Showing papers on "Electron-beam lithography published in 1991"
TL;DR: The design and fabrication of fully 2-D surface relief diffraction elements that can split a single collimated beam into many beams in an arbitrary intensity distribution are reported on.
Abstract: We report on the design and fabrication of fully 2-D surface relief diffraction elements that can split a single collimated beam into many beams in an arbitrary intensity distribution. These splitters were designed by computer using simulated annealing, and made into phase gratings by electron-beam lithography followed by plasma etching into quartz glass. Both two and four phase level gratings have been fabricated, allowing a wide range of uniform and weighted spot patterns to be generated. These grating elements have a measured diffraction efficiency of over 74%, with the beam intensity ratios accurate to within 1% of their target values.
144 citations
TL;DR: In this article, two procedures for the construction of submicrometer microelectrodes particularly suited for use in SECM are described, where an electrochemically sharpened Pt wire is sealed in a glass capillary and exposed via mechanical polishing, and electron beam lithography using a commercial scanning electron microscope is used to produce sub-micrometers features at the tip of a polymer-coated polyshed Pt wire.
Abstract: In this report, we describe two procedures for the construction of submicrometer microelectrodes particularly suited for use in SECM. In one, an electrochemically sharpened Pt wire is sealed in a glass capillary and the submicrometer tip is exposed via mechanical polishing, and in the other, electron beam lithography using a commercial scanning electron microscope is used to produce submicrometer features at the tip of a polymer-coated polyshed Pt wire
102 citations
TL;DR: In this article, the first time, the fabrication of a periodically reversed domain structure for LiNbO3 has been achieved at room temperature and the domain boundary is perpendicular to the positive c-face and is very deep which is advantageous for quasiphasematching SHG.
Abstract: For the first time, the fabrication of a periodically reversed domain structure for LiNbO3 has been achieved at room temperature. The domain boundary is perpendicular to the positive c-face and is very deep which is advantageous for quasiphasematching SHG.
99 citations
Patent•
04 Mar 1991
TL;DR: In this paper, a method for a raster scan particle or light beam lithography system for writing in multiple passes interleaved in such a manner as to achieve a composite result nearly identical to normal single-pass writing with overlapped spots is presented.
Abstract: A method for a raster scan particle or light beam lithography system for writing in multiple passes interleaved in such a manner as to achieve a composite result nearly identical to normal single pass raster scan writing with overlapped spots. Multiple pass writing, achieved with little or no degradation or throughput or lithography quality, provides an ideal platform for implementation of known image averaging techniques to improve lithography quality. This technique is combined with the known writing technique of "Virtual Addressing" to improve resolution with little or no degradation of throughput.
75 citations
TL;DR: In this paper, an ultranarrow InGaAs/InP buried quantum well wires were fabricated by means of electron beam lithography and reverse mesa wet etching, and the lateral dimension of the wires was reduced to 10 nm.
Abstract: We have fabricated ultranarrow InGaAs/InP buried quantum well wires by means of electron beam lithography and reverse mesa wet etching. Owing to the reverse mesa etching profile, the lateral dimension of the wires has been reduced to 10 nm. Furthermore, we investigated the optical characteristics of these wires by photoluminescence and observed, for the first time, clear dependence of luminescence wavelength upon the wire width even for wires down to 10 nm, which is well explained by the theoretical calculation. The blue‐shifted shoulder structures were also observed and they were assigned theoretically to be the second quantized level.
65 citations
Patent•
31 Dec 1991
TL;DR: In this paper, an apparatus and method for the nonplanar treatment of a volumetric workpiece or substrate utilizing exposure beam lithography are disclosed, where the substrate is then moved in at least two degrees of freedom of movement relative to the beam, with one degree of freedom being the rotating of the substrate about an axis generally perpendicular to the electron beam.
Abstract: An apparatus and method for the nonplanar treatment of a volumetric workpiece or substrate utilizing exposure beam lithography are disclosed. The method includes supplying one or more layers of one or more semiconductor materials to surfaces of the substrate, applying a resist over the semiconductor layers, setting the resist, and then directing an exposure beam, such as an electron beam, toward the substrate. The substrate is then moved in at least two degrees freedom of movement, relative to the beam, with one degree of freedom of movement being the rotating of the substrate about an axis generally perpendicular to the beam. The other degree of freedom of movement could be moving the substrate linearly in a direction generally parallel to the axis. By such movement, the resist is exposed to the beam in a predetermined pattern. The exposed resist is then developed and a layer or layers under the exposed resist are etched. The remaining resist is then removed yielding the desired semiconductor device.
63 citations
TL;DR: In this article, the authors used electron beam lithography and polymethylmethacrylate (PMMA) e-beam resist to produce 100 nm wide lines with vertical side walls and aspect ratio as high as 4:1.
Abstract: Copper lines with a minimum width of 100 nm were fabricated by selective electroless copper deposition (SED). The deposition reaction is based on the neutralization of positive copper ions in a basic solution by electrons which are the result of the reaction between formaldehyde and the hydroxyl ions. The reduction reaction requires a high pH typically in the range of 11.5-13 at the deposition temperature which is between 55 degrees C and 70 degrees C. The high pH required for the deposition reaction is achieved either by using alkaline bases, like sodium-hydroxide, or alkaline-free bases, like tetramethylammonium hydroxide (TMAH). Experimental data show similar results for both alkaline and alkaline-free deposition solutions. The copper nanolines were produced using electron beam lithography and polymethylmethacrylate (PMMA) e-beam resist due to its compatibility with the high pH of the deposition solution. The first approach, which is described here for making copper nanolines, produced 100 nm wide lines with vertical side walls and aspect ratio (height/width) as high as 4:1. The lines were uniform over both small and large areas and the deposition was only on the pre-designated regions (i.e. full selectivity). A second fabrication technique, which is also described, formed a fully-planar topography in which the copper is buried in an interlevel dielectric. 150 nm wide copper lines buried in 250 nm deep trenches in chemically-vapor-deposited (CVD) silicon-dioxide were made using that technique. Both techniques are described in detail and experimental results are presented in the form of SEM pictures. Selective copper deposition introduces some new problems in general and there are also some particular problems that are associated with the techniques described. Specific problems, such as step coverage and copper line shapes are discussed as well as more general problems like the compatibility with integrated circuit manufacturing technology.
56 citations
TL;DR: In this article, a minimum feature size of 95 nm was obtained from exposure with a 17 nm (1/e diameter) 50 kV electron beam using a vacuum scanning tunneling microscope (STM).
Abstract: We report studies of minimum feature sizes in 50 nm films of the high‐resolution negative electron beam resist, SAL‐601‐ER7 from the Shipley Corporation. Developed linewidths of 27 nm and line spacing of 55 nm, from center to center, were produced by lithography with a vacuum scanning tunneling microscope (STM). In contrast, a minimum linewidth of 95 nm was obtained from exposure with a 17 nm (1/e diameter) 50 kV electron beam. Patterns written in the STM at electron energies down to 15 eV were visible in the developed resist. The limit at 15 eV is related to the operation of the STM and does not represent an exposure threshold energy for the resist.
54 citations
TL;DR: In this article, the authors have fabricated submicron resonant tunneling devices from double-barrier AlGaAs/GaAs heterostructures using electron beam lithography and wet chemical etching.
Abstract: We have fabricated submicron resonant tunneling devices from double‐barrier AlGaAs/GaAs heterostructures using electron beam lithography and wet chemical etching. These devices exhibit step‐like features in the current‐voltage curves. We interpret these steps as arising from additional size quantization of the electronic states in the well due to in‐plane lithographic confinement. Magnetotunneling experiments on these devices are reported for the first time. A simple model calculation describes well the experimental data.
53 citations
TL;DR: A three-dimensional topographical simulator PEACE (photo and electron beam lithography analyzing computer engineering system) is discussed and an algorithm based on the cell removal model provides accurate and stable results for the three- dimensional resist development process.
Abstract: A three-dimensional topographical simulator PEACE (photo and electron beam lithography analyzing computer engineering system) is discussed One of the difficulties in resist topographical simulation exists due to the three-dimensional resist development algorithm An algorithm based on the cell removal model provides accurate and stable results for the three-dimensional resist development process The program has been adapted to a supercomputer for quick computation The simulator can successfully perform the three-dimensional development in an absolutely stable manner, and good agreement can be obtained with experiments for both photo and electron beam lithography >
47 citations
TL;DR: In this article, the authors developed methods for analyzing the performance of potential mask materials and constructions and used them to determine the composition of a prototype mask, which was then used to construct a mask.
Abstract: The choice of mask materials and fabrication route for a projection electron‐beam lithography system is subject to a variety of constraints. Some are encountered in most lithographic techniques, while some are unique to the scattering with regular limitation for projection electron lithography SCALPEL technique. We have developed methods for analyzing the performance of potential mask materials and constructions. These have been used to determine the composition of a prototype mask. Results from such a mask are presented.
30 Jan 1991
TL;DR: In this article, the use of numerically controlled E-beam-based NPL techniques for fabricating both monolithic micromachines and micro-components for use in larger systems.
Abstract: The authors present specific nonplanar lithographic (NPL) techniques for use in fabricating both monolithic micromachines and microcomponents for use in larger systems. The emphasis is on the use of numerically controlled E-beam-based lithography, with the resist exposed over nonplanar surfaces. Previously, nonplanar, optical-mask-based approaches have been used to fabricate devices such as wobble motor rotors, but with less success than the NPL techniques due to depth-of-field problems. The specific focus is on etching cylindrically shaped metal structures which are either (1) homogeneous or (2) layered by successive deposition, masking, and etching. Structures on the order of 80 to 500 microns in diameter have been constructed of either solid metals or sputtered thin metallic layers on quartz shafts. A number of either deep or shallow patterns have been fabricated on and through the structures, with promising results. Examples include helices, longitudinal lines, holes, notches, flexures, barbs, alphanumeric characters, and electrostatic field emitting patterns for use in wobble motors. Efforts are now proceeding toward generating complete systems, including transducers and actuators for industrial and medical applications. >
TL;DR: In this paper, a high energy 50kV electron beam direct writing system with a gas introduction line has been developed, and the electron beam size has been improved to less than 5 nm.
Abstract: A high energy 50-kV electron beam direct writing system which has a gas introduction line has been developed. Several aspects of the performance of this system are demonstrated. The electron beam size has been improved to be less than 5 nm. 10-nm width line patterns with 50-nm periods in PMMA resist on a thick Si substrate are demonstrated. It is observed that fewer proximity effects occur when a high-energy electron beam is used. 20-nm-width lines and 20-nm-diameter Au-Pd metal patterns have been fabricated by a lift-off method. 14-nm-diameter carbon dot patterns were deposited on a Si substrate by electron-beam-induced deposition using Styrene gas.
TL;DR: In this paper, an unconventional GaAs heterostructure is used to form a 2-dimensional electron gas (2 DEG) whose density can be tuned by the gate voltage applied to its conductive substrate.
Abstract: Results are reported for low temperature measurements of the conductance through small regions of a two-dimensional electron gas (2 DEG). An unconventional GaAs heterostructure is used to form a 2 DEG whose density can be tuned by the gate voltage applied to its conductive substrate. Electron beam lithography is used to pattern a narrow channel in the 2 DEG interrupted by two constrictions, defining a small 2 DEG island between them. The conductance is found to oscillate periodically with the gate voltage, namely with electron density. Calculations of the capacitance between the substrate and the island show that the period of oscillation corresponds to adding one electron to the island. The oscillatory behavior results primarily from the discreteness of charge and the Coulomb interaction between electrons. However, the observed temperature dependence of these oscillations requires a more sophisticated treatment which includes the quantized electron energy levels as well. The magnetic field dependence of the oscillations allows us to extract the discrete energy spectrum of the quantum dot in the quantum-Hall regime.
01 Jan 1991
TL;DR: In this paper, the authors describe some preliminary experimental results of quantum effect modulation-doped field effect transistors (MODFETs) with a variety of nanometer gate geometries.
Abstract: The authors describe some preliminary experimental results of quantum-effect modulation-doped field-effect transistors (MODFETs) with a variety of nanometer gate geometries. The gate geometries were such that various quantum wells and barriers were formed in the channel of the MODFETs through the field effect imposed by the novel gate structures, and the transport of the electrons was affected by resonant tunneling. The devices were fabricated using a combination of molecular beam epitaxy and electron beam lithography. Electrical measurements of the devices at 4.2 K showed resonant tunneling effects and, in particular, showed that resonant tunneling is more pronounced for a system of quantum wells confined in three dimensions than in two. For these quantum effects to be appreciable at practical temperatures, about 77 K, the feature size of the gate geometries should be smaller than 50 nm. >
TL;DR: By etching a periodic array of holes through a ;mobility two-dimensional electron gas, the authors defined high-a lateral, anti-dot-type superlattice with periods a=200 and a=300 nm, much smaller than the electron mean free path in the unpatterned material.
Abstract: By etching a periodic array of holes through a ;mobility two‐dimensional electron gas we define high‐a lateral, ‘‘anti’’‐dot‐type superlattice with periods a=200 and a=300 nm, much smaller than the electron mean free path in the unpatterned material. The devices are fabricated using electron beam lithography and reactive ion etching techniques, and characterized by magnetotransport experiments. Commensurability effects and the observed quenching of the Hall effect indicate that the electron gas between the etched holes essentially maintains its initial high electron mobility.
TL;DR: In this article, the scanning tunneling microscope (STM) operated in the field emission mode is shown to have important lithographic applications, and the potential of the technique is demonstrated by patterning films up to 80 nm thick of SAL•601•ER7, a negative resist from Shipley.
Abstract: The scanning tunneling microscope (STM) operated in the field emission mode is shown to have important lithographic applications. The technological potential of the technique is demonstrated by patterning films up to 80 nm thick of SAL‐601‐ER7, a negative resist from Shipley. With the STM, 22 nm lines of developed resist have been written on Si and 35 nm lines on GaAs. For comparison, exposures were made with a 50 kV, 17 nm 1/e diameter electron beam in identically prepared and processed resist films on a variety of substrates. The 50 kV probe produced minimum linewidths of: 60 nm on a 200 nm Si3N4 membrane; 70 nm on a 200 nm Si3N4 film on a bulk Si substrate; 95 nm on a bulk Si substrate; and 186 nm on a bulk GaAs substrate. The strong substrate dependence indicates that the resolution, at 50 kV, is determined by electron scattering rather than the post exposure processing of the resist. Low voltage lithography with an STM offers a technique which greatly reduces the effects of electron scattering with a...
TL;DR: In this paper, the fabrication and characterization of facetless Bragg reflector surface-emitting AlGaAs/GaAs laser arrays with variable pitch grating pairs is described.
Abstract: We report the fabrication and characterization of facetless Bragg reflector surface‐emitting AlGaAs/GaAs lasers. Both first‐order (120‐nm period) and second‐order (240‐nm period) gratings were fabricated by electron‐beam lithography and chemically assisted ion‐beam etching (CAIBE). These grating pairs provide the optical feedback of the laser, eliminating the need for cleaved or etched mirror facets. Specifically, this work includes: the fabrication and testing of a variable pitch grating‐laser array which demonstrates optical emission peaks with 5‐A separation for adjacent lasers; demonstration of facetless Bragg reflector lasers with 120/240‐nm grating pairs that show lower threshold currents, higher quantum efficiencies, and improved beam width compared to conventional facetless second‐order grating lasers; and a demonstration of grating surface‐emitting diode lasers with hybrid first‐order and nonresonant, 120/307‐nm, grating pairs that produced a directed beam at 45° with respect to the substrate. Th...
TL;DR: In this paper, the authors used a holographically produced grid, which is essentially a permanently recorded interference pattern, to map out the distortion in the deflection field in an electron-beam lithography system.
Abstract: Metrology in an electron‐beam lithography system is typically carried out by a combination of beam scan and laser‐interferometer‐controlled sample motion. The high‐resolution technique presented in this paper avoids the stage motion by using a holographically produced grid, which is essentially a permanently recorded interference pattern. This grid can be at least as accurate as the interferometer, and no stage motion, with the potential for additional error sources, is required to map out the distortion in the deflection field. The quality of the grid is critical since it is the reference to which the distortion is compared. With careful control of the holographic exposure system, high‐quality low‐distortion orthogonal grids were fabricated. We have produced grids with a period of 200 nm and orthogonality of a few arc seconds using an UV laser holographic system. Once the grid is processed to produce a high‐contrast signal for either back‐scattered or transmitted electrons, both scanning and signal‐proce...
TL;DR: In this paper, a new exposure technique called block exposure was proposed to increase the throughput of direct writing of memory LSI devices using an electron beam, where the beam is projected to a block of aperture patterns in the stencil mask to change the beam shape.
Abstract: A new exposure technique called block exposure was examined in order to increase the throughput of direct writing of memory LSI devices using an electron beam. With this technique, an electron beam is projected to a block of aperture patterns in the stencil mask to change the beam shape. Frequently used LSI pattern components are defined as blocks to be reused during the exposure. Patterns that are rarely used are exposed by using a variable-shape beam. With the demagnification ratio of one percent, masks are easy to fabricate and very reliable. The patterns with a 0.13-µm minimum feature size are well projected on a single-layer resist. With block exposure, any shape can be accurately transferred irrespective of the pattern shape or size. The throughput of about ten 8-in wafers per hour is estimated for several pattern layers of a 64-Mbit dynamic random-access memory (DRAM).
TL;DR: It is demonstrated that resist kinoforms can be used for laser micromachining with a diffraction efficiency of 68% and Marking in a silicon wafer is demonstrated.
Abstract: We demonstrate that resist kinoforms can be used for laser micromachining. A 10-level resist kinoform, manufactured by electron-beam lithography, was shown to have a diffraction efficiency of 68%. Nine diffraction-limited holes were simultaneously drilled in 0.10-mm-thick stainless steel. Marking in a silicon wafer is also demonstrated.
TL;DR: In this paper, the patterning of the superconductor YBa2Cu3O7−x (YBCO) on single crystal SrTiO3 wafers by a selective epitaxy approach is presented.
Abstract: A novel method for submicron patterning of high Tc superconductor thin films is presented. Specifically, we describe the patterning of the superconductor YBa2Cu3O7−x (YBCO) on single crystal SrTiO3 wafers by a selective epitaxy approach. A silicon nitride template is formed on the SrTiO3 using electron beam lithography and reactive ion etching. A thin film of YBCO is then deposited on the wafer, e.g., by laser ablation. Selective epitaxy occurs during the deposition process, the YBCO film grows epitaxially on SrTiO3, while the film depositing on the nitride forms insulating clusters. Good epitaxial films and patterns have been obtained as‐deposited without the need for further annealing or other process steps. Lines as narrow as 130 nm have been fabricated which show no significant decrease in Tc as compared with the original blanket film.
24 Jun 1991
TL;DR: In this paper, the formation of Mo interconnections was achieved on the surface of deep U-shaped grooves, where the magnetic field is parallel to the wafer surface.
Abstract: Micromachined solenoids on silicon wafer for highly sensitive vector magnetic field sensors have been proposed. The feature of the solenoids is that the magnetic field is parallel to the wafer surface. In order to realize interconnections on three-dimensional structure, direct electron beam lithography was utilized. The formation of Mo interconnections was achieved on the surface of deep U-shaped grooves. Applications of the solenoids are also discussed. >
01 Mar 1991
TL;DR: In this paper, a dry etching system for high resolution transfer of e-beam generated pattern for a viable submicron lithography was proposed, where the underlayer of 1 micron polyimid was etched in a microwave downstream RF-biased etch system developed by Plasma Technology Ltd (UK).
Abstract: In this paper we discuss some properties of a novel dry etching system for high resolution transfer of e-beam generated pattern for a viable submicron lithography. In order to achieve pattern transfer by an e-beam lithography a tn-layer system has been used. The submicron pattern which has been generated in a 300 nm PBS-layer (imaging layer) was transfered into a 300 nm anorganic intermediate layer (Si3N4) by RIE with a CHF3-plasma. The underlayer of 1 micron polyimid was etched in a microwave downstream RF-biased etching system developed by Plasma Technology Ltd (UK). E-beam lithography generated structures of 75 nm size with very low image size bias were etched in Si3N4. After patterning in the polyimid layer structures with very high aspect ratio (10) could be achieved. It was observed that anisotropy is enhanced by crack-products that originate from the microwave downstream oxygen plasma and the CHF3+CH4 mixture in the space between the parallel-plate electrodes.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this article, a multi-layer resist scheme was proposed for high resolution optical lithography with excellent resolution capability and reducing the problems associated with the use of conventional micro-lithographic resists.
Abstract: This paper contains details of a multi-layer resist scheme which provides excellent resolution capability as well as reducing many of the problems associated with the use of conventional microlithographic resists. In the “PASS” (planarized arsenic/sulfur/silver) scheme, surface planarization is first achieved by spinning on a layer which is self levelling by spin-casting. A thin film of A3S67 (at. %) is then vacuum deposited on this layer and topped with silver. The planar nature of the resist scheme reduces the problems of focus variations at steps in the circuit topology for optical lithography. During exposure, the silver diffuses rapidly into the As-S with little lateral spread. The As-S compound is soluble in a CF4 plasma whereas the As-S-Ag ternary compound is extremely insoluble under the same conditions. We can therefore dry develop the active layer. The unremoved ternary is then used to selectively protect the planarizing layer during the subsequent dry etch of this material. In experimental studies, the resist system exhibited extremely high resolution; contrast is typically in excess of 13 for optical illumination and electron-beam direct writing has produced 35 nm lines spaced by 35 nm in the active layer.
TL;DR: In this paper, the authors have fabricated metal-semiconductor-metal photodetectors with sub-50 nm finger spacing and finger width on GaAs grown by molecular beam epitaxy, which are, to the knowledge, the smallest ever reported.
Abstract: Using high‐resolution electron beam lithography, we have fabricated metal–semiconductor–metal photodetectors with sub‐50 nm finger spacing and finger width on GaAs grown by molecular beam epitaxy, which are, to our knowledge, the smallest ever reported. dc measurements showed that they have low dark current and high sensitivity. Proper scaling of the detectors to reduce the finger resistance and detector capacitance and to increase detector speed was studied. The resistances of thin metal lines with various widths were measured and compared with the value calculated from resistivity for bulk metal. Monte Carlo simulation demonstrates that for the photodetectors with 30 nm finger spacing and width, the response time is below picosecond and the cut‐off frequency is over 1 THz.
Patent•
IBM1
TL;DR: In this article, a method of partitioning design shapes into subshapes such that a constant dose may be applied to an E-beam sensitive resist within each subshape was proposed.
Abstract: A method of partitioning design shapes, in an E-beam lithography system, into subshapes such that a constant dose may be applied to an E-beam sensitive resist within each subshape. Within each subshape the constant dose corresponds to an approximation to an indicator function, indicative of the degree of the proximity effect, such as the effective exposure of the resist from backscattered electrons or the required dose. The error of the approximation is equal to a predetermined value for each subshape, and can depend upon the position of the subshape within the shape and the influence of errors in the applied dose at that position on the position, on development, of the edge of the shape.
TL;DR: In this paper, silylation was applied to focused ion-beam (FIB) lithography to overcome deleterious substrate effects and to achieve smaller linewidths.
Abstract: Silylation processes have previously been applied to optical lithography to overcome deleterious substrate effects and to achieve smaller linewidths. We have applied silylation to focused ion‐beam (FIB) lithography, thereby eliminating the need for exposure throughout the entire resist thickness. This approach permits the use of Ga+ ions which have a limited range in the resist but are available from high brightness sources. Thus FIB lithography writing speed can be dramatically improved. Sensitivity of 8×1011 ions/cm2 was found with 30‐keV Ga+ using SAL 601 resist, and linewidths below 100 nm have been demonstrated.
01 Aug 1991
TL;DR: In this article, a range of focused ion beam techniques and processing methods designed specifically for nanofabrication are discussed and the types of structures used to investigate the physics, the physical phenomena explored with them are considered.
Abstract: Quantum transport effects have been explored in semiconductors using a two-dimensional electron gas confined by lateral nanostructures. Once the lateral sizes and the layer thickness are reduced to be smaller than the phase coherence length of the electrons in the material, quantum effects become pronounced; it is this aspect of nanofabrication that is considered. The structures defined by a number of different methods are considered and the techniques required to make them are described. Special electron beam lithography systems and processes and a range of focused ion beam techniques and processing methods designed specifically for nanofabrication are discussed. After defining the types of structures used to investigate the physics, the physical phenomena explored with them are considered briefly. >
TL;DR: In this paper, the authors have fabricated III-V semiconductor quantum wires which display a variety of novel transport and optical phenomena and have been analyzed by magnetotransport studies and emission spectroscopy.
Abstract: We have fabricated III–V semiconductor quantum wires which display a variety of novel transport and optical phenomena. For the definition of structures with widths down to 40 nm high resolution electron beam lithography and dry etching have been used. For the observation of dimensionality dependent effects in optical spectra buried quantum wires have been developed by overgrowth of dry etched structures and implantation induced intermixing. The physical properties of the nanometer structures have been analyzed by magnetotransport studies and emission spectroscopy.