JP3388059B2 - Method for manufacturing semiconductor integrated circuit device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming method and a film forming apparatus, and a semiconductor integrated circuit device manufacturing method and semiconductor manufacturing apparatus technology, and more particularly, to a focused ion beam (hereinafter, referred to as FIB). The present invention relates to a technique effectively applied to the used film forming method.

[0002]

2. Description of the Related Art A film forming technique using FIB is a method for irradiating FIB by irradiating FIB radiated from an ion source onto a film forming region adsorbed by a raw material gas and decomposing adsorbed gas molecules. This is a technique for selectively forming a predetermined film in a region.

Regarding this FIB film forming technique, for example, “Industrial Research Council”, issued on November 22, 1991, “19.
1992 edition, separate volume of electronic materials, VLSI manufacturing / testing apparatus guidebook "P87 to P91, and describes FIB film forming technology, FIB etching technology and the FIB apparatus.

By the way, according to the result of examination by the present inventor, when irradiating the FIB, the FIB having a certain intensity is considered without considering the stepped state of the beam irradiation surface, the adsorbed gas molecule concentration distribution and the like. Irradiate uniformly.

[0005]

However, the present inventor has found that the above technique in which FIB is uniformly irradiated has the following problems.

That is, there is a large difference in the thickness of the formed film, such that the film thickness formed in the inclined region in the FIB irradiation region or in the connection hole becomes smaller than the film thickness formed in the flat region. There is.

The reason why the film thickness becomes smaller in the inclined region is that F is different between the case of irradiating the inclined region and the case of irradiating the flat region even if the beam diameter of the FIB is the same.
This is because when the irradiation area of IB is different and the irradiation area is inclined, the irradiation area of FIB becomes larger and the ion irradiation density of FIB becomes lower.

Further, the reason why the film thickness in the connection hole is thin is that the source gas is not sufficiently supplied into the connection hole because the connection hole is fine. Moreover, at the bottom of the connection hole, the FIB irradiation amount becomes excessive with respect to the supply amount of the raw material gas due to the small supply amount of the raw material gas, and as a result, etching progresses at the bottom of the connection hole to cause damage. There is a problem to give. On the other hand, if the ion irradiation density of the FIB is lowered so that etching does not occur at the bottom of the contact hole, there arises a problem that the film formation efficiency around the contact hole is reduced.

It is an object of the present invention to provide a film forming technique using an energy beam, which can make the thickness of a formed film uniform.

It is another object of the present invention to provide a film forming technique using an energy beam, which can form a predetermined film without causing damage in the connection hole.

It is another object of the present invention to provide a film forming technique using an energy beam, which can improve film forming efficiency.

The above and other objects and novel features of the present invention will be apparent from the description of the specification and the accompanying drawings.

[0013]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, according to the film forming method of the present invention, a predetermined gas is supplied to the film forming area of the substrate to be processed, and the energy beam is irradiated to selectively form a predetermined film in the energy beam irradiation area. In the formation, the irradiation amount of the energy beam is locally changed according to at least one of the irradiation area of the energy beam and the adsorption concentration of the predetermined gas.

Further, the film forming apparatus of the present invention comprises a gas supply means for supplying a predetermined gas to the film forming region of the substrate to be processed, and a beam radiation source for irradiating the film forming region with an energy beam. A film forming apparatus comprising: storage means for storing data for locally changing the irradiation amount of the energy beam according to at least one of the irradiation area of the energy beam and the adsorption concentration of the predetermined gas. And control means for controlling the operation of the beam radiation source based on the data of the storage means.

Further, in the method for manufacturing a semiconductor integrated circuit device of the present invention, a predetermined gas is supplied to the film formation region on the semiconductor substrate, and the energy beam is irradiated,
When selectively forming a predetermined film in the irradiation region of the energy beam, depending on at least one of the irradiation area of the energy beam or the adsorption concentration of the predetermined gas,
The irradiation amount of the energy beam is locally changed.

Further, the semiconductor manufacturing apparatus of the present invention comprises a gas supply means for supplying a predetermined gas to the film formation region of the semiconductor substrate, and a beam radiation source for irradiating the film formation region with an energy beam. A semiconductor manufacturing apparatus comprising: storage means for storing data for locally changing an irradiation amount of the energy beam according to at least one of an irradiation area of the energy beam and an adsorption concentration of the predetermined gas. Control means for controlling the operation of the beam radiation source based on the data of the storage means.

[0018]

According to the present invention described above, the beam irradiation density in the beam irradiation region can be made uniform by changing the irradiation amount of the energy beam according to the irradiation area of the energy beam. It is possible to make the thickness uniform.

Further, by changing the irradiation density of the energy beam according to the concentration of the adsorbed gas molecules, for example, by lowering the irradiation density of the energy beam at the bottom of the connection hole having a low concentration of the adsorbed gas molecules, the bottom of the connection hole is excessive. It is possible to form a predetermined film by using all of the adsorbed gas in the connection hole for film formation without inviting the etching phenomenon due to the irradiation of various energy beams.

Further, by lowering the surface ion irradiation density in the connection hole and not in the periphery of the connection hole, it is possible to form a predetermined film without reducing the film formation efficiency in the periphery of the connection hole. . Therefore, it is possible to improve the film forming efficiency in the film forming technique using the energy beam.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a plan view of a main portion of a substrate to be processed used in a film forming method according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. FIGS. 4A to 4A are explanatory views for explaining the state of the irradiation area of the energy beam with respect to the state of the irradiation region of the energy beam.
5D is an explanatory view for explaining the state of the irradiation density of the energy beam and the state of the formed film thickness when the irradiation amount of the energy beam is constant, and FIGS.
5 is an explanatory diagram for explaining a state of an irradiation amount of an energy beam and a state of an irradiation density of an energy beam and a state of a formed film thickness, which correspond to the state of an energy beam irradiation amount in a film forming method which is one embodiment of the present invention. FIG. FIG. 7B is an explanatory diagram for explaining the method of forming the energy beam irradiation amount state, FIG. 7 is an explanatory diagram for explaining the configuration of the film forming apparatus that is one embodiment of the present invention, and FIG. 8 is the present invention. 9 is a cross-sectional view of an essential part of the semiconductor substrate when a film is formed by a film forming method which is an embodiment of
FIG. 9 is a cross-sectional view of an essential part of the semiconductor substrate after the film forming process of FIG.

In the first embodiment, the case where the film forming method of the present invention is applied to the logic correction of a semiconductor integrated circuit device will be described.

FIG. 1 is a plan view of a semiconductor chip in a semiconductor wafer. The semiconductor chip 1 is composed of a semiconductor substrate (substrate to be processed) 1a such as a p-type or n-type silicon (Si) single crystal or the like, and a main surface thereof has a predetermined logic circuit such as a microprocessor. Are formed.

The main surface of the semiconductor chip 1 is provided with, for example, two connection holes 2a and 2b. In the first embodiment, a case will be described in which, for example, the wiring 3 that connects the connection holes 2a and 2b is formed by, for example, the FIB (energy beam) film forming technique to correct the logic.

FIG. 2 shows a sectional view of the connection hole 2a taken along the line II-II. Wirings 5 are formed on the insulating film 4 deposited on the semiconductor substrate 1a. The wiring 5 is made of, for example, aluminum (Al) or an Al alloy such as an Al—Si—copper (Cu) alloy, and is covered with a surface protective film 6.

The surface protection film 6 is formed of, for example, a single layer film of a silicon dioxide (SiO ₂ ) film or a laminated film in which a silicon nitride film is laminated on SiO ₂ . The above-mentioned connection hole 2a is formed in a part of the surface protective film 6 in a state where a part of the wiring 5 is exposed. The above-mentioned connection hole 2b (see FIG. 1) has the same structure. Connection hole 2
The diameters of a and 2b are, for example, about 2 to 5 μm. The depth is about 1 to 10 μm.

By the way, as shown in FIGS. 3 (a) and 3 (b), when the FIB 7 is irradiated to the flat region and the inclined region, respectively, even if the diameter of the irradiated FIB 7 is the same,
The area of the irradiation surface of B7 is different between the case of irradiating the flat region and the case of irradiating the inclined region, and the FIB irradiation area Sa of the flat region (FIG. 3A) is the FIB irradiation area Sb ( It can be seen that it is smaller than that in FIG. That is, it can be expressed as Sa <Sb.

Here, if the beam current is Ib, the ion irradiation density Da in the flat region can be expressed as Ib / Sa, and the ion irradiation density Db in the inclined region can be expressed as Ib / Sb. Therefore, from Sa <Sb, it is understood that the ion irradiation density Da in the flat region is higher than the ion irradiation density Db in the inclined region. That is, Da> Db
It can be expressed as. As a result, it can be seen that the film formed has a larger thickness in the flat region and a smaller thickness in the inclined region.

Here, it is assumed that an electrode is formed in the connection hole by using FIB. FIG. 4A is a schematic view of the cross section of the connection hole 2a, and the positions A to K are attached to the respective positions. The figure (b) shows the relationship between the positions AK and the ion irradiation dose J, the figure (c) shows the relationship between the positions AK and the surface ion irradiation density D, and the figure (d) shows the position. A to K and the formed film thickness t are shown.

As shown in FIG. 4B, when the ion irradiation dose is constant, as shown in FIG. 4C, the surface ion irradiation density D varies in the inclined regions (positions B to E and positions G to J). )
It can be seen that the film thickness becomes smaller in the flat region and becomes thinner in the inclined region, as shown in FIG.

Therefore, in the first embodiment, for example, as shown in FIG. FIG. 5A is a schematic view of the cross section of the connection hole 2a similarly to FIG. 4A, FIG. 5B shows the relationship between the positions A to K and the ion irradiation amount J, and FIG. Position A ~
The relationship between K and surface ion irradiation density D is shown in FIG.
Indicates the relationship between the positions A to K and the formed film thickness t.

That is, in the first embodiment, as shown in FIG.
As shown in (b), the ion irradiation amount applied to the inclined regions (positions B to E and positions G to J) in the connection hole 2a is flat regions (positions A to B, positions E to G and position J). ~ K) is set so as to be larger than the amount of ion irradiation. As a result, the overall surface ion irradiation density can be made uniform as shown in FIG. 5 (c), so that the formed film thickness is made uniform as a whole as shown in FIG. 5 (d). It is possible.

As a method of increasing the ion irradiation amount, for example, as shown in FIG. 6A, the number of times of scanning the FIB in the inclined regions (positions B to E and positions G to J) in the connection hole 2a is increased. To do. The number of scans is set so that the ion irradiation density in the flat area and the ion irradiation density in the inclined area are equal. Note that FIG. 6B includes the same graph as FIG. 5B for easy understanding.

The data indicating the relationship between such position coordinates and the number of FIB scans is created in advance by the experience of an operator, an experiment, or a simulation. This data is
It may be created by an operator, or if it is simple to some extent, it may be automatically created by inputting predetermined condition data into a computer or the like.

The condition data includes, for example, the type of film formation, the environment of the FIB device or the product conditions. The type of film formation is, for example, conditions such as whether the film formation location is a connection hole or a flat area, and the environment of the FIB device is, for example, conditions such as the distance between the gas nozzle and the surface of the substrate to be processed and the positional relationship. Yes, the product conditions are conditions such as film thickness, width, shape or material.

Next, the FIB apparatus (film forming apparatus, semiconductor manufacturing apparatus) of the first embodiment will be described with reference to FIG. FIB
The device 8 includes an ion source 9, a condenser lens 10, an ion separation filter 11, an astigmatism correction electrode 12, an objective lens 13, a scanning deflector 14, and stages 15x, 15.
y, a gas supply unit 16, a secondary electron detector 17, and a control system 18.

The ion source 9 has a structure in which the surface of a metal needle made of tungsten or the like whose tip is thinly sharpened to about several tens of μm is wet with a liquid metal such as gallium (Ga). The structure is such that a Ga ion beam can be emitted from the tip of the metal needle.

However, the ionic species is not limited to Ga and can be variously changed, and may be Si, indium (In), gold (Au), Au—Si alloy or the like.

The condenser lens 10 has a control electrode 10a.
And a lead electrode 10b and a cathode 10c.
The control electrode 10a is an electrode for keeping the strength of the FIB constant. The extraction electrode 10b is an electrode for extracting Ga ions from the ion source 9.

The ion separation filter 11 is an electric field / magnetic field orthogonal type mass analyzer, which allows only the necessary ions to go straight ahead and be taken out. The FIB that has passed through the ion separation filter 11 passes through the astigmatism correction electrode 12, is focused by the objective lens 13, and is further irradiated onto a desired position by the scanning deflector 14.

The beam diameter of FIB7 is, for example, 0.05 μm.
It can be set to about 2 μm. The scan residence time is, for example, about 1 μsec to 5 μsec, and the scan region is, for example, 4 μsec.
It is approximately 4 μm to 20 × 20 μm. A current value measuring electrode (not shown) or the like is installed between the objective lens 13 and the scanning deflector 14 so that the FIB current can be measured.

The stages 15x and 15y are constructed so as to be movable in directions orthogonal to each other. The semiconductor substrate 1a forming the semiconductor wafer can be placed on the stage 15x. The potential difference between the ion source 9 and the stage 15x is set to about 25 KV, for example.

The gas supply unit 16 is a component for supplying the deposition gas used for the film forming process, and the deposition gas can be supplied from the tip of the gas nozzle 16a to the main surface of the semiconductor substrate 1a. It has a structure.
As the deposition gas, for example, a metal organic compound gas such as tungsten carbonyl (W (CO) ₆ ) can be used.

The secondary electron detector 17 makes it possible to observe the state of the semiconductor substrate 1a by detecting secondary electrons emitted from the semiconductor substrate 1a when the semiconductor substrate 1a is irradiated with a predetermined FIB 7. It is a constituent part for.

The control system 18 is a control unit for controlling the operation of the entire FIB device 8. The control system 18 also has a storage unit for storing data such as the above-described position coordinates of the FIB 7 and the number of scans. The control system 18 has a structure capable of transmitting a predetermined control command to the FIB device 8 based on the data in the storage unit.

Next, a case where the film forming method of the first embodiment is applied to, for example, a logic correcting method of a semiconductor integrated circuit device will be described with reference to FIGS.

First, as shown in FIG. 7, the semiconductor substrate 1a
Are mounted on the stage 15x of the FIB device 8. At this time, as shown in FIG. 1, the semiconductor chip 1 of the semiconductor substrate 1a has the connection holes 2a and 2b already formed therein. It is also possible to form the connection holes 2a and 2b by etching with the FIB 7.

Then, as shown in FIG. 8, for example, W (C
O) ₆ gas, metal-organic compound gas such as gas nozzle 1
The FIB 7 is scanned onto the film formation region in a state of being jetted from 6a to the film formation region on the semiconductor substrate 1a (formation region of the connection hole 2a).

At this time, the control system 18 of the FIB device 8 scans the FIB 7 based on the data previously stored in the storage section. That is, in the inclined region of the side surface of the connection hole 2a,
The number of scans is increased so that the ion irradiation amount becomes larger than the ion irradiation amount in the peripheral region, the bottom region, and the like of the connection hole 2a.

As a result, as shown in FIG.
It is possible to form the metal film 3a made of, for example, tungsten in a with a uniform film thickness. This metal film 3a
Is a part of the wiring 3. Note that the film forming process for the connection hole 2b and the film forming process for the wiring 3 connecting the connection holes 2a and 2b are the same, so description thereof will be omitted.

As described above, according to the first embodiment, the following effects can be obtained.

In the film forming process using the FIB 7, for example, the number of FIB scans in an inclined region such as the inner side surfaces of the connection holes 2a and 2b is determined by the FIB scan number in a flat region such as the periphery or bottom of the connection holes 2a and 2b. Since the ion irradiation density in the inclined region and the ion irradiation density in the flat region can be made substantially uniform by increasing the number of scanning times, the inside of the connection holes 2a, 2b and the connection holes 2a, 2 can be made.
It is possible to make the thickness of the metal film 3a selectively formed around b the substantially uniform.

(Embodiment 2) FIGS. 10 (a) and 10 (b) are explanatory views for explaining the states of the adsorbed gas concentration and the current density of the energy beam in the connection hole, FIGS.
FIG. 1D is an explanatory diagram for explaining the state of the formed film thickness in the case where the irradiation density of the energy beam is kept constant in a state of being increased to the extent that all adsorbed gas molecules are decomposed.
2 is a partial cross-sectional view of the semiconductor substrate in the case of the setting of FIG. 11, and FIGS. 13A to 13D are constant in a state where the irradiation density of the energy beam is lowered to the extent that the adsorbed gas molecules in the connection hole are decomposed. 14 (a) to 14 (e) are explanatory views for explaining the state of the formed film thickness in the case of performing the energy beam irradiation amount and the irradiation density state in the film forming method which is another embodiment of the present invention. FIG. 15 is an explanatory view for explaining the state of the formed film thickness, FIG. 15 is a sectional view of a main part of the semiconductor substrate in the case of the setting of FIG. 14, and FIG.
FIG. 17C is an explanatory diagram for explaining the method of forming the energy beam irradiation amount state, and FIGS. 17A to 17E show the energy beam irradiation amount and the energy beam irradiation amount in the film forming method according to another embodiment of the present invention. FIG. 18 is an explanatory view for explaining the state of the formed film thickness in the state of the irradiation density, and FIG. 18 is a cross-sectional view of the main part of the semiconductor substrate in the case of the setting of FIG.

In the second embodiment, the film forming technique studied from the viewpoint of the adsorption concentration of the deposition gas as the film forming material will be described. FIG. 10A is a schematic view of the connection hole 2a of FIG. 2 which is the same as FIG. 4A used in the first embodiment,
FIG. 6B is a graph showing the concentration of the deposition gas and the FIB current density in and around the connection hole 2a.

As can be seen from FIG. 10B, the concentration of the deposition gas (one-dot chain line) becomes lower as it approaches the bottom of the connection hole 2a because the connection hole 2a is fine.
On the other hand, the current density (solid line) of the FIB becomes low in the inclined region and becomes high again in the bottom portion of the flat connection hole 2a due to the operation described in the first embodiment. For this reason,
At the bottom of the connection hole 2a, the amount of deposition gas may be insufficient with respect to the irradiation density of FIB.

This will be described in detail with reference to FIGS. 11 to 13. 11 (a) and 13 (a) are shown in FIG. 10 (a).
FIG. 3 is a schematic view of the same connection hole as that of FIG. Figure 11
13B and FIG. 13B are graphs showing the distribution of the gas molecule adsorption concentration N of the deposition gas corresponding to the positions AK. Nt indicates a high concentration region, and Nb indicates a low concentration region.

11 (c) and 13 (c) show the position A.
FIG. 11D is a graph showing the surface ion irradiation density D with respect to K, and FIGS. 11D and 13D are graphs showing the formed film thickness t with respect to positions AK. In FIG. 11, α indicates a film formation rate coefficient, and β indicates an etching rate coefficient.

Here, as shown in FIG. 11 (c), when the surface ion irradiation density D is increased to a constant value Dt until all the gas molecules adsorbed on the horizontal surface are decomposed, the inside of the connection hole 2a is defined. In particular, since the surface ion irradiation density Dt is too higher than the adsorption density of gas molecules at the bottom, the film once formed is removed by etching, and the formed film thickness is significantly reduced. In some cases, the bottom portion of the connection hole 2a is removed by etching as shown in FIG. 12 and may be damaged.

On the other hand, as shown in FIG. 13 (c), when the surface ion irradiation density D is lowered to a constant value Db until the gas molecules adsorbed on the bottom of the connection hole 2a are decomposed, the above is described. It is possible to make the thickness of the formed film uniform throughout without causing the problem of serious damage, but in this case, the film forming efficiency in the flat region is significantly reduced.

Therefore, in the second embodiment, such adsorbed gas molecules are taken into consideration, for example, as shown in FIG. FIG. 14A is a schematic view of the cross section of the connection hole 2a similarly to FIG. 4A, and FIG. 14B shows the relationship between the positions A to K and the surface gas molecule adsorption concentration N, and FIG. ) Is position AK
And the ion dose J are shown in FIG.
˜K and the surface ion irradiation density D are shown, and FIG. 7E shows the relationship between the positions AK and the formed film thickness t.

That is, in the second embodiment, as shown in FIG.
As shown in (c) and (d), the ion irradiation amount and irradiation density in the connection hole 2a, in particular, the ion irradiation amount and irradiation density at the bottom of the connection hole 2a are set to the adsorbed gas molecule concentration in the connection hole 2a. Adjust to lower. However, connection hole 2
In the inclined region of “a”, the ion irradiation amount is increased as in the first embodiment, but the upper portion thereof is gradually lowered toward the center of the connection hole 2a.

That is, the ion irradiation density in the connection hole 2a is made lower than the surface ion irradiation density around the connection hole 2a. As a result, almost all of the adsorbed gas molecules in the connection hole 2a can be effectively used for film formation, and excess FIB can be used.
Since it is possible to prevent the etching phenomenon from occurring, the metal film 3 can be formed without damaging the bottom of the connection hole 2a as shown in FIGS.
It is possible to form a.

Further, by reducing the surface ion irradiation density only inside the connection hole 2a, it is possible to form the metal film 3a without reducing the film formation efficiency in the periphery of the connection hole 2a.

As a method of increasing / decreasing the ion irradiation dose, as in the first embodiment, for example, as shown in FIG. 16, the number of scanning times of the FIB of the connection hole inclined regions (positions B to E and positions G to J) is set. The area at the bottom of the connection hole (position E
To G), the number of FIB scans is reduced. At this time, in the inclined region, the ion irradiation area is changed for each scanning so that the inclination is formed above the ion irradiation amount.

When the connection hole 2a becomes finer and the adsorbed gas concentration in the connection hole 2a is extremely low, as shown in FIG. 17B, the connection hole 2a is connected as shown in FIG. The ion irradiation amount at the bottom of the hole 2a is set to zero, and the ion irradiation density at the bottom of the connection hole 2a is set to zero, as shown in FIG.

In this case, as shown in FIGS. 17 (e) and 18, the bottom of the connection hole 2a is not damaged,
No metal film is formed. However, the formed metal film 3a
The lower wiring 5 is electrically connected to the lower wiring 5 through the metal film 3a formed on the side surface of the connection hole 2a.

As described above, according to the second embodiment, the following effects can be obtained.

(1) In the film forming process using FIB, for example, the ion irradiation density in the connection holes 2a, 2b is lowered in accordance with the concentration of the adsorbed gas in the connection holes 2a, 2b. , 2b can be used for film formation without causing an etching phenomenon due to excessive FIB irradiation at the bottoms of the connection holes 2a, 2b, so that the bottoms of the connection holes 2a, 2b are damaged. It becomes possible to form the metal film 3a without the need.

(2). The surface ion irradiation density is set to the connection holes 2a, 2
By lowering only the inside of b, the metal film 3a can be formed without lowering the film forming efficiency around the connection holes 2a and 2b.

(Embodiment 3) FIG. 19 is a cross-sectional view of an essential part of a substrate to be processed at the time of a film forming process in a film forming method according to another embodiment of the present invention, and FIG. 20 is an adsorbed gas concentration and ion irradiation of FIG. It is explanatory drawing for demonstrating the state of a density.

In the third embodiment, as shown in FIG. 19, the gas injected from the gas nozzle 16a is sufficiently disturbed by the CCB (Controlled Collapse Bonding) bump electrode 19 formed on the semiconductor substrate 1a. The case where the present invention is applied to the case where the film is not supplied to the film formation regions of to E will be described.

The state of the surface gas molecule adsorption concentration in this case is shown in FIG. Surface gas molecule concentration is at positions AE
It is increasing as you go to. In particular, at the positions B and C, it can be seen that the adsorbed gas molecules are further reduced because the upper surface of the surface protective film 6 is inclined rightward in FIG.

Therefore, in the third embodiment, the ion irradiation density is locally changed according to the state of the surface gas molecule adsorption concentration shown in FIG. In particular, as shown in FIG.
The ion irradiation density is lowered at the positions B and C. As a result, the deposition gas can be effectively used for film formation, and a good metal film can be formed without causing damage or the like.

As described above, also in the third embodiment, the same effect as in the second embodiment can be obtained.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-mentioned Embodiments 1 to 3 and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

For example, in the above-described first to third embodiments, the case where the present invention is applied to the film forming technique at the time of logic correction has been described, but the present invention is not limited to this and various applications are possible. It can also be applied to a film forming process performed when switching a connection path between a normal circuit part and a normal circuit part, a film forming process for forming a film for an electrode during a test / inspection, and the like.

Further, as shown in FIG. 21, it can be applied to a case where a metal film 3a is formed so as to cross a plurality of wirings 5 and 5 in order to connect the wirings 5 and 5. Is. Also in this case, the metal film 3a can be formed without causing damage or the like in the valley portion between the adjacent wirings 5 and 5.

Further, in the first to third embodiments, the case where the present invention is applied to the film forming process using the FIB has been described, but the present invention is not limited to this. For example, light (energy beam) is used. CVD (Chemical Vapor)
Deposition) It can also be applied to film formation processing.

In the above description, the case where the invention made by the present inventor is mainly applied to the film forming method used in the manufacturing process of the semiconductor integrated circuit device which is the background field of application has been described, but the invention is not limited to this. Instead, it can be applied variously, and can be applied to other film forming methods such as a film forming method for forming a predetermined film on a liquid crystal substrate and a film forming method used for manufacturing a micromachine.

[0081]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

According to the present invention, the beam irradiation density in the beam irradiation region can be made uniform by changing the irradiation amount of the energy beam according to the irradiation area of the energy beam. Can be made uniform.

Further, by changing the irradiation density of the energy beam according to the adsorbed gas molecule concentration, for example, by lowering the irradiation density of the energy beam at the bottom of the connection hole having a low adsorbed gas molecule concentration, the energy beam irradiation density becomes excessive at the bottom. It is possible to form a predetermined film by using all of the adsorbed gas in the connection hole for film formation without inviting the etching phenomenon due to the irradiation of various energy beams.

Further, by lowering the surface ion irradiation density in the connection hole and not in the periphery of the connection hole, it is possible to form a predetermined film without reducing the film formation efficiency in the periphery of the connection hole. . Therefore, it is possible to improve the film forming efficiency in the film forming technique using the energy beam.

[Brief description of drawings]

FIG. 1 is a plan view of an essential part of a substrate to be processed used in a film forming method according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 (a) and 3 (b) are explanatory diagrams for explaining the state of the irradiation area of the energy beam with respect to the state of the irradiation region of the energy beam.

FIG. 4A to FIG. 4D are explanatory diagrams for explaining the state of the irradiation density of the energy beam and the state of the formed film thickness when the irradiation amount of the energy beam is constant.

5 (a) to 5 (d) illustrate a state of an irradiation amount of an energy beam and a state of an irradiation density of an energy beam and a state of a formed film thickness corresponding to the state of an irradiation amount of an energy beam in a film forming method which is an embodiment of the present invention. It is explanatory drawing for doing.

FIG. 6 is an explanatory diagram for explaining a method of forming the energy beam irradiation amount state of FIG. 5B.

FIG. 7 is an explanatory diagram illustrating a configuration of a film forming apparatus that is an embodiment of the present invention.

FIG. 8 is a fragmentary cross-sectional view of a semiconductor substrate when a film is formed by a film forming method according to an embodiment of the present invention.

9 is a cross-sectional view of an essential part of the semiconductor substrate after the film forming process of FIG.

10 (a) and 10 (b) are explanatory diagrams for explaining the states of adsorbed gas concentration and energy beam current density in a connection hole.

11 (a) to (d) are explanatory diagrams for explaining the state of the formed film thickness when the irradiation density of the energy beam is made constant in a state where it is made large enough to decompose all the adsorbed gas molecules. .

FIG. 12 is a partial cross-sectional view of the semiconductor substrate in the case of the setting of FIG.

13A to 13D are explanatory views for explaining the state of the formed film thickness when the irradiation density of the energy beam is kept constant in a state of being lowered to the extent of decomposing adsorbed gas molecules in the connection holes. It is a figure.

14A to 14E are explanatory views for explaining the state of the formed film thickness in the state of the irradiation amount and the irradiation density of the energy beam in the film forming method which is another embodiment of the present invention. .

FIG. 15 is a cross-sectional view of essential parts of the semiconductor substrate in the case of the setting shown in FIG.

FIG. 16 is an explanatory diagram for explaining a method of forming the energy beam irradiation amount state of FIG. 14C.

17 (a) to 17 (e) are explanatory views for explaining the state of the formed film thickness in the state of the irradiation amount and the irradiation density of the energy beam in the film forming method which is another embodiment of the present invention. .

FIG. 18 is a cross-sectional view of an essential part of a semiconductor substrate in the case of the setting of FIG.

FIG. 19 is a fragmentary cross-sectional view of a target substrate during a film forming process in a film forming method according to another embodiment of the present invention.

20 is an explanatory diagram for explaining states of the adsorbed gas concentration and the ion irradiation density in FIG.

FIG. 21 is a fragmentary cross-sectional view of a target substrate during a film forming process in a film forming method according to another embodiment of the present invention.

[Explanation of symbols]

1 semiconductor chip 1a semiconductor substrate (substrate to be processed) 2a, 2b connection hole 3 wiring 3a metal film 4 insulating film 5 wiring 6 surface protection film 7 focus ion beam (energy beam) 8 focus ion beam apparatus (film forming apparatus, semiconductor manufacturing) Device 9 Ion source 10 Condenser lens 10a Control electrode 10b Extraction electrode 10c Cathode 11 Ion separation filter 12 Astigmatism correction electrode 13 Objective lens 14 Scan deflector 15x, 15y Stage 16 Gas supply unit 16a Gas nozzle 17 Secondary electron detector 18 Control System 19 CCB bump electrode

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Otsuka 5-20-1 Kamimizuhoncho, Kodaira-shi, Tokyo Within Hitachi Ultra LSI Engineering Co., Ltd. (72) Inventor Toshio Yamada Tokyo 2326 Imai, Ome-shi, Ltd., Device Development Center, Hiritsu Seisakusho Co., Ltd. (72) Inventor, Yuichi Masho 1-280, Higashikoigakubo, Kokubunji, Tokyo (56) Reference, Japanese Patent Laid-Open No. 6-297168 JP, A) JP 4-131377 (JP, A) JP 2-6094 (JP, A) JP 5-315287 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21 / 205,21 / 365 C23C 16/00-16/56

Claims (6)

(57) [Claims] 1. A by irradiating the focus ion bi <br/> over beam in a state in which connection holes are supplying a predetermined gas into the film forming region formed on a semiconductor substrate, the focus ion Bee <br/> In the process of selectively forming a predetermined metal film on the irradiation area of the
The focused ion beam in the connection hole
The irradiation dose of
The method of manufacturing a semiconductor integrated circuit device according to claim to Rukoto lower than the dose of over Kas ion beam. 2. Manufacturing of the semiconductor integrated circuit device according to claim 1.
In the manufacturing method, with respect to the inclined region of the side surface of the connection hole
The irradiation amount of the focused ion beam is equal to that of the connection hole.
It should be gradually smaller from the outer circumference toward the center.
And a method for manufacturing a semiconductor integrated circuit device. 3. A semiconductor integrated circuit according to claim 1 or 2.
In the method for manufacturing the device, the flap at the bottom of the connection hole is
The number of scans of the focus ion beam is set around the connection hole.
Number of scans of the focused ion beam in the flat region of
Semiconductor integrated circuit device characterized by being less than
Manufacturing method. 4. The method for manufacturing a semiconductor integrated circuit device according to claim 1, 2 or 3 , wherein the predetermined gas is a gas molecule of a metal organic compound, and the predetermined metal film is a metal film for wiring. A method of manufacturing a semiconductor integrated circuit device, comprising: 5. A focused ion beam on a semiconductor substrate
The step of forming a connection hole by
In the state where a predetermined gas is supplied to the film-forming region,
By irradiating the ion beam, the focus
Selectively forming a predetermined metal film in the ion beam irradiation area
And a film forming step for performing the connection in the film forming step.
The irradiation amount of the focused ion beam in the hole is
The focus ion beam in the flat area around the connection hole
Integrated semiconductor characterized by lowering the irradiation dose
Method of manufacturing circuit device. 6. A focused ion beam on a semiconductor substrate
Of forming a connection hole having an inclined region on the side surface by
And supplying a predetermined gas to the film formation region where the connection hole is formed.
Irradiation with the focused ion beam
The position of the focused ion beam irradiation area.
And a film-forming machining extent of selectively forming a constant of the metal film, the
In the film forming step, the above-mentioned in the inclined region of the side surface of the connection hole
Adjust the irradiation dose of the focus ion beam around the connection hole.
Of the focused ion beam in the flat area of
Manufacture of semiconductor integrated circuit devices characterized by higher
Build method.