Contact resistance

About: Contact resistance is a research topic. Over the lifetime, 15262 publications have been published within this topic receiving 232144 citations. The topic is also known as: electrical contact resistance & ECR.

Metal–semiconductor contact in organic thin film transistors

Abstract: Optimization of the interface between the source/drain electrode and the organic semiconductor is one of the important factors for organic thin film transistor (OTFT) performance along with the insulator–semiconductor interface. In this Feature Article, items needed for the optimization of the metal–semiconductor interface and methods to measure interface properties are reviewed. Various electrode materials are compared in terms of the work function, contact resistance and the pentacene OTFT performance. The effect of surface modification is also discussed. Experimental data obtained in LAMP is introduced to show the effect of the various material properties more clearly.

Spatially Resolved Transport Properties of Pristine and Doped Single-Walled Carbon Nanotube Networks

Abstract: We use noninvasive atomic force microscopy to probe the spatial electrical conductivity of isolated junctions of pristine and nitric acid treated single-walled carbon nanotube networks (SWCNT-N). By analyzing the local IV curves of SWCNTs and bundles with various diameters, the resistance per unit length and the contact resistance of their junctions are estimated to be 3–16 kΩ/μm and 29–532 kΩ, respectively. We find that the contact resistance decreases with increasing SWCNT or bundle diameter and depends on the contact morphology, reaching a value of 29 kΩ at a diameter of 10 nm. A nitric acid treatment moderately dopes SWCNTs and reduces their average contact resistance by a factor of 3 while the resistance of the nanotubes remains largely unaltered. Remarkably, the same treatment on an SWCNT-N shows similar reduction in the sheet resistance by a factor of 4. These results suggest that the resistance reduction mechanism is related to the contact modulation with no major impact on conductance of SWCNTs.

Photovoltaic contact and wiring formation

Abstract: A method and apparatus for fabricating a solar cell and forming metal contact is disclosed. Solar cell contact and wiring is formed by depositing a thin film stack of a first metal material and a second metal material as an initiation layer or seed layer for depositing a bulk metal layer in conjunction with additional sheet processing, photolithography, etching, cleaning, and annealing processes. In one embodiment, the thin film stack for forming metal silicide with reduced contact resistance over the sheet is deposited by sputtering or physical vapor deposition. In another embodiment, the bulk metal layer for forming metal lines and wiring is deposited by sputtering or physical vapor deposition. In an alternative embodiment, electroplating or electroless deposition is used to deposit the bulk metal layer.

A high-power AlGaN/GaN heterojunction field-effect transistor

Abstract: We fabricated an AlGaN/GaN heterojunction field effect transistor (HFET) with a very low on-state resistance. An undoped Al0.2Ga0.8N(30 nm)/GaN(2 μm) heterostructure was grown on a sapphire substrate using gas-source molecular-beam epitaxy. The undoped GaN layer had a high resistivity (above 10 M Ω ) and the breakdown field of the undoped layer was about 2 MV/cm. Si-doped GaN with a carrier concentration of 5×1019 cm−3 was selectively grown in the source and drain regions for obtaining a very low contact resistance. As a result, a very low ohmic below 1×10−7 Ω cm2 was obtained. After that, an Al0.2Ga0.8N/GaN HFET was fabricated. The gate width was 20 cm and the gate length was 2 μm. The ohmic electrode materials were Al/Ti/Au and the Schottky electrodes were Pt/Au. The distance between the source and the drain was 13 μm. The HFET was operated at a current of over 20 A. A higher switching speed of HFET was obtained.

Experimental evidence of direct contact formation for the current transport in silver thick film metallized silicon emitters

Abstract: Great advances have been achieved in the development of silver pastes. The use of smaller silver particles, higher silver content, and, thus, less glass frit allow modern silver pastes to contact high resistive emitters without the necessity of a selective emitter or subsequent plating. To identify the microscopic key reasons behind the improvement of silver paste, it is essential to understand the current transport mechanism from the silicon emitter into the bulk of the silver finger. Two current transport theories predominate: i) The current flows through the Ag crystallites grown into the Si emitter, which are separated by a thin glass layer or possibly in direct contact with the silver finger. ii) The current is transported by means of multistep tunneling into the silver finger across nano-Ag colloids in the glass layer, which are formed at optimal firing conditions; the formation of Ag crystallites into the Si surface is synonymous with over-firing. In this study, we contact Si solar cell emitters wi...