Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed and p-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n-type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution-processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p-type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n- and p-type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n- and p-type oxide transistors as well as the fabrication of CMOS devices with and on paper.

Oxide Semiconductor Thin‐Film Transistors: A Review of Recent Advances

With advances in exfoliation and synthetic techniques, atomically thin films of semiconducting transition metal dichalcogenides have recently been isolated and characterized. Their two-dimensional structure, coupled with a direct band gap in the visible portion of the electromagnetic spectrum, suggests suitability for digital electronics and optoelectronics. Toward that end, several classes of high-performance devices have been reported along with significant progress in understanding their physical properties. Here, we present a review of the architecture, operating principles, and physics of electronic and optoelectronic devices based on ultrathin transition metal dichalcogenide semiconductors. By critically assessing and comparing the performance of these devices with competing technologies, the merits and shortcomings of this emerging class of electronic materials are identified, thereby providing a roadmap for future development.

Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides

https://iopscience.iop.org/article/10.1088/1468-6996/11/4/044305/pdf

Present status of amorphous In–Ga–Zn–O thin-film transistors

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

The present invention provides a heterocyclic compound and an organic light-emitting device including the heterocyclic compound. The organic light-emitting devices using the heterocyclic compounds have high-efficiency, low driving voltage, high luminance and long lifespan.

Organic light-emitting device

A field-effect transistor includes a substrate, a source electrode, a drain electrode, a gate electrode, a gate-insulating film, and an active layer. The active layer contains an oxide having a transmittance of 70% or more in the wavelength range of 400 to 800 nm. A light-shielding member is provided as a light-shielding structure for the active layer, for example, on the bottom face of the substrate.

Field-effect transistor including transparent oxide and light-shielding member, and display utilizing the transistor

A method for manufacturing a field-effect transistor includes the steps of forming a source electrode and a drain electrode each containing hydrogen or deuterium; forming an oxide semiconductor layer in which the electrical resistance is decreased if hydrogen or deuterium is added; and, causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer.

Field-effect transistor and method for manufacturing the same

We review the features of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs), as well as circuit operation based on these TFTs. We also report a novel TFT structure which improves environmental stability of the TFT operation by taking full advantage of the a-IGZO properties, where a conventional PECVD a-SiNX:H films serve not only as an effective barrier layer but also as a hydrogen source to form the coplanar source and drain.

42.1: Invited Paper: Improved Amorphous In‐Ga‐Zn‐O TFTs

Thin film transistors (TFTs) using polycrystalline tin oxides (SnO–SnO2) channels were formed on glass by a conventional sputtering method and subsequent annealing treatments. SnO-channel TFTs showed p-type operation with on/off current ratios of ∼102 and field-effect mobilities of 0.24 cm2 V−1 s−1. Incorporation of excess oxygen to SnO channel layers did not generate holes but did electrons, which in turn led to n-type operation. This result is explained by transformation to a local SnO2-like structure and finally to SnO2. We propose a simple method to fabricate complimentary circuits by simultaneous selective formation of p- and n-channel TFTs.

Sputtering formation of p-type SnO thin-film transistors on glass toward oxide complimentary circuits

A fabrication process of coplanar homojunction thin-film transistors (TFTs) is proposed for amorphous In–Ga–Zn–O (a-IGZO), which employs highly doped contact regions naturally formed by deposition of upper protection layers made of hydrogenated silicon nitride (SiNX:H). The direct deposition of SiNX:H reduced the resistivity of the semiconductive a-IGZO layer down to 6.2×10−3 Ω cm and formed a nearly ideal Ohmic contact with a low parasitic source-to-drain resistance of 34 Ω cm. Simple evaluation of field-effect mobilities (μsat) overestimated their values especially for short-channel TFTs, while the channel resistance method proved that μsat was almost constant at 9.5 cm2 V−1 s−1.

/pdf/amorphous-in-ga-zn-o-coplanar-homojunction-thin-film-6voiezihtq.pdf

Ryo Hayashi

Papers

Field-effect transistor including transparent oxide and light-shielding member, and display utilizing the transistor

Field-effect transistor and method for manufacturing the same

42.1: Invited Paper: Improved Amorphous In‐Ga‐Zn‐O TFTs

Sputtering formation of p-type SnO thin-film transistors on glass toward oxide complimentary circuits

Amorphous In–Ga–Zn–O coplanar homojunction thin-film transistor