An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

Since 1993, InGaN light-emitting diodes (LEDs) have been improved and commercialized, but these devices have not fulfilled their original promise as solid-state replacements for light bulbs as their light-emission efficiencies have been limited. Here we describe a method to enhance this efficiency through the energy transfer between quantum wells (QWs) and surface plasmons (SPs). SPs can increase the density of states and the spontaneous emission rate in the semiconductor, and lead to the enhancement of light emission by SP–QW coupling. Large enhancements of the internal quantum efficiencies (etaint) were measured when silver or aluminium layers were deposited 10 nm above an InGaN light-emitting layer, whereas no such enhancements were obtained from gold-coated samples. Our results indicate that the use of SPs would lead to a new class of very bright LEDs, and highly efficient solid-state light sources.

/pdf/surface-plasmon-enhanced-light-emitters-based-on-ingan-4ithz2fei5.pdf

Surface-Plasmon-Enhanced Light Emitters Based on InGaN Quantum Wells

Semiconductor nanowires (NWs) have been studied extensively for over two decades for their novel electronic, photonic, thermal, electrochemical and mechanical properties. This comprehensive review article summarizes major advances in the synthesis, characterization, and application of these materials in the past decade. Developments in the understanding of the fundamental principles of "bottom-up" growth mechanisms are presented, with an emphasis on rational control of the morphology, stoichiometry, and crystal structure of the materials. This is followed by a discussion of the application of nanowires in i) electronic, ii) sensor, iii) photonic, iv) thermoelectric, v) photovoltaic, vi) photoelectrochemical, vii) battery, viii) mechanical, and ix) biological applications. Throughout the discussion, a detailed explanation of the unique properties associated with the one-dimensional nanowire geometry will be presented, and the benefits of these properties for the various applications will be highlighted. The review concludes with a brief perspective on future research directions, and remaining barriers which must be overcome for the successful commercial application of these technologies.

/pdf/25th-anniversary-article-semiconductor-nanowires-synthesis-4ccslz11ke.pdf

25th Anniversary Article: Semiconductor Nanowires – Synthesis, Characterization, and Applications

Synthesis and applications of one-dimensional semiconductors

A system includes a semiconductor device. The semiconductor device includes a first single crystal silicon layer comprising first transistors, first alignment marks, and at least one metal layer overlying the first single crystal silicon layer, wherein the at least one metal layer comprises copper or aluminum more than other materials; and a second single crystal silicon layer overlying the at least one metal layer. The second single crystal silicon layer comprises a plurality of second transistors arranged in substantially parallel bands. Each of a plurality of the bands comprises a portion of the second transistors along an axis in a repeating pattern.

System comprising a semiconductor device and structure

A method of manufacturing a substrate having a thin film thereabove includes: forming a thin film above the substrate; and crystallizing at least a predetermined area of the silicon thin film into a crystallized area through relative scan of the silicon thin film which is performed while the thin film is being irradiated with a continuous wave light beam, wherein in the crystallizing, a projection of the light beam on the thin film has a major axis in a direction crossing a direction of the relative scan, and the formed crystallized area includes a strip-shaped first area extending in the direction crossing the direction of the relative scan and a second area adjacent to the strip-shaped first area, the strip-shaped first area including crystal grains having an average grain size larger than that of crystal grains in the second area.

Method of manufacturing substrate having thin film thereabove, method of manufacturing thin-film-device substrate, thin-film substrate, and thin-film-device substrate

A polycrystalline silicon thin-film forming method includes: preparing a substrate; forming a precursor of a first silicon thin film including a first polycrystalline silicon phase and a non-crystalline silicon phase; exposing the first polycrystalline silicon phase; and growing, above the first silicon thin film which the first polycrystalline silicon phase is exposed, a second polycrystalline silicon phase using the first polycrystalline silicon phase as a seed crystal by a plasma chemical vapor deposition method, wherein the first polycrystalline silicon phase is formed continuously in any direction perpendicular to a thickness direction of the first silicon thin film.

Polycrystalline silicon thin-film forming method, polycrystalline silicon thin-film substrate, silicon thin-film solar cell, and silicon thin-film transistor device

We developed double-crystalline silicon channel thin film transistors (TFTs) whose active region consisted of a polysilicon layer and a microcrystalline silicon layer. The polysilicon layer was formed by continuous-wave green laser annealing with scalability to large substrates. The microcrystalline silicon layer formed on the polysilicon layer provides a sufficient channel etching margin for the fabrication of TFTs on large substrates without degradation of TFT mobility. The kink-free output characteristics were realized by a band-gap engineering method using a microcrystalline silicon layer. The TFT characteristics desirable for organic light-emitting diode display applications, namely, high mobility, high reliability, and kink-free output characteristics, have been successfully demonstrated.

http://iopscience.iop.org/article/10.7567/JJAP.52.03BB02/pdf

Double-Crystalline Silicon Channel Thin Film Transistors Fabricated Using Continuous-Wave Green Laser for Large Organic Light-Emitting Diode Displays

A thin-film transistor used for a display device includes a gate electrode formed on an insulating substrate; a gate insulating film formed on the substrate so as to cover the gate electrode; a semiconductor layer composed of first semiconductor layer and second semiconductor layer formed on the gate insulating film; an ohmic contact layer formed on the semiconductor layer; and a source electrode and a drain electrode formed on the ohmic contact layer so as to be spaced from each other. The transistor further includes an etching stopper made of spin-on glass (SOG) on a channel-forming region of the semiconductor layer.

Display device, thin-film transistor used for display device, and method of manufacturing thin-film transistors

A field effect transistor is provided with a semiconductor layer (14); a source electrode (15) and a drain electrode (16) which are electrically connected with the semiconductor layer (14); and a gate electrode (12) for applying electric field to the semiconductor layer (14) between the source electrode (15) and the drain electrode (16). The semiconductor layer (14) includes a plurality of fine wires, which are composed of inorganic semiconductor, and an organic semiconductor material.

Takahiro Kawashima

Papers

Method of manufacturing substrate having thin film thereabove, method of manufacturing thin-film-device substrate, thin-film substrate, and thin-film-device substrate

Polycrystalline silicon thin-film forming method, polycrystalline silicon thin-film substrate, silicon thin-film solar cell, and silicon thin-film transistor device

Double-Crystalline Silicon Channel Thin Film Transistors Fabricated Using Continuous-Wave Green Laser for Large Organic Light-Emitting Diode Displays

Display device, thin-film transistor used for display device, and method of manufacturing thin-film transistors

Field effect transistor, method for manufacturing the same and electronic device using the field effect transistor