JP6887343B2 - Processing method, semiconductor equipment and processing equipment - Google Patents

Description

The present invention relates to a processing method, a semiconductor device, and a processing device technology, and relates to, for example, a processing technique using a focused ion beam (FIB).

As a background technique in this technical field, there is Japanese Patent Application Laid-Open No. 2016-110734 (Patent Document 1). The following techniques are described in this publication. That is, after the first deposition film is formed on the sample with the defocused ion beam (first deposition film forming step), the defocusing amount is smaller than the defocusing amount in the first defocused film forming step. A second deposition film is formed on the first deposition film with the ion beam of (second deposition film forming step).

Japanese Unexamined Patent Publication No. 2016-10734

However, in Patent Document 1, since the pattern is formed by the defocused ion beam, the blur of the ion beam becomes large. Therefore, since the film is formed in a range considerably wider than the spot diameter of the ion beam, there is a problem that it is difficult to miniaturize the pattern.

An object of the present invention is to provide a technique capable of miniaturizing a pattern formed by an ion beam.

In order to solve the above problems, the present invention comprises a step of forming a first layer with a focus ion beam on an insulating film and a step of forming a second layer with a focus ion beam on the first layer. The outer periphery of the second layer is located inside the outer periphery of the first layer. The amount of sputtering etching of the insulating film at the time of forming the first layer is the sputtering etching of the insulating film when the second layer is directly formed on the insulating film by the focus ion beam without forming the first layer. It is smaller than the quantity.

According to the present invention, the pattern formed by the ion beam can be miniaturized.

Issues, configurations and effects other than those described above will be clarified by the following description of the embodiments.

The left is a cross-sectional view of a main part of a semiconductor substrate at the initial stage of forming a tungsten film by FIB, and the right is a cross-sectional view of a main part of a semiconductor substrate after the film formation of a tungsten film by FIB is completed. The left is a cross-sectional view of a main part of the semiconductor substrate at the time of the first film formation of the tungsten film by the ion beam, and the right is a cross-sectional view of the main part of the semiconductor substrate at the time of the second film formation of the tungsten film by the ion beam. FIG. 5 is a cross-sectional view of a main part of a semiconductor substrate in which patterns of tungsten films formed by the method of FIG. 2 are arranged side by side. It is a graph which compared and showed the sputtering rate at the time of forming a film of various materials using a Ga, Xe ion beam. The left is a cross-sectional view of a main part of a semiconductor substrate after a material having a small amount of sputter etching of an insulating film is formed by FIB treatment, and the right is a semiconductor after forming a tungsten film by FIB treatment after FIB formation on the left in FIG. It is a cross-sectional view of a main part of a substrate. FIG. 5 is a cross-sectional view of a main part of a semiconductor substrate showing a case where the laminated patterns of FIG. 5 are arranged adjacent to each other. It is a block diagram of an example of the processing apparatus of Embodiment 1. It is a flowchart of an example of the FIB film formation method of Embodiment 1. It is sectional drawing of the main part of the semiconductor substrate in the 1st FIB film formation process of Embodiment 1. FIG. 9 is a cross-sectional view of a main part of a semiconductor substrate during a second FIB film forming step following the first FIB film forming step of FIG. FIG. 5 is a plan view of a main part of an example of the semiconductor device of the first embodiment. FIG. 11 is a cross-sectional view taken along the line I-I of FIG. It is sectional drawing of the main part of the semiconductor substrate in the 1st FIB film formation process of the modification 1. FIG. FIG. 3 is a cross-sectional view of a main part of a semiconductor substrate during a second FIB film forming step following the first FIB film forming step of FIG. It is sectional drawing of the main part of the semiconductor substrate in the 1st FIB film formation process of the modification 2. FIG. FIG. 5 is a cross-sectional view of a main part of a semiconductor substrate during a second FIB film forming step following the first FIB film forming step of FIG. It is a top view of an example of the semiconductor device of the modification 2. FIG. 17 is a cross-sectional view taken along the line II-II of FIG. It is a graph which shows that the tungsten film formed by W (CO) _{6 depends on the film thickness of the underlying insulating film.} It is a graph which shows the relationship between the pulse width (horizontal axis) of FIB and the temperature (vertical axis) of a FIB irradiation region at the time of film formation by general FIB. FIG. 5 is a graph showing an example of the relationship between the pulse width (horizontal axis) of the FIB and the temperature (vertical axis) of the FIB irradiation region at the time of film formation by the FIB of the second embodiment. It is a graph which shows the relationship between the irradiation time (horizontal axis) of FIB and the temperature of a substrate surface. It is a graph which shows an example of the relationship between the pulse width (horizontal axis) of FIB at the time of film formation by FIB of Embodiment 2 when the stage temperature is raised, and the temperature (vertical axis) of the FIB irradiation region. It is a graph which shows another example of the relationship between the pulse width (horizontal axis) of FIB at the time of film formation by FIB of Embodiment 2 when the stage temperature is raised, and the temperature (vertical axis) of a FIB irradiation area. .. It is a block diagram of an example of the processing apparatus of Embodiment 2. It is sectional drawing of the main part of the semiconductor substrate in the FIB film formation process of Embodiment 2. FIG. 5 is a cross-sectional view of a main part of a semiconductor substrate showing a modified example of a laminated pattern formed by the FIB film forming technique of the second embodiment.

Hereinafter, embodiments will be described with reference to the drawings. However, the present invention is not construed as being limited to the description of the embodiments shown below. It is easily understood by those skilled in the art that a specific configuration thereof can be changed without departing from the idea or gist of the present invention.

In the configuration of the invention described below, the same reference numerals may be commonly used for the same parts or parts having similar functions even between different drawings, and duplicate description may be omitted. In addition, the notations such as "first", "second", and "third" in the present specification and the like are attached to identify the components, and do not necessarily limit the number or order. ..

In addition, the position, size, shape, range, etc. of each configuration shown in the drawings and the like may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings and the like.

Components represented in the singular form herein shall include the plural form unless explicitly indicated in the context. In the specification of the present application, the plan view means a case where the semiconductor substrate is viewed from a direction perpendicular to the main surface.

<Inventor's examination>
In thin film formation by FIB (Focused Ion Beam), film formation and etching proceed at the same time. Specifically, (1) adsorption of precursors (precursors, precursors), (2) reaction of adsorbed species by FIB, and (3) sputtering of membrane by FIB are proceeding at the same time, and these (1) to (1) to The film formation rate and the amount of scraping of the base (sputter etching amount) are determined by the magnitude relationship of (3). Generally, in the film formation of tungsten (W) by FIB, scraping (etching) of the base film is likely to occur, and it becomes particularly remarkable under the condition of forming a film with a large current.

The left side of FIG. 1 is a cross-sectional view of a main part of a semiconductor substrate at the initial stage of forming a W film by FIB, and the right side of FIG. 1 is a cross-sectional view of a main part of a semiconductor substrate after the film formation of a W film by FIB is completed. The semiconductor substrate 50 is made of, for example, silicon (Si), and the insulating film 51 is made of, for example, silicon oxide (SiO ₂ ). While spraying a precursor (raw material gas) containing W on the surface of the underlying insulating film 51, the FIB 52 using, for example, gallium (Ga) or xenon (Xe) as an ion source in a desired region within the sprayed region of the precursor. Is pulse-irradiated to form a W film 53. In this film forming process, it is known that the phenomenon of (3) above causes damage to the underlying insulating film 51, and depending on the film forming conditions, the underlying insulating film 51 is easily scraped 54. To do.

As a method of suppressing such damage to the substrate, a method as shown in FIG. 2 (Patent Document 1) has been proposed. FIG. 2 left is a cross-sectional view of a main part of the semiconductor substrate at the time of the first film formation of the W film by the ion beam, and FIG. 2 right is a cross-sectional view of the main part of the semiconductor substrate at the time of the second film formation of the W film by the ion beam. In this method, as shown on the left side of FIG. 2, the first deposition film 55a is formed on the insulating film 51 by using the ion beam defocused at the time of the first film formation. Subsequently, the second deposition film 55b is formed on the first deposition film 55a by using an ion beam having a defocus amount smaller than the defocus amount of the ion beam at the time of the first film formation. According to this method, the current density can be reduced by increasing the spot diameter of the ion beam by defocusing, so that etching and damage of the underlying insulating film 51 can be suppressed. Moreover, since the current amount of the ion beam is the same, the aperture of the FIB device is not changed.

However, when the spot diameter of the ion beam is increased by defocusing as in Patent Document 1, the blurring of the beam on the surface of the insulating film 51 also increases, so that the W film pattern is formed in a range considerably wider than the spot diameter. Will be done. Therefore, in Patent Document 1, there is a problem that it is difficult to miniaturize the pattern of the W film. Further, FIG. 3 is a cross-sectional view of a main part of a semiconductor substrate in which patterns of W films formed by the method of FIG. 2 are arranged side by side. As shown in FIG. 3, in this case, there is a problem that the interval D50 of the adjacent W film patterns (first deposition film 55a and second deposition film 55b) cannot be miniaturized. Further, since the tail of the pattern edge of the W film (the hem portion of the outer periphery of the first deposition film 55a) functions as an electrode or wiring even if the film thickness is extremely small, the capacitance of the capacitor obtained for each element can be obtained. There is also the problem of large variations. Therefore, Patent Document 1 cannot be applied to the microfabrication required in the present embodiment.

In order to solve the above-mentioned problems, as a material at the initial stage of film formation, a material having a small sputtering rate with respect to FIB is formed with FIB, and then a W film is formed with FIB. The sputter rate is the rate at which the film-forming material is sputter-etched during FIB film formation, and the larger the sputter rate, the easier it is for the film-forming material to be sputter-etched. This sputtering rate is indicated by the number of atoms that are blown off during film formation, and the unit is (atoms / ion). FIG. 4 is a graph showing a comparison of the sputtering rates when various materials are formed by using Ga and Xe ion beams. The vertical axis represents the type of film-forming material (Si, titanium (Ti), aluminum (Al), W), and the horizontal axis represents the sputtering rate SPR with respect to the Ga, Xe ion beam. The acceleration energy Eg is, for example, 30 keV. The sputtering rate of Ti and Si is 63% smaller for Ga ions and 48% smaller for Xe ions than W. That is, in the case of Ti and Si, the deposition component can be made larger than the sputtering component as compared with W, so that damage to the substrate can be caused without reducing the current density of the ion beam (even without defocusing). Shaving can be suppressed. The sputtering rate (atoms / ion) for Xe irradiation (acceleration energy Eg = 30 keV) is W (8.507)> Ta (6.681)> Mo (6.592)> Ti (4.112)> Si. (3.793). In this way, the sputtering rate of each material is different with respect to the ion beam used. For example, when W is formed into a film, the W film is easily sputtered by an ion beam (that is, the sputtering rate is large), so that the time during which the substrate is exposed becomes long. Therefore, the amount of sputter etching of the underlying insulating film increases. On the other hand, since Ti has a small sputtering rate, the exposure time of the base is shortened. Therefore, the amount of sputter etching of the underlying insulating film is small.

Here, FIG. 5 left is a cross-sectional view of a main part of a semiconductor substrate after a material having a small amount of sputter etching of an insulating film is deposited by FIB treatment, and FIG. 5 right is a FIB treatment of a W film after FIB film formation on the left of FIG. It is a cross-sectional view of a main part of a semiconductor substrate after forming a film in. The semiconductor substrate 1S is made of, for example, Si, and the insulating film 2i on the semiconductor substrate 1S is made of, for example, silicon oxide.

First, as shown on the left of FIG. 5, a pattern of a material (first layer, first focus ion beam) having a FIB (focused ion beam: an ion beam focused on a film-forming surface) and a low sputtering rate. The forming layer) 3a is formed on the insulating film 2i. The amount of sputtering etching of the insulating film 2i in this step is smaller than the amount of sputtering etching of the insulating film 2i when the W film is directly formed on the insulating film 2i by FIB without performing this step. Therefore, even if the pattern 3a is formed by FIB, damage and scraping (etching) to the underlying insulating film 2i can be suppressed. That is, the scraping amount (sputter etching amount) of the insulating film 2i can be reduced as compared with the case where the W film is formed directly on the insulating film 2i by FIB.

Then, a W film pattern (second layer, second focus ion beam forming layer) 3b is formed on the lower pattern 3a by FIB (focused ion beam focused on the film forming surface). A laminated pattern 3 of patterns 3a and 3b is formed. When the upper W film pattern 3b is formed by FIB, the position of the outer periphery of the upper W film pattern 3b is set to the outer periphery of the lower pattern 3a so as not to damage the underlying insulating film 2i. It is formed so as to be located more inside. That is, in a plan view, the patterns 3a and 3b overlap each other, and the region of the pattern 3b is made smaller than the region of the pattern 3a. Therefore, an offset (distance) Df is provided between the outer circumference of the pattern 3b of the upper W film and the outer circumference of the pattern 3a of the lower layer. Since this offset Df is determined by the alignment accuracy of the FIB device, it can be miniaturized. Specifically, the offset Df can be set within 10% of the maximum width of the pattern 3a in the lower layer. That is, the length between the outer circumference of the pattern 3a in the lower layer and the outer circumference of the pattern 3b in the upper layer (specifically, between the side portion of the pattern 3a and the side portion of the pattern 3b immediately adjacent to the side portion of the pattern 3a). The width is within 10% of the maximum width of the pattern 3a in the lower layer. In other words, the lower layer pattern 3a has a portion protruding from the outer periphery of the upper layer pattern 3b on the outer peripheral portion thereof, and the length (offset Df) of the protruding portion is within 10% of the maximum width of the lower layer pattern 3a. Is.

When a material having a small sputtering rate is formed by FIB, the amount of scraping of the insulating film 2i during FIB film formation can be reduced. That is, since FIB (ion beam focused and focused on the film formation surface) can be used, the laminated pattern 3 (patterns 3a and 3b) can be miniaturized as a whole. Further, since the tail of the edge of the pattern 3a in the lower layer is smaller than that in FIG. 3, the fluctuation of the capacitor capacitance can be reduced.

Further, FIG. 6 is a cross-sectional view of a main part of the semiconductor substrate showing a case where the laminated patterns of FIG. 5 are arranged adjacent to each other. When a material having a small sputtering rate is used, the interval D1 between adjacent patterns 3b and 3b can be made smaller than the interval D50 in FIG. Further, if the offset Df is too long or too short, the capacitance between adjacent patterns varies, which makes it difficult to design the device. On the other hand, in the present embodiment, since the offset Df is defined, the capacitance variation between adjacent patterns 3b and 3b can be limited. Therefore, even a device that requires microfabrication can be easily designed.

(Embodiment 1)
<Configuration example of FIB device>
A configuration example of the FIB device according to the first embodiment will be described with reference to FIG. 7. FIG. 7 is a configuration diagram of an example of the processing apparatus of the first embodiment.

The FIB device (processing device) 5 of the first embodiment includes a beam irradiation unit 5a, a processing chamber 5b, a stage 5c, a gas supply unit 5d, a secondary electron detector 5e, a control unit 5f, and a main component. It has a drive unit 5g, a stage drive unit 5h, a display unit 5i, a storage unit 5j, a storage medium 5k, and an operation unit 5m.

The beam irradiation unit 5a of the FIB device 5 is a component that irradiates the semiconductor substrate (base) 1S mounted on the stage 5c in the processing chamber 5b with the FIB 5iB, and includes the ion generation unit 5ai and the beam optical system. It has 5ab and. Here, the ion beam in the beam irradiation unit 5a is referred to as an ion beam iB, and the ion beam emitted from the beam irradiation unit 5a is referred to as a FIB 5iB.

The ion generation unit 5ai is a component that generates an ion beam iB, and has an ion source 5ag, an extraction electrode 5aw, and an acceleration electrode 5as. The extraction electrode 5aw is an electrode for extracting ions from the ion source 5ag. Further, the acceleration electrode 5as is an electrode that accelerates the ions extracted by the extraction electrode 5aw.

The beam optical system 5ab is an optical system that guides the ion beam iB emitted from the ion generating unit 5ai to the film formation position of the semiconductor substrate 1S. In this beam optical system 5ab, a focusing lens 5af, a blanking electrode 5ak, a variable multi-aperture 5aa, a deflector 5ap, and an objective lens 5aj are arranged in order along the radiation direction of the ion beam iB. ..

The focusing lens 5af is a lens that focuses the ion beam iB generated from the ion generating unit 5ai, and is composed of, for example, an electrostatic lens. The blanking electrode 5ak is an electrode that controls on and off of irradiation of the ion beam iB focused by the focusing lens 5af.

The variable multi-aperture 5aa is a component that selectively limits the current of the ion beam iB when it is turned on. The variable multi-aperture 5aa is provided with a plurality of diaphragm holes having different diameters, and it is possible to selectively limit the current of the ion beam iB by switching the diaphragm holes arranged on the path of the ion beam iB. ing.

The deflector 5ap is a component that deflects the ion beam iB whose current is selectively limited by the variable multi-aperture 5aa. By deflecting the ion beam iB by the deflector 5ap, the ion beam iB can be two-dimensionally scanned in the main surface of the semiconductor substrate 1S. The objective lens 5aj is a lens for aligning the focus of the ion beam iB with the film forming surface (deposition position) on the main surface of the semiconductor substrate 1S, and is composed of, for example, an electrostatic lens.

The processing chamber 5b of the FIB device 5 is mechanically connected to an exhaust system (not shown), so that the inside of the processing chamber 5b can be maintained at a high degree of vacuum. Further, in the processing chamber 5b, a pressure gauge (not shown) for measuring the degree of vacuum (pressure) in the processing chamber 5b is installed. Further, a load lock chamber, a transfer robot (not shown), and the like are installed in the processing chamber 5b, whereby the semiconductor substrate 1S can be carried into the processing chamber 5b, and the semiconductor substrate 1S in the processing chamber 5b can be moved. It is possible to carry it out.

The stage 5c in the processing chamber 5b is a table on which the semiconductor substrate 1S is placed, and can be moved in the horizontal direction (X direction and the Y direction orthogonal to the X direction) and the axial direction (Z direction orthogonal to the X and Y). In addition, it is possible to rotate in the rotation direction and tilt in the tilt direction. The semiconductor substrate 1S is placed on the stage 5c while being held by a holder (not shown).

The gas supply unit 5d is a component that sprays the raw material gas (precursor) onto the film formation region on the main surface of the semiconductor substrate 1S. When the sprayed region of the raw material gas is irradiated with FIB5iB, the secondary electrons emitted from the surface of the semiconductor substrate 1S react with the raw material gas to form a film. Thereby, a desired pattern can be formed in the irradiation region of FIB5iB.

The secondary electron detector 5e is a detector that detects secondary electrons generated when the FIB 5iB irradiates the semiconductor substrate 1S, and has, for example, a scintillator and a photomultiplier tube. The secondary electron detector 5e is electrically connected to the control unit 5f, and the signal detected by the secondary electron detector 5e is sent to the control unit 5f as image data synchronized with the scanning signal of the FIB 5iB. The signal sent from the secondary electron detector 5e is image-processed (processed to generate a SIM (Scanning Ion Microscope) image or the like) by the control unit 5f and displayed on the display unit 5i. The display unit 5i is a display device that displays an image (SIM image or the like) generated by the control unit 5f, and is composed of, for example, an LCD (Liquid Crystal Display) or a CRT (Cathode Ray Tube).

The control unit 5f performs various controls and calculations according to the program of the storage medium 5k. That is, the control unit 5f controls various operations of the beam irradiation unit 5a, the gas supply unit 5d, and the stage 5c through the main drive unit 5g and the stage drive unit 5h. Then, the control unit 5f controls the beam irradiation unit 5a to form a desired pattern on the main surface of the semiconductor substrate 1S. In the first embodiment, the control unit 5f has a first control for forming the lower layer pattern 3a (see FIG. 5) with the FIB and a second control for forming the upper layer pattern 3b (see FIG. 5) with the FIB. And are supposed to be done.

The main drive unit 5g is a component that electrically and mechanically drives the beam irradiation unit 5a and the gas supply unit 5d. The main drive unit 5g is electrically connected to the control unit 5f and is controlled by the control unit 5f. The stage drive unit 5h is a component that drives the stage 5c. The stage drive unit 5h is electrically connected to the control unit 5f and is controlled by the control unit 5f.

The storage unit 5j is a memory area that serves as a work area (work area) of the control unit 5f, and is composed of, for example, a RAM (Random Access Memory). The storage unit 5j is used to store programs, data, and the like for performing various controls and calculations of the control unit 5f. The storage unit 5j is also used to temporarily store the calculation results and the like calculated according to various programs. The storage unit 5j is provided with, for example, a beam irradiation range of processing conditions (focus condition, spot diameter, current amount, acceleration energy, etc.) at the time of film formation processing by FIB, and various patterns (the lower layer pattern 3a and the upper layer pattern 3b). Various information such as (position coordinates) and film formation time (FIB irradiation time) are recorded.

The storage medium 5k is a medium that can be read by a computer, and stores programs, data, and the like. The storage medium 5k is composed of, for example, an optical disk (CD, DVD), a magneto-optical disk (MO), a magnetic disk, a hard disk, a magnetic tape, a ROM (Read Only Memory), or the like. The storage medium 5k can store a program for operating the computer as each unit of the control unit 5f.

The operation unit 5m is an input device for inputting an operation signal corresponding to the operation to the control unit 5f, and is composed of, for example, a button, a keyboard, a touch panel type display, a microphone, or the like.

In such a FIB device 5, the raw material gas is supplied onto the main surface of the semiconductor substrate 1S through the gas supply unit 5d, and the FIB 5iB is scanned by the beam irradiation unit 5a in the gas supply region, thereby forming the scanning region of the FIB 5iB. The desired pattern can be formed.

<Example of film formation method>
An example of the FIB film forming method (processing method) of the first embodiment will be described with reference to FIGS. 7 to 10. FIG. 8 is a flowchart of an example of the FIB film forming method of the first embodiment, and FIGS. 9 and 10 are cross-sectional views of a main part of the semiconductor substrate during the FIB film forming process of the first embodiment.

First, as shown in FIG. 9, a lower layer pattern (first layer, first focus ion beam) made of, for example, Ti (a metal containing Ti as a main component) is formed on the insulating film 2i on the semiconductor substrate 1S. Layer: 3am (corresponding to the above pattern 3a) is formed with FIB5iB (S100 in FIG. 8). That is, the raw material gas (precursor: first raw material gas) is sprayed onto the upper surface of the insulating film 2i from the gas supply unit 5d, and the FIB (focused and focused on the film forming surface is focused on the film forming region of the sprayed region of the raw material gas). (Ion beam) 5iB is irradiated to selectively form a lower pattern 3am in the beam irradiation region.

Specifically, as shown in FIG. 7, the control unit 5f of the FIB device 5 controls the beam irradiation unit 5a based on the information of the storage unit 5j to blow the raw material gas from the gas supply unit 5d. The sprayed area is irradiated with FIB5iB to form a pattern 3am (see FIG. 9) (first control). At this time, the control unit 5f brings the focus of the ion beam iB focused by the focusing lens 5af to the film forming surface on the upper surface of the insulating film 2i by the objective lens 5aj. As a result, Ti is deposited in the irradiation region (scanning region) of FIB5iB to form the lower pattern 3am.

The ion source at the time of forming the FIB film is, for example, Ga or Xe. The raw material gas is, for example, titanium tetrachloride (TiCl ₄ ) or titanium nitrate (Ti (NO ₃ ) ₄ ). The spot diameter of FIB5iB is, for example, about 100 nm to several μm. The amount of current during FIB film formation is, for example, about 0.1 μA to 1 μA, and the acceleration energy is, for example, about 20 keV to 30 keV. The temperature of the stage 5c is room temperature (for example, 20 ° C to 30 ° C). The thickness of the pattern 3am is, for example, 50 nm or less. The above-mentioned "main component" means a material contained in the largest amount among the constituent materials of the member. The intent of the term "main component" in the present specification is, for example, when a member is basically composed of a main component (here, Ti, etc.) but contains other impurities (material, component) in the member. Means not to exclude.

In such a film formation of a Ti film by FIB, as described above, since the sputtering rate (amount of scraping) of Ti is small, the surface of the underlying insulating film 2i is immediately coated with Ti. Therefore, even if the pattern 3am is formed by the FIB 5iB, damage or scraping to the underlying insulating film 2i can be suppressed. Further, since the pattern 3am can be formed by FIB5iB, a fine pattern 3am with high dimensional accuracy can be formed.

Next, as shown in FIG. 10, an upper pattern (second layer, second focus ion beam forming layer: the above pattern) composed of, for example, W (a metal containing W as a main component) is placed on the lower pattern 3am. 3bm (corresponding to 3b) is formed with FIB5iB (S101 in FIG. 8). That is, the raw material gas (precursor: second raw material gas) is sprayed from the gas supply unit 5d onto the upper surface of the lower pattern 3am, and the FIB (focused and focused on the film forming surface) is focused on the film forming region of the spraying region of the raw material gas. The combined ion beam) 5iB is irradiated to selectively form an upper pattern 3bm in the beam irradiation region.

Specifically, as shown in FIG. 7, the control unit 5f of the FIB device 5 controls the beam irradiation unit 5a based on the information of the storage unit 5j to blow the raw material gas from the gas supply unit 5d. The sprayed area is irradiated with FIB5iB to form a pattern 3bm (see FIG. 10) (second control). At this time, the control unit 5f makes the focus of the ion beam iB focused by the focusing lens 5af aligned with the film formation surface on the upper surface of the pattern 3am (see FIG. 10) by the objective lens 5aj. As a result, W is deposited in the irradiation region (scanning region) of the FIB5iB to form the upper layer pattern 3bm, and the laminated pattern 3 in which the pattern 3bm is laminated on the pattern 3am is formed.

In the film forming process of the upper layer pattern 3bm, the control unit 5f prevents the upper layer W film pattern 3bm from protruding from the lower layer Ti film pattern 3am so as not to damage the underlying insulating film 2i. To do. That is, the position of the outer circumference of the upper layer pattern 3bm is controlled to be located inside the outer circumference of the lower layer pattern 3am (in a plan view, the region of the upper layer pattern 3bm is controlled to be the region of the lower layer pattern 3am). Do: # 1) in FIG. Then, the control unit 5f controls so that the offset Df between the outer circumference of the upper layer pattern 3bm and the outer circumference of the lower layer pattern 3am is within 10% of the maximum width of the lower layer pattern 3am (FIG. 8). # 2).

The raw material gas for the FIB film formation of the pattern 3 bm in the upper layer is, for example, hexacarbonyl tungsten (W (CO) ₆ ). The thickness of the pattern 3 bm is, for example, 300 to 500 nm. The ion source at the time of FIB film formation, the spot diameter of FIB5iB, the amount of current at the time of FIB film formation, the acceleration energy, and the temperature of the stage 5c are the same as in the case of the lower pattern 3am.

In the film formation of the W film by FIB, since the pattern 3am is formed in the lower layer of the W film, damage and scraping to the underlying insulating film 2i can be suppressed. Further, since the upper layer pattern 3bm can be formed by FIB5iB, a fine pattern 3bm with high dimensional accuracy can be formed. Therefore, even when the laminated patterns 3 are arranged side by side, the interval between adjacent patterns 3 bm can be made smaller than that in the case of FIG. Further, since the offset Df is defined, the capacitance variation between adjacent patterns 3b and 3b can be limited. Therefore, the design of the device can be facilitated.

<Example of semiconductor device>
Next, an example of the semiconductor device formed by the FIB film forming method will be described with reference to FIGS. 11 and 12. FIG. 11 is a plan view of a main part of an example of the semiconductor device according to the first embodiment, and FIG. 12 is a cross-sectional view taken along the line II of FIG.

Here, a MOS (Metal Oxide Semiconductor) type capacitor Cm is shown as an example of a semiconductor device. The capacitor Cm has a semiconductor substrate 1S as a lower electrode, a laminated pattern 3 as an upper electrode, and an insulating film 2i between them as a capacitive insulating film. The plane dimension of the pattern 3am in the lower layer of the laminated pattern 3 is, for example, about 100 μm × 100 μm. The length (offset Df) between the outer circumference of the upper layer pattern 3bm and the outer circumference of the lower layer pattern 3am is within 10% of the maximum width of the lower layer pattern 3am. In this case, since the pattern 3a in the lower layer is square in a plan view, the maximum width of the pattern 3a may be the width of any of the four sides of the pattern 3a.

In the first embodiment, the amount of scraping of the insulating film 2i can be reduced as compared with the case where the W film is directly formed on the insulating film 2i by FIB, so that the dielectric strength of the capacitive insulating film of the capacitor Cm can be improved. .. Therefore, the electrical characteristics and reliability of the capacitor Cm can be improved.

(Modification example 1)
Next, an example of the FIB film forming method (processing method) of the modification 1 of the first embodiment will be described with reference to FIGS. 7, 8, 13, and 14. 13 and 14 are cross-sectional views of a main part of the semiconductor substrate during the FIB film forming process of Modification 1.

First, as shown in FIG. 13, a pattern (first layer, first focus ion beam) of a lower layer made of, for example, silicon oxide (a film containing Si as a main component) is placed on the insulating film 2i on the semiconductor substrate 1S. Forming layer: Corresponding to the above-mentioned pattern 3a) 3as is selectively formed by FIB5iB in the same manner as the above-mentioned patterns 3am and 3bm (S100 in FIG. 8). The lower layer pattern 3as made of silicon oxide has a function as a sacrificial film or a base protective film when forming the subsequent upper layer pattern 3bm. The control of the control unit 5f is the same as that of the pattern 3am in the lower layer.

The raw material gas for FIB film formation of the pattern 3as in the lower layer is, for example, TEOS, TMCTS (tetramethylcyclotetrasiloxane: HSiCH ₃ O ₄ ) or OMCTS (octamethylcyclotetrasiloxane: C ₈ H ₂₄ O ₄ Si ₄ ). Etc. is a cyclic siloxane. The thickness of the pattern 3as is, for example, 50 nm or less. The ion source at the time of FIB film formation, the spot diameter of FIB5iB, the amount of current at the time of FIB film formation, the acceleration energy and the temperature of the stage 5c are the same as in the case of the above-mentioned lower layer pattern 3am.

In such a film forming process of the silicon oxide film by FIB5iB, as described above, since the sputtering rate of the insulating film 3as is small, the surface of the underlying insulating film 2i is instantly covered with the insulating film 3as. That is, even if the pattern 3as is formed by the FIB 5iB, damage or scraping to the underlying insulating film 2i can be suppressed. Further, since the pattern 3as can be formed by FIB5iB, a fine pattern 3as with high dimensional accuracy can be formed.

Next, as shown in FIG. 14, on the lower pattern 3as, for example, the upper pattern 3bm made of W (a metal containing W as a main component) is selectively formed by FIB5iB in the same manner as described above (FIG. 8). S101). The control of the control unit 5f in this case is the same as described above. In this case as well, the control unit 5f prevents the pattern 3bm of the upper W film from protruding from the pattern 3as of the lower silicon oxide film so as not to damage the underlying insulating film 2i. That is, the outer circumference of the upper layer pattern 3bm is controlled to be located inside the outer circumference of the lower layer pattern 3as (in a plan view, the upper layer pattern 3bm region is controlled to be less than the lower layer pattern 3as region: FIG. 8 # 1). Then, the control unit 5f controls so that the length (offset Df) between the outer circumference of the pattern 3bm of the upper layer W film and the outer circumference of the pattern 3as of the lower layer is within 10% of the maximum width of the pattern 3as of the lower layer. (# 2 in FIG. 8).

In this way, a laminated pattern of the pattern 3as made of the silicon oxide film and the pattern 3bm made of the W film on the insulating film 2i is formed on the insulating film 2i. Also in this case, the length (offset Df) between the outer circumference of the upper layer pattern 3bm and the outer circumference of the lower layer pattern 3as is within 10% of the maximum width of the pattern 3as.

In such a film formation of the W film by FIB5iB, since the pattern 3as is formed in the lower layer of the W film, the pattern 3as is damaged or scraped, but the damage or scraping to the underlying insulating film 2i can be suppressed. Therefore, the electrical characteristics of the element can be improved.

Further, since the upper layer pattern 3bm can be formed by FIB5iB, a fine pattern 3bm with high dimensional accuracy can be formed as described above. Therefore, even when the patterns 3bm are arranged side by side, the interval between adjacent patterns 3bm can be made smaller than in the case of FIG.

(Modification 2)
Next, an example of the FIB film forming method (processing method) of the modified example of the modified example 1 will be described with reference to FIGS. 7, 8, 15, and 16. 15 and 16 are cross-sectional views of a main part of the semiconductor substrate during the FIB film forming process of Modification 2.

First, as shown in FIG. 15, the lower pattern 3as is selectively formed on the insulating film 2i on the semiconductor substrate 1S with the FIB 5iB in the same manner as described above (S100 in FIG. 8). Here, the thickness Z1 of the lower pattern 3as is the amount that the insulating film 2i is scraped when the W film (pattern 3bm) is directly formed on the insulating film 2i by the FIB without forming the lower pattern 3as. It is set to the thickness (depth). Other than this, it is the same as the first modification.

Next, as shown in FIG. 16, the upper pattern 3bm is selectively formed on the lower pattern 3as with the FIB 5iB in the same manner as described above (S101 in FIG. 8). At this time, the lower pattern 3as is scraped in the formation region of the pattern 3bm, and the upper surface of the underlying insulating film 2i is exposed. Therefore, the pattern 3bm made of the W film is formed on the insulating film 2i in a state of being in contact with the underlying insulating film 2i. Other than this, it is the same as the above-mentioned modification 1.

As described above, in the modified example 2, the pattern 3bm can be directly formed on the underlying insulating film 2i while suppressing damage and scraping of the underlying insulating film 2i. The other effects are the same as those of the first modification.

<Example of semiconductor device of modification 2>
Next, an example of a semiconductor device manufactured by applying the FIB film forming technique of Modification 2 will be described with reference to FIGS. 17 and 18. FIG. 17 is a plan view of an example of the semiconductor device of the second modification, and FIG. 18 is a sectional view taken along line II-II of FIG.

For example, an insulating film 2ii made of silicon oxide is formed on the main surface of the semiconductor substrate 1S. For example, wirings 7L1 and 7L2 containing aluminum as a main component are formed on the insulating film 2ii in a state of being separated from each other.

Further, an insulating film 2i is formed on the insulating film 2ii so as to cover the wirings 7L1 and 7L2. The insulating film 2i is formed with connection holes 8 and 8 in which a part of the upper surface of the wirings 7L1 and 7L2 is exposed, and inside the connection holes 8 and 8, for example, a plug 7P1 containing W as a main component. , 7P2 is embedded.

The plugs 7P1 and 7P2 are joined to the above-mentioned pattern 3bm and are electrically connected to each other through the pattern 3bm. That is, the wirings 7L1 and 7L2 are electrically connected through the plugs 7P1, 7P2 and the pattern 3bm.

In the case of this structure, when the film forming method of Modification 1 is applied, the pattern 3as of the insulating film is left in the lower layer of the pattern 3bm, so that the pattern 3bm cannot be brought into contact with the plugs 7P1 and 7P2. That is, the plugs 7P1 and 7P2 cannot be electrically connected to each other.

On the other hand, when the film forming method of Modification 2 is applied, the pattern 3as of the insulating film is not left in the lower layer of the pattern 3bm, so that the pattern 3bm can be brought into contact with the plugs 7P1 and 7P2. That is, the plugs 7P1 and 7P2 can be electrically connected to each other. Therefore, the wirings 7L1, 7L2 can be electrically connected through the plugs 7P1, 7P2 and the pattern 3bm.

In this case, the shape of the lower layer pattern 3as in a plan view is rectangular (belt-shaped), but the length (offset Df) between the outer circumference of the upper layer pattern 3bm and the outer circumference of the lower layer pattern 3as is the lower layer pattern. It is within 10% of the maximum width of 3as. Here, for example, the offset Df is the same on the maximum width side and the minimum width side of the pattern 3a according to the maximum width of the pattern 3as in the lower layer. However, in this case, the length of the offset Df may be changed between the maximum width side and the minimum width side of the pattern 3as in the lower layer. For example, the offset Df on the minimum width side of the lower pattern 3as may be set to be within 10% of the minimum width of the lower pattern 3as, and may be shorter than the offset Df on the maximum width side of the lower pattern 3as.

Further, the FIB film forming technique of Modification 2 is preferably applied, for example, when forming the upper electrode of the MOS type capacitor Cm described with reference to FIGS. 11 and 12. By applying the FIB film forming method of Modification 2 when forming the upper electrode (pattern 3 bm) of the capacitor Cm, the capacitive insulating film of the capacitor Cm (insulating film 2i) is ensured while ensuring the dielectric strength of the capacitive insulating film of the capacitor Cm. ) Can be set with high accuracy.

(Embodiment 2)
<Inventor's examination>
FIG. 19 is _{a graph showing that the W film formed by W (CO) 6} depends on the film thickness of the underlying insulating film. The vertical axis is the thickness of the W film TH-W, and the horizontal axis is the thickness of the underlying insulating film TH-SiO. Reference numerals B1 and B2 indicate the type of ion beam. From FIG. 19, _{it can be seen that the film formation of the W film by W (CO) 6} depends on the film thickness of the underlying insulating film (silicon oxide film). This differs depending on the base material, and the film formation rate of the W film becomes high on a material having a low thermal conductivity (a material in which heat does not easily escape). That is, since the film formation rate of the W film is increased, the amount of scraping of the base material can be significantly suppressed.

Here, in W (CO) ₆ , at a low temperature of about 100 ° C. or lower, the material is only adsorbed on the surface of the substrate and no film formation occurs. On the other hand, when the temperature rises to 110 ° C. or higher, _{the “-CO” of W (CO) 6} dissociates and film formation begins to occur (CVD (Chemical Vapor Deposition) mode). On the other hand, if the thermal conductivity is large like that of a Si substrate, the increase in the substrate surface temperature is suppressed, so that film formation does not occur.

By utilizing this phenomenon, the above-mentioned problems can be solved. That is, when the W film is formed, the CVD reaction is assisted to increase the film forming speed of the W film. Specifically, only the temperature of the irradiation region of the FIB is set to be equal to or higher than the decomposition temperature of _{the raw material gas (here, for example, W (CO) 6).} The decomposition temperature of W (CO) ₆ is the temperature at which the bond between W and other elements is broken.

FIG. 20 is a graph showing the relationship between the pulse width PW (horizontal axis) of the FIB and the temperature TE (vertical axis) of the FIB irradiation region at the time of film formation by a general FIB. The symbol DT indicates the decomposition temperature of the raw material gas. _{The decomposition temperature DT of W (CO) 6} , which is the raw material gas (precursor) of the W film, is, for example, about 110 ° C. to 140 ° C. FIB ion current density is small and, when the pulse width is long, not reach the decomposition temperature DT of the temperature W _{(CO) 6} in the FIB irradiation region, the decomposition of W _{(CO) 6} is stuck (temperature Equilibrium between heat generation and heat dissipation).

On the other hand, FIG. 21 is a graph showing an example of the relationship between the pulse width PW (horizontal axis) of the FIB at the time of film formation by the FIB of the second embodiment and the temperature TE (vertical axis) of the FIB irradiation region. In this case, the temperature of the irradiation region of the FIB is changed to the decomposition temperature of the _{raw material gas (W (CO) 6} ) by increasing the ion current density of the FIB and significantly shortening the pulse width (irradiation time of the beam of one shot). It is more than DT. As a result, the film formation rate of the W film can be increased, so that damage and scraping of the underlying insulating film can be suppressed (the temperature rises because heat generation is larger than heat dissipation).

By the way, in the example of FIG. 21, the ion current density and the pulse width of the FIB are controlled in order to make the temperature of the FIB irradiation region equal to or higher than the decomposition temperature of the raw material gas as described above. It can also be achieved by raising the stage temperature on which the substrate is placed (heating the substrate).

FIG. 22 is a graph showing the relationship between the irradiation time Tb (horizontal axis) of the FIB and the temperature Ts on the surface of the substrate. The broken line shows the case where the stage temperature is room temperature. The broken line in the lower row shows the case where the substrate is a single Si substrate, and the broken line in the upper row shows the case where the substrate is a silicon oxide film laminated on the Si substrate. The solid line shows the case where the stage temperature is raised. The solid line in the lower row shows the case where the substrate is a single Si substrate, and the practice in the upper row shows the case where the substrate is a silicon oxide film laminated on the Si substrate.

From FIG. 22, it can be seen that when the stage temperature is raised, the temperature of the FIB irradiation region reaches the decomposition temperature of the raw material gas or higher even if the substrate is a Si substrate. Further, it can be seen that the time required for the temperature in the FIB irradiation region to reach the decomposition temperature of the raw material gas or higher can be shortened as compared with the case where the stage temperature is not raised. That is, the time from the irradiation of FIB to the start of W film deposition can be significantly shortened.

FIG. 23 shows an example of the relationship between the pulse width PW (horizontal axis) of the FIB and the temperature TE (vertical axis) of the FIB irradiation region at the time of film formation by the FIB of the second embodiment when the stage temperature is raised. It is a graph diagram. In this case, even if the ion current density and the pulse width are the same as in the general case, the temperature of the FIB irradiation region can be set to be equal to or higher than the decomposition temperature of the raw material gas, so that the film formation rate of the W film is higher than that in the case of FIG. can do. Therefore, damage and scraping of the underlying insulating film can be suppressed.

Further, FIG. 24 shows the relationship between the pulse width PW (horizontal axis) of the FIB and the temperature TE (vertical axis) of the FIB irradiation region at the time of film formation by the FIB of the second embodiment when the stage temperature is raised. It is a graph which shows the example of. In this case, since the temperature of the irradiation region of the FIB can be made higher than the decomposition temperature of the raw material gas faster than in the case of FIG. 21, the film formation rate of the W film can be made higher than in the case of FIG. Therefore, damage and scraping of the underlying insulating film can be suppressed as compared with the case of FIG. 21.

<Structure example of the FIB device of the second embodiment>
A configuration example of the FIB apparatus according to the second embodiment will be described with reference to FIG. FIG. 25 is a configuration diagram of an example of the processing apparatus of the second embodiment.

In the FIB device (processing device) 5 of the second embodiment, a heating unit 5n for heating the semiconductor substrate 1S is installed on the stage 5c on which the semiconductor substrate 1S is placed. The heating unit 5n is composed of, for example, a resistance heating type heating device including a resistance heating element, and is electrically connected to the control unit 5f. A lamp heating (light heating) type heating device may be used as the heating unit 5n.

Further, a temperature measuring instrument 5p for measuring the stage temperature is installed on the stage 5c. The temperature measuring instrument 5p includes, for example, a thermocouple and is electrically connected to the control unit 5f. The control unit 5f can adjust (control) the heating temperature of the heating unit 5n (that is, the stage temperature and the temperature of the semiconductor substrate 1S) based on the temperature information measured by the temperature measuring instrument 5p.

In the FIB apparatus 5 of the second embodiment, when the FIB film forming conditions (including, for example, the type and thickness of the underlying insulating film) are input, the control conditions (ion current density and pulse width) of the beam irradiation unit 5a are input. ) And the stage temperature can be automatically set to the optimum values.

The control unit 5f of the FIB device 5 of the second embodiment controls the stage 5c to be heated by the heating unit 5n prior to the film forming process by the FIB 5iB. As a result, during the film forming process on the FIB 5iB, the temperature of the irradiation region of the FIB 5iB can be made faster than the decomposition temperature of the raw material gas, so that the film forming rate can be further increased. As a result, it is possible to suppress the occurrence of damage or scraping of the underlying insulating film 2i. Other configurations and effects are the same as those described with reference to FIG.

<Example of film formation method>
An example of the FIB film forming method (processing method) of the second embodiment will be described. FIG. 26 is a cross-sectional view of a main part of the semiconductor substrate during the FIB film forming process of the second embodiment.

First, on the insulating film 2i on the semiconductor substrate 1S, for example, a pattern 3c made of W (a metal containing W as a main component) is formed by FIB5iB. That is, the raw material gas (precursor) is sprayed from the gas supply unit 5d onto the upper surface of the insulating film 2i, and the FIB (ion beam focused on the film-forming surface) 5iB is applied to the film-forming region of the raw material gas spraying region. Pattern 3c is selectively formed in the beam irradiation region by irradiating with.

Specifically, as shown in FIG. 25, the control unit 5f of the FIB device 5 controls the beam irradiation unit 5a based on the information of the storage unit 5j to blow the raw material gas from the gas supply unit 5d. The sprayed area is irradiated with FIB5iB. At this time, the control unit 5f brings the focus of the ion beam iB focused by the focusing lens 5af to the film forming surface on the upper surface of the insulating film 2i by the objective lens 5aj. As a result, W is deposited in the irradiation region (scanning region) of FIB5iB to form the pattern 3c. The spot diameters of the raw material gas, the ion source, and the FIB5iB at the time of the FIB film formation are the same as the case of the upper layer pattern 3bm in the current amount and the acceleration energy at the time of the FIB film formation. The thickness of the pattern 3c is also the same as the thickness of the pattern 3bm.

Further, in the second embodiment, the temperature of the irradiation region of the FIB5iB is set to be equal to or higher than the decomposition temperature of the raw material gas during the film forming process by the FIB5iB. That is, as described in FIG. 21, the control unit 5f of the FIB device 5 controls the beam irradiation unit 5a to adjust (control) the ion current density and the pulse width, so that the temperature of the irradiation region of the FIB 5iB becomes W. The temperature should be equal to or higher than the decomposition temperature of (CO) _6. As a result, the film formation rate of the W film can be further increased, so that damage or scraping of the underlying insulating film 2i can be suppressed.

Further, as another example for making the temperature of the beam irradiation region equal to or higher than the decomposition temperature of the raw material gas, the stage 5c of the FIB apparatus 5 is heated by the heating unit 5n to heat the semiconductor substrate 1S prior to the irradiation of the FIB 5iB. You may. As a result, as described with reference to FIG. 23, the temperature of the irradiation region of the FIB5iB can be made faster than the decomposition temperature of the raw material gas during the film formation process by the FIB5iB, so that the film formation rate of the W film is further increased. be able to. Therefore, it is possible to further suppress the occurrence of damage or scraping of the underlying insulating film 2i.

Here, the temperature of the stage 5c is set to, for example, 80 ° C. or higher and 100 ° C. or lower. If the temperature is lower than 80 ° C., the start of film formation is delayed, and there is a concern that the underlying insulating film 2i may be affected during film formation. Further, if the temperature is higher than 100 ° C., the temperature becomes close to the decomposition temperature of the raw material gas up to the region not irradiated with FIB5iB, and there is a concern that film formation may occur in the region other than the beam irradiation region.

Further, in order to make the temperature of the beam irradiation region equal to or higher than the decomposition temperature of the raw material gas, both the beam irradiation unit 5a and the heating unit 5n of the FIB device 5 may be controlled. That is, prior to the irradiation of the FIB 5iB, the stage 5c of the FIB device 5 is heated by the heating unit 5n to raise the temperature of the semiconductor substrate 1S, and the beam irradiation unit 5a is controlled during the irradiation of the FIB 5iB to control the ion current density and the ion current density. Adjust (control) the pulse width. As a result, as described with reference to FIG. 24, the temperature of the irradiation region of the FIB5iB can be made higher than the decomposition temperature of the raw material gas during the film formation process by the FIB5iB, so that the film formation rate of the W film can be further increased. It can be made larger. Therefore, it is possible to further suppress the occurrence of damage or scraping of the underlying insulating film 2i.

(Modification 1 of Embodiment 2)
The FIB film forming technique of the second embodiment can also be applied at the time of forming the pattern 3bm of the upper layer described in the first embodiment. That is, as shown in FIG. 10, when the pattern 3bm is formed on the lower pattern 3am, the beam irradiation unit 5a (ion _{) so that the temperature of the beam irradiation region becomes equal to or higher than the decomposition temperature of W (CO) 6.} The current density and pulse width) are controlled, the heating unit 5n is controlled, or both are controlled.

In this case, since damage and scraping of the lower layer pattern 3am can be suppressed during film formation of the pattern 3bm, the reliability of the laminated pattern 3 can be improved as compared with the case of the first embodiment. Since Ti is not affected by temperature, when controlling by the heating unit 5n, the stage 5c (that is, the semiconductor substrate) by the heating unit 5n is performed from the preparatory stage before forming the Ti film (lower layer pattern 3am). The heating of 1S) may be started. If the heating of the stage 5c is started immediately before the film formation of the upper layer pattern 3bm, it takes time for the stage temperature to stabilize at the target temperature, so that the start of FIB irradiation for the film formation of the upper layer pattern 3b is delayed. On the other hand, by heating the stage 5c before forming the lower pattern 3am, the stage temperature has already reached the target temperature when the lower pattern 3am is formed, so that the lower pattern 3am is formed. Later, FIB irradiation for film formation of the upper pattern 3 bm can be started at a relatively early stage.

Further, FIG. 27 is a cross-sectional view of a main part of the semiconductor substrate showing a modified example of the laminated pattern formed by the FIB film forming technique of the second embodiment. When the upper pattern 3bm is formed on the lower pattern 3am by the FIB film forming technique of the second embodiment, it is possible to suppress damage or scraping of the underlying insulating film 2i when the upper pattern 3bm is formed. it can. Therefore, as shown in FIG. 27, the outer circumference of the pattern 3bm in the upper layer may protrude to the outside from the outer circumference of the pattern 3am in the lower layer. In this case, the work function can be set to a value determined by the Ti film (lower layer pattern 3am).

Further, the FIB film forming technique of the second embodiment can be applied to the formation of the upper layer pattern 3bm described in the first modification of the first embodiment.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace other configurations with respect to a part of the configurations of each embodiment.

Further, the terms "electrode" and "wiring" in the present specification do not functionally limit these components. For example, an "electrode" may be used as part of a "wiring" and vice versa. Further, the terms "electrode" and "wiring" include the case where a plurality of "electrodes" and "wiring" are integrally formed.

Further, in the above-described embodiment, the case where the FIB processing technique of the present embodiment is applied to a MOS type capacitor or a wiring connection portion has been described, but the present invention is not limited to this, and various applications are possible. For example, it can be applied to the correction of the wiring disconnection portion. Further, for example, it can be applied to a processing technique in MEMS (Micro Electro Mechanical Systems: semiconductor device).

Further, in the above-described embodiment, the first layer or the first focus ion beam forming layer is Ti or silicon oxide, but the present invention is not limited thereto.

[Appendix 1]
A beam irradiation unit that irradiates the substrate with a focus ion beam,
A gas supply unit that supplies the raw material gas onto the insulating film formed on the substrate, and
A control unit that controls the beam irradiation unit and
With
The control unit is a processing device that controls the temperature of the irradiation region of the focus ion beam to be equal to or higher than the decomposition temperature of the raw material gas.

[Appendix 2]
In the processing apparatus of Appendix 1,
The control unit is a processing device that controls the beam irradiation unit so that the temperature of the irradiation region of the focus ion beam becomes equal to or higher than the decomposition temperature of the raw material gas.

[Appendix 3]
In the processing apparatus of Appendix 1,
A heating unit for heating the substrate is provided.
The control unit is a processing device that controls the heating unit so that the temperature of the irradiation region of the focus ion beam becomes equal to or higher than the decomposition temperature of the raw material gas.

[Appendix 4]
(A) In a state where the first raw material gas is supplied onto the insulating film formed on the substrate, the focus ion beam is irradiated to the supply region of the first raw material gas to cause the first raw material gas to be supplied onto the insulating film. The process of forming layers,
(B) With the second raw material gas supplied onto the first layer, the focus ion beam is irradiated to the supply region of the second raw material gas, so that the first layer is made of metal. The process of forming the second layer,
Have,
The outer circumference of the second layer is located inside the outer circumference of the first layer.
A processing method in which the first layer is smaller than the second layer in terms of the sputtering rate, which indicates the rate at which the film-forming material is sputter-etched during film formation with the focus ion beam.

1S semiconductor substrate 2i insulating film 2ii insulating film 3 laminated pattern 3a, 3am, 3as pattern 3b, 3bm pattern 3c pattern 5 FIB device 5a beam irradiation unit 5b processing room 5c stage 5d gas supply unit 5f control unit 5j storage unit 5k storage medium Heating unit 5p temperature measuring instrument 5iB FIB
7L1,7L2 wiring 7P1,7P2 plug 8 connection hole iB ion beam

Claims (14)

(A) In a state where the first raw material gas is supplied onto the insulating film formed on the substrate, the focus ion beam is irradiated to the supply region of the first raw material gas to cause the first raw material gas to be supplied onto the insulating film. The process of forming layers,
(B) With the second raw material gas supplied onto the first layer, the focus ion beam is irradiated to the supply region of the second raw material gas, so that the first layer is made of metal. The process of forming the second layer,
Have,
The outer circumference of the second layer is located inside the outer circumference of the first layer.
The amount of sputter etching of the insulating film in the step (a) is the supply region of the second raw material gas in a state where the second raw material gas is supplied onto the insulating film without performing the step (a). A processing method that is smaller than the sputter etching amount of the insulating film when the second layer is directly formed on the insulating film by irradiating the focus ion beam. In the processing method according to claim 1,
A processing method in which the length between the outer circumference of the second layer and the outer circumference of the first layer is within 10% of the maximum width of the first layer. In the processing method according to claim 1,
The first layer is made of a metal containing titanium as a main component.
A processing method in which the second layer is made of a metal containing tungsten as a main component. In the processing method according to claim 1,
The first layer contains silicon as a main component and contains silicon.
A processing method in which the second layer is made of a metal containing tungsten as a main component. In the processing method according to claim 4,
The first layer is made of silicon oxide and is made of silicon oxide.
The thickness of the first layer is such that the focus ion beam is applied to the supply region of the second raw material gas in a state where the second raw material gas is supplied onto the insulating film without performing the step (a). A processing method, which is a thickness at which the insulating film is scraped when the second layer is directly formed on the insulating film by irradiating the insulating film. In the processing method according to claim 1,
A processing method in which the temperature of the irradiation region of the focus ion beam at the time of forming the second layer is equal to or higher than the decomposition temperature of the second raw material gas. The insulating film provided on the semiconductor substrate and
The first focus ion beam cambium provided on the insulating film and
A second focus ion beam cambium made of metal formed on the first focus ion beam cambium, and a second focus ion beam cambium.
With
The outer circumference of the second focus ion beam forming layer is located inside the outer circumference of the first focus ion beam forming layer.
The amount of scraping of the insulating film at the time of forming the first focus ion beam forming layer is such that the second focus ion beam forming layer is formed on the insulating film without forming the first focus ion beam forming layer. A semiconductor device that is smaller than the amount of scraping of the insulating film when it is directly formed. In the semiconductor device according to claim 7, the length between the outer circumference of the second focus ion beam forming layer and the outer circumference of the first focus ion beam forming layer is the length of the first focus ion beam forming layer. A semiconductor device that is within 10% of the maximum width. In the semiconductor device according to claim 7,
The first focus ion beam cambium is made of a metal containing titanium as a main component.
A semiconductor device in which the second focus ion beam cambium is made of a metal containing tungsten as a main component. In the semiconductor device according to claim 7,
The first focus ion beam cambium contains silicon as a main component and contains silicon.
A semiconductor device in which the second focus ion beam cambium is made of a metal containing tungsten as a main component. In the semiconductor device according to claim 10,
The first focus ion beam cambium is made of silicon oxide.
The thickness of the first focus ion beam forming layer is such an insulation when the second focus ion beam forming layer is directly formed on the insulating film without forming the first focus ion beam forming layer. A semiconductor device that is the thickness at which the film is scraped. A beam irradiation unit that irradiates the substrate with a focus ion beam,
A gas supply unit that supplies the raw material gas onto the insulating film formed on the substrate, and
A first control for controlling the beam irradiation unit to form a first focus ion beam forming layer on the insulating film, and a second focus ion beam made of metal on the first focus ion beam forming layer. A control unit that executes the second control for forming the cambium, and
With
The control unit is provided so that the outer periphery of the second focus ion beam forming layer is located inside the outer periphery of the first focus ion beam forming layer and with the outer periphery of the second focus ion beam forming layer. The beam irradiation unit is controlled so that the length between the first focus ion beam forming layer and the outer periphery thereof is within 10% of the maximum width of the first focus ion beam forming layer.
The amount of scraping of the insulating film at the time of forming the first focus ion beam forming layer is such that the second focus ion beam forming layer is formed on the insulating film without forming the first focus ion beam forming layer. A processing device that is smaller than the amount of scraping of the insulating film when it is directly formed. In the processing apparatus according to claim 12,
The control unit is a processing device that controls the beam irradiation unit so that the temperature of the irradiation region of the focus ion beam in the second control becomes equal to or higher than the decomposition temperature of the raw material gas. In the processing apparatus according to claim 12,
A heating unit for heating the substrate is provided.
The control unit is a processing device that controls the heating unit so that the temperature of the irradiation region of the focus ion beam in the second control becomes equal to or higher than the decomposition temperature of the raw material gas.

Images