
With the configuration of 22, the display of the ammeter 21 becomes almost equal to the beam current of the FIB1 irradiated on the current detection plate. Therefore, the beam current of the FIB is measured in advance, and the display of the ammeter 21 is displayed on the FIB.
When the beam current becomes almost equal to the FIB, the entire FIB has penetrated the thin film, and the processing end point can be detected. In addition, by setting the current detection plate 22 to a positive potential (about 10 V may be sufficient) with respect to the thin film, generation of a secondary electron current is further suppressed, and the processing end point detection accuracy is improved. FIG. 6 is a configuration diagram of an FIB device used in another embodiment. This device is a three-axis manipulator,
200 and a gas introduction mechanism 201 are added. By fixing the thin film 2 to the tip of this manipulator arm,
After processing, it becomes possible to transport the fine parts to a desired place. Further, by introducing a gas such as W (CO) ₆ from a gas source into the FIB irradiation unit, a volume film can be formed. FIG. 7 shows a case where the gear 3a is fitted to the fine shaft 5 formed on the base (FIGS. 7A and 7B), and further, the cap 3b is fitted to the shaft 5 (FIGS. 7C and 7D). FIG. 10 is a process diagram of an embodiment in which the cap 3b and the shaft 5 are bonded to a ladder (FIG. 10E) to realize a gear mechanism (FIG. 10F) that rotates about the shaft. The steps will be described below in order. (A) The stage 103 is moved, and the shaft 5 is moved near the optical axis of FIB1. In addition, the gear 3a is transported to fit on the shaft 5. The gear 3a is held on the thin film 2 via the arm 4, and can be moved in an arbitrary direction by the triaxial manipulator 200. [FIG. 7 (a)] (b) The gear 3a is fitted to the shaft 5, and the FIB 1 is irradiated to the arm 4 to cut it.
The gear 3a is free from the thin film 2. [Fig. 7 (b)]
(C) The manipulator is driven, and the cap 3b is fitted on the shaft 5. [FIGS. 7 (c) and (d)] (d) The FIB1 is irradiated to the arm 4 and cut. Cap 3b
Is free from the thin film 2. [FIG. 7 (d)] (e) Irradiate FIB1 on the top of the cap 3b and the shaft 5 in the gas atmosphere 7 from the gas supply nozzle 6 to deposit the film 8
Is formed, and the shaft 5 and the cap 3b are mechanically connected. [FIG. (E)] (f) Through the steps described above, a fine gear mechanism rotating around the shaft 5 can be realized. [FIG. 6F] When the thin film 2 is mounted on the manipulator 200, the thin film 2 may be inadvertently broken during chucking, particularly if the thin film 2 is a brittle material. Therefore, only the chucking portion of the thin film 2 was formed with a large film thickness, and a measure was taken to improve the mechanical strength of the chucking portion. In this embodiment, the FIB is used only for cutting the arm 4 and forming the deposited film 8. However, the FIB can form an ion implantation layer in a small area in principle. It is possible to improve mechanical properties (hardness, coefficient of friction, etc.). Further, it is also possible to make a manufactured part to have many functions mechanically and electrically, such as lubrication and insulation, by using a thin film as a multilayer film. In addition, it is also possible to manufacture a fine component on a substrate by using a laminated substrate including a thin film layer as a material and subjecting at least the thin film layer to penetrating processing. The substance to be processed can be determined by mass spectrometric analysis of secondary ions generated at the time of etching processing or spectral analysis of light. Therefore, it is possible to accurately monitor to which layer of the laminated substrate the processing is progressing. A fine component manufactured by this method functions as a single component by removing a surrounding layer by etching or the like. FIG. 8 shows another embodiment, in which the procedure for cutting out is devised. As employed in the above-described embodiment, if the fine part is processed while leaving the arm, and a window is formed around the fine part, it is convenient for transportation and assembly after the processing. In order to perform such a cutting process, the parts 3
And through the outline 4 of the arm 4 and the window frame 34, the window 33
Separates from the thin film. Therefore, the cutout processing is completed with a small processing volume, and high-speed processing can be realized. If the method of processing all the windows 33 (all processing parts including the part contour parts) by beam irradiation is used, the processing time will be long. Since a blanking method can be used, there is an advantage that hardware can be simplified. When the thin film 2 is made of a brittle material such as silicon, there is no particular problem if the contour is processed in any procedure. However, when the thin film 2 is made of a ductile material such as stainless steel, the thin film base material 2 and the window 33 are formed at a limited portion immediately before the completion of the processing.
When the connection was slightly connected, a phenomenon was observed in which the window 33 was carelessly bent with the connected portion as a hinge. When the hinge portion is generated in the contour of the component 3 or the arm 4, the window 33 may not be removed from the component 3, and a countermeasure is required. Therefore, in this embodiment, as shown in the figure, at least the part 3 and the arm 4
The contour portion of was first pierced to prevent a hinge portion from being generated at this portion. Thus, even if the window 33 is bent, the components 3 are not affected, and processing with a high yield can be performed.

【The invention's effect】

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to process a micro component with high precision, without being affected by electrostatic attraction force or surface tension.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a schematic configuration diagram of a focused ion beam system embodying the present invention, and FIGS. 3, 4, and 5 show a method of detecting a processing end point. FIG. 6 is a schematic configuration diagram of a focused ion beam system used in another embodiment, FIG. 7 is a process explanatory diagram showing an assembling procedure of a rotary gear mechanism, and FIG. 8 is another embodiment. It is a perspective view. DESCRIPTION OF SYMBOLS 1 ... Focused ion beam, 2 ... Thin film material 3 ... Fine parts, 4 ... Arm 5 ... Shaft, 6 ... Nozzle 7 ... Gas, 8 ... Volume film 9 ... Secondary particles, 10 ... … Wiring pattern 200 …… Triaxial manipulator 201 …… Gas introduction mechanism

Continuation of front page (56) References JP-A-63-260692 (JP, A) JP-A-53-51160 (JP, A) JP-A-62-197284 (JP, A) JP-A-1-180791 (JP) JP-A-63-280209 (JP, A) JP-A-63-55957 (JP, A) JP-A-58-160680 (JP, U) JP-A-52-125192 (JP, U) 38-5746 (JP, B1) Japan Society for the Promotion of Science, 132nd Committee, “Electron / Ion Beam Handbook” (Showa 50-7-25) Nikkan Kogyo Shimbun (58) Field surveyed (Int. Cl. ⁶⁾ , DB name) B23K 15 / 00,15 / 08

Claims (5)

(57) [Claims] The thin-film base material supported by a transport manipulator is irradiated with a focused ion beam, and the thin-film base material is supported by a part of the thin-film base material. Removing the peripheral portion of the thin film member, and then transferring the thin film base material using the transfer manipulator so that the part of the thin film member which is to be the component is positioned on the component in the connection relationship. The process of
Irradiating the ion beam between the part serving as the part and the base material after the step to separate the part and the base material, thereby separating the two. 2. The method according to claim 1, wherein the removing step comprises:
An ion beam processing method, comprising: a step of cutting an outer periphery of a part to be a part; and a step of forming an edge of an opening including the part to be a part. 3. The method according to claim 2, wherein the removing step comprises:
A step of cutting the outer periphery and a step of forming an edge of the opening in this order. 4. The method according to claim 1, wherein the base material is provided with a current detector for detecting a change in current based on the irradiation of the base material with the charged particle beam. Determining the end of the separating step. 5. The apparatus according to claim 1, further comprising a current detector below the base material for detecting a current based on the irradiation of the charged particle beam, and ending the disconnecting step by a change in the detection current of the current detector. Beam processing method characterized by determining