This paper reports that the organic field-effect transistors with hybrid contact geometry were fabricated, in which the top electrodes and the bottom electrodes were combined in parallel resistances within one transistor. With the facility of the novel structure, the difference of contact resistance between the top contact geometry and the bottom contact geometry was studied. The hybrid contact devices showed similar characteristics with the top contact configuration devices, which provide helpful evidence on the lower contact resistance of the top contact configuration device. The origin of the different contact resistance between the top contact device and the bottom contact device was discussed.
In this paper, improvements of resistive random access memory (RRAM) using doping technology are summarized and analyzed. Based on a Cu/ZrO2/Pt device, three doping technologies with Ti ions, Cu, and Cu nanocrystal, respectively, are adopted in the experiments. Compared to an undoped device, improvements focus on four points: eliminating the electroforming process, reducing operation voltage, improving electrical uniformity, and increasing device yield. In addition, thermal stability of the high resistance state and better retention are also achieved by the doping technology. We demonstrate that doping technology is an effective way of improving the electrical performance of RRAM.
WANG YanLIU OiLU HangBingLONG ShiBingWANG WeiLI YingTaoZHANG SenLIAN WenTaiYANG JianHongLIU Ming
Resistive random access memory (RRAM) has received significant research interest because of its promising potential in terms of down-scaling,high density,high speed and low power. However,its endurance,retention and uniformity are still imperfect. In this article,the physical mechanisms of filament-type RRAM and the approaches for improving the switching performance,including doping,process optimization and interface engineering,are introduced.
LIAN WenTaiLONG ShiBingLU HangBingLIU QiLI YingTaoZHANG SenWANG YanHUO ZongLiangDAI YueHuaCHEN JunNingLIU Ming
This paper proposes an effective method of fabricating top contact organic field effect transistors by using a pho- tolithographic process. The semiconductor layer is protected by a passivation layer. Through photolithographic and etching processes, parts of the passivation layer are etched off to form source/drain electrode patterns. Combined with conventional evaporation and lift-off techniques, organic field effect transistors with a top contact are fabricated suc- cessfully, whose properties are comparable to those prepared with the shadow mask method and one order of magnitude higher than the bottom contact devices fabricated by using a photolithographic process.
A novel diffractive optical element, named phase zone photon sieve （PZPS）, is presented. There are three kinds of phase plates in PZPSs： PZPS1, PZPS2, and PZPS3. Each of the PZPSs has its own structure and is made on quartz substrate by etching. The three PZPSs have stronger diffraction peak intensity than a photon sieve （PS） when the margin pinhole and zone line width are kept the same. The PZPS3 can produce a smaller central diffractive spot than the ordinary PS with the same number of zones on the Fresnel zone plate. We have given the design method for and the simulation of PZPS and PS. PZPS has potential applications in optical maskless lithography.
Among the many possible device configurations for organic memory devices,organic field-effect transistor (OFET) memory is an emerging technology with the potential to realize lightweight,low-cost,flexible charge storage media.In this feature article,the recent progress in the classes of OFET-based memory,including floating gate OFET memory,polymer electret OFET memory,ferroelectric OFET memory and several other kinds of OFET memories with unique configurations,are introduced.Finally,the prospects and problems of OFETs memory are discussed.
WANG HongPENG YingQuanJI ZhuoYuLIU MingSHANG LiWeiLIU XingHua
