scholarly journals Microfabrication of Microlens by Timed-Development-and-Thermal-Reflow (TDTR) Process for Projection Lithography

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 277
Author(s):  
Jun Ying Tan ◽  
Gyuhyeong Goh ◽  
Jungkwun Kim
Keyword(s):  
Development Time ◽  
Focal Length ◽  
Surface Profile ◽  
Radius Of Curvature ◽  
Aperture Size ◽  
Reflow Process ◽  
Projection Lithography ◽  
Relationship Of ◽  
The Relationship ◽  
Thermal Reflow

This paper presents a microlens fabrication process using the timed-development-and-thermal-reflow process, which can fabricate various types of aperture geometry with a parabolic profile on a single substrate in the same batch of the process. By controlling the development time of the uncrosslinked negative photoresist, a state of partial development of the photoresist is achieved, called the timed development process. The thermal reflow process is followed after the timed development, which allows the photoresist to regain its liquid state to form a smooth meniscus trench surrounded by a crosslinked photoresist sidewall. Microlens with larger aperture size forms deeper trench with constant development time. With constant aperture size, longer developing time shows deeper meniscus trench. The depth of the meniscus trench is modeled in the relationship of the development time and aperture size. Other characteristics for the microlens including the radius of curvature, focal length, and the parabolic surface profile are modeled in the relationship of the microlens thickness and diameter. Microlens with circular, square, and hexagonal bases have been successfully fabricated and demonstrated where each geometry of the lens-bases shows different fill factors of the lens arrays. To test the fabricated lenses, a miniaturized projection lithography scheme was proposed. A centimeter-scale photomask pattern was photo-reduced using the fabricated microlens array with a ratio of 133, where the smallest linewidth was measured as 2.6 µm.

Development of a Multi-Ball-Cantilever AFM for Measuring Resist Surface

2006 ◽  
Vol 18 (6) ◽  
pp. 698-704 ◽  
Author(s):  
Shujie Liu ◽  
◽  
Shuichi Nagasawa ◽  
Satoru Takahashi ◽  
Kiyoshi Takamasu
Keyword(s):  
High Speed ◽  
Surface Deformation ◽  
Surface Profile ◽  
Displacement Curve ◽  
The Finite Element Method ◽  
Measuring Surface ◽  
Surface Profiles ◽  
Relationship Of ◽  
The Relationship ◽  
Force Displacement

Semiconductor processing must be fast and highly accurate when measuring the surface profile of soft thin films such as photoresists. We propose doing so using a multi-ball-cantilever AFM, which covers a wide area at high speed. Each cantilever has a ball stylus with a diameter that does not plastically deform measured surfaces. We studied resist profiles and the influence of the AFM stylus on the resist surface. To verify our proposal’s feasibility, we simulated the relationship of the indenter shape, size, and load and resist surface deformation using the finite element method (FEM). We discuss the influence of the AFM stylus based on the force-displacement curve. Experiments using the multi-ball-cantilever AFM confirmed its feasibility for measuring surface profiles highly accurately.

Developmental studies on Anagyrus mangicola (Hymenoptera: Encyrtidae), a parasitoid of the mealybug Rastrococcus invadens (Homoptera: Pseudococcidae)

1992 ◽  
Vol 82 (3) ◽  
pp. 307-312 ◽  
Author(s):  
A.E. Cross ◽  
D. Moore
Keyword(s):  
Development Time ◽  
Adult Longevity ◽  
Developmental Studies ◽  
Fruit Crops ◽  
Larval Stages ◽  
Immature Development ◽  
Rastrococcus Invadens ◽  
Host Stage ◽  
Relationship Of ◽  
The Relationship

AbstractAnagyrus mangicola Noyes, a primary parasitoid of the mealybug Rastrococcus invadens Williams, a pest of fruit crops in West Africa, was studied under controlled conditions at 27°C and 75% r.h. Data are given on the larval stages, their morphology and duration of immature development. The sex ratios of emerging parasitoids, adult longevity, host stage preference, the relationship of the size of the emerging parasitoid to host stage and development time are also investigated.

Geometric Analysis of a Foldable Barrel Vault With Origami

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Jianguo Cai ◽  
Yixiang Xu ◽  
Jian Feng
Keyword(s):  
Geometric Analysis ◽  
Radius Of Curvature ◽  
Spherical Trigonometry ◽  
Longitudinal Length ◽  
Relationship Of ◽  
The Relationship

This paper investigates the geometry of a foldable barrel vault with modified Miura-ori patterns, which displays a curvature during the motion. The principal of spherical trigonometry was used to obtain the relationship of the inclined angles between adjacent folded papers of Miura-ori. Then, the radius, span, rise, and longitudinal length of the foldable barrel vault in all configurations throughout the motion are determined. The results show that the radius of curvature grows exponentially and the span increases during deployment. Furthermore, the rise increases first, followed by a decrease with increasing deployment angle.

scholarly journals Necessary conditions of physical realizability of the bifocal lens collimator

2020 ◽  
pp. 68-78
Author(s):  
Maksim Stepanov ◽  
◽  
Yulia Nikulina ◽  
Keyword(s):  
Necessary Conditions ◽  
Optical Axis ◽  
Focal Point ◽  
Focal Length ◽  
Necessary Condition ◽  
Systems Of Inequalities ◽  
Relationship Of ◽  
The Relationship ◽  
Lens Surface ◽  
Physical Realizability

The conditions of physical realizability of one of the varieties of aplanitic lens collimators, a bifocal lens collimator, which has two points of perfect focus and do not lie on the main optical axis, are considered. Based on the relationship of the parameters specified during the design of the bifocal lens collimator (aperture size, thickness, focal length, distance from the main optical axis to the focal point, tilt of the phase front in the aperture), conditions that are necessary for the synthesis of a physically feasible collimator are formulated. The solution of this problem is based on the properties of an ellipse of equal edges and the geometry of a bifocal lens collimator. The graphic dependencies of the obtained expressions are given and analyzed. Based on this analysis, the mutual dependence of the parameters specified at the beginning of the calculation of the lens surface is determined. Systems of inequalities that establish the conditions for the realizability of a bifocal lens collimator are written. A number of restrictions on the initial parameters of the bifocal lens collimator are recorded. The fulfillment of the inequalities obtained in the article is a necessary condition for the physical realizability of the bifocal lens collimator.

New Camera Parameters Calibration Method of Binocular Vision System

2013 ◽  
Vol 712-715 ◽  
pp. 2372-2377
Author(s):  
Hong E Ren ◽  
Si Li
Keyword(s):  
Binocular Vision ◽  
Theoretical Basis ◽  
Simulation Experiment ◽  
Vision System ◽  
Focal Length ◽  
Calibration Method ◽  
Camera Parameters ◽  
Relationship Of ◽  
The Relationship ◽  
Binocular Vision System

About the key problems of the binocular vision system design which was used to video log examining, and according to the binocular parallax theory and triangle measuring theory, the paper researched the basic principle of camera imaging, proposed the camera parameters calibration method that could determine the best placed baseline distance of two cameras and the camera focal length together, inferred the relationship of the best baseline distance and the camera focal length by analyzing to many groups calibration results. The simulation experiment results show that this method is simple, practical, and has a high precision, provides a theoretical basis for design of tow cameras positions in the binocular vision system.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Resolution Attainable With the Present Day STEM

1973 ◽  
Vol 31 ◽  
pp. 230-231 ◽  
Author(s):  
J. S. Wall ◽  
J. P. Langmore ◽  
H. Isaacson ◽  
A. V. Crewe
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Aperture Size ◽  
Magnetic Lens ◽  
Peak Intensity ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Half Angle

The scanning transmission electron microscope (STEM) constructed by the authors employs a field emission gun and a 1.15 mm focal length magnetic lens to produce a probe on the specimen. The aperture size is chosen to allow one wavelength of spherical aberration at the edge of the objective aperture. Under these conditions the profile of the focused spot is expected to be similar to an Airy intensity distribution with the first zero at the same point but with a peak intensity 80 per cent of that which would be obtained If the lens had no aberration. This condition is attained when the half angle that the incident beam subtends at the specimen, 𝛂 = (4𝛌/Cs)¼

Sign in / Sign up

Export Citation Format

Share Document