JP2003303953A - Manufacturing method of compound/alloy structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively form a fine compound/alloy structure, using simple processes. <P>SOLUTION: Regions having a diameter of 1 μm or smaller in a plurality of material substances 2 and 3, that are deposited on a substrate are locally heated and fused for forming a structure 6 made of either a compound or an alloy. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a compound / alloy structure, and more particularly to a recording device such as a magnetic recording medium or a magnetic head, an electronic device such as an LSI, field emission or field ionization, and charge. The present invention relates to a method for producing a compound / alloy structure, which is characterized by a method for producing a fine structure that constitutes a display device, a molecular device, or the like using injection or the like.

[0002]

2. Description of the Related Art At present, the production of device structures by optical lithography is industrially the mainstream, but electron beam (EB) lithography and focused ion beam (FIB) are used for the production of experimental fine structures. Method of cutting the material by using high energy EB,
An ion beam chemical vapor deposition (CVD) method or an EB chemical vapor deposition method in which a material gas introduced into the apparatus by an ion beam such as FIB or EB is decomposed and deposited on a substrate may be used.

On the other hand, aiming at further miniaturization of the structure,
Several structure manufacturing methods using a scanning tunneling microscope (STM) have also been proposed. As a manufacturing method using this STM, there are "a fine processing method and its apparatus" (Japanese Patent Laid-Open No. 2-173278) and " Micropart processing method and apparatus and micropart analysis method and apparatus "(Patent Document 4)
No. 34824), “Ultrafine processing method by scanning tunneling microscope” (Japanese Patent Laid-Open No. 4-368762), a method using electric field evaporation of a material to be processed,
Similarly, a method of processing a material by using a chemical reaction in combination with a field evaporation, a method of conversely depositing an STM probe material on a substrate by field evaporation, a kind of EB-CVD by a tunnel current or a field emission current from the probe. There are laws etc.

Further, "lithographic mask manufacturing method and lithographic apparatus" (Japanese Patent Laid-Open No. 3-41449)
As disclosed in Japanese Patent Laid-Open Publication No. 2003-242242, a method using a chemical reaction or a phase change due to a tunnel current of STM is also proposed as a lithography resist preparation or exposure method.

[0005]

However, the lithographic method, which is currently the mainstream, requires a multi-step operation of pattern formation, exposure, development and etching, and the material to be processed is not a semiconductor. If it is a metal, anisotropic etching is currently difficult,
There is a problem that it is difficult to manufacture a fine structure with a high aspect ratio.

Further, in the cutting using the FIB, when an attempt is made to increase the resolution by strengthening the convergence of the ions, there is a problem that the ion current is drastically reduced and the processing speed becomes very small, and in the FIB, both cutting and deposition are performed. There is a problem that contamination with the used ions, for example, Ga ions occurs.

On the other hand, in the method of vaporizing using EB, there is a problem that it takes a lot of time to vaporize the other portion while leaving a part of the material. Further, in the CVD method using EB, the apparatus is used. Since the material gas having a relatively high pressure is introduced into the device, there is a problem in that the material gas or the residual gas in the apparatus is taken in to cause contamination.

Furthermore, the STMs that have been proposed so far
Among the fine structure manufacturing methods using, the method utilizing electric field evaporation of the material to be processed has a problem that it takes a lot of time to leave a part of the material as in the case of evaporation by EB.

Further, in the method of depositing the STM probe material, since the probe is consumed as it evaporates, it becomes difficult to control the tunnel current that largely depends on the state of the probe, and the probe is frequently used. There is a problem that it needs to be replaced.

Further, in the case of the EB-CVD method using STM, there is a problem that the same problem of contamination as in the normal EB-CVD method cannot be avoided.

Further, in the formation of a lithographic pattern using STM, there is a problem in that multi-step operation is required, which is the same as in ordinary lithography.
The same applies to the problem when the material is metal.

Therefore, an object of the present invention is to selectively form a fine compound / alloy structure by a simple process.

[0013]

FIG. 1 is an explanatory view of the principle configuration of the present invention. Here, the means for solving the problems in the present invention will be described with reference to FIG. In order to solve the above problems, the present invention is directed to a method for producing a compound / alloy structure, in which a plurality of material substances 2 and 3 deposited on a substrate are locally formed in a region having a diameter of 1 μm or less. It is characterized in that the structure 6 made of either a compound or an alloy is formed by heating and melting.

As described above, by locally heating, it is possible to selectively form a structure 6 made of a compound or an alloy having an arbitrary fine shape and a predetermined composition, without a mask. Become.

The size of such a fine structure 6 has a maximum diameter of 1 which is difficult to process by lithography.
It is preferably μm or less, and more preferably 100 nm or less.
Further, in this case, the material substances 2 and 3 may be directly deposited on the substrate, or may be deposited on the substrate via the base 1.

Further, by depositing the material substances 2 and 3 on the structure 6 and performing the local heat treatment,
It is possible to form a structure such as a fine heterojunction in which different kinds of substances 2 and 3 are in contact with each other at their boundaries. In this case, when the probe 4 such as the STM is used, the position of the structure 6 can be confirmed by observing the STM before the re-machining, and thus the alignment during the re-machining becomes easy.

The local heating means in this case is ST
Either tunnel current 5, contact current, or field emission current using the probe 4 such as M may be used, or an energy beam of electron beam, laser light, or synchrotron radiation light may be used. You can use it,
The amount of energy given to the materials 2 and 3, for example,
By controlling the amount of current applied, or in the case of an energy beam, the energy of the beam itself, the number of beams, and the change over time, it is possible to form a structure 6 having an arbitrary shape and composition.

In this case, since it is possible to perform the operations from film formation to processing of the material substances 2 and 3 in a high vacuum,
It is possible to avoid contamination caused by the manufacturing atmosphere,
When the probe 4 such as the STM is used, the probe 4 is not consumed because the material is supplied from the substrate, not from the probe 4, and the problem caused by the consumption can be avoided.

As the structure 6 thus formed, I
III-V group compound semiconductor structure using materials 2 and 3 made of group II element and materials 2 and 3 made of group V element, II
A compound structure such as a 11-VI group compound semiconductor structure using the material substances 2 and 3 made of a group element and the material substances 2 and 3 made of a group VI element, or a material substance 2 made of a magnetic metal or a nonmagnetic metal , 3 are typical non-magnetic alloy structures, ferromagnetic alloy structures, or antiferromagnetic alloy structures.

Further, the composition of the structure 6 can be arbitrarily controlled by changing the thickness ratio of the plurality of material substances 2 and 3, whereby a mixed crystal compound semiconductor structure or alloy having an arbitrary composition can be controlled. A structure can be formed.

Further, by utilizing the difference in the physical or chemical properties between the material substances 2 and 3 and the formed structure 6, unnecessary parts other than the structure are removed to select by lithography or EB. It is possible to form only the fine structure 6 at an arbitrary position by a simple maskless etching process without using an evaporation method.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Now, a process of manufacturing a fine heterojunction structure according to a first embodiment of the present invention will be described with reference to FIGS. First, the Sb thin film 1 having a thickness of 100 nm or less, for example, 10 nm is formed on the Al ₂ O ₃ substrate 11 by using the vacuum deposition method.
2, and an In thin film 13 having a thickness of 100 nm or less, for example, 10 nm is sequentially deposited to form a multilayer film.

Next, referring to FIG. 2B, the STM probe 14 is brought close to the multilayer film to the extent that a tunnel current flows, and the tunnel current is locally flown to locally heat the In thin film 13 and the Sb thin film 12. The heated portion is melted and alloyed to form the InSb dot 15. In this case, the size of the InSb dot 15 depends on the amount of tunneling current, but the maximum diameter is 100 nm or less, for example, 2 by flowing about several μA.
InSb dots 15 having a size of 0 to 30 nm are obtained.

Next, referring to FIG. 3 (c), the thickness is reduced to 1 on the entire surface by using the vacuum evaporation method again.
An Al thin film 16 having a thickness of 00 nm or less, for example, 10 nm is deposited.

Next, referring to FIG. 3D, again, the STM probe 14 is brought close to the Al thin film 16 corresponding to the InSb dot 15 to the extent that a tunnel current flows, and the tunnel current is locally passed to locally heat the tunnel current. An InAlSb / InSb heterojunction can be formed by melting and alloying the heated portions of the Al thin film 16 and the InSb dots 15 to form the InAlSb dots 17. In this case, the STM probe 1
Since the No. 4 is used, the position of the InSb dot 15 can be confirmed by observing with the STM before the reprocessing, and therefore the alignment at the time of the reprocessing becomes easy.

Next, as shown in FIG. 4 (f), the unreacted Al thin films 16 and I are etched by etching with an etchant composed of dilute hydrochloric acid having a small etching rate for the InAlSb dots 17.
The n thin film 13 is selectively removed.

Finally, referring to FIG. 4 (g), by lightly etching with aqua regia, the unreacted Sb thin film 12 is removed to form an isolated InAlSb / InSb heterojunction. In this case, the exposed portions of the InAlSb dots 17 and the InSb dots 15 are also etched.

As described above, in the first embodiment of the present invention, since the STM probe is used to locally heat by using the tunnel current, a fine heterojunction junction structure is formed at an arbitrary position. It becomes possible to form objects.

During the thin film deposition, In and Sb are doped with an n-type impurity such as Si, and Al is doped with a p-type impurity such as Zn to form a pn junction hetero diode. It will be possible.

In this case, a refractory metal wiring pattern such as W is provided on the Al ₂ O ₃ substrate, and InSb dots are formed on the refractory metal wiring pattern to form one electrode of the pn junction hetero diode. be able to.

For the other electrode, for example, after an Al thin film is deposited again on the entire surface including the pn junction hetero diode, local heating is repeated until the pn junction hetero diode is reached while moving the STM probe. By melting and solidifying Al, it is possible to form an Al wiring pattern that is thicker than other portions, and then lightly etch with dilute acid to remove the rest of the Al film to form the other electrode. be able to. In this case, A
It is necessary to consider the formation location of the InSb tod and the like so that the 1 wiring and the W wiring are not short-circuited.

Next, the manufacturing process of the non-magnetic alloy dot of the second embodiment of the present invention will be described with reference to FIG. First, referring to FIG. 5A, a Ta substrate 21 having a thickness of 1 is formed by a vacuum evaporation method.
A Cu thin film 22 having a thickness of 00 nm or less, for example, 12 nm, and a Ni thin film 23 having a thickness of 100 nm or less, for example, 8 nm are sequentially deposited to form a multilayer film.

Next, referring to FIG. 5B, the STM probe 24 is brought close to the multilayer film to the extent that a tunnel current flows, and the tunnel current is locally flown to locally heat the Ni thin film 23 and the Cu thin film 22. The heated portions are melted and alloyed to form Cu _0.6 Ni _0.4 dots 25.

As described above, in the second embodiment of the present invention, the Cu _0.6 Ni _0.4 dots 25, which is a non-magnetic alloy, in the Ni thin film 23, which is a ferromagnetic metal, are isolated at arbitrary positions. Can be present. The composition ratio of this alloy dot is the same as that of the Cu thin film 22 and Ni that are deposited first.
It depends substantially on the film thickness ratio of the thin film 23.

Next, with reference to FIG. 6, a manufacturing process of the ferromagnetic alloy dot according to the third embodiment of the present invention will be described. First, as shown in FIG. 6A, a Ta substrate 31 having a thickness of 1 is formed by vacuum deposition.
A Cu thin film 32 having a thickness of 00 nm or less, for example, 12 nm, an Al thin film 33 having a thickness of 100 nm or less, for example, 6 nm, and a Mn thin film 34 having a thickness of 100 nm or less, for example, 6 nm are sequentially deposited to form a multilayer film. .

Next, referring to FIG. 6B, the STM probe 35 is brought close to the multilayer film to the extent that a tunnel current flows, and the tunnel current is locally passed to locally heat the Mn thin film 34 to the Cu thin film 32. Cu ₂ Al is formed by melting and alloying the heated parts.
The Mn dot 36 is formed.

As described above, in the third embodiment of the present invention, the Cu thin film 32 and the Al thin film 3 which are nonmagnetic metals are used.
3, Mn thin film 34 in the ferromagnetic alloy Cu ₂ AlMn
The dots 36 can be scattered in arbitrary positions in an isolated state. In this case, the Cu thin film 32 and Al to be deposited are deposited so as to correspond to the composition ratio of Cu ₂ AlMn.
The film thicknesses of the thin film 33 and the Mn thin film 34 are set.

Next, the manufacturing process of the antiferromagnetic alloy dots according to the fourth embodiment of the present invention will be described with reference to FIG. First, referring to FIG. 7A, a Ta substrate 41 having a thickness of 1 is formed by a vacuum evaporation method.
A Pt thin film 42 having a thickness of 00 nm or less, for example, 6 nm, a Pd thin film 43 having a thickness of 100 nm or less, for example, 6 nm, and a Mn thin film 44 having a thickness of 100 nm or less, for example, 12 nm are sequentially deposited to form a multilayer film. .

Next, referring to FIG. 7B, the STM probe 45 is brought close to the multilayer film to the extent that a tunnel current flows, and the tunnel current is locally passed to locally heat the Mn thin film 44 to the Pt thin film 42. PtPdM by melting and alloying the heating points
The n ₂ dot 46 is formed.

As described above, in the fourth embodiment of the present invention, the Pt thin film 42 and the Pd thin film 4 which are nonmagnetic metals are used.
3, PtPdMn which is an antiferromagnetic alloy in the Mn thin film 44
_{The two} dots 46 can be scattered in arbitrary positions in an isolated state. In this case also, the Pt thin films 42 and Pd to be deposited are deposited so as to correspond to the composition ratio of PtPdMn _2.
The film thicknesses of the thin film 43 and the Mn thin film 44 are set.

Although the respective embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the respective embodiments, and various modifications can be made. For example, in the above description of each embodiment, the tunnel current from the STM probe is used to melt the multilayer film.
The current is not limited to the tunnel current, and a field emission current or a contact current may be used. Needless to say.

That is, the "tunnel current" is applied between the positive and negative electrodes by applying a voltage between the positive and negative electrodes that does not exceed the work function of the material forming each electrode, for example, a voltage of about 5 to 6 V or less. Tunnels through the potential barrier formed in the
The current is almost zero when the distance is more than 1 nm.

On the other hand, the "field emission current" is due to the electrons emitted in the free space when a voltage larger than the work function of the material forming each electrode is applied between the positive and negative electrodes,
If the applied voltage is increased, a current can flow even at intervals of several nm to μm, but if the applied voltage is too high, the resolution becomes poor.

The "contact current" is a current that flows in the state where the positive and negative electrodes are in contact with each other and there is no potential barrier when electrons move between the electrodes, and the resolution depends on the contact area of the probe. , Generally, the resolution becomes poor. For example, when the dimension of the structure is about several nm or more, it is desirable to use a probe made of a refractory metal of a contact type AFM (atomic force microscope).

Further, the heating means locally is not limited to such an electric current, and electron beam, laser light or synchrotron radiation light may be used.
It is effective when the size of the structure is relatively large.

In the first embodiment, the unreacted Sb thin film is removed by using aqua regia, but it may be removed by sputter etching using a rare gas such as Ar gas in a vacuum. The whole may be lightly etched.

In each of the above-mentioned embodiments, binary and ternary compounds or alloys are formed. However, the multi-layer film has a structure of four layers or more to form a mixed crystal compound or alloy of quaternary or more. It may be formed.

In each of the above embodiments, II
Although it is described as a manufacturing process of the IV compound semiconductor,
The thin film material is not limited to III-V group compound semiconductors, and group II elements such as Hg and Cd and group VI elements such as Te may be used to form II-VI group compound semiconductors such as HgCdTe. Further, a compound semiconductor of another group may be formed.

Here, the detailed configuration of the present invention will be described again with reference to FIG. Again, see FIG. 1 (Appendix 1) A structure made of either a compound or an alloy by locally heating and melting a region having a diameter of 1 μm or less of a plurality of material substances 2 and 3 deposited on a substrate. A method for producing a compound / alloy structure, comprising: (Supplementary Note 2) On the structure 6, the material 2,
The method for producing a compound / alloy structure according to appendix 1, characterized in that after 3 is deposited, a local heat treatment is performed. (Supplementary Note 3) In the step of locally heating the plurality of material substances 2 and 3, any one of a tunnel current 5, a contact current, or a field emission current is used. Method for manufacturing compound / alloy structure. (Supplementary Note 4) The method for producing a compound / alloy structure according to Supplementary Note 1 or 2, wherein irradiation of an energy beam is used in the step of locally heating the plurality of material substances 2, 3. (Supplementary Note 5) The method for producing a compound / alloy structure according to Supplementary Note 4, wherein the energy beam is an electron beam, a laser beam, or synchrotron radiation. (Supplementary Note 6) The above-mentioned plurality of material substances 2 and 3 are material substances 2 (3) made of a group III element and material substance 3 made of a group V element.
(2) The structure 6 is a group III-V compound semiconductor structure, and the structure 6 is any one of appendices 1 to 5.
The method for producing the compound / alloy structure according to 1. (Supplementary Note 7) The above-mentioned plurality of material substances 2 and 3 are material substances 2 (3) made of a group II element and material substances 3 made of a group VI element.
(2), wherein the structure 6 is an 11-VI group compound semiconductor structure, any one of appendices 1 to 5
The method for producing the compound / alloy structure according to 1. (Supplementary Note 8) The plurality of material substances 2 and 3 are made of a magnetic metal or a nonmagnetic metal, and the structure 6 is a nonmagnetic alloy structure, a ferromagnetic alloy structure, or an antiferromagnetic alloy structure. 6. The method for producing a compound / alloy structure according to any one of appendices 1 to 5, which is any one of the above. (Supplementary Note 9) The compound / alloy structure according to any one of Supplementary Notes 1 to 8, wherein the composition of the structure 6 is changed by changing the thickness ratio of the plurality of material substances 2 and 3. Manufacturing method. (Supplementary Note 10) After the formation of the structure 6, by utilizing the difference in physical or chemical properties between the material substances 2 and 3 and the formed structure 6, unnecessary parts other than the structure 6 are removed. The method for producing the compound / alloy structure according to any one of appendices 1 to 9, characterized by removing the compound / alloy structure.

[0050]

EFFECTS OF THE INVENTION According to the present invention, a multilayer film having different materials is formed and then locally heated and melted to be alloyed. It becomes possible to directly form a fine structure of an alloy or compound having a size on a substrate, and this contributes to ultra-miniaturization exceeding the lithography limit of electronic devices and magnetic devices.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a principle configuration of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process up to the middle of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a manufacturing process up to the middle of FIG. 2 and subsequent steps of the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of the manufacturing process after FIG. 3 of the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of a manufacturing process according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a manufacturing process according to the third embodiment of the present invention.

FIG. 7 is an explanatory diagram of a manufacturing process according to the fourth embodiment of the present invention.

[Explanation of symbols]

1 Substrate 2 Material substance 3 Material substance 4 Probe 5 Tunnel current 6 Structure 11 Al ₂ O ₃ substrate 12 Sb thin film 13 In thin film 14 STM probe 15 InSb dot 16 Al thin film 17 InAlSb dot 21 Ta substrate 22 Cu thin film 23 Ni thin film 24 STM probe 25 Cu _0.6 Ni _0.4 dot 31 Ta substrate 32 Cu thin film 33 Al thin film 34 Mn thin film 35 STM probe 36 Cu ₂ AlMn dot 41 Ta substrate 42 Pt thin film 43 Pd thin film 44 Mn thin film 45 STM Probe 46 PtPdMn ₂ dots

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01J 37/30 H01J 37/30 Z H01L 21/28 ZNM H01L 21/28 ZNMK 29/12 29/91 H 29 / 861 29/14 (72) Inventor Yuji Kataoka 4-1-1 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa F-term of Fujitsu Limited (reference) 4M104 BB36 CC01 5C034 AA02 AA03 AA07

Claims (5)

[Claims] 1. A structure in which a plurality of material substances deposited on a substrate are locally heated in a range of 1 μm or less in diameter and melted to form a structure made of either a compound or an alloy. Method for manufacturing compound / alloy structure. 2. The method for producing a compound / alloy structure according to claim 1, further comprising depositing a material on the structure and then performing local heat treatment. 3. A tunnel current, a contact current, or a field emission current is used in the step of locally heating the plurality of material substances.
Alternatively, the method for producing the compound / alloy structure according to item 2. 4. The method for producing a compound / alloy structure according to claim 1, wherein irradiation of an energy beam is used in the step of locally heating the plurality of material substances. 5. After the structure is formed, an unnecessary portion other than the structure is removed by utilizing a difference in physical or chemical properties between the material and the formed structure. The method for producing the compound / alloy structure according to any one of claims 1 to 4.