WO2003054945A1

WO2003054945A1 - Method for ion beam fine patterning of inorganic multilayer resist, and semiconductor device, quantum device, micromachine component and fine structure manufactured by the method

Info

Publication number: WO2003054945A1
Application number: PCT/JP2002/012919
Authority: WO
Inventors: Tadaaki Kaneko; Yasushi Asaoka; Naokatsu Sano
Original assignee: The New Industry Research Organization
Priority date: 2001-12-11
Filing date: 2002-12-10
Publication date: 2003-07-03
Also published as: AU2002354455A1

Abstract

A method for ion beam fine patterning of an inorganic multilayer resist, which comprises forming, on the surface of a semiconductor substrate(X), an inorganic material (Y) layer capable of forming a thermally and chemically stable oxidized film layer preventing the oxidation of the substrate(X) and, forming, on the surface of the inorganic material(Y)layer, an inorganic material (Z) layer capable of forming a thermally unstable natural oxidation film preventing the oxidation of the inorganic material (Y) layer and a forced oxidation film which is weaker than the above (Y) layer but is chemically stable, implanting a metal ion in the presence of a naturally formed oxidized surface film being formed on the surface of the (Z) layer or under the irradiation of molecular oxygen, to thereby selectively substitute a stable forced oxidized film (Z') layer for the above naturally formed oxidized surface film, increasing the amount of the ion implanted, to form a thermally and chemically stable oxidized film (Y') layer on the above (Y) layer through propagation of an O ion from the above naturally oxidized film or the above forced oxidized film (Z') layer and through sputtering of (Z)layer, and then subjecting the surface of the above substrate (X) to a dry etching with good accuracy using a reactive etching gas, to thereby remove the above surface oxidized film exclusive of the part substituted with the above forced oxidized film (Z') layer or the above oxidized film (Y') layer, the (Z) layer, the (Y) layer and a part of the substrate(X).

Description

Specification

Ion beam micromachining method for inorganic multilayer resist, semiconductor device, quantum device, micromachine component and microstructure by this method

The present invention includes a semiconductor substrate made of S i, S i C, G a I n including the _{_{A s X G a 1 χ Α}} s y P i y and _{_{A 1 X G a lx A s}} y P inorganic material such as _ly The present invention relates to an ion beam microfabrication method for a surface and a semiconductor device, a quantum device, and a micro machine component by the method. Background art

In recent years, with the increase in the integration of ULSI, which is the core of microelectronics, the circuit patterns in these quantum devices are becoming ever smaller. For this reason, the development of microfabrication technology in the nano-range is being actively pursued.

Conventionally, there is a pattern transfer type optical lithography as a typical example of a fine processing technology for a circuit pattern of such a quantum device. Although this optical lithography technology aims to achieve higher precision by using extreme ultraviolet light and X-rays, it is necessary to fabricate high-precision fine masks. In addition, the resolution in using photoresist is approaching its limit. In addition, development costs from these conventional methods are not negligible, and there is a need for the development of new microfabrication methods.

In the manufacturing process of semiconductor devices, basic technology for removing unnecessary parts of insulating films and metal thin films with high precision according to resist patterns A semiconductor crystal etching method is widely used. As a means for this etching method, dry etching using halogen gas is being studied. Since this dry etching is performed in a relatively clean atmosphere in an ultra-high vacuum, it is expected that fine quantum devices can be processed.

For example, for Si as a typical device material, a dry etching process using fluorine and chlorine-based halogen gas is being studied. However, so far, even in the case of Si, a dry etching process for fabricating a finer quantum device has not yet been completed. Then, although _{_{G a x I n! _ X}} A s y P y and _{_{_{G a X A 1 X _ X}}} A s y report on a dry etching process also compound semiconductor P _y such often include G a A s, The technical means that enable the production of quantum devices, like Si, have not been completed yet.

For example, GaAs is a material that has a higher electron mobility than Si and can operate at higher frequency and higher speed than Si, and is industrial scale in terms of resource abundance, crystal integrity, etc. It has been attracting attention for its excellent properties and diversity as a kind of compound semiconductor that overcomes its limitations instead of Si. In addition, the molecular crystal epitaxy (MBE) method and metal organic chemical vapor deposition (Metal Organic Chemical Vapor Deposition) Technology such as the MOCVD method has advanced and uniform crystal growth has become possible, and the importance of compound semiconductors as device materials is increasing.

Accordingly, the present inventor has proposed a dry etchant that overcomes the technical limitations of the conventional dry etching method for compound semiconductors using a halogen gas. As a method of dry etching, a method of dry etching the surface of a semiconductor crystal with a bromide in units of one atomic layer has been developed and disclosed in Japanese Patent Application Laid-Open No. 8-321483.

However, in order to accurately form a circuit pattern on the surface of a GaAs substrate, it was necessary to form a dry etching mask even when dry etching was performed on an atomic layer basis. As described above, the dry etching mask is approaching the limit of miniaturization of the dry etching mask with the recent miniaturization and complexity of circuit patterns in quantum devices.

In addition, a surface oxide film such as SiO ₂ , As ₂ O ₃ , As ₂₀ , and Ga O is naturally formed on the surface of the Si or GaAs substrate, and a dry etching mask is provided. In forming GaN, it was necessary to remove these surface oxide films.

The present invention has been made in view of the above problems, and it is not necessary to previously remove a surface oxide film of a multilayer substrate made of an inorganic material such as Si, SiC, and GaAs, and Fine two-dimensional and three-dimensional circuit patterns used for quantum devices can be formed on the surface of a multilayer substrate made of inorganic materials without forming a dry etching mask for forming complicated and miniaturized circuit patterns. It is an object of the present invention to provide an ion beam fine processing method for forming an ion beam. DISCLOSURE OF THE INVENTION> The ion beam microfabrication method of an inorganic multilayer resist of the present invention for solving the above-mentioned problem, comprising: preventing oxidation of the substrate X on the surface of a semiconductor substrate X; An inorganic material capable of forming an oxide film layer is formed, and furthermore, the Y layer is prevented from being oxidized on the surface of the Y layer and is thermally unstable. An inorganic material that can form a natural oxide film or a forced oxide film that is weaker than the Y layer but is chemically stable. After the layer is formed, the presence of a surface natural oxide film that is naturally formed on the layer surface Alternatively, the surface natural oxide film is selectively replaced with a stable forced oxide film Z ′ layer by metal ion implantation under oxygen molecule radiation, and the amount of implanted ions is further increased, and the natural oxide film or After the formation of a thermally and chemically stable oxide film Y ′ layer in the layer by the propagation of o ions from the forced oxide film and the layer and the sputtering of the layer, X surface is dry-etched with a reactive etching gas with high accuracy, and the surface oxide film, the Ζ layer, the Υ layer and the substrate X other than the portion replaced with the forced oxide film Ζ ′ layer and the oxide film Y ′ layer are removed. Some are removed.

By forming the inorganic material layer on the surface of the inorganic material substrate X, the oxidation of the substrate X is suppressed. This layer is preferably formed by the MB method or the CVD method. By being formed by MBE or CVD, the thickness can be controlled on an atomic layer basis. An inorganic material Z layer is further formed on the surface of the Y layer. This Z layer is also preferably formed by the MBE method or the CVD method similarly to the aforementioned Y layer. Since the thickness can be controlled in atomic layer units by being formed by the MBE method or the CVD method, the propagation amount of O ions to the Y layer can be controlled. This Z layer also functions as a buffer layer. The surface of the natural oxide film formed on the surface of the Z layer is directly irradiated with a focused ion beam of relatively heavy metal ions such as Ga adjusted to an arbitrary ion beam diameter and ion current density. The surface native oxide film is selectively replaced with a chemically stable forced oxidation oxide film Z ′ layer. By the propagation of O ions from the Z 'layer and the sputtering of the Z layer, a chemically and thermally stable oxide film Y' layer is formed on the surface of the Y layer, and other oxide films, the Z layer, Y layer and part of substrate X Dry etching under a reduced pressure of about ⁸ Pa or less to leave chemically stable Y 'allows any circuit pattern to be freely formed without using a mask on substrate surface X, which is an inorganic material Note it is possible to form the, here, as the inorganic material forming the semiconductor substrate X, S i, S i C , G a x I n X _ X a s y P preparative _y and G a _X a containing GaAs the 1 _{_X} _ _X a s _y P E -y or the like can be used. The inorganic material Y layer that can prevent oxidation of the substrate X and form a chemically and thermally stable oxide film layer includes G a _X A 1! _ _X including Al and A 1 As. A s yP _{y and the} like. Still Ζ layer formed on the surface of the Y layer, or an amorphous S i layer, and the like _{_{G a x I n! _ X}} A s y P containing Ga A s.

Further, in the method for finely processing an ion beam of an inorganic multilayer resist according to the present invention, the size of the oxide film Y 'formed on the surface of the Y layer is controlled by controlling the thickness of the Z layer. .

The inorganic material Z layer is preferably formed by MBE or CVD. This is because the thickness is controlled by the thickness of the atomic layer unit. Thus, the amount of o-ions propagated to the Y layer can be controlled by the thickness of the Z layer, and the size of the oxide film Y and the layer formed on the surface of the Y layer can be controlled. The method for finely processing an ion beam of an inorganic multilayer resist according to the present invention includes controlling the size of the oxide film Y ′ layer formed on the surface of the Y layer by controlling the amount of the metal ions implanted. is there.

For example, by controlling the amount of implanted metal ions such as Ga, it becomes possible to control the size of the forced oxide film Z and the layer formed on the surface of the Z layer. As a result, the amount of O ions propagated from the Z and layer can be controlled, and the size of the oxide film Y 'formed on the surface of the Y layer can be controlled. Further, the ion beam microfabrication method for an inorganic multilayer resist according to the present invention is characterized in that the size of a portion to be replaced by the forced oxide film z ′ and the oxide film Y ′ layer and the removal amount by the dry etching are controlled. The substrate surface can be processed into either a negative type or a positive type. By controlling the size of the chemically stable Z 'layer and the thermally and chemically stable Y' layer, and controlling the amount of etching, the surface of the substrate X can be made negative or positive. It can be freely processed into any of the molds. For this reason, it becomes possible to cope with complicated and fine circuit patterns, such as circuit patterns used in recent quantum devices. The ion beam microfabrication of an inorganic multilayer Regis Bok of the present invention, the reactive etching gas, in which there use the A s B r, A s B r 2, A s B r 3.

Etching can be performed in atomic layer units, and an arbitrary circuit pattern can be freely formed on the substrate X surface.

Further, the ion beam microfabrication method of the inorganic multilayer resist of the present invention comprises forming an A 1 layer on the surface of a Si wafer substrate, further forming an Si amorphous layer on the surface of the A 1 layer, Metal ions are implanted into a desired shape through a mask capable of selectively absorbing an ion beam into an arbitrary shape on the surface of the amorphous layer, and the presence of a surface natural oxide film naturally formed on the surface of the Si amorphous layer or emission of oxygen molecules. by narrowing Chi metal ions hitting under the surface native oxide film selectively is replaced forced oxidation film S i _x O _y, and further increase the ejection amount of ions, the forced oxidation film S i _x O y after generating the a 1 _x O _y in a portion of the a 1 layer by sputtering of heat播及Pi said S i amorphous layer of O ions from one atomic layer by reactive Etsuchingugasu the S i wafer first substrate surface unit Doraie' and quenching, other than the forced oxidation film S i _x O _y and A 1 _x O _y substituted moiety the And a part of one substrate of the surface natural oxide film, the Si amorphous layer, the A1 layer and the Si wafer.

An A1 layer is formed on the Si wafer substrate surface, and a Si amorphous layer is formed on the surface. A predetermined pattern is formed on the surface of the Si amorphous layer, and a mask that does not transmit the ion beam is installed in a portion other than a necessary portion, and metal ions are naturally applied to the surface of the Si amorphous layer through the mask. Irradiation is performed in the presence of a surface native oxide film formed on the surface or under the emission of oxygen molecules. Then, the metal ions that have passed through the pattern formed on a mask, a surface natural oxide film which is naturally formed is optionally substituted in a chemically stable oxide layer S io ₂ to S i amorphous layer surface . When the amount of implanted ions is further increased, the chemically stable A 1 _x O _y , for example, A 1 _{2 is} formed on the surface of the A 1 layer by the propagation of O ions from the Si 0 ₂ or the sputtering of the Si amorphous layer. 0 ₃ is formed. Then, after removing the mask, S i wafer substrate surface to form the S I_〇 _2, and S i amorphous layer of A 1 _x O _y other portion, the portion of A 1 So及Pi S i wafer substrate under a reduced pressure of lower than about 10- ⁸ P a, by dry etching, chemically by leaving stable a 1 ₂ 0 _3, to freely form the structure and pattern of any shape S i substrate surface Can be. Here, as a metal ion to be used, it is preferable to use a relatively heavy metal such as Ga.

Here, the A1 layer formed on the surface of the Si substrate must be formed by MBE or chemical vapor (Chemical Vapor Deposition: ¾xCVD) or MO by MOCVD. Is preferred. This is because the thickness can be controlled in atomic layer units by being formed by the MBE method, the CVD method, or the MOC VD method. The Si amorphous layer formed on the surface of the A1 layer can also be formed by MBE or CVD or Is preferably formed by MOCVD. This is because the thickness can be controlled on an atomic layer basis, so that the amount of O-ion propagation to the surface of the A1 layer of the second layer can be accurately controlled.

Further, the ion beam microfabrication method of the inorganic multilayer resist according to the present invention comprises the steps of: forming an A 1 layer on the surface of the Si wafer substrate; forming an Si amorphous layer on the surface of the A 1 layer; After injecting metal ions into a desired shape through a mask capable of selectively absorbing an ion beam into an arbitrary shape on the layer surface, the mask is removed, and a focused ion beam of metal ions controlled to an arbitrary ion beam diameter and an ion current density is formed. wherein S i by implantation metal ions in the presence or molecular oxygen emission surface natural oxide film naturally formed on the amorphous layer surface before Symbol surface natural oxide film selectively forced oxidation film S i _x o It is substituted to _y, further increasing the ejection amount of i oN, sputtering ◦ propagation and the S i amorphous layer of ions from the forced oxidation film S i _x O _y After generating A 1 _x O _y in a part of the A 1 layer by dry etching, the surface of the Si wafer substrate is dry-etched in a unit of atomic layer with a reactive etching gas to form the forced oxide film S _x O _y and the surface natural oxide film other than the portion substituted on a 1 _x O _y, S i amorphous layer, and removing a portion of the a 1 layer and S i wafer substrate.

After irradiating the metal ions using the mask, the mask is removed, and the metal ions that have passed through the mask are further exposed to the chemically stable S i 0 ₂ and A 1 _x O _{y formed} by the metal ions. By implanting, it is possible to increase the dose of ions implanted into them and to control the size of Al _x O _y formed. As a result, it is possible to efficiently perform drawing with a focused ion beam partially on the surface of one Si wafer substrate, and perform predetermined fine processing on the entire surface of the Si wafer substrate. In addition, fine processing can be performed partially.

In addition, the method for finely processing an ion beam of an inorganic multilayer resist according to the present invention comprises controlling an arbitrary ion beam diameter to be implanted into a surface native oxide film after removing the mask and a controlled ion ion implantation amount of a metal ion. the sputtering a portion of the a 1 _x O _y layer, the a l _x O _y pattern by fine processing into an arbitrary shape, by controlling freely the entire and local both patterns, nanometric The microstructure and / or electronic circuit can be efficiently formed on the entire surface of the Si wafer substrate.

After removing the mask, the beam diameter and ion current density of the ion beam to be implanted are controlled. Then, for example, a metal ion beam is implanted at an ion beam density power of, for example, 6 × 10 ¹⁶ (pieces / cm ² ) or more so that the ions to be implanted have a predetermined concentration or more. With this, a microfabricated shape can be arbitrarily formed in addition to the shape obtained by the metal ion implantation using the mask. For this reason, it is possible to process both the entire surface and the local portion of the Si wafer substrate surface, a microstructure having a predetermined pattern on the order of millimeters to nanometers and a semiconductor or electronic circuit.

The method for finely processing an inorganic multilayer resist according to the present invention can control the size of A 1 _x O _y formed on the surface of the A 1 layer by controlling the thickness of the Si amorphous layer. It is.

By controlling the thickness of the Si amorphous layer formed on the surface in atomic layer units by MBE, CVD, or MOCVD, it is possible to control the amount of O ions transmitted to the A1 layer of the second layer. can, it is possible to control the magnitude of a 1 _x O _y layer is formed on the a 1 layer surface. When the ion beam density is increased to, for example, 6 × 10 ¹⁶ (pieces / cm ² ) or more, Cause puttering. Then, a part of the A 1 _x O _y layer and the Si substrate is scraped off, and a micro-machined shape can be arbitrarily formed in addition to the shape obtained by Ga ion implantation using a mask. It can freely form a wide range of shapes from millimeter to nano order.

The ion beam microfabrication of an inorganic multilayer resist of the present invention, the S i _x O _y and A 1 _x O wherein by controlling the amount removed by the size and the dry etching of the portion to be replaced in the _y S i The wafer substrate surface can be processed into both negative and positive types of nano-order size.

By controlling the size of chemically stable S _x O _y and A 1 _x O _y and controlling the amount of etching, the microfabricated area formed on the surface of the S i wafer substrate can be reduced. It can be controlled freely

The surface of the Si wafer substrate can be freely processed into either a negative type or a positive type. For this reason, it is possible to deal with complicated and miniaturized circuit patterns, such as circuit patterns used in recent quantum devices.

The ion beam microfabrication of an inorganic multilayer resist of the present invention, the reactive etching gas, Ru der those using B i F ₃ or X e F _2.

Etching can be performed in atomic layer units, and any circuit pattern can be freely formed on the Si wafer substrate surface.

In addition, the method for finely processing an ion beam of an inorganic multilayer resist according to the present invention is capable of processing the surface of an inorganic material into an arbitrary shape. Therefore, the production of a semiconductor device, a quantum device, a micromachine component, and a fine structure Is possible. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram for explaining a difference in a forming process due to a difference in ion dose (ion implantation amount) in an embodiment of an ion beam fine processing method according to the present invention. FIG. 2 is a schematic cross-sectional view when the surface of the substrate after the ion implantation shown in FIG. 1 is dry-etched, and is a schematic cross-sectional view when the etching amount is small. FIG. 3 is a schematic cross-sectional view when the substrate surface after the ion implantation shown in FIG. 1 is dry-etched, and a schematic cross-sectional view when the etching amount is large. FIG. 4 is a diagram for explaining an ion dose amount during ion beam scanning. FIG. 5 is a diagram for explaining a method of forming a three-dimensional circuit pattern. FIG. 6 is a diagram showing an example of a three-dimensional lattice circuit pattern. FIG. 7 is a diagram showing an example of a method of microfabrication performed by superimposing ion beams. FIG. 8 is a view for explaining a step of ion-implanting an entire structure having a large area into a Si substrate by using a mask of an example of an embodiment of an ion beam fine processing method for an inorganic multilayer resist according to the present invention. FIG. Fig. 9 shows the removal of the mask after the ion implantation using the mask shown in Fig. 8, and the implantation of ions of any size and current density by the focused ion drawing method to process the entire structure. FIG. 4 is a diagram for explaining a step of also performing fine processing of details. FIG. 10 is a schematic cross-sectional view when the surface of the substrate after the ion implantation shown in FIG. 8 is dry-etched, and is a view showing a state where the Si substrate is not etched. The first 1 Figure shows the state in which case the etching amount is a diagram showing a cross-sectional schematic view of a etching amount is large is often been shaved part of the S i board and has a circuit carrying the A 1 ₂ 0 ₃ FIG. FIG. 12 is a diagram showing AFM images of substrate surfaces having different ion dose amounts (ion implantation amounts) in the ion beam fine processing method according to the present invention. FIG. 13 shows the ion beam according to the present invention on the surface of the Si substrate and the GaAs substrate. FIG. 3 is a diagram showing an AFM image when a fine processing method is used. FIG. 14 is a diagram showing an AFM image of a microstructure on an Si wafer substrate according to an example of the present embodiment using a mask. FIG. 15 is a diagram showing a conceptual diagram of a quantum wire. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an example of an embodiment of an ion beam fine processing method for an inorganic multilayer resist according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view in a state where Ga ions are implanted, FIGS. 2 and 3 are schematic cross-sectional views in a case where dry etching is performed for each atomic layer, and FIG. 2 is an etching diagram. The one with a small amount is shown in Fig. 3, and the one with a large etching amount is shown.

In Figure 1, 1 is G a _x I n including the S i and G a A s - is _{_X} A s _{_y} P _α _ _y made of an inorganic material such as the substrate X. 2 is formed on the surface of the substrate X 1 by MBE, CVD, or MOC VD to prevent oxidation of the surface of the substrate X 1 and form a chemically and thermally stable oxide film layer A 1 or A It represents an inorganic material Y layer, such as Ga _X a 1 _x As yP _y containing 1 As. 3 prevents oxidation of the layer 2 formed on the surface of the layer 2 by the CVD method, the CVD method or the MOC VD method, and is weaker to some extent than the thermally unstable surface oxide film or the layer. stable force can form an oxide film had been One of a plurality of oxide films, amorphous S i layer serving as a resist layer, G aA s layer, I n a G a containing _S layer _{_x} I _ni _ _x a s

Layer. 4 shows a surface natural oxide film of the S i 0 ₂ and A s ₂ 0 front surface, such as _3, which is naturally formed on the surface of the Z layer 3. In addition, from the left to the right of the drawing, the amount of implanted metal ions, for example, Ga ions, is increasing as shown in FIGS. 1 (a) to ( _e ). First, the ion beam microfabrication method of the inorganic multilayer resist according to the present invention is applied to the surface of G _{x In} — _X A s _y P _y substrate X 1 including S i, S i C and G a As. Ga _x a l _{_X} a s yP including a 1 and a 1 As formed on arbitrary thickness by MB E or CVD - inorganic material Y layer 2 of _y like, and § motor Norefasu S i layer, G a laminating a _{_{G a x I ni- X a s}} y inorganic material Z layer 3 of the _y layer and the like including a a s layer and I n a s layer. Then, without removing the S i 0 ₂ and As ₂ 0 surface natural oxide film 4 such as _3, which is naturally formed on the surface of the Z layer 3,. Ion beam towards the surface of the surface native oxide film 4 An ion made of a relatively heavy metal, preferably a Ga ion 5 having a diameter of 0.5 μπι or less, preferably 0.3 / m or less, more preferably 0.1 μm or less, Irradiation is performed below to inject ions into the surface native oxide film 4. By injection of a metal ion 5, surface natural S i 0 ₂ of the oxide film 4, As ₂ 0 oxide such as _3, S I_〇 ₂ below some injection volume is chemically stable oxide, G a ₂ 0 is replaced by a forced oxidation film Z 'layer 6 of ₃ like (see FIG. 1 (a)). Then, the injection amount or thickness of the Z layer 3 of metal ions 5 can control the sputtering quantity of oxygen amount or Z layer propagating in .Y layer 2, oxide such as A 1 ₂ 0 ₃ on the surface of the Y layer 2 The film Y 'layer 7 is formed (see FIG. 1 (b)). The chemically stable forced oxide film Z ′ layer 6 and oxide film Y ′ layer 7 serve as a mask during dry etching. In addition, since the size of the oxide film Y 'layer 7 is about 1/10 of the size of the forced oxide film Z' layer 6, fine patterning is more likely than when only the forced oxide film Z 'layer 6 is formed. I can do it. For this reason, the surface is dry-etched with bromide in atomic layer units to remove portions other than those replaced by the forced oxide film Z 'layer 6 and oxide film Y' layer 7 (see Fig. 2 (b)). Thus, the surface of the substrate XI can be processed so as to have a predetermined circuit pattern. The focused ion beam irradiating the surface of the surface native oxide film 4 is shown in Fig. 4. As shown, the beam tip is circular. For this reason, as shown in FIG. 4 (a), when the ion beam 5 is superposed on the surface native oxide film 4 at a constant speed, a portion where the ion beam 5 overlaps is formed. For this reason, as shown in FIG. 4 (b), the amount of ion dose implanted into the surface natural oxide film 4 increases near the center of the ion beam 5. That is, the ion region exerted on the surface native oxide film 4 becomes smaller than the actual diameter of the ion beam 5, and the region can be set to a size of 2/3 to 1/2 of the ion beam diameter to be irradiated. For this reason, it is possible to process a pattern of a line having a thickness of 23 to の of the ion beam diameter of the ion beam 5 on the surface of the surface native oxide film 4.

Here, according to the dry etching according to the present embodiment, a surface with good flatness can be obtained with good reproducibility. Specifically, for example, in the etching with a reactive etching gas composed of bromide or the like, the atoms to be etched are the step positions on the surface, and the steps constituting the surface irregularities are preferentially removed. Atomic layers can be etched in single layers. The surface obtained as a result of such single layer etching is extremely flat. That is, a flat surface at the atomic level can be obtained. Furthermore, this method enables the same etching on the cleaved (1 110) plane regardless of the plane index.

In this dry etching, using a reactive etching gas in ultrahigh vacuum, for example after evacuation to 1 0 ⁸ P a level, 5 0 0~6 0 0 ° C in 1 0 ⁶ -1 0 Etching can be performed by introducing an etchant gas at a gas partial pressure of ⁵ Pa. Here, the reactive etching gas used as the etchant gas is preferably a compound with bromine, for example, AsBr. Are exemplified as typical examples. Of course, other types may be used.

Thus, the surface and the natural oxide film 4, amorphous S i layer, 0 _{& 31} 1 n xAs containing G GaAs layer and I _{1 3-layer}

Layer 3 Inorganic material such as G a _X A 1 _X _ _X A _sy P _y layer including A 1 layer and A 1 As layer.Since it is possible to etch the Y layer 2 in units of one atomic layer. , G a chemically formed by implantation of ions stable _{_{S i 0 2 G a 2 O}} 3 a 1 2 O 3 of forced oxidation film Z, the layer 6 and the oxide film Y, a layer 7 during dry etching ing As a mask, a structure having a high aspect ratio and fine dimensions can be easily formed with good reproducibility.

0 FIG. 1 (a) shows a state in which a predetermined amount of metal ions 5 are implanted and a forced oxide film Z ′ layer 6 is formed only on a part of the surface native oxide film 4. In this state, as a reactive etching gas, for example, after evacuation of using bromide gas in ultrahigh vacuum, for example to 10- ⁸ P a level, 500

The introduction of Etsu etchant gas in the gas partial pressure of 15 600 ° C at 10- ⁶ 10- ⁵ P a those performing dry etching shown in FIG. 2 (a). By controlling the etch ing amount, as shown in FIG. 2 (a), S i Oh _{_{Rui, G a s I n X A}} s y substrate X 1 of P or the like including a GaA s and I n A s The surface is processed into a convex shape leaving the part replaced by the forced oxide film Z 'layer 6

20.

Further, when the etching is performed, the portion replaced by the forced oxide film Z 'layer 6 is also etched, and becomes a flat surface as shown in FIG. ₃ ( _a ). FIG. 1 (b) shows a case where the implantation amount of the metal ions 5 exceeds a predetermined implantation amount. As shown in FIG. 1 (b), when the implantation amount of the metal ion 255 exceeds a predetermined implantation amount, the forced oxide film Z ′ layer 6 is sputtered and the metal ion penetrates the inorganic material Z layer 3, This inorganic material Z A metal ion penetration region 8 in which metal ions are implanted in the layer 3 is formed. The O ions of the metal ion intrusion region 8 reaches the inorganic material Y layer 2 such as A 1 layer and A 1 A s layer, oxide film Y such A 1 ₂ 0 ₃ on the surface of the inorganic material Y layer 2 ' Layer 7 is formed. At this time, the oxide film Y and the layer 7 formed on the surface of the inorganic material Y layer 2 containing Al and A 1 As are controlled by the thickness of the inorganic material Z layer 3.

In this state, dry etching is performed, and the one with a small etching amount is shown in FIG. 2 (b). When the etching amount is small, the forced oxide film Z 'layer 6 formed on the surface native oxide film 4 and the oxide film Y and the layer 7 formed on the surface of the inorganic material Y layer 2 act as a mask. The ion invasion region 8 into which metal ions have penetrated is made amorphous and exhibits a higher etching rate than the inorganic material Z layer 3 into which no ions have penetrated. Therefore, when dry etching is performed, portions other than the forced oxidation film Z 'layer 6 and the oxide film Y' layer 7 are etched, and a convex portion having a deep groove 9 formed in the center is formed. It is formed on the surface of the substrate X1.

Furthermore, when the etching, as shown in FIG. 3 (b), except A 1 ₂ 0 3 7 portion is etched, the convex portion is formed on the substrate 1.

As shown in FIG. 1 (c), when metal ions are further implanted into the surface native oxide film 4, the surface native oxide film 4 formed on the surface is replaced by the forced oxide film Z ′ layer 6. However, there is also a limit on the concentration of metal ions in those that are replaced with the forced oxide film Z 'layer 6, and when a certain amount or more of metal ions are implanted, the forced oxide film Z' layer 6 Is sputtered to form a wide groove 9. In this case, O ions are more easily propagated to the surface of the inorganic material Y layer 2, and the oxide film Y and the layer 7 are formed in a wide range on the surface of the inorganic material Y layer 2.

When etching is performed in this state, if the etching amount is small, As shown in FIG. 2 (c), a convex portion having a wide groove 9 is formed on the substrate XI. Fig. 3

As shown in (c), the portions other than the oxide film Y and the layer 7 are etched, and a convex portion is formed on the substrate X1.

Further, as the amount of the metal ions 5 to be implanted is increased, as shown in FIG. 1 (d), the range in which the inorganic material Z layer 3 is made amorphous expands, and the metal material 5 is sputtered. The oxide film Y and the layer 7 formed on the surface of the inorganic material Y layer 2 are also sputtered by the metal ions to form the grooves 10. The surface of the substrate XI, after notice of in ultrahigh vacuum using the same way as described above reactive etching gas, for example, to 1 0- ⁸ P a leveled Honoré, 1 5 0 0~6 0 0 ° C 0 one ⁶ -1 0 ⁵ when subjected to dry etching by the introduction of Etsu etchant gas in the gas partial pressure P a, which has a wide deep grooves 9 on the front surface, convex groove 1 0 to the bottom portion is formed The shape can be machined (see Fig. 2 (d)). Also, by increasing the etching amount, as shown in FIG. 3 (d), the portions other than the oxide film Y 'layer 7 are etched, and a convex portion having a groove 10 is formed on the substrate X1. You.

Further, as the amount of the metal ions 5 to be implanted is increased, as shown in FIG. 1 (e), the range in which the inorganic material Z layer 3 is made amorphous expands, and sputtering is performed by the metal ions 5. Similarly, the range in which the inorganic material Y layer 2 is made amorphous is also expanded and sputtered by the metal ions 5 to form a deep V-shaped groove 11 on the surface. The surface of the substrate 1 is evacuated to a level of, for example, 10 to ⁸ Pa in an ultra-high vacuum using a reactive etching gas as described above, and then the surface is heated to 500 to 600 Pa. When C performs Delahaye Tsuchingu the introduction of Etsu etchant gas in the gas partial pressure of 1 0 6 to 1 0 one ⁵ P a, the amorphized portion of the inorganic material Z layer 3 and the like As shown in FIG. 2 (e), etching is performed under the mask by the forced oxidation film Z 'layer 6 to form a wide groove 9 and a wide and deep groove 1 at the bottom. A convex portion having 0 can be processed. In addition, by increasing the etching amount, as shown in FIG. 3 (e), the portion other than the oxide film Y 'layer 7 is etched, and a rectangular portion having the groove 10 is formed on the substrate XI.

Thus, G a _x I n ₁ comprising S i or G a A s and I n A s _- to _x As _{_y} Pi _y substrate X the surface of the inorganic material, such as, A 1 layer, A 1 A s layer An inorganic material Y layer such as a Ga _X A 1 iiASyP _y layer containing and a Z layer of an inorganic material such as Ga _x InnASyP— _y containing GaAs and InAs are laminated. Then, without removing the surface native oxide film such as A s ₂ 0 ₃ which is naturally formed on the surface of the inorganic material Z layer, injecting a heavy metal ion of such G a in the surface native oxide film By controlling the chemically stable oxide film on the surface, and the injection amount of metal ion and the thickness of the inorganic material Z layer, G a _X including the A 1 layer and the A 1 As layer can be adjusted. it is possible to form an oxide film Y 'layer, such as a 1 ₂ 0 ₃ to a 1 _{_X} _ _X a s _yy layer inorganic materials Y layer surface or the like. Then, by controlling the amount of metal ions to be implanted, the surface of the substrate X after the dry etching with the reactive etching gas can be processed into either a negative type or a positive type. Further, by drawing the surface of the substrate X with an ion beam so as to form a predetermined circuit pattern at the time of Ga ion implantation, an arbitrary circuit pattern can be easily processed with good reproducibility. This makes it possible to apply not only to semiconductor devices but also to wavelength discrimination devices, micromachining of micromachining and microcomponents, and quantum wires.

Also includes a inorganic materials Y layer, such as 0 _{& ¾} 1 ₁ 8 layer comprising one layer Ya 1 3-layer, amorphous S i layer, a G a A s layer or I nA s layer Since _{G a x I n ^ x AS} y P ^ y layer including inorganic material Z layer are laminated, enables you to form a chemically stable different oxide film by connexion formed on Ion implantation In addition to the conventional two-dimensional circuit pattern design, the degree of freedom in design is expanded, and three-dimensional circuit patterns can be designed.

As one of means for forming a three-dimensional circuit pattern, for example, as shown in FIG. 5, there is a method of forming a spatial modulation mask using a variable dose beam. At this time, by adjusting the dose and controlling the beam irradiation position, it is possible to form a pattern as shown in FIGS. 6 (a) to 6 (c).

In addition, since the position accuracy of the Ga ion beam can be controlled in units of 10 nm, for example, as shown in Fig. 7, it is possible to process even finer circuit patterns by overlapping the ion beams. Becomes In the present embodiment, the description has been made by exemplifying the Ga ion. However, the ion implanted into the substrate surface is not limited to the Ga ion, and an ion made of another metal may be used. It is possible.

Next, an example of an embodiment of the ion beam microfabrication method of the present invention for a case where a mask is used on the surface of an Si wafer substrate will be described. Fig. 8 is a schematic cross-sectional view of a state in which ions are implanted in a shower using a mask, and Fig. 9 is a state in which ions are implanted with the mask removed, the ions are finely focused, and the implantation amount is changed depending on the location. FIG. 10 is a schematic sectional view, and FIG. 10 is a schematic sectional view when dry etching is performed in atomic layer units. FIG. 11 shows one having a larger etching amount than FIG. Here, the ion used is not particularly limited as long as it is a relatively heavy metal ion, and generally, a widely used Ga ion is preferable because existing equipment can be used as it is. In FIG. 8, 21 is an Si wafer substrate, 22 is an A1 layer formed on the surface of the Si wafer substrate 21 by MBE, CVD, or MOCVD, and 23 is A 1 is a Si amorphous layer formed on the surface of layer 22 by MBE, CVD or MOCVD, and 24 is Si 0 ₂ which is naturally formed on the surface of Si amorphous layer 23. , 25 indicates a mask, and 26 indicates a Ga ion used as a metal ion.

Here, as the mask 25, a metal such as gold can be exemplified, but it is preferable to appropriately select the mask 25 depending on ions to be irradiated. Further, the mask 25 may be a mask in which an arbitrary pattern is processed on a single mask, a mask in which a predetermined pattern is formed by combining a plurality of masks, and ion irradiation with a plurality of masks. A predetermined pattern may be repeatedly formed.

In the present embodiment, first, an A1 layer 22 is formed on the surface of the Si wafer substrate 21 to an arbitrary thickness by MBE or CVD. On the surface of the A1 layer 22, a Simorphous layer 23 is laminated. Then, without removing the S i 0 ₂ surface native oxide film 2 4 such that is naturally formed on the surface of that, the mask 2 5 on which a predetermined pattern is formed on the surface native oxide film 2 4 Is installed, and a Ga ion beam 26 is irradiated through a mask 25 in a vacuum. At this time, the Ga ion beam 26 may be applied to the entire surface in a shower shape, or the focused Ga ion beam 26 may be scanned at a constant speed to irradiate the entire surface. You may do it.

By implantation of the Ga ion beam 26, a chemically stable oxide SiO ₂ layer 27 is generated in the surface native oxide film 24. And S i O O ions of the _second layer 27 propagate in the Si amorphous layer 23 to form an ion penetration region 32 in the Si amorphous layer 23. Furthermore, G when a increasing the injection amount of the ion beam 26, S i 0 of the _two-layer 27 of the O ions propagate, or S i 0 ₂ layer 27 and the S i § mode more ion intrusion region for sputtering of the fastest layer 23 32 Ο ions reach the surface of the A 1 layer 22. Then, A 1 ₂ 0 ₃ layer 28 by O ions have been propagated in A 1 layer 22 is formed on the surface. Role of chemically stable S i 0 ₂ layer 27 and the A l ₂ 0 ₃ layer 28 at the time of the dry etching mask.

FIG. 9 shows a state where the mask 25 is removed after the implantation of the Ga ion beam 26 using the mask 25 of FIG. 8 and the focused ion beam 29 of the Ga ion is implanted in a vacuum. At this time, the focused ion beam 29 of the Ga ion (a) has an ion implantation amount of 6 × 10 ¹³ (pieces Zcm ² ), and (b) has a ion implantation amount of 6 × 10 ¹⁵

A (c) is 6 X 10 ¹⁶ (number Zcm ^2), (d) and (e) are 6X 10 ¹⁷ (number / cm ^2). Here, FIG. 9 (e) shows an example in which a focused ion beam 29 of the Ga ion is irradiated in addition to the place where the light has passed through the mask 25 and has already been irradiated with the Ga ion beam 26.

Here, it is preferable that the focused ion beam 29 of the Ga ion has a diameter of not more than 0.5 im, preferably not more than 0.5, more preferably not more than 0.1 / zm. The focused ion beam 9 of the Ga ion has a circular beam tip. For this reason, when the surface natural oxide film 24 is scanned at a constant speed, a portion where the ion beam overlaps is formed in each portion (see FIG. 4). For this reason, the amount of ions implanted into the surface native oxide film 4 increases near the center of the focused ion beam 29 of the Ga ions. That is, the ion region exerted on the surface native oxide film 24 is smaller than the diameter of the actual focused ion beam 29 of the Ga ion. The area can be 2/3 to 1/2 the diameter of the focused ion beam to be irradiated. For this reason, it becomes possible to process a line pattern having a thickness of 2/3 to 1 の 2 of the ion beam diameter of the focused ion beam 9 of G ion on the surface of the surface native oxide film 24.

The focused ion beam 29 of G a ion irradiation in vacuum, when implanted into the surface native oxide film 24, the surface of the natural oxide film 24 forced oxides S i 0 ₂ 27 that chemically stable in some implantation amount or more Is replaced (see Figure 9). Then, G by injection amount and the thickness of S i Amoru Fass layer 23 of the focused ion beam 29 of a ion, S i 0 ₂ 27 ion penetration region G a ions S i § Amorphous layer 23 by O ions are implanted 32 is formed. When the implantation amount of the focused ion beam 29 of Ga ions further increases, the O ions of SiO ₂ 27 propagate through the ion penetration region 32 to the A 1 layer 22, or the Si amorphous layer 23 is sputtered. is-rings, the size of the a 1 ₂ 0 ₃ layer 28 formed on the a 1 layer 22 that are controlled (see FIG. 9). The chemically stable S i 0 ₂ layers 27 and A 1 ₂ O ₃ layer 2 8 serves as a mask during dry etching. Further, because the size of the A 1 ₂ 0 ₃ layer 28 is the size of about 1 Bruno 10 S i 0 ₂ layer 27, it is possible to fine Kai putter Jung. Therefore the surface to remove non-substituted portion reactive Etsuchinguga scan by dry etching with atomic layer more units S i 0 ₂ layers 27 and A 1 ₂ O ₃ layer 28 (see FIG. 3), S i The surface of the wafer substrate 21 can be processed into a predetermined nano-order size circuit pattern. Examples of the reactive E Tsuchingugasu usable, it is possible to use B i F ₃ or Xe F _2. Here, according to the dry etching according to the present embodiment, a surface with good flatness can be obtained with good reproducibility. Specifically, when etching with a reactive etching gas, the atoms being etched are Is the atom at the step position on the surface, and the steps constituting the surface irregularities are preferentially removed, so that the atomic layer can be etched in single layers. The surface obtained as a result of such single-layer etching is extremely flat. That is, a flat surface at the atomic level can be obtained. Furthermore, this method is cleaved (1 1

The same etching is possible on the 0) plane regardless of the plane index. Therefore, the surface of the Si or A1 crystal is (1 00), (1 1 0), (1 1

1) Etching can be performed in units of any surface regardless of the surface index.

In this dry etching, in ultrahigh vacuum using a reactive etching gas, for example 10 ^{- 8} after evacuation to P a level, 500 to 60 0 ° C at ^{^{10- 6 ~: L 0- 5 P}} a gas Etching can be performed by introducing an etchant gas at a partial pressure. Here, the Etsu etchant gas, B i F ₃ or X e F ₂ is illustrated as a representative. Of course, other types may be used.

FIG. 10 shows a state in which the surface natural oxide film 24, the Si mono-reflective layer 23, the A1 layer 22, and the ion penetration region 32 have been removed by dry etching. i O ₂ layer 27 and A

Shows a state in which 1 ₂ 0 ₃ layer 28 is formed. FIG. 11 shows a state in which the dry etching of FIG. 10 has been further advanced. In this case, the Si wafer substrate 2

Some of 1 indicates the state is etched A 1 ₂ 0 ₃ layer 28 and the S i wafer substrate 21 is formed in a convex shape.

In Figure 10, A is in which A 1 ₂ 0 ₃ layer 28 is formed by ion which has passed through the mask is not, was de dry etching portions may separately implanting ions. As a result, Figs. 10 and

As shown in FIG. 11, it is possible to provide a wide convex portion. Also, As described above, the portions a to d in FIGS. 10 and 11 show different ion implantation amounts, and show changes in the morphology after dry etching as the ion implantation amount increases. Things. Also,

1 e portion at 0 view and first FIG. 1 is obtained by further implanting ions into A 1 ₂ 0 ₃ layer 2 8 is formed partially Te cowpea the ions that have passed through the mask.

In FIG. 10, part a is a convex fine wire formed by dry etching by reducing the amount of ion implantation to replace the surface native oxide film 4 with the forced oxide SiO ₂ layer 27. Is shown. b portion is S i Amoru ion intrusion region 3 2 G a ion implanted into Fas layer 2 3 is formed, O ions to form A 1 ₂ 0 ₃ layer 2 8, 3 1 0 ₂ layers A convex thin line having a groove 30 in the center of 27 is shown. Further, c portion is an ion implantation amount is excessive, the central portion of the A 1 ₂ 0 ₃ layer 2 8 formed on the surface by ion is sputtered, with V-shaped grooves 3 1 is formed, the central portion of its This shows that a wide groove 30 is formed. The part d shows that the ion implantation amount is further increased and a part of the Si wafer substrate 21 is processed by sputtering to form a wide groove 33. The first 1 Figure, as described above, shows a state of further advancing the Doraietsuchin grayed, a portion by etching, S i 0 ₂ layers 2 7, and the S i Amorufasu layer 2 3 thereunder a 1-layer 2 2 elutes, fine pattern having an a 1 ₂ 0 ₃ layer 2 8 on the surface was formed.

In this way, by using a mask and controlling the amount of the focused ion beam 9 of the Ga ions to be implanted, negative-type and positive-type fine processing from millimeter-size to nano-order size can be performed on a Si wafer substrate. It can be applied freely on top.

In addition, surface native oxide film 24, Si amorphous layer 23, A1 layer 2 2 can be etched for each atomic layer, so that chemically stable oxides formed by ion implantation can be used as a mask during dry etching to produce fine particles with a high aspect ratio. A structure having dimensions can be easily formed with good reproducibility.

Also, the S i substrate surface, A 1 So及Pi laminating S i amorphous layer, without removing the surface natural oxide film of the S i 0 ₂ or the like which is naturally formed on the surface of the S i amorphous layer , to inject G a ion to the surface naturally acid i arsenide film, chemically to form a stable S i 0 _2, further adjusting the thickness of G a ion Note Iriryou and S i amorphous layer it is possible to form the a 1 ₂ 0 ₃ in a 1 layer surface of the lower layer by. By controlling the amount of Ga ion to be injected, the dry etching mask on the surface of the Si wafer / substrate after dry etching with a reactive etching gas can be processed into either a negative type or a positive type. Becomes In addition, by combining irradiation with masking with ion beams and drawing without a mask on the surface of the Si wafer substrate so that a predetermined circuit pattern is obtained when implanting Ga ions, any circuit pattern can be easily processed with good reproducibility. can do. This makes it possible to apply not only semiconductor devices, but also wavelength discriminating devices, micromachining such as micromachining / microcomponents, and quantum wires.

In addition, since the A1 layer and the Si layer are stacked, it is possible to form chemically stable masks with different atomic sizes, which are formed by ion implantation. Not only the design but also the degree of freedom of design is expanded, and it is also possible to design circuit patterns in three dimensions.

The method for processing a Si semiconductor microstructure by ion beam implantation lithography of an inorganic multilayer resist according to the present invention is described in the above embodiment. The A 1 layer formed on the surface of the Si wafer substrate and preventing oxidation of the Si wafer substrate is a G a _X A 1! _ _X A s yP -y layer. Is also possible. It is also possible to _{Ga x I i ^ xA S yP} ^ y layer instead of the S i amorphous layer. In addition, by not only laminating the inorganic material in multiple layers on the surface of one Si wafer substrate, but also making a part of the inorganic layer into a single layer, it becomes possible to process into a more complicated three-dimensional microstructure.

As described above, by injecting metal ions into the A1 layer laminated on the Si wafer substrate surface and the surface native oxide film formed on the surface of the Si amorphous layer, the reactive etching gas It is possible to form a fine pattern of Si 0 ₂ or A 1 ₂ _{3 serving} as a chemically stable mask that is not etched. Further, by controlling the amount of metal ions implanted, it becomes possible to process the pattern formed on the Si substrate surface into either a positive type or a negative type. In addition, since it is possible to form a mask having different stability, not only two-dimensional but also three-dimensional circuit pattern design can be designed. For this reason, it is possible to manufacture various semiconductor devices, elements, quantum wires, quantum boxes, diffraction gratings, and micromachine components utilizing various quantum device characteristics.

FIG. 12 shows an example in which the ion dose propagating to the A1 layer can be adjusted by drawing the ion beams so as to overlap each other, and a projection or a depression can be formed on the surface of the Si substrate. An atomic force microscope (AFM) image of the Si substrate surface is shown. FIG. 12 (a) shows the case where the convex portion is formed by increasing the thickness of the Si amorphous layer, and FIG. 12 (b) shows the case where the thickness of the Si amorphous layer The ion dose is increased by making it thinner than that in Fig. It was formed. As described above, since it reacts very sensitively to the ion dose, the surface of the Si amorphous layer is controlled by controlling the thickness of the Si amorphous layer or by controlling the ion irradiation amount to adjust the ion dose. The shape can be freely designed.

Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1)

A Si substrate was used as the inorganic material substrate X, and an A1As layer having a thickness of 3 nm was formed as an inorganic material Y layer on the surface of the Si substrate by the MBE method, and a Ga layer having a thickness of 30 nm was formed as an inorganic material Z layer. An As layer is formed. Then, G a A s layer table surface G a ion vacuum in focused to 0. 1 im Kotsu Te ion beam diameter on the surface of the surface native oxide film such as A s ₂ 0 ₃ which is naturally formed in 6 X 1 0 ¹⁶ atoms / ^ 111 ^2, was irradiated at an acceleration voltage 30 kV, implanting G a ion on the surface native oxide film. After Ga ion implantation, and placed in an ultra-high vacuum apparatus, 10- 8 P a level to contact Kigo, A s B r in gas partial pressure of 1 0- ⁶ ~10- ⁵ P a at 500 to 600 ° C Etching is performed by introducing _three gases.

Figure 13 (a) shows an AFM image of the surface. As shown in the first FIG. 3 (a), the Ga As substrate surface, A s B r ₃ is G a ion implantation has not been Etsuchin grayed by gas surface oxide film is replaced by G a ₂ 0 ₃ It can be observed that the bent portion is formed in a convex shape.

(Example 2)

After implanting the Ga ions in the same manner as in Example 1 except that the dose of the Ga ions was set to 6 × 10 ¹⁷ / cm ² , the surface was dry-etched with AsBr ₃ gas. I did it.

Figure 13 (b) shows an AFM image of the surface. As shown in FIG. 13 (b), a circular pattern of deep grooves can be observed on the surface of the Si substrate. (Example 3)

A GaAs substrate was used as the inorganic material substrate X, and an A1As layer having a thickness of 30 nm as an inorganic material Y layer and a thickness of 300 as an inorganic material Z layer were formed on the surface of the GaAs substrate by the MBE method. A nm GaAs layer is formed. Then, the G a ion focused ion beam diameter toward the surface of the surface native oxide film such as A s ₂ 0 ₃ which is naturally formed on the G a A s layer surface 0. 1 mu m at a true air 6 X 10 ¹⁶ ^! !! ^2. Irradiate at an accelerating voltage of 30 kV and implant Ga ions into the native oxide film on the surface. After G a ion implantation, and placed in an ultra-high vacuum device, after the gas to 10- ⁸ P a leveled Honoré, 500-600. Etched by introducing As B r ₃ gas at the gas partial pressure of C at ^{^{10- 6 ~ 1 0- 5 P a}} . Figure 13 (c) shows an AFM image of the surface. As shown in the first FIG. 3 (c), Ga A s the substrate surface, A s B r ₃ G a ions were not Etsuchin grayed by the gas is injected surface acid I arsenide film G a ₂ 0 ₃ It can be observed that the portion replaced with is formed in a convex shape.

(Example 4)

Ga ions were implanted in the same manner as in Example 3 except that the amount of Ga ions implanted was 6 × 10 ¹⁷ cm ² and irradiation was performed, and then the surface was dry-etched with AsBr ₃ gas. Was.

Figure 13 (d) shows an AFM image of the surface. As shown in Fig. 13 (d), it can be observed that a convex pattern having a deep groove is formed on the surface of the GaAs substrate.

As described above, an inorganic material Y layer that acts as a strong mask during etching to prevent oxidation of the substrate X and a Z layer that prevents oxidation of the inorganic material Y layer is laminated on the surface of the inorganic material substrate X that is to be a semiconductor substrate. By injecting metal ions into the surface natural oxide film formed on the surface of the inorganic material Z layer, it is not etched by a reactive etching gas such as bromide. Histological becomes a stable mask A 1 ₂ 0 ₃ and G a ₂ 0 ₃ or S i 0 oxidation film Y 'layer, Z', such as ₂ can be formed layer. Further, by controlling the amount of metal ions to be implanted, the pattern formed on the surface of the substrate X can be processed into either a positive type or a negative type. The substrate or the substrate is not particularly limited as long as it is an inorganic material. For example, in the case of Si or GaAs commonly used as a semiconductor substrate, the surface thereof is finely processed into an arbitrary shape. It can be performed.

In addition, since it is possible to perform microfabrication to a predetermined size, not only two-dimensional but also three-dimensional circuit pattern design can be designed. Therefore, it is possible to manufacture various semiconductor devices and elements utilizing various quantum device characteristics, for example, quantum wires, quantum boxes, diffraction gratings, and micromachine components shown in FIG.

(Example 5)

A 20 nm thick A1 layer and a 30 nm thick Si amorphous layer are formed on the Si substrate surface by MBE. Then, a mask patterned in a predetermined pattern with an opening diameter of 100 m and a thickness of 500 μιη is applied to the surface of the surface native oxide film such as SiO ₂ which is naturally formed on the surface of the Si amorphous layer. prepared by method of LI GA, S i C deeds masking installed in S i on the substrate as a thin plate mask gold attached to the frame Ga ions 6 X 1 0 ¹⁵ (number Z cm ^2), the acceleration Irradiate in a shower at a voltage of 30 kV to implant Ga ions into the surface oxide layer. Then, after removing the mask, the Ga ion whose ion beam diameter was reduced to 0.1 μπι was irradiated in the same vacuum with 6 X 10 ¹⁵ Z cm ² and acceleration voltage of 30 kV to obtain a native oxide film on the surface. Is implanted with Ga ions. After G a ion implantation, installed in ultra-high vacuum apparatus, 10- ⁸ P After evacuation to _a level, B i F in gas partial pressure of 1 0 one ⁶ ~ 10- ⁵ P a at 600 to 700 ° C _3Introduce gas to etch Was done.

Fig. 14 shows an AFM image of the Si wafer substrate surface. As shown in Fig. 14, after removing the mask, it is relatively easy to form a high-aspect-ratio fine structure of a predetermined shape, such as by forming a groove locally by partially implanting the ion beam. Thus, it can be formed on the Si wafer substrate surface. Industrial applicability

As described above in detail, according to the present invention, a resist layer made of an inorganic material is laminated on the surface of a substrate made of an inorganic material, and the surface natural oxide film naturally formed on the surface is not removed. By implanting metal ions into the oxide film, a chemically stable oxide is formed, and etching is performed in units of atomic layers, so that the pattern formed on the substrate surface can be processed into either a positive or negative type. Will be able to

. In addition, since oxides with different atomic sizes can be formed, the degree of freedom in circuit pattern design is expanded, and useful elements that make use of various quantum device characteristics, such as quantum wires, quantum boxes, diffraction gratings, micro Machine realization is also possible.

Claims

The scope of the claims

1. On the surface of the semiconductor substrate X, an inorganic material Y layer capable of preventing oxidation of the substrate X and forming a chemically and thermally stable oxide film layer is formed, and further, the Y layer surface is formed on the surface of the Y layer. After forming a natural oxide film that prevents oxidation of the layer and forms a thermally unstable natural oxide film or a forced oxide film that is weaker than the Y layer but chemically stable, a Z layer is formed on the surface of the Z layer. The natural oxide film on the surface is selectively replaced with a stable forced oxide film Z ′ layer by the presence of a surface natural oxide film formed on the surface or by metal ion implantation under the emission of oxygen molecules. By increasing the amount of implanted ions, propagating O ions from the natural oxide film or the forced oxide film Z and the layer and sputtering the Z layer, the oxide film Y ′ layer that is thermally and chemically stable on the Y layer After the substrate X is generated, the surface of the substrate X is precisely exposed to the reactive etching gas. An ion beam of an inorganic multilayer resist which is subjected to light etching to remove a part of the surface oxide film, the Z layer, the Y layer, and a part of the substrate X other than a portion replaced with the forced oxide film Z ′ layer and the oxide film Y ′ layer. Fine processing method.

2. The method according to claim 1, wherein the size of the oxide film Y 'formed on the surface of the Y layer is controlled by controlling the thickness of the Z layer. .

3. The method according to claim 1, wherein the size of the oxide film Y formed on the surface of the Y layer and the size of the layer are controlled by controlling the amount of the metal ions implanted. .

4. By controlling the size of the portion to be replaced by the forced oxygen film Z ′ layer and the oxide film Y ′ layer and the removal amount by the dry etching, the substrate surface can be made into a negative type or a positive type. 2. The ion beam fine processing method for an inorganic multilayer resist according to claim 1, which can be processed into any of them.

5. The reactive Etsuchingugasu, A s B r, A s B r 2, A s B r 3 The method for finely processing an ion beam of an inorganic multilayer resist according to claim 1, wherein the method is:

6. After forming the A1 layer on the surface of the Si wafer and further forming the Si amorphous layer on the surface of the A1 layer, the ion beam can be selectively absorbed into an arbitrary shape on the surface of the Si amorphous layer. A metal ion is implanted into a required shape through a mask, and the surface of the Si amorphous layer is spontaneously formed by the presence of a surface natural oxide film or a metal ion implantation under the emission of oxygen molecules. oxide film selectively is replaced forced oxidation film S i _x O _y, and further increase the ejection amount of ions, spa of the forced oxidation film S i _x O Den播及Pi of O ions from _y the S i amorphous layer after generating the a '1 _x O _y in a portion of the a 1 layer by Ttaringu, the S i is dry etched wafer substrate surface in one atomic layer by reactive etching gas, the forced oxidation film S i _x O _y and A 1 _x An ion beam microfabrication method for an inorganic multilayer resist that removes a part of the surface native oxide film, the Si amorphous layer, the A 1 layer, and the Si wafer substrate other than the portion replaced with O _y .

7. After forming the A1 layer on the surface of the Si wafer substrate and further forming the Si amorphous layer on the surface of the A1 layer, the ion beam can be selectively absorbed into an arbitrary shape on the surface of the Si amorphous layer. After the metal ion is injected into a required shape through the mask, the mask is removed, and a focused ion beam of the metal ion controlled to an arbitrary ion beam diameter and ion current density is formed on the surface of the Si amorphous layer. the implantation metal ions in the presence or under the oxygen molecules radiating surface natural oxide film which is the surface native oxide film selectively is replaced forced oxidation film S i _x O _y, and ejection amount of further ion The propagation of O ions from the forced oxide film Si _x O _y and the sputtering of the Si amorphous layer After generating A 1 _x O _y in a part of the A 1 layer, the Si wafer substrate surface is dry-etched in a single atomic layer unit by a reactive etching gas, and the forced oxide films S _x O _y and A 1 _x O wherein the surface resolute oxide film other than substituted moiety to _y, S i amorphous layer, a 1 layer and S i inorganic multilayer resist to remove portions of the wafer substrate ion beam microfabrication methods.

8. After removing the mask, a part of the A 1 _x O _y layer is controlled by controlling an ion beam diameter and an ion current density controlled to an arbitrary ion beam diameter and an ion current density to be implanted into the surface native oxide film. Sputter the A

By finely processing 1 _x _Oy patterns to an arbitrary shape and controlling both the entire and local patterns freely, nano-order-sized microstructures and semiconductors or electronic circuits can be applied to the entire surface of the Si wafer substrate. 8. The method for finely processing an ion beam of an inorganic multilayer resist according to claim 7, which can be efficiently formed.

9. By controlling the thickness of the S i amorphous layer, Ionbimu fine inorganic multilayer resist according to claim 6, wherein A 1 layer can control the magnitude of A 1 _x O _y which is formed on the surface Processing method.

10. By controlling the thickness of the S i amorphous layer, Ionbimu fine inorganic multilayer resist according to claim 7 capable of controlling the magnitude of A 1 _x O _y which is formed on the A 1 layer surface Processing method.

1 1. The S i _x O _y及of Pi A 1 _x O _y moiety substituted the size and the S i © E hard substrate surface by controlling the amount removed by the dry etching, nanometric 7. The ion beam fine processing method for an inorganic multilayer resist according to claim 6, which can be processed into either a negative type or a positive type.

1 2. The S i © E by controlling the amount removed by the size and the dry etching of said S i _x O _y and A 1 _x O _y moiety substituted 8. The ion beam fine processing method for an inorganic multilayer resist according to claim 7, wherein the surface of the substrate can be processed into either a negative type or a positive type having a nano-order size.

1 3. The reactive etching gas, B i F ₃ or X e F ₂ ion beam micromachining how inorganic multilayer resist according to paragraph 6 range billed using.

14. The method for finely processing an inorganic multilayer resist according to claim 7, wherein BiF ₃ or XeF ₂ is used as the reactive etching gas.

15. A semiconductor device manufactured by the method according to any one of claims 1 to 14.

16. A quantum device manufactured by the method according to any one of claims 1 to 14.

17. A micromachine component manufactured by the method according to any one of claims 1 to 14. '

18. A microstructure manufactured by the method according to any one of claims 1 to 14.