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Phase-shift Mask
Phase-shift masks are photomasks that take advantage of the interference generated by phase differences to improve image resolution in photolithography. There exist alternating and attenuated phase shift masks. A phase-shift mask relies on the fact that light passing through a transparent media will undergo a phase change as a function of its optical thickness. Types and effects A conventional photomask is a transparent plate with the same thickness everywhere, parts of which are covered with non-transmitting material in order to create a pattern on the semiconductor wafer when illuminated. In ''alternating phase-shift masks'', certain transmitting regions are made thinner or thicker. That induces a phase-shift in the light traveling through those regions of the mask (see the illustration). When the thickness is suitably chosen, the interference of the phase-shifted light with the light coming from unmodified regions of the mask has the effect of improving the contrast on som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-shift Illustration
In physics and mathematics, the phase (symbol φ or ϕ) of a wave or other periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is expressed in such a scale that it varies by one full turn as the variable t goes through each period (and F(t) goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or 2\pi as the variable t completes a full period. This convention is especially appropriate for a sinusoidal function, since its value at any argument t then can be expressed as \varphi(t), the sine of the phase, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.) Usually, whole turns are ignored when expressing the phase; so that \varphi(t) is also a periodic function, with the same period as F, that repeatedly scans the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Shift Mask (4 Types) N
Phase or phases may refer to: Science *State of matter, or phase, one of the distinct forms in which matter can exist *Phase (matter), a region of space throughout which all physical properties are essentially uniform *Phase space, a mathematical space in which each possible state of a physical system is represented by a point also referred to as a "microscopic state" **Phase space formulation, a formulation of quantum mechanics in phase space *Phase (waves), the position of a point in time (an instant) on a waveform cycle **Instantaneous phase, generalization for both cyclic and non-cyclic phenomena *AC phase, the phase offset between alternating current electric power in multiple conducting wires **Single-phase electric power, distribution of AC electric power in a system where the voltages of the supply vary in unison **Three-phase electric power, a common method of AC electric power generation, transmission, and distribution *Phase problem, the loss of information (the phase) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photomask
A photomask (also simply called a mask) is an opaque plate with transparent areas that allow light to shine through in a defined pattern. Photomasks are commonly used in photolithography for the production of integrated circuits (ICs or "chips") to produce a pattern on a thin wafer of material (usually silicon). In semiconductor manufacturing, a mask is sometimes called a reticle. In photolithography, several masks are used in turn, each one reproducing a layer of the completed design, and together known as a mask set. A curvilinear photomask has patterns with curves, which is a departure from conventional photomasks which only have patterns that are completely vertical or horizontal, known as manhattan geometry. These photomasks require special equipment to manufacture. History For IC production in the 1960s and early 1970s, an opaque rubylith film laminated onto a transparent mylar sheet was used. The design of one layer was cut into the rubylith, initially by hand on an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interference (wave Propagation)
In physics, interference is a phenomenon in which two coherent waves are combined by adding their intensities or displacements with due consideration for their phase difference. The resultant wave may have greater amplitude (constructive interference) or lower amplitude (destructive interference) if the two waves are in phase or out of phase, respectively. Interference effects can be observed with all types of waves, for example, light, radio, acoustic, surface water waves, gravity waves, or matter waves as well as in loudspeakers as electrical waves. Etymology The word ''interference'' is derived from the Latin words ''inter'' which means "between" and ''fere'' which means "hit or strike", and was used in the context of wave superposition by Thomas Young in 1801. Mechanisms The principle of superposition of waves states that when two or more propagating waves of the same type are incident on the same point, the resultant amplitude at that point is equal to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase (waves)
In physics and mathematics, the phase (symbol φ or ϕ) of a wave or other periodic function F of some real variable t (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t. It is expressed in such a scale that it varies by one full turn as the variable t goes through each period (and F(t) goes through each complete cycle). It may be measured in any angular unit such as degrees or radians, thus increasing by 360° or 2\pi as the variable t completes a full period. This convention is especially appropriate for a sinusoidal function, since its value at any argument t then can be expressed as \varphi(t), the sine of the phase, multiplied by some factor (the amplitude of the sinusoid). (The cosine may be used instead of sine, depending on where one considers each period to start.) Usually, whole turns are ignored when expressing the phase; so that \varphi(t) is also a periodic function, with the same period as F, that repeatedly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Image Resolution
Image resolution is the level of detail of an image. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how close lines can be to each other and still be visibly ''resolved''. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtense. Instead of single lines, line pairs are often used, composed of a dark line and an adjacent light line; for example, a resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm). Photographic lens are most often quoted in line pairs per millimeter. Types The resolution of digital cameras can be described in many different ways. Pixel count The term ''resolution'' is often considered eq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photolithography
Photolithography (also known as optical lithography) is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer. The process begins with a photosensitive material, called a photoresist, being applied to the substrate. A photomask that contains the desired pattern is then placed over the photoresist. Light is shone through the photomask, exposing the photoresist in certain areas. The exposed areas undergo a chemical change, making them either soluble or insoluble in a developer solution. After development, the pattern is transferred onto the substrate through etching, chemical vapor deposition, or ion implantation processes. Ultraviolet, Ultraviolet (UV) light is typically used. Photolithography processes can be classified according to the type of light used, including ultraviolet lithography, deep ultraviolet lithography, extreme ultraviolet lithography, extreme ultraviolet lithography ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wafer (electronics)
In electronics, a wafer (also called a slice or substrate) is a thin slice of semiconductor, such as a crystalline silicon (c-Si, silicium), used for Semiconductor device fabrication, the fabrication of integrated circuits and, in photovoltaics, to manufacture solar cells. The wafer serves as the substrate (materials science), substrate for microelectronic devices built in and upon the wafer. It undergoes many microfabrication processes, such as doping (semiconductor), doping, ion implantation, Etching (microfabrication), etching, thin-film deposition of various materials, and Photolithography, photolithographic patterning. Finally, the individual microcircuits are separated by wafer dicing and Integrated circuit packaging, packaged as an integrated circuit. History In the semiconductor industry, the term wafer appeared in the 1950s to describe a thin round slice of semiconductor material, typically germanium or silicon. The round shape characteristic of these wafers comes f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Ratio
The contrast ratio (CR) is a property of a display system, defined as the ratio of the luminance of the brightest shade (white) to that of the darkest shade (black) that the system is capable of producing. A high contrast ratio is a desired aspect of any display. It has similarities with dynamic range. There is no official, standardized way to measure contrast ratio for a system or its parts, nor is there a standard for defining "Contrast Ratio" that is accepted by any standards organization so ratings provided by different manufacturers of display devices are not necessarily comparable to each other due to differences in method of measurement, operation, and unstated variables. Manufacturers have traditionally favored measurement methods that isolate the device from the system, whereas other designers have more often taken the effect of the room into account. An ideal room would absorb all the light reflecting from a projection screen or emitted by a cathode-ray tube, and the on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scattered Light From Phase Defect
Scattered may refer to: Music * ''Scattered'' (album), a 2010 album by The Handsome Family * "Scattered" (The Kinks song), 1993 * "Scattered", a song by Ace Young * "Scattered", a song by Lauren Jauregui * "Scattered", a song by Green Day from ''Nimrod'' * "Scattered (Let's Think About Livin')", a song by Neil Young from his 1996 album '' Broken Arrow'' Other uses * Scattered (rave), a rave party based in Sydney, Australia * "Scattered" (Battlestar Galactica), a 2005 ''Battlestar Galactica'' episode * Scattered radiation * Scattered space In mathematics, a scattered space is a topological space ''X'' that contains no nonempty dense-in-itself subset. Equivalently, every nonempty subset ''A'' of ''X'' contains a point isolated in ''A''. A subset of a topological space is called a s ..., a property of topological spaces See also * Scatter (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
