EP1115648A1 - Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs - Google Patents

Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs

Info

Publication number
EP1115648A1
EP1115648A1 EP99955747A EP99955747A EP1115648A1 EP 1115648 A1 EP1115648 A1 EP 1115648A1 EP 99955747 A EP99955747 A EP 99955747A EP 99955747 A EP99955747 A EP 99955747A EP 1115648 A1 EP1115648 A1 EP 1115648A1
Authority
EP
European Patent Office
Prior art keywords
gasb
semiconductor material
structures
compound semiconductor
ion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP99955747A
Other languages
German (de)
English (en)
Inventor
Stefan Fascko
Heinrich Kurz
Clemens Koerdt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19932880A external-priority patent/DE19932880A1/de
Application filed by Individual filed Critical Individual
Publication of EP1115648A1 publication Critical patent/EP1115648A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic

Definitions

  • the invention relates to a method according to the preamble of claim 1 for producing regular semiconductor structures with sizes in the range from a few nanometers to a few tens of nanometers. It is referred to as "self-organized ion sputtering", where ion sputtering means removal or sputtering by ion bombardment.
  • the structures produced with it show exceptional electronic and optical properties.
  • the created nanometer structuring / texturing of surfaces is therefore of great interest.
  • Islands or wires made of semiconductor materials of uniform size in the nanometer range, which are produced on the basis of this method, so-called “quantum dots” or “quantum wires” are in particular as an active medium in semiconductor lasers ("quantum dot lasers”) or in Tunnel components of importance.
  • the technical field to which the invention relates relates to semiconductor structures, compound semiconductors, ion sputtering, semiconductor lasers, tunnel components, nanometer structuring, quantum dots.
  • Nanometer structures can be produced using conventional lithographic processes. For this purpose, multi-quantum wells are structured by means of photolithography or electron beam lithography, thus limiting the charge carriers in three dimensions [12].
  • the size of the structures produced by lithography can be up to 20 nm.
  • AFM (atomic force microscopy) lithography can further reduce the size of the structures. Disadvantages of the lithographic methods are high technical expenditure and, in the case of electron beam and AFM lithography, a high expenditure of time due to the serial processing.
  • Self-organized growth The epitaxial growth of fewer monolayers of a semiconductor on a substrate creates islands of uniform size under certain conditions [11].
  • the "self-organized" growth is observed in various material systems: e.g. InAs on GaAs [4], GaSb on GaAs [5], Ge on Si [6]. It is based on the difference in the lattice constants of the materials, which leads to elastic tension in a two-dimensional layer. One way of relaxing this layer is to form three-dimensional islands.
  • Stranski-Krastanov growth mode a wetting layer is first created and then islands of the same size and shape. The size of these islands (mostly pyramids) is a few nanometers to a few tens of nanometers. Measurements of photoluminescence and electroluminescence on quantum structures produced in this way clearly show that the electrons are locked in three dimensions [7, 13].
  • Contamination- or defect-induced masking Locations where the sputtering rate is locally lower than in the environment due to foreign atoms or defects on or immediately below the surface, result in outward-looking structures.
  • an element can be enriched by preferentially sputtering an element on the surface. Diffusion leads to the separation of the atoms present in excess and thus a masking of the surface.
  • Foreign atoms can also be applied in a defined manner by sputter deposition and masking can be achieved in this way.
  • Microscopic sputtering The sputtering rate is a function of the angle at which the ions hit the surface. The roughness is increased microscopically by the sputtering probability of individual surface atoms, while the roughness is reduced mesoscopically by sputtering. A steady state is reached when the sputter rate on the textured surface is constant everywhere, which can lead to regular structures with at least one short-range order.
  • the first case is more likely, since the sputtering rates of the elements differ greatly and therefore preferred sputtering of a component occurs.
  • the object of the invention is to provide a further method and a device for producing regular structures in the nanometer range. This task is solved by the method according to saying 1 and the device according to claim 11.
  • the new process is based on a new self-ordering principle that occurs in ion sputtering if suitable ion energies are used and the surface to be processed is prepared appropriately.
  • the nanometer structure according to the invention consists of a large number of individual, isolated islands made of a compound semiconductor material, which are located on a substrate.
  • This substrate can be the same compound semiconductor as the compound semiconductor material or another semiconductor material.
  • the individual islands have largely the same shape and configuration as possible, they are largely arranged regularly on the substrate.
  • the invention relates to a method for changing the morphology of a semiconductor surface.
  • a system is required to generate a homogeneous ion or neutralized ion beam with a kinetic energy of the ions or atoms from 10 to 50000 eV, in particular 50 - 2000 eV. 300 - 1000 eV have proven to be particularly advantageous for GaSb.
  • This requires a vacuum chamber that can be operated at pressures below normal pressure, in particular ⁇ 10 " 3 mbar.
  • a device In the vacuum chamber, in addition to the ion or atom source, a device (holder) is required to hold the material to be processed.
  • This holder is used the solid is brought into thermal contact and cooled on the back via the holder. It is advantageous to regulate the temperature during the ion sputtering.
  • the ion or neutralized ion beam from the ion or atom source is directed perpendicularly or at a different angle onto the surface of the solid whereby atoms are knocked out of the surface of the material (ion tern, ion etching).
  • a device for measuring the ion current before and during the ion bombardment is necessary to determine the rate at which the surface is bombarded and thus the time required.
  • An analysis method that detects the sputtered elements is also of great advantage for determining the end point.
  • the surface of this material can also be structured indirectly via an additionally applied GaSb layer.
  • a GaSb layer is applied to the material with a thickness of a few 10 nm to many 100 nm, preferably at least 250 nm, using a suitable deposition method (e.g. molecular beam epitaxy (MBE), vapor phase deposition (CVD), sputter deposition, etc.)
  • MBE molecular beam epitaxy
  • CVD vapor phase deposition
  • sputter deposition etc.
  • the material must consist of at least two layers.
  • the most suitable materials are usually tactical process. It is important to lock the electrons in the generated quantum dots, ie that islands of the first layer remain isolated on the layer below (eg GaSb islands on AlSb or on GaAs).
  • the new process allows nanometer structures of high density (eg 5 * 10 10 cm “ 2 ) and narrow size distribution to be produced, with sizes of typically 10-60 nm and with a hexagonal short-range order.
  • the new process can be used in industrial ion etching plants in the Manufacture of homogeneous large-scale nano-structuring or texturing or of quantum dots (up to 50cm x 50cm possible) compared to epitaxially grown nanostructures, eg with molecular beam epitaxy (Molecular Beam Epitaxy, MBE) or metal organic gas phase epitaxy (Molecular Organic Vapor Phase Epitaxy, MOVPE ) the requirements for the vacuum and the purity of the vacuum chamber are much lower, compared to lithographic processes the new technology has the advantage of a reduced expenditure of time.
  • FIG. 2 the morphology according to FIG. 1 in a magnification of 200,000 times 3 shows a basic illustration of a plasma ion etching system (also: plasma sputter system) with a quadrupole mass spectrometer for the shutdown control,
  • a plasma ion etching system also: plasma sputter system
  • a quadrupole mass spectrometer for the shutdown control
  • FIG. 4 a basic representation of the plasma ion etching system according to 3 shows an enlarged detail from FIG. 3, in particular a holder for the sample,
  • Fig. 5 a schematic representation of a sputtering system, as for the
  • Fig. 7 a graph corresponding to Fig. 6, after a long sputtering time
  • Fig. 8 a graph corresponding to Fig. 7, after a longer sputtering time.
  • the charge carriers must also be locked perpendicular to the surface in addition to the lateral extent, which is achieved in that a suitable sequence of epitaxial grown layers is removed until isolated GaSb islands remain on the underlying layer (eg AlSb, GaAs).
  • a suitable sequence of epitaxial grown layers is removed until isolated GaSb islands remain on the underlying layer (eg AlSb, GaAs).
  • the removed atoms are detected by mass spectrometry.
  • the transition from GaSb to AlSb can be determined when the Ga signal disappears.
  • GaSb quantum dots were produced on AlSb and GaAs substrates.
  • the ion sputtering plant acc. FIGS. 3 and 4, which was used to produce the structures, is a mass spectrometry system for depth profile analysis (INA3 from Leybold).
  • the system consists of a plasma chamber 20 and a sample transfer chamber. Both chambers are UHV compatible.
  • the plasma chamber 20 can be filled with argon gas via a metering valve. The valve controls the argon pressure in the chamber with a control mechanism.
  • a plasma is ignited in the plasma chamber via a coil 22 (rf coil) and an HF generator, which plasma is maintained at pressures of 1 * 10 " 3 mbar to 1 * 10" 4 mbar.
  • the plasma consists of Ar ions and electrons in Ar gas.
  • a piece of 8 x 8 mm is cut out of a GaSb wafer ((100) orientation ⁇ 0.5 °, undoped, 50.8 mm diameter, 500 ⁇ m thick, front side "Epi-ready", supplied by Crystec) and cut into a sample holder 24 installed (see Fig. 2 left).
  • the sample 26 is pressed onto the copper block 30 by means of a Cu orifice 28 (orifice diameter: 2 mm).
  • the copper block of the sample holder is cooled by the continuous flow of water or liquid nitrogen or another coolant which is particularly suitable for generating lower temperatures. By default, sample temperatures from - 80 ° C to + 60 ° C are set.
  • the sample holder is transferred from the transfer chamber to the plasma chamber.
  • the GaSb, ie the sample 26, in the sample holder 24 is separated from the Ar plasma by a front panel (see FIG. 3).
  • the ion etching see plasma and back copper block 30 of the sample holder.
  • the voltage accelerates Ar + ions from the plasma to a kinetic energy of 500 eV and hits the sample 26, ie the GaSb piece, perpendicular to the surface.
  • the current that is measured here indicates the total ion current from the plasma to the sample and aperture. This amounts to 0.4 mA when manufacturing the nanostructures on GaSb.
  • the ion current that is responsible for sputtering can be estimated at 0.15 mA, which corresponds to an ion current density of lxlO 16 cm- 2 s _1 .
  • sputtering takes 300 seconds, which corresponds to a total dose of approximately 3 ⁇ 10 18 cm 2 .
  • the plasma chamber 20 also has a mass spectrometer 34 in which the sputtered atoms that ionize in the plasma are detected.
  • the elements present in the material are tracked (e.g. Ga, Sb and Al in the case of a GaSb on AlSb layer structure) in order to determine the time of demolition in the case of multilayer structures made of different materials, so that isolated GaSb islands are formed on the surface.
  • the production of the nanometer structures on the sample 26 from GaSb was also shown in a commercial sputtering system (PLS 500 P from Balzers, ECR ion source 40 RRISQ 76 ECR from Roth and Rau, sketch see FIG. 3).
  • PPS 500 P from Balzers, ECR ion source 40 RRISQ 76 ECR from Roth and Rau, sketch see FIG. 3
  • ECR electron cyclotron resonance
  • the plasma chamber 20 is separated from the process chamber 38 by a grid system 36.
  • the first grid serves to shield the plasma, while the second grid accelerates the ions.
  • the ions extracted from the plasma are neutralized by bombardment with an electron beam from a so-called plasma bridge neutralizer 42.
  • a GaSb sample, cut from a GaSb wafer ((100) orientation ⁇ 0.5 °, undoped, 50.8 mm diameter, 500 ⁇ m thickness, front side "Epi ready” po- lated, supplied by Crystec) is applied to a sample holder 24, which is attached at a distance of 10 cm from the accelerating grid of the ion source.
  • a pressure of ⁇ 10 " 5 mbar is in the process chamber 38.
  • Sputtering is carried out under perpendicular incidence with a kinetic energy of the Ar atoms of 500 eV.
  • the sample holder 24 is cooled while the process is being carried out and regulated to room temperature. This is done with this method processed samples show a homogeneous distribution of the quantum dots on an area of 1cm x 1cm.
  • 43 designates a gas inlet which opens into the plasma chamber 20.
  • the systems are located in a vacuum chamber, the walls of which are labeled 44.
  • 46 is a microwave arrangement.
  • the formation of the morphology was carried out and verified on GaSb and InSb. From the explanatory approaches, the following condition must be placed on the material: the material must consist of at least two components with different sputtering rates. This is the case, for example, with elements with different masses or surface binding energies. In addition, the element enriched on the surface must show a tendency to accumulate, in particular it should not wet the surface. The concentration of the atoms from a catchment area then determines the density and the size of the resulting structures.
  • a morphology of a layer GaSb applied to this material with a thickness of a few 10 nm to many 100 nm, preferably at least 250 nm ( epitaxially or amorphously) to the underlying substrate by further ion etching.
  • the nanometer structures achieved are largely homogeneously distributed.
  • the sputtering rate of the preferentially sputtered element should be at least 3%, preferably at least 5%, in particular at least 7% and possibly at least 10% greater than that of the other element.
  • This criterion also has an approximate correspondence in the mass numbers of the elements: the atomic masses of the elements of the compound semiconductor differ by at least 10%, preferably by 20% and in particular by 50%.
  • the average penetration depth of Ar ions with a kinetic energy of 500 eV in GaSb is 2 nm with a maximum range of 5 nm, i.e. smaller than the extension of the nanometer structures.
  • the destruction of the crystal structure by the incident ions is therefore limited to the surface, which means that the structures remain crystalline. This is also the prerequisite for using these structures as quantum dots. If the penetration depth of the ions is greater than the resulting structures, the structures will be amorphized by the destruction of the crystal structure. With GaSb this can already be expected with Ar ions with an energy of 2 keV. In general, the penetration depth and destruction by the primary ions must be determined or estimated for each material.
  • the penetration depth of the ions is preferably chosen to be smaller than the size of the nanometer structures.
  • the density of the resulting structures is 5 * 10 10 cm- 2 , which corresponds to an average distance of the quantum dots of 50 nm.
  • the formation of the structures is a continuous process that begins with small structures, whereby the density does not change during the ion etching.
  • the size of the structures depends on the sputtering time and thus on the ion dose or thickness of the removed layer. The maximum size of 50 nm is reached when the structures bump into each other, so they can no longer enlarge. This steady state is reached with a removed layer of 500 nm.
  • the surface morphology is then transferred into the volume to depths of a few ⁇ m.
  • FIGS. 6 to 8 show the size distributions of the nanometer structures after different sputtering times (the ion etching times increase from FIG. 6 to FIG. 9).
  • the narrow size distribution of the structures indicates a self-ordering principle and is better than many size distributions of self-organized quantum structures in epitaxial growth shown in the literature.
  • the narrow size distribution is one of the primary requirements for quantum dots, since it determines the spectral width of the photoluminescence and thus the efficiency of a laser based on these structures.
  • the sample When cooled with liquid nitrogen, the sample has a temperature of - 80 ° C to -50 ° C.
  • the structures that were produced at these temperatures have a somewhat greater density of 1.4 * 10 n cm -2 with an average distance of 30 nm. Otherwise, the same behavior and the same narrow size distribution are observed.
  • the structures are very evenly distributed over large areas. You can find the same density of structures on the edge and in the middle of a sputtered surface.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Nanotechnology (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Composite Materials (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Physical Vapour Deposition (AREA)
  • Physical Deposition Of Substances That Are Components Of Semiconductor Devices (AREA)

Abstract

L'invention concerne un procédé permettant de produire sur des surfaces de semi-conducteurs, des structures de l'ordre du nanomètre, régulières, notamment des structures pyramidales et ondulées régulières, ayant une répartition dimensionnelle étroite et des dimensions allant de 2 à 100 nm, notamment entre 10 et 60 nm, en particulier en termes de diamètre, de largeur et de hauteur. Ce procédé se caractérise en ce qu'on utilise un matériau semi-conducteur comprenant au moins et de préférence deux composants et étant également un semi-conducteur de connexion. Des ions de gaz rares (éventuellement neutralisés) provenant d'une source d'ions ayant une énergie allant de 10 à 50.000 eV, notamment de 50 à 2.000 eV, sont dirigés sur ce matériau de connexion semi-conducteur et servent à enlever la surface du matériau, sous l'action de vide, par pulvérisation d'ions, jusqu'à ce que la structure de l'ordre du nanomètre soit obtenue.
EP99955747A 1998-09-23 1999-09-18 Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs Withdrawn EP1115648A1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE19843675 1998-09-23
DE19843675 1998-09-23
DE19932880A DE19932880A1 (de) 1998-09-23 1999-07-16 Verfahren zur Herstellung von Nanometerstrukturen auf Halbleiteroberflächen
DE19932880 1999-07-16
PCT/DE1999/002998 WO2000017094A1 (fr) 1998-09-23 1999-09-18 Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs

Publications (1)

Publication Number Publication Date
EP1115648A1 true EP1115648A1 (fr) 2001-07-18

Family

ID=26049042

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99955747A Withdrawn EP1115648A1 (fr) 1998-09-23 1999-09-18 Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs

Country Status (2)

Country Link
EP (1) EP1115648A1 (fr)
WO (1) WO2000017094A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5840294B2 (ja) 2011-08-05 2016-01-06 ウォステック・インコーポレイテッドＷｏｓｔｅｃ， Ｉｎｃ ナノ構造層を有する発光ダイオードならびに製造方法および使用方法
US9057704B2 (en) 2011-12-12 2015-06-16 Wostec, Inc. SERS-sensor with nanostructured surface and methods of making and using
WO2013109157A1 (fr) * 2012-01-18 2013-07-25 Wostec, Inc. Agencements à caractéristiques pyramidales ayant au moins une surface nanostructurée et leurs procédés de fabrication et d'utilisation
US9134250B2 (en) 2012-03-23 2015-09-15 Wostec, Inc. SERS-sensor with nanostructured layer and methods of making and using
WO2014142700A1 (fr) 2013-03-13 2014-09-18 Wostec Inc. Polariseur basé sur grille nanofilaire
US20170194167A1 (en) 2014-06-26 2017-07-06 Wostec, Inc. Wavelike hard nanomask on a topographic feature and methods of making and using
US10672427B2 (en) 2016-11-18 2020-06-02 Wostec, Inc. Optical memory devices using a silicon wire grid polarizer and methods of making and using
WO2018156042A1 (fr) 2017-02-27 2018-08-30 Wostec, Inc. Polariseur à grille de nanofils sur une surface incurvée et procédés de fabrication et d'utilisation

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3708717A1 (de) * 1987-03-18 1988-09-29 Hans Prof Dr Rer Nat Oechsner Verfahren und vorrichtung zur bearbeitung von festkoerperoberflaechen durch teilchenbeschuss

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0017094A1 *

Also Published As

Publication number Publication date
WO2000017094A1 (fr) 2000-03-30

Similar Documents

Publication Publication Date Title
DE3789814T2 (de) Energiereiche oberflächenreaktionen unter verwendung eines cluster-strahls.
DE69815348T2 (de) Vorrichtung und verfahren zur keimbildung und abscheidung von diamant mittels heissdraht-dc-plasma
DE102005004402B4 (de) Hartstoff-Schichtsystem und Verfahren zu dessen Bildung
EP0625218B1 (fr) Procede et dispositif de modification de surfaces par reactions physico-chimiques de gaz ou de vapeurs sur les surfaces a l'aide d'ions fortement charges
Zhao et al. Electron stimulated polymerization of solid C60
DE69532805T2 (de) Verfahren zum amorphen diamantbeschichten von klingen
DE3888463T2 (de) Anordnung mit Supergitter-Struktur und Verfahren und Vorrichtung zu ihrer Herstellung.
DE3881077T2 (de) Verfahren zur herstellung eines diamantfilms.
EP0021140A1 (fr) Source ionique dans une chambre sous vide et procédé pour son fonctionnement
DE2631881C2 (de) Verfahren zur Herstellung eines Halbleiterbauelementes
EP2313913B1 (fr) Procédé de gravure, induite par un faisceau d'électrons, de couches implantees par du gallium
WO1986007391A1 (fr) Procede et appareil d'enduction de substrats par decharge de plasma
DE3884033T2 (de) Verfahren zur Herstellung einer Halbleiteranordnung mit einer Mehrschichtstruktur.
DE10080124B3 (de) Substratverarbeitungssystem, dessen Verwendung sowie Verfahren zur Bearbeitung eines Substrates
Yoshida et al. Formation of GaN self-organized nanotips by reactive ion etching
DE3335107A1 (de) Verfahren zum herstellen eines gegenstandes mit einem mehrkomponentenmaterial
EP0681314A2 (fr) Structure composite pour dispositif électronique et procédé de fabrication
DE2726265A1 (de) Verfahren zum zuechten genetischer halbleiteroxidschichten
WO2000017094A1 (fr) Procede permettant de produire des structures de l'ordre du nanometre sur des surfaces de semi-conducteurs
DE2643893C3 (de) Verfahren zur Herstellung einer mit einer Struktur versehenen Schicht auf einem Substrat
DE19932880A1 (de) Verfahren zur Herstellung von Nanometerstrukturen auf Halbleiteroberflächen
WO2020221525A1 (fr) Procédé de fabrication d'un matériau 2d, matériau 2d et ses applications
DE2522921C3 (de) Verfahren zur epitaktischen Abscheidung dotierter III-V-Verbindungshalbleiter-Schichten
DE3709448C2 (fr)
DE60220183T2 (de) Verfahren zur herstellung von partikeln mit diamant -struktur

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20010423

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB NL

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20060706