WO2014054497A1

WO2014054497A1 - Method for manufacturing target for x-ray generation and target for x-ray generation

Info

Publication number: WO2014054497A1
Application number: PCT/JP2013/076043
Authority: WO
Inventors: 直三杉本; 康敏梅原
Original assignee: 東京エレクトロン株式会社
Priority date: 2012-10-04
Filing date: 2013-09-26
Publication date: 2014-04-10
Also published as: TW201421524A

Abstract

This method for manufacturing a target for x-ray generation is characterized by including an addition step in which a metal precursor for a metal that forms material for a target for x-ray generation is added to a supercritical fluid and a deposition step in which the supercritical fluid is brought into contact with a substrate (1) in which a hole (3) with a bottom is formed and a metal (10) is deposited in the hole (3). Thus, a method for manufacturing a target for x-ray generation in which a target part can be suitably formed and a target for x-ray generation can be achieved.

Description

X-ray generation target manufacturing method and X-ray generation target

Various aspects and embodiments of the present invention relate to a method for manufacturing an X-ray generation target and an X-ray generation target.

X-ray generators are used in various fields such as X-ray non-destructive inspection. The X-ray generator includes a filament part that emits electrons and an X-ray generation target that is irradiated with electrons emitted from the filament part. The X-ray generator irradiates the outside with X-rays by colliding electrons emitted from the filament part with an X-ray generation target.

Here, the target for X-ray generation includes a substrate and a target portion embedded in the substrate. For example, there is a method of manufacturing an X-ray generation target using an ion beam (FIB) processing apparatus.

Specifically, a bottomed hole is formed in the substrate by irradiating the substrate with an ion beam and performing sputtering. Then, by irradiating the hole of the substrate with an ion beam while flowing the material gas of the target for X-ray generation near the hole of the substrate, metal is deposited in the hole to form the target portion.

JP 2011-77027 A

However, the above-described conventional technique has a problem that the target portion is not properly formed. For example, a VOID (void or void) may be formed at the hole bottom of the substrate. Further, for example, the metal accumulated in the target part may contain impurities.

The point that a VOID (void, void) is formed at the hole bottom of the substrate will be described. The holes formed by ion beam sputtering are finely processed, so that the hole diameter is small and the hole aspect ratio is large. As a result, the material gas does not easily flow into the hole, and the concentration of the material gas tends to decrease toward the bottom of the hole. In addition, holes formed by sputtering with an ion beam have a hole diameter that decreases toward the bottom, and the side wall of the hole may be formed in a tapered shape.

Here, if the ion beam is irradiated while flowing the material gas while scanning in the radial direction of the hole, the ion beam may collide with the tapered side wall before reaching the bottom of the hole. Then, the ion beam is more likely to react with the material gas on the tapered side wall than the bottom of the hole, so that the metal is deposited on the side wall before the metal is deposited on the bottom of the hole. As a result, the VOID is formed on the bottom of the hole. There is a risk of formation.

Also, for example, it is conceivable to irradiate with fixing the ion beam at the center of the hole without scanning. In this case, when the concentration of the material gas at the bottom is lowered, the deposited metal is cut by the ion beam, so that the metal deposition does not proceed.

The point that the metal accumulated in the target part contains impurities will be described. It has been found that when a target portion is formed using an ion beam, impurities implanted as a gas may be mixed with the metal. As a result, in the method of creating a target portion using an ion beam, it is difficult to increase the purity of the metal as a result of impurities contained in the metal accumulated in the target portion.

The disclosed X-ray generation target manufacturing method includes an addition step of adding a metal precursor of a metal, which is a material of the X-ray generation target, to the supercritical fluid, and a bottomed hole is formed in one example of the embodiment A deposition step of depositing the metal in the hole by bringing the formed substrate into contact with the supercritical fluid.

According to various aspects and embodiments of the present invention, it is possible to realize an X-ray generation target manufacturing method and an X-ray generation target capable of appropriately forming a target portion.

FIG. 1 is a diagram for explaining a cross-sectional configuration of an X-ray generation target according to the first embodiment. FIG. 2 is an exploded perspective view of the target for X-ray generation according to the first embodiment. FIG. 3 is a diagram for explaining a cross-sectional configuration of the X-ray generation target according to the first embodiment. FIG. 4 is a diagram for explaining a cross-sectional configuration of the X-ray generation target according to the first embodiment. FIG. 5 is a diagram illustrating an example of a schematic configuration of the FIB apparatus according to the first embodiment. FIG. 6 is a diagram illustrating an example of a schematic configuration of the supercritical fluid device according to the first embodiment. FIG. 7 is a flowchart for explaining an example of a method for manufacturing an X-ray generation target according to the first embodiment. FIG. 8 is a diagram for explaining an example of a method for manufacturing an X-ray generation target according to the first embodiment. FIG. 9 is a diagram showing a cross-sectional configuration of the X-ray generator in the first embodiment. FIG. 10 is a diagram illustrating a configuration of a mold power supply unit in the first embodiment. FIG. 11 is a diagram illustrating an example of an X-ray generation target in which a plurality of holes are formed in a substrate.

(First embodiment)
In one embodiment, a method for manufacturing an X-ray generation target according to the first embodiment includes an addition step of adding a metal precursor of a metal, which is a material of the X-ray generation target, to the supercritical fluid, A deposition step of bringing the metal into the hole by bringing the substrate having the hole in the shape into contact with the supercritical fluid.

In one embodiment, a method for producing an X-ray generation target according to a first embodiment forms a liner layer on a substrate before depositing metal in the hole by bringing the substrate into contact with a supercritical fluid. It further includes a forming step.

In one embodiment, the method for producing an X-ray generation target according to the first embodiment further includes a reduction step of reducing the metal precursor after bringing the substrate into contact with the supercritical fluid.

In one embodiment, the method for manufacturing an X-ray generation target according to the first embodiment performs a reduction process by heating while supplying H2 gas to a supercritical fluid in the reduction step.

The manufacturing method of the target for X-ray generation which concerns on 1st Embodiment further includes the grinding | polishing process which removes the metal deposited on the surface of the board | substrate by grind | polishing the surface of a board | substrate in one embodiment.

In one embodiment, the target for X-ray generation according to the first embodiment is superposed on a contact step in which the material of the target for X-ray generation is brought into contact with a supercritical fluid, and a substrate having a bottomed hole. And a deposition step of depositing the material of the target for X-ray generation in the hole by contacting the critical fluid.

Hereinafter, various embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

The X-ray generation target T1 according to the first embodiment will be described with reference to FIG. 1 and FIG. FIG. 1 is a diagram for explaining a cross-sectional configuration of an X-ray generation target according to the first embodiment. FIG. 2 is an exploded perspective view of the target for X-ray generation according to the first embodiment.

The X-ray generation target T1 includes a substrate 1 and a target unit 10 as shown in FIGS.

The substrate 1 is made of diamond and is formed into a disk shape. The board | substrate 1 has the one surface 1a of a plate surface, and the back surface 1b on the opposite side of a plate surface. The board | substrate 1 is not restricted to a disk shape, You may form in other shapes, for example, a square plate shape. The thickness of the substrate 1 is set to about 100 μm, for example. The outer diameter of the substrate 1 is set to about 3 mm, for example.

Thus, by forming the hole 3 in diamond, it is possible to efficiently diffuse the heat generated when generating X-rays, and a large current can be applied.

A bottomed hole 3 is formed in the substrate 1 from the surface 1a side. The hole 3 has an inner space formed by the bottom surface 3a and the side wall surface 3b. The inner space of the hole 3 is formed in a cylindrical shape, for example. However, the inner space of the hole 3 is not limited to the cylindrical shape, and may be any shape such as a prismatic shape. The inner diameter of the hole 3 is set to about 100 nm, for example. The depth of the hole 3 is set to about 1 μm, for example. Thus, the hole 3 is formed with a small hole diameter and a large aspect ratio of the hole.

The target unit 10 is disposed in the hole 3 formed in the substrate 1. The target portion 10 is made of metal and has a cylindrical shape corresponding to the inner space of the hole 3. The target unit 10 has a first end surface 10a, a second end surface 10b, and an outer surface 10c. Examples of the metal constituting the target unit 10 include copper, tungsten, gold, and platinum.

The target portion 10 is formed by depositing metal from the bottom surface 3a of the hole 3 toward the surface 1a side. As a result, the entire first end surface 10 a of the target unit 10 is in close contact with the bottom surface 3 a of the hole 3. The entire outer surface 10 c of the target unit 10 is in close contact with the side wall surface 3 b of the hole 3.

The target portion 10 is formed corresponding to the shape of the inner space of the hole 3. The axial length of the columnar shape is, for example, about 1 μm. The length of the cylindrical shape in the radial direction is, for example, about 100 nm.

FIG. 3 is a diagram for explaining a cross-sectional configuration of the X-ray generation target according to the first embodiment. FIG. 4 is a diagram for explaining a cross-sectional configuration of the X-ray generation target according to the first embodiment. As shown in FIGS. 3 and 4, the X-ray generation target T <b> 1 may include a conductive layer 12. The conductive layer 12 is formed in a film shape on the surface 1 a side of the substrate 1. The conductive layer 12 is formed of, for example, diamond doped with impurities (for example, boron or the like). The thickness of the conductive layer 12 is, for example, about 50 nm.

The conductive layer 12 shown in FIG. 3 is formed on the surface 1a so as to cover the surface 1a of the substrate 1 and the second end face 10b of the target unit 10. The conductive layer 12 shown in FIG. 4 is formed on the surface 1a so that the second end face 10b of the target unit 10 is exposed.

Subsequently, an example of the FIB apparatus for forming the hole 3 in the target T1 for generating X-rays will be described. FIG. 5 is a diagram illustrating an example of a schematic configuration of the FIB apparatus. The FIB apparatus shown in FIG. 5 is an example, and the FIB apparatus used in manufacturing the X-ray generation target according to the embodiment is not limited to the FIB apparatus shown in FIG. An apparatus may be used.

As shown in FIG. 5, the FIB apparatus 100 includes a liquid metal ion source storage unit 112, a blanker 114, an aperture 116, a scanning electrode 118, and an objective lens 120 in a first housing 110. The FIB apparatus 100 also includes a mounting table 132 and a gas gun 134 in a second casing 130 connected to the first casing 110. The FIB apparatus 100 includes a pump 136 connected to the second housing 130.

The liquid metal ion source storage unit 112 stores, for example, a Ga liquid metal ion source. The blanker 114 is a deflector that deflects the ion beam irradiated from the liquid metal ion source storage unit 112. For example, when the blanker 114 irradiates the ion beam, the ion beam is deflected from the state in which the ion beam is applied to the hole 3 (ON state), thereby not irradiating the hole 3 with the ion beam (OFF). Switch to (status).

The aperture 116 selectively restricts the current of the ion beam irradiated from the liquid metal ion source storage unit 112 by the aperture hole. The scanning electrode 118 scans (scans) the ion beam irradiated from the liquid metal ion source storage unit 112 according to, for example, the diameter of the hole 3 of the substrate 1. The objective lens 120 focuses the ion beam irradiated from the liquid metal ion source storage unit 112.

The mounting table 132 mounts an X-ray generation target T1. The pump 136 keeps the inside of the first housing 110 and the second housing 130 in a predetermined vacuum state by performing vacuum exhaust.

FIB apparatus 100 irradiates ion beam 122 from liquid metal ion source storage unit 112 to target T1 for X-ray generation via blanker 114, aperture 116, scanning electrode 118, and objective lens 120.

Here, the FIB apparatus 100 forms the hole 3 by irradiating the substrate 1 with the ion beam 122 and performing sputtering while scanning.

An example of a supercritical fluid device 200 for manufacturing the target T1 for generating X-rays will be described. FIG. 6 is a diagram illustrating an example of an outline of a supercritical fluid device. In the example illustrated in FIG. 6, the supercritical fluid device 200 includes a reaction vessel 210, a supply device 220, and an exhaust device 230. The supercritical fluid device 200 shown in FIG. 6 is an example, and the supercritical fluid device 200 used for manufacturing the target for X-ray generation according to the embodiment is limited to the supercritical fluid device 200 shown in FIG. Any supercritical fluid device may be used as long as the substrate and the supercritical fluid can be brought into contact with each other.

The reaction vessel 210 accommodates an object to be processed inside. Specifically, the reaction vessel 210 accommodates the substrate 1 in which the bottomed hole 3 is formed. The reaction vessel 210 is provided with a mantle heater 211 for adjusting the internal temperature of the reaction vessel 210 around the reaction vessel 210. The mantle heater 211 has two heaters, for example, an upper mantle heater 211a that heats the inside of the reaction vessel 210 from above and a lower mantle heater 211b that heats the inside of the reaction vessel 210 from below. The upper mantle heater 211a and the lower mantle heater 211b operate independently of each other, for example, and individually heat the inside of the reaction vessel 210 from the upper part or the lower part. However, it is not limited to this, The mantle heater 211 may have only one mantle heater.

The supply device 220 supplies a supercritical fluid into the reaction vessel 210. Specifically, the supply device 220 supplies a supercritical fluid to which a metal precursor of a metal that is a material for an X-ray generation target is added. As a result, inside the reaction vessel 210, a metal that is a material of the target for X-ray generation is deposited in the bottomed hole of the substrate using the supercritical fluid.

The supply device 220 includes a supercritical fluid supply device 221, a metal precursor supply device 222, and a hydrogen supply device 223. The supercritical fluid supply device 221, the metal precursor supply device 222, and the hydrogen supply device 223 may be operated independently of each other.

The supercritical fluid supply device 221 includes a supercritical fluid storage device 221a, a liquefaction device 221b, and a supercritical fluid delivery device 221c. The supercritical fluid supply device 221 is provided at the most upstream part in the supercritical fluid flow path in the supercritical fluid device 200 that goes from the supply device 220 to the exhaust device 230 through the reaction vessel 210. The supercritical fluid supply device 221 supplies the raw material of the supercritical fluid toward the reaction vessel 210. For example, the supercritical fluid supply device 221 supplies carbon dioxide, water, acetone, hexane, ammonia, and the like.

Here, carbon dioxide becomes a super critical fluid (Super Critical Fluid) which is a kind of fluid in an atmosphere of about 7.4 MPa at about 31 degrees. Supercritical fluids are indistinguishable from gas phase (gas) and liquid phase (liquid), and have both gas phase and liquid phase properties. Below, although the case where the supercritical fluid which consists of carbon dioxide is used is demonstrated to an example, it is not limited to this.

The supercritical fluid storage device 221a is, for example, a siphon cylinder. The supercritical fluid delivery device 221c is, for example, a high pressure pump. For example, the supercritical fluid storage device 221a stores carbon dioxide in a substantially liquid state. The carbon dioxide taken out from the supercritical fluid storage device 221a is cooled and liquefied by the liquefying device 221b. The liquefied carbon dioxide is pressurized by the supercritical fluid delivery device 221c and sent toward the reaction vessel 210. For example, the supercritical fluid delivery device 221c pressurizes liquid carbon dioxide to 10 MPa.

The metal precursor supply device 222 includes a metal precursor storage device 222a, a metal precursor delivery device 222b, and a metal precursor delivery valve 222c. The metal precursor supply device 222 is connected to the supercritical fluid flow path of the supercritical fluid device 200 upstream of the reaction vessel 210 and downstream of the supercritical fluid supply device 221. The metal precursor supply apparatus 222 supplies a metal precursor of a metal, which is a material for the target for X-ray generation, dissolved in a supercritical fluid. In that case, the auxiliary solvent may be used together with the metal precursor to facilitate the addition of the metal precursor to the supercritical fluid. The cosolvent may be any solvent that dissolves with the metal precursor, for example, an organic solvent.

The metal precursor storage device 222a stores the metal precursor. The metal precursor storage device 222a uses, for example, Cu (hfac) 2, Cu (dpm) 2, Cu (hfac) (butyne), bis (2,2,6,6-tetramethyl-3,5) as metal precursors. -Heptanededato) copper etc. are stored. For example, the metal precursor storage device 222a stores the metal precursor dissolved in an auxiliary solvent. The metal precursor delivery device 222b is, for example, a pump.

For example, the metal precursor stored in the metal precursor storage device 222a is taken out from the metal precursor storage device 222a while being dissolved in the auxiliary solvent by the metal precursor delivery device 222b. The metal precursor taken out from the metal precursor storage device 222a is added to the supercritical fluid sent from the supercritical fluid supply device 221 by opening the metal precursor delivery valve 222c. That is, the metal precursor is further dissolved in the supercritical fluid while being dissolved in the auxiliary solvent. As a result, the metal precursor is supplied toward the inside of the reaction vessel 210 together with the supercritical fluid, which is a metal precursor of the X-ray generation target.

The hydrogen supply device 223 includes a hydrogen storage device 223a and a mixing device 223b. The hydrogen supply device 223 is connected to the supercritical fluid flow path of the supercritical fluid device 200 upstream of the metal precursor supply device 222 and downstream of the supercritical fluid supply device 221. The hydrogen supply device 223 supplies a reaction accelerator that promotes metal deposition from the metal precursor into the supercritical fluid. For example, the hydrogen supply device 223 supplies hydrogen as a reaction accelerator. However, the present invention is not limited to this, and an arbitrary substance may be used.

The hydrogen storage device 223a is, for example, a siphon cylinder. Hydrogen stored in the hydrogen storage device 223a is mixed into the supercritical fluid by the mixing device 223b provided at the connection between the hydrogen supply device 223 and the supercritical fluid flow path from the supercritical fluid supply device 221 to the reaction vessel 210. Is done.

Also, the supercritical fluid device 200 has a supercritical fluid delivery valve 250 in the flow path, upstream of the metal precursor supply device 222 and downstream of the mixing device 223b. By opening the supercritical fluid delivery valve 250, the supercritical fluid or the supercritical fluid to which hydrogen is added is supplied toward the inside of the reaction vessel 210.

The exhaust device 230 has a pressure gauge 231, a pressure control valve 232, a pressure regulator (Back Pressure Regulator: BPR) 233 and a separator 234. The exhaust device 230 discharges the supercritical fluid from the inside of the reaction vessel 210 to the outside. Specifically, in the exhaust device 230, by opening the pressure adjustment valve 232 and operating the pressure adjustment device 233, the flow passages downstream of the reaction vessel 210 among the supercritical fluid passages in the supercritical fluid device are operated. The pressure is set lower than the internal pressure of the reaction vessel 210. As a result, the supercritical fluid is discharged from the inside of the reaction vessel 210 to the outside. Here, for example, the pressure gauge 231 monitors the pressure in the flow path downstream from the reaction vessel 210, and the pressure regulating valve 232 and the pressure regulating device 233 control the pressure based on the pressure obtained by the pressure gauge 231. To do.

The supercritical fluid discharged from the reaction vessel 210 is sent to a separator (separator) 234 provided on the downstream side of the pressure adjusting device 233. The separator 234 collects the unreacted metal precursor contained in the supercritical fluid by separating it.

Also, the flow path of the supercritical fluid from the connection between the supercritical fluid supply device 221 and the hydrogen supply device 223 to the reaction vessel 210 is provided inside the temperature adjustment device 240. The temperature adjustment device 240 adjusts the temperature of carbon dioxide, which is a raw material of the supercritical fluid, to a temperature at which the supercritical state can be maintained. Considering that carbon dioxide is in a supercritical state at about 31 ° C., the temperature adjustment device 240 keeps the inside at 40 degrees, for example.

(Example of manufacturing method flow)
FIG. 7 is a flowchart for explaining an example of a method for manufacturing an X-ray generation target according to the first embodiment. FIG. 8 is a diagram for explaining an example of a method for manufacturing an X-ray generation target according to the first embodiment.

As shown in FIG. 7, in the method for manufacturing the target T1 for generating X-rays according to the first embodiment, the substrate 1 is placed on the mounting table 132 of the FIB apparatus 100 (step S101). Then, the FIB apparatus 100 forms the hole 3 in the substrate 1 (step S102). Specifically, the FIB apparatus 100 forms a bottomed hole 3 in the substrate 1. For example, the FIB apparatus 100 irradiates the substrate 1 with an ion beam 122 such as Ga + to sputter from the surface 1a side, thereby forming the hole 3 as shown in FIG. For example, the FIB apparatus 100 forms a hole 3 having a diameter of 100 nm and a depth of 600 nm in the substrate 1. However, the present invention is not limited to this, and the diameter of the hole 3 may be smaller than 100 nm and the depth may be deeper than 600 nm as long as the supercritical fluid penetrates inside.

Here, the hole 3 formed by sputtering the substrate 1 with the ion beam 122 has a diameter that decreases toward the bottom surface 3a, and the side wall surface 3b may be tapered. In the example shown in FIG. 8A, for the sake of convenience, the case where the side wall surface 3b is formed perpendicular to the bottom surface 3a is shown as an example.

And the formation process which forms liner layer 4 is performed (Step S103). Specifically, as shown in FIG. 8B, the liner layer 4 is formed on the substrate 1 before the metal is deposited in the hole 3 by bringing the substrate 1 into contact with the supercritical fluid. By providing the liner layer 4, the adhesion between the metal deposited in the hole 3 and the substrate 1 can be improved. The liner layer 4 is preferably formed using a material having a lattice spacing close to that of the deposited metal from the viewpoint of improving the adhesion between the deposited metal and the substrate 1. For example, when copper is deposited, it is preferable to use Ru (ruthenium) or WCN. A more detailed example will be described. In the substrate 1, a WCN layer and a Ru layer may be formed on the eye plane of the substrate 1 by about 4 nm and 20 nm, respectively. These serve as a Glue layer for improving the adhesion between the deposited metal and the substrate 1.

The liner layer 4 may be formed using an arbitrary method, for example, using an ALD (Atomic Layer Deposition) method, or using a supercritical fluid. When the liner layer 4 is formed using a supercritical fluid, the liner layer 4 is formed on the substrate 1 after the substrate 1 is placed in the reaction vessel 210 and before performing step S104 described later. In this case, the metal used as the material of the liner layer and the target for X-ray generation can be continuously formed in the same reaction vessel.

Then, the supercritical fluid device 200 executes an addition process of adding a metal precursor of a metal that is a material of the target for X-ray generation to the supercritical fluid (step S104). For example, in the supercritical fluid device 200, in the metal precursor supply device 222, the metal precursor delivery device 222b takes out the metal precursor stored in the metal precursor storage device 222a from the metal precursor storage device 222a. When the metal precursor delivery valve 222c is opened, the metal precursor delivery device 222b allows the metal precursor taken out from the metal precursor storage device 222a to be sent from the supercritical fluid supply device 221. Add into the fluid. For example, the metal precursor supply device 222 receives Cu (hfac) (butyne) and bis (2,2,6,6-tetramethyl-3,5-heptanedionato) copper from the supercritical fluid supply device 221. Add to carbon dioxide supercritical fluid.

Then, the supercritical fluid device 200 performs a deposition process for depositing metal in the hole 3 by bringing the substrate 1 having the bottomed hole into contact with the supercritical fluid (step S105). Specifically, the substrate 1 and the supercritical fluid are brought into contact with each other by supplying the supercritical fluid to which the metal precursor is added into the reaction vessel 210. As a result, as shown in FIG. 8C, a metal that is a material for the target for X-ray generation is deposited on the substrate 1. For example, when the metal precursor comes into contact with the substrate 1, it is reduced by the substrate 1 to deposit metal, or the metal precursor itself is deposited.

Here, as a result of the supercritical fluid added with the metal precursor contacting not only the hole 3 of the substrate 1 but also the other outer surface, as shown in FIG. The metal to be deposited is deposited not only on the hole 3 of the substrate 1 but also on the surface of the substrate 1.

Further, the supercritical fluid device 200 performs the reduction treatment of the metal precursor after bringing the substrate 1 into contact with the supercritical fluid (step S106). Specifically, the supercritical fluid device 200 performs a reduction process by heating while supplying H2 gas to the supercritical fluid. The mixing device 223b of the hydrogen supply device 223 introduces the hydrogen gas into the reaction vessel 210 by mixing the hydrogen gas stored in the hydrogen storage device 223a with the supercritical fluid. Further, the pressure and temperature inside the reaction vessel 210 are set higher than those in the deposition step. For example, the pressure inside the reaction vessel 210 is set to 9.5 MPa, and the temperature is heated from 40 degrees to 220 degrees at a temperature increase rate of 4.5 degrees per minute. Thus, by heating while supplying the hydrogen gas, the metal is reduced from the metal precursor added to the supercritical fluid, and the deposition of the metal on the substrate 1 can be promoted.

Also, by performing the reduction treatment, even if the metal precursor is deposited in the hole 3, the organic functional group portion can be removed from the metal precursor, and the purity can be improved. For example, when the metal precursor is CuL2, the removal of L that becomes an organic functional group portion is expressed by the following mechanism.

CuL2 + H2 → Cu + 2HL

Thereafter, a polishing process is performed to remove the metal deposited on the surface 1a of the substrate 1 by polishing the surface of the substrate 1 (step S107). For example, the surface 1a of the substrate 1 is polished using a CMP (Chemical Mechanical Polishing) apparatus. An arbitrary apparatus may be used as the CMP apparatus. As a result, the metal is removed from the surface 1a of the substrate 1 as shown in FIG.

Then, the conductive layer 12 is formed (step S108). The conductive layer 12 is formed so as to cover the surface 1 a of the substrate 1 and the upper part of the metal deposited in the hole 3. The conductive layer 12 is formed using, for example, a known microwave plasma CVD apparatus. Explaining with a more detailed example, the conductive layer 12 uses a microwave plasma CVD apparatus to generate and grow diamond particles on the surface 1a and the metal by microwave plasma CVD while doping boron. Is formed. As a result, a conductive layer 12 is formed on the surface 1a of the substrate 1 as shown in FIG.

Note that the processing procedure of the manufacturing method described with reference to FIGS. 7 and 8 is not limited to the above order, and may be appropriately changed within a range in which the processing contents are not contradictory. For example, the above step S103 may be omitted, and S106 and S105 may be performed simultaneously.

(Example of X-ray generator)
An X-ray generation apparatus using the X-ray generation target T1 will be described. FIG. 9 is a diagram illustrating an example of a cross-sectional configuration of an X-ray generation apparatus using the X-ray generation target T1 according to the first embodiment. FIG. 10 is a diagram illustrating an example of a mold power supply unit of the X-ray generation apparatus using the X-ray generation target T1 according to the first embodiment. The X-ray generator described with reference to FIGS. 9 and 10 is an example, and the present invention is not limited to this.

As shown in FIG. 9, the X-ray generation device 21 is an open type, and unlike a closed type for disposable use, a vacuum state can be arbitrarily created, and filament parts F and X-rays that are consumables. The generation target T1 can be exchanged. The X-ray generator 21 has a cylindrical stainless steel cylindrical portion 22 that is in a vacuum state during operation. The cylindrical part 22 is divided into two parts by a fixing part 23 located on the lower side and an attaching / detaching part 24 located on the upper side, and the attaching / detaching part 24 is attached to the fixing part 23 via a hinge part 25. Therefore, the upper part of the fixing part 23 can be opened by rotating the detachable part 24 so as to lie down via the hinge part 25, and the filament part (cathode) accommodated in the fixing part 23. Enable access to F.

A pair of upper and lower

cylindrical coil portions

26, 27 that function as an electromagnetic deflection lens are provided in the detachable portion 24, and an electron path is provided in the longitudinal direction of the cylindrical portion 22 so as to pass through the centers of the

coil portions

26, 27. 28 extends, and the electron passage 28 is surrounded by the

coil portions

26 and 27. A disk plate 29 is fixed to the lower end of the detachable portion 24 so as to cover it, and an electron introduction hole 29 a is formed in the center of the disk plate 29 so as to coincide with the lower end side of the electron passage 28.

The upper end of the attaching / detaching portion 24 is formed in a truncated cone, and an X-ray generation target T1 that forms an electron transmission type X-ray emission window located on the upper end side of the electron passage 28 is attached to the top portion. The X-ray generation target T1 is accommodated in a detachable rotary cap 31 in a grounded state. Therefore, the removal of the rotary cap portion 31 enables the replacement of the X-ray generation target T1 which is a consumable item. Moreover, the filament part F is accommodated in the cap part 30 which can be attached or detached, and replacement | exchange of the filament part F is also attained by removal of the cap part 30. FIG.

The vacuum pump 32 is fixed to the fixing part 23. The vacuum pump 32 is for making the inside of the cylindrical part 22 into a high vacuum state. That is, when the X-ray generator 21 is equipped with the vacuum pump 32, the filament part F and the X-ray generation target T1 which are consumables can be replaced.

A mold power supply unit 34 that is integrated with the electron gun 36 is fixed to the proximal end side of the cylindrical portion 22. The mold power supply 34 is molded with an electrically insulating resin (for example, epoxy resin) and is housed in a metal case 40. And the lower end (base end) of the fixing | fixed part 23 of the cylindrical part 22 is firmly fixed to the upper board 40b of case 40 by the screwing etc. in the sealed state.

As shown in FIG. 10, a high voltage generator having a transformer configured to generate a high voltage (for example, a maximum of −160 kV when the X-ray generation target T1 is grounded) is formed in the mold power supply unit 34. 35 is enclosed. Specifically, the mold power supply unit 34 includes a block-shaped power supply main body 34a that is positioned on the lower side and forms a rectangular parallelepiped shape, and a columnar neck portion that protrudes upward from the power supply main body 34a into the fixing unit 23. 34b. Since the high voltage generator 35 is a heavy component, it is preferably enclosed in the power supply main body 34a and arranged as low as possible from the weight balance of the entire X-ray generator 21.

At the tip of the neck portion 34b, an electron gun 36 is mounted so as to face the X-ray generation target T1 so as to sandwich the electron passage 28.

As shown in FIG. 10, an electron emission control unit 51 that is electrically connected to the high voltage generation unit 35 is enclosed in the power supply main body 34 a of the mold power supply unit 34. Controls the timing of discharge and tube current. The electron emission control unit 51 is connected to the grid terminal 38 and the filament terminal 50 via the grid connection wiring 52 and the filament connection wiring 53, respectively, and each

connection wiring

52, 53 is applied to a high voltage. Therefore, it is enclosed in the neck portion 34b.

The power supply main body 34 a is accommodated in a metal case 40. A high voltage control unit 41 is disposed between the power supply main body 34 a and the case 40. A power supply terminal 43 for connection to an external power supply is fixed to the case 40, and the high voltage control unit 41 is connected to the power supply terminal 43, and the high voltage generation unit 35 and the electron emission control in the mold power supply unit 34. It is connected to the part 51 via

wirings

44 and 45, respectively. Based on an external control signal, the high voltage control unit 41 controls the voltage that can be generated by the high voltage generation unit 35 constituting the transformer from a high voltage (for example, 160 kV) to a low voltage (0 V). The electron emission control unit 51 controls electron emission timing, tube current, and the like.

In the X-ray generator 21, power and control signals are respectively transmitted from the high voltage control unit 41 in the case 40 to the high voltage generation unit 35 and the electron emission control unit 51 of the mold power supply unit 34 based on the control of a controller (not shown). Supplied. At the same time, power is supplied to the

coil portions

26 and 27. As a result, an electron beam is emitted from the filament portion F with an appropriate acceleration, the electron beam is appropriately converged by the controlled

coil portions

26 and 27, and the electron beam is irradiated to the X-ray generation target T1. The irradiated electron beam collides with the X-ray generation target T1, so that the X-ray is irradiated to the outside.

By the way, in the X-ray generator, high resolution can be obtained by accelerating the electron beam with a high voltage (for example, about 50 to 150 keV) and focusing on a fine focus on the target. X-rays, so-called bremsstrahlung X-rays, are generated when electrons lose energy in the target. At this time, the focal spot size is almost determined by the spot size of the irradiated electron beam.

In order to obtain a fine focal spot size of X-rays, the electron beam may be converged to a small spot. In order to increase the amount of generated X-rays, the amount of electron beams may be increased. However, due to the space charge effect, the spot size of the electron beam and the amount of current are in a contradictory relationship, and a large current cannot flow through a small spot. When a large current is passed through a small spot, the target may be easily consumed due to heat generation.

In the present embodiment, as described above, the X-ray generation target T1 includes the substrate 1 made of diamond and the target portion 10 that is in close contact with the bottom surface 3a and the side wall surface 3b of the hole 3, and thus heat radiation. The X-ray generation target T1 can be prevented from being consumed even under the above-described circumstances.

In addition, since the target portion 10 is nano-sized, even when electrons are irradiated with the high acceleration voltage (for example, about 50 to 150 keV) as described above, The line focal spot diameter does not widen, and degradation of resolution is suppressed. Further, the X-ray dose can be increased by increasing the depth of the target unit 10. That is, a resolution determined by the size of the target unit 10 is obtained. Therefore, the X-ray generation apparatus 21 using the X-ray generation target T1 can obtain nano-order (several tens to several hundreds of nanometers) resolution while increasing the X-ray dose.

As described above, according to the above-described embodiment, the metal precursor of the metal used as the material for the X-ray generation target is added to the supercritical fluid, and the substrate 1 and the supercritical fluid in which the bottomed hole 3 is formed. Since the X-ray generation target T1 is manufactured by depositing metal in the hole 3, the X-ray generation target portion can be appropriately formed.

For example, in the method of forming a target for X-ray generation using an ion beam, a VOID (void or void) may be formed at the hole bottom of the substrate 1, whereas according to the above-described embodiment, supercriticality is achieved. By depositing metal in the hole 3 using a fluid, it becomes possible to prevent the formation of VOID (voids, voids), and it is possible to easily increase the aspect ratio compared to the method using an ion beam. is there. That is, it is possible to manufacture an X-ray generation target portion having no VOID and having a minute pillar.

For example, when a supercritical fluid is used, the supercritical fluid penetrates into the hole 3 even if the diameter of the hole 3 is about 20 nm. For example, it is possible to set the diameter of the hole 3 to 100 nm and the depth to 1000 nm. As a result, the diameter of the hole 3 can be reduced, the depth can be increased, formation of VOID can be prevented, and the purity of the metal can be improved as compared with the technique of depositing using an ion beam. By using the target for X-ray generation manufactured by the manufacturing method according to the first embodiment, the hole 3 can be made smaller as compared with the method of depositing using an ion beam. As a result, the X-rays become thinner and the resolution can be improved. In addition, by using the X-ray generation target manufactured by the manufacturing method according to the first embodiment, the depth of the hole 3 can be increased as compared with the technique of depositing using an ion beam, and X-ray generation It becomes possible to increase the X-rays irradiated by the apparatus.

Further, as described above, the outer shape of the substrate 1 is about 3 mm, and it can be applied even if the reaction vessel 210 of the supercritical fluid device 200 is small. Since the inside of the supercritical fluid processing apparatus 200 has a very high pressure, it is difficult to increase the size of the apparatus.

Also, for example, in the method of forming an X-ray generation target by an ion beam, impurities implanted as a gas may be mixed with the metal, and it is assumed that the purity cannot be increased. On the other hand, according to the above-described embodiment, when the ion beam is used, the implanted impurities are not mixed, and the purity can be improved.

In addition, according to the above-described embodiment, the method further includes forming the liner layer 4 on the substrate before depositing the metal in the hole by bringing the substrate into contact with the supercritical fluid. As a result, it is possible to efficiently deposit metal on the substrate. That is, the conductivity of diamond used as a substrate is not high compared to the conductivity of other substances. In consideration of this, the metal can be efficiently deposited by forming the liner layer 4 in advance.

In addition, according to the above-described embodiment, the method further includes a reduction step of performing a reduction treatment of the metal precursor after bringing the substrate into contact with the supercritical fluid. As a result, it is possible to improve the purity of the metal deposited in the hole 3 by promoting the deposition of the metal and removing the organic functional group from the metal precursor deposited on the substrate 1.

Further, according to the above-described embodiment, in the reduction process, the reduction process is performed by heating while supplying H2 gas to the supercritical fluid. As a result, the reduction process can be easily performed continuously from the deposition process.

Further, according to the above-described embodiment, the method further includes a polishing step of removing metal deposited on the surface of the substrate by polishing the surface of the substrate. When a metal is deposited using a supercritical fluid, the metal is deposited not only on the hole 3 but also on the surface 1 a of the substrate 1. In consideration of this, by polishing the surface of the substrate and removing the metal from the surface 1a, it is possible to manufacture an X-ray generation target portion without an extra layer.

(Other embodiments)
The first embodiment has been described so far, but other embodiments may be implemented in addition to the above-described embodiment. Therefore, other embodiments will be described below.

(Number of holes provided on the board)
For example, in the first embodiment, the case where the substrate 1 has one hole 3 has been described as an example. FIG. 11 is a diagram illustrating an example of an X-ray generation target in which a plurality of holes are formed in a substrate. In the example shown in FIG. 11, the case where the substrate 1 has the holes 3-1 to 3-9 is shown. In other words, the case where the substrate 1 has nine holes 3 is shown as an example.

In this way, the substrate 1 has a plurality of holes 3, and metal is deposited in each of the plurality of holes 3 to function as an X-ray generation target, so that one substrate 1 can be used for a long time. Become. For example, even if one X-ray generation target provided on the substrate 1 cannot be used, another X-ray generation target can be used, and one substrate can be used for a long time.

Even if the substrate 1 has a plurality of holes 3, it is possible to deposit metal in each of the plurality of holes 3 using the same manufacturing method as described in the first embodiment. In addition, according to the manufacturing method according to the embodiment, it is possible to easily create a plurality of X-ray generation targets.

(metal)
In the first embodiment, the case where copper is deposited as the metal in the hole 3 is described as an example. However, the present invention is not limited to this, and any metal that can be deposited using a supercritical fluid is used. Good. For example, W (tungsten), Pt (platinum), Au (gold) may be used, and any heavy metal may be used. For example, when W is used, the metal precursor may be W (CO) 6. In the case of using Pt, the metal precursor may be Pt (COD) (CH3) 2 or Pt (hfac) 2. When using Au, Au (acac) (CH3) 2 may be used as a metal precursor.

(Ion dope)
In the first embodiment, the case where the liner layer 4 is formed on the substrate 1 has been described as an example. However, the present invention is not limited to this, and the liner layer 4 may not be formed. Instead, ion doping may be performed.

(Liner layer 4)
For example, in the first embodiment, the case where the liner layer 4 is provided has been described as an example, but the present invention is not limited to this. For example, metal may be deposited without forming the liner layer 4. When the liner layer 4 is formed, it may be formed in a supercritical fluid, or the substrate 1 on which the liner layer 4 has been previously formed may be brought into contact with the supercritical fluid.

DESCRIPTION OF SYMBOLS 1 Board | substrate 1a Front surface 1b Back surface 10 Target part 10 Metal 12 Conductive layer T1 Target for X-ray generation

Claims

An addition step of adding a metal precursor of a metal, which is a material for the target for X-ray generation, to the supercritical fluid;
A method for producing an X-ray generation target, comprising: depositing the metal in the hole by bringing the supercritical fluid into contact with the substrate on which a bottomed hole is formed.
The X-ray according to claim 1, further comprising forming a liner layer on the substrate before depositing the metal in the hole by bringing the substrate into contact with the supercritical fluid. A method for producing a target for generation.
The method for producing a target for X-ray generation according to claim 1, further comprising a reduction step of reducing the metal precursor after bringing the substrate into contact with the supercritical fluid.
4. The method of manufacturing a target for X-ray generation according to claim 3, wherein in the reduction step, the reduction process is performed by heating the supercritical fluid while supplying H2 gas.
The method for producing a target for X-ray generation according to claim 1, further comprising a polishing step of removing the metal deposited on the surface of the substrate by polishing the surface of the substrate.
6. The method for producing a target for X-ray generation according to claim 1, wherein a plurality of the holes are formed in the substrate.
A contact step of bringing the material of the target for X-ray generation into contact with the supercritical fluid;
An X-ray generation target manufactured by a method comprising: depositing a material of an X-ray generation target in the hole by bringing the supercritical fluid into contact with a substrate having a bottomed hole formed therein.