The phase-shifting mask consists of a normal transmission mask that has been coated with a transparent layer patterned to ensure that the optical phases of nearest apertures are opposite. Destructive interference between waves from adjacent apertures cancels some diffraction effects and increases the spatial resolution with which such patterns can be projected. A simple theory predicts a near doubling of resolution for illumination with partial incoherence σ < 0.3, and substantial improvements in resolution for σ < 0.7. Initial results obtained with a phase-shifting mask patterned with typical device structures by electron-beam lithography and exposed using a Mann 4800 10× tool reveals a 40-percent increase in usuable resolution with some structures printed at a resolution of 1000 lines/mm. Phase-shifting mask structures can be used to facilitate proximity printing with larger gaps between mask and wafer. Theory indicates that the increase in resolution is accompanied by a minimal decrease in depth of focus. Thus the phase-shifting mask may be the most desirable device for enhancing optical lithography resolution in the VLSI/VHSIC era.

Improving resolution in photolithography with a phase-shifting mask

Algae are fast growing biomass and can be converted to Biodiesel fuel. The demand of biodiesel is growing worldwide. Microalgae need a light:dark regime for productive photosynthesis. Light conditions and Temperature affect directly the growth rate of microalgae (duration and intensity).Literature review of some Green algae species Chlorella, Spirogyra, Chlamydomonas, Botryococcus, Scenedesmus, Neochloris, Haematococcus, Nannochloropsis, Ulva species and few species of brown algae, red algae, blue green algae were chosen to study the effect of temperature and light intensity on their growth. Optimum temperature range 20 °C to30 °C was observed for growth of different algae species. Light irradiance varies between 33 µmol m−2 s−1 to 400 µmol m−2 s−1. Maximum growth rate was found 1.73 d−1 for Selenastrum minutum at 35 °C and 420 µmol m−2 s−1 irradiance. Minimum growth rate (0.10 d−1) was reported for Botryococcus braunii KMITL 2 strain at temperature 25 °C, photoperiod 24:0 and 200 µmol m−2 s−1 irradiance.

Effect of temperature and light on the growth of algae species: A review

The field of plasma etching is reviewed. Plasma etching, a revolutionary extension of the technique of physical sputtering, was introduced to integrated circuit manufacturing as early as the mid 1960s and more widely in the early 1970s, in an effort to reduce liquid waste disposal in manufacturing and achieve selectivities that were difficult to obtain with wet chemistry. Quickly, the ability to anisotropically etch silicon, aluminum, and silicon dioxide in plasmas became the breakthrough that allowed the features in integrated circuits to continue to shrink over the next 40 years. Some of this early history is reviewed, and a discussion of the evolution in plasma reactor design is included. Some basic principles related to plasma etching such as evaporation rates and Langmuir–Hinshelwood adsorption are introduced. Etching mechanisms of selected materials, silicon, silicon dioxide, and low dielectric-constant materials are discussed in detail. A detailed treatment is presented of applications in current silicon integrated circuit fabrication. Finally, some predictions are offered for future needs and advances in plasma etching for silicon and nonsilicon-based devices.

/pdf/plasma-etching-yesterday-today-and-tomorrow-4a8eftp390.pdf

Plasma etching: Yesterday, today, and tomorrow

Technology 4403 Microfabrication 4403 Assembly and Interfacing 4404 Optical Integration 4405 Flow Control 4405 Standard Operations 4406 Sample Preparation 4406 Injection and Separation 4407 Fluidic Reactors 4407 Particle and Cell Sorting 4409 Cell Trapping and Culture 4409 Applications 4410 Clinical Diagnostics 4410 Nucleic Acids 4411 Proteins 4412 Cell and Tissue Studies 4413 Environmental Monitoring 4414 Literature Cited 4414

Micro total analysis systems: latest achievements.

Microreactor technology and continuous flow processing in general are key features in making organic synthesis both more economical and environmentally friendly. Heterogeneous catalytic hydrogenation reactions under continuous flow conditions offer significant benefits compared to batch processes which are related to the unique gas-liquid-solid triphasic reaction conditions present in these transformations. In this review article recent developments in continuous flow heterogeneous catalytic hydrogenation reactions using molecular hydrogen are summarized. Available flow hydrogenation techniques, reactors, commonly used catalysts and examples of synthetic applications with an emphasis on laboratory-scale flow hydrogenation reactions are presented.

Heterogeneous Catalytic Hydrogenation Reactions in Continuous‐Flow Reactors

An array of miniaturized cylindrical quadrupole ion traps, with a radius of 20 microm, is fabricated using silicon micromachining using phosphorus doped polysilicon and silicon dioxide for the purpose of creating a mass spectrometer on a chip. We have operated the array for mass-selective ion ejection and mass analysis using Xe ions at a pressure of 10(-4). The scaling rules for the ion trap in relation to operating pressure, voltage, and frequency are examined.

Microfabricated quadrupole ion trap for mass spectrometer applications.

In this paper, a full-Stokes imaging polarimeter operating at 580 nm using an array of elliptical polarizers is presented. The division-of-focal-plane polarimeter utilizes a set of four optimized measurements which represent a regular tetrahedron inscribed in the Poincare sphere. Results from the device fabrication, instrument calibration and characterization are presented. The performance of the optimized full Stokes polarimeter, as defined by size of the standard deviation of the degree of circular polarization, is found to be approximately five times better than the performance of the simple full-Stokes polarimeter.

Full-Stokes imaging polarimeter using an array of elliptical polarizer

We demonstrate submicron resolution imaging using picosecond acoustic phonon pulses. High-frequency acoustic pulses are generated by impulsive thermoelastic excitation of a patterned 15-nm-thick metal film on a crystalline substrate using ultrafast optical pulses. The spatiotemporal diffracted acoustic strain field is measured on the opposite side of the substrate, and this field is used in a time-reversal algorithm to reconstruct the object. The image resolution is characterized using lithographically defined 1-micron-period Al structures on Si. Straightforward technical improvements should lead to resolution approaching 45nm, extending the resolution of acoustic microscopy into the nanoscale regime.

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/71146/APPLAB-84-25-5180-1.pdf?sequence=2

Imaging nanostructures with coherent phonon pulses

This paper presents a polarization microscope using an infrared (IR) full-Stokes imaging polarimeter. The IR polarimeter utilizes an optimized interference-based micropolarizer design, and provides full-Stokes images with resolution of 1608 × 1208 at 35 frames/second. The device fabrication, instrument calibration, performance evaluation, and measurement results are presented. The measurement error of the imaging polarimeter is less than 3.5%, and the standard deviations are less than 2%.

Polarization microscope using a near infrared full-Stokes imaging polarimeter

The authors fabricated and tested a compact optical sensor with an integrated waveguide and a microchannel in spiral geometry. The multimode waveguide, consisting of an SU-8 core of 40μm thick and 50μm wide and a fluid cladding layer of 60μm thick, realizes a light-fluid interaction length of 110mm within a device area of 4cm2. The waveguide sensor measures changes in liquid sample concentration and is sensitive to changes in liquid refractive index. Absorbance measurements using the spiral waveguide sensor demonstrate increased sensitivity compared with a linear geometry sensor.

Stanley Pau

Papers

Microfabricated quadrupole ion trap for mass spectrometer applications.

Full-Stokes imaging polarimeter using an array of elliptical polarizer

Imaging nanostructures with coherent phonon pulses

Polarization microscope using a near infrared full-Stokes imaging polarimeter

Integrated waveguide with a microfluidic channel in spiral geometry for spectroscopic applications