Dual field alignment display and control for electron micropattern generator

Application of electron beam lithography to replace photolithography process in fabrication of integrated circuits is discussed. Procedure for using electron beam lithography equipment is described. Diagram of electron micropattern generator is provided

Diffractive lens fabrication by replica molding

Diffractive lenses and 2-D gratings were fabricated using electron-beam lithography and replica molding. With electron-beam lithography, feature sizes smaller than 60 nm can be achieved. We demonstrate that we can achieve similar feature sizes with replica molding. High-fidelity replica molding can become an important tool to complement electron-beam lithography in the fabrication of DOEs and other nanostructures

Alignment verification for electron beam lithography

Alignment between lithography layers is essential for device fabrication. A minor defect in a single marker can lead to incorrect alignment and this can be the source of wafer reworks. In this paper we show that this can be prevented by using extra alignment markers to check the alignment during patterning, rather than inspecting vernier patterns after the exposure is completed. Accurate vernier patterns can often only be read after pattern transfer has been carried out. We also show that by using a Penrose tile as a marker it is possible to locate the marker to about 1 nm without fully exposing the resist. This means that the marker can be reused with full accuracy, thus improving the layer to layer alignment accuracy. Lithography tool noise limits the process

Nanometer-spaced platinum electrodes with calibrated separation

We have fabricated pairs of platinum electrodes with separation between 20 and 3.5 nm. Our technique combines electron beam lithography and chemical electrodeposition. We show that the measurement of the conductance between the two electrodes through the electrolyte provides an accurate and reproducible way to control their separation. We have tested the robustness of the electrodes by applying large voltages across them and by using them to measure the transport properties of Au nano-clusters. Our results show that the technique reliably produces metallic electrodes with a separation that bridges the minimum scale accessible by electron beam lithography with the atomic scale.Comment: 4 pages, 4 figure

Metrology for electron-beam lithography and resist contrast at the sub-10 nm scale

Exploring the resolution limit of electron-beam lithography is of great interest both scientifically and technologically. However, when electron-beam lithography approaches its resolution limit, imaging and metrology of the fabricated structures by using standard scanning electron microscopy become difficult. In this work, the authors adopted transmission-electron and atomic-force microscopies to improve the metrological accuracy and to analyze the resolution limit of electron-beam lithography. With these metrological methods, the authors found that sub-5 nm sparse features could be readily fabricated by electron-beam lithography, but dense 16 nm pitch structures were difficult to yield. Measurements of point- and line-spread functions suggested that the resolution in fabricating sub-10 nm half-pitch structures was primarily limited by the resist-development processes, meaning that the development rates depended on pattern density and/or length scale.China Scholarship Council (Fellowship)United States. Dept. of Energy. Center for Excitonics (Award DE-SC0001088)Information Storage Industry ConsortiumNanoelectronics Research InitiativeNational Science Foundation (U.S.

Two-speed deflection system for electron micropattern generator

Development of dual speed deflection system for electron beam micropattern generator system is discussed. Factors affecting application of electron beam lithography are analyzed. Procedure for using two speed deflection system is described

Extremely uniform lasing wavelengths of InP microdisk lasers heterogeneously integrated on SOI

A standard deviation in lasing wavelength lower than 500pm is characterized on nominally identical and optically-pumped microdisk lasers, heterogeneously integrated on the same SOI circuit. This lasing wavelength uniformity is obtained using electron-beam lithography

Assessment of lithographic process variation effects in InGaAsP annular Bragg resonator lasers

Optical microresonators based on an annular geometry of radial Bragg reflectors have been designed and fabricated by electron-beam lithography, reactive ion etching, and an epitaxial transfer process. Unlike conventional ring resonators that are based on total internal reflection of light, the annular structure described here is designed to support optical modes with very small azimuthal propagation coefficient and correspondingly large free spectral range. The effect of lithographic process variation upon device performance is studied. Laser emission wavelength and threshold optical pump power are found to vary between similar devices given different electron doses during electron-beam lithography. As the resonance wavelength and quality factor of these resonators are very sensitive to environmental changes, these resonators make ideal active light sources that can be integrated into large arrays for gas and liquid sensing applications and are easily interrogated