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

A transistor is provided, which is entirely and partially transparent by the use of a transparent channel layer made of zinc oxide or the like A channel layer 11 formed of a transparent semiconductor such as zinc oxide ZnO A transparent electrode is used for all of a source 12 , a drain 13 and a gate 14 , or a part of them As the transparent electrode, a transparent conductive material such as conductive ZnO doped with, for example, group III elements is used As a gate insulating layer 15 , a transparent insulative material such as insulative ZnO doped with elements capable of taking a valence of one as a valence number or group V elements is used If a substrate 16 must be transparent, for example, glass, sapphire, plastic or the like can be used as a transparent material

Transistor and semiconductor device

A method of making a thin film transistor comprises (a) solution depositing a dispersion comprising semiconducting metal oxide nanoparticles onto a substrate, (b) sintering the nanoparticles to form a semiconductor layer, and (c) optionally subjecting the resulting semiconductor layer to post-deposition processing.

Method for making electronic devices using metal oxide nanoparticles

A thin film transistor (TFT) includes a source electrode, a drain electrode, and a gate electrode. A gate insulator is coupled to the source electrode, drain electrode, and gate electrode. The gate insulator includes room temperature deposited high-K materials so as to allow said thin film transistor to operate at low operating voltage.

Low voltage flexible organic/transparent transistor for selective gas sensing, photodetecting and CMOS device applications

Several hundred thousands of tons of ZnO are used by per year, e.g. as an additive to concrete or to rubber. In the field of optoelectronics, ZnO holds promises as a material for a blue/UV optoelectronics, alternatively to GaN, as a cheap, transparent, conducting oxide, as a material for electronic circuits, which are transparent in the visible or for semiconductor spintronics. The main problem is presently, however, a high, reproducible and stable p-doping. We review in this contribution partly critically the material growth, fundamental properties of ZnO and of ZnO-based nanostructures, doping as well as present and future applications, with emphasis on the electronic and optical properties including stimulated emission. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

ZnO : From basics towards applications

Results are presented for ZnO-based ultraviolet light emitting diodes (LEDs) that employ a BeZnO∕ZnO active layer comprised of seven quantum wells. Arsenic and gallium are used for p-type and n-type layers. The ZnO-based LEDs show two dominant electroluminescence peaks located in the ultraviolet spectral region between 360 and 390nm, as well as a broad peak at 550nm.

Next generation of oxide photonic devices : ZnO-based ultraviolet light emitting diodes

A wide-band gap oxide alloy, BeZnO, is proposed and studied in this letter The BeZnO films were deposited on sapphire substrates by our hybrid beam deposition growth method The value of the energy band gap of BeZnO can be efficiently engineered to vary from the ZnO band gap (34 eV) to that of BeO (106 eV) BeZnO can be used for fabricating films and heterostructures of ZnO-based electronic and photonic devices and for other applications Changes in the measured energy band gap and lattice constant values with Be content are described for BeZnO alloys

Wide-band gap oxide alloy: BeZnO

The authors have fabricated ultraviolet (UV) laser diodes based on ZnO∕BeZnO films The devices have p-n heterojunction structures with a multiple quantum well (MQW) active layer sandwiched between guide-confinement layers The MQW active layer comprises undoped ZnO and BeZnO, while the two guide-confinement layers were As-doped p-type ZnO∕BeZnO and Ga-doped n-type BeZnO∕ZnO films, respectively The exciton binding energy in the MQW region is exceptionally large (263meV) Exciton-related lasing was observed by optically pumping the MQWs ZnO∕BeZnO-based diodes showed laser action by current injection at room temperature The lasing mechanism is inelastic exciton-exciton collision

Excitonic ultraviolet lasing in ZnO-based light emitting devices

The potential use of ZnO-based photonic and electronic devices has been demonstrated by the fabrication of prototype ultraviolet (UV) photodetector and field-effect transistor (FET) devices that contain films of p-type ZnO with arsenic as the p-type dopant. These p-type films have high crystalline quality and show long-term stability. The ZnO UV photodetectors are based on p-n junctions. The FETs are made with metal-semiconductor Schottky contacts on p-type ZnO and are normally off (enhancement) devices. The spectral and electrical characteristics of these devices are presented and explained.

ZnO devices: Photodiodes and p-type field-effect transistors

A p-type zinc oxide film and a process for preparing the film and p-n or n-p junctions is disclosed. In a preferred embodiment, the p-type zinc oxide film contains arsenic and is grown on a gallium arsenide substrate. The p-type zinc oxide film has a net acceptor concentration of at least about 1015 acceptors/cm3, a resistivity of no greater than about 1 ohm-cm, and a Hall mobility of between about 0.1 and about 50 cm2/Vs.

Yungryel Ryu

Papers

Next generation of oxide photonic devices : ZnO-based ultraviolet light emitting diodes

Wide-band gap oxide alloy: BeZnO

Excitonic ultraviolet lasing in ZnO-based light emitting devices

ZnO devices: Photodiodes and p-type field-effect transistors

Zinc oxide films containing p-type dopant and process for preparing same