Field effect

About: Field effect is a research topic. Over the lifetime, 4018 publications have been published within this topic receiving 92613 citations.

Lateral resonant tunneling transistors employing field-induced quantum wells and barriers

Abstract: The authors describe some preliminary experimental results of quantum-effect modulation-doped field-effect transistors (MODFETs) with a variety of nanometer gate geometries. The gate geometries were such that various quantum wells and barriers were formed in the channel of the MODFETs through the field effect imposed by the novel gate structures, and the transport of the electrons was affected by resonant tunneling. The devices were fabricated using a combination of molecular beam epitaxy and electron beam lithography. Electrical measurements of the devices at 4.2 K showed resonant tunneling effects and, in particular, showed that resonant tunneling is more pronounced for a system of quantum wells confined in three dimensions than in two. For these quantum effects to be appreciable at practical temperatures, about 77 K, the feature size of the gate geometries should be smaller than 50 nm. >

Semiconductor device and method for fabricating the same

Abstract: A semiconductor device having such a structure as a light emitting layer of an organic matter or the like is sandwiched between a work function control single layer carbon nanotube cathode including donor of low ionization potential and a work function control single layer carbon nanotube anode including accepter of large electron affinity. A semiconductor device represented by an organic field effect light emitting element which can reduce emission start voltage, enhance characteristics/function such as emission efficiency, enhance reliability such as the lifetime, and enhance productivity such as reduction in fabrication cost is provided along with its fabrication process.

Increasing the selectivity of Pt-gate SiC field effect gas sensors by dynamic temperature modulation

Abstract: Based on a diode coupled silicon carbide field effect transistor with platinum as catalytic gate material, the influence of dynamic temperature modulation on the selectivity of GasFETs has been investigated. This operating mode, studied intensively for semiconductor gas sensors, is applied for the first time with gas sensors based on the field effect. A suitable T-cycle for detection of typical exhaust gases (CO, NO, C 3 H 6 , H 2 , NH 3 ) was developed and combined with appropriate signal processing based on multivariate statistics, e.g. linear discriminant analysis (LDA). Measurements have proven that several gases can be discriminated based on T-cycle data. Furthermore, quantitative determination of gases is also possible. In addition to varying the measurement conditions (e.g. background oxygen) experiments regarding stability and reproducibility were also carried out. Based on these preliminary studies the performance of field effect gas sensors can be enhanced considerably by T-cycling.

Semiconductor device combining a MOSFET structure and a vertical-channel trench-substrate field effect device

Abstract: A semiconductor device that provides for substrate current exiting a MOSFET structure, and hence the performance thereof, to be independently and controllably tuned. The semiconductor device includes a semiconductor substrate of a first conductivity type, a conventional MOSFET structure disposed thereon, and at least one vertical-channel trench-substrate field effect device disposed in the semiconductor substrate. The vertical-channel trench-substrate field effect device includes a vertical-channel region beneath the MOSFET structure. During operation, substrate current exiting the MOSFET structure can be independently and controllably tuned by applying a potential bias to the vertical-channel trench-substrate field effect device that “pinches-off” the vertical-channel region. The vertical-channel trench-substrate field effect device includes an expanded trench that extends from an upper surface of the semiconductor substrate to beneath the MOSFET structure and a dielectric shallow trench spacer (e.g., silicon dioxide or silicon nitride dielectric shallow trench spacer) that is disposed along an upper portion of the sidewall of the expanded trench. The vertical-channel trench-substrate field effect device also includes a SiO2 trench liner layer disposed on those portions of the sidewall of the expanded trench that are not covered by the dielectric shallow trench spacer, and an electrically conductive trench fill layer (e.g., in-situ doped polysilicon) in the expanded trench. The vertical-channel region can be “pinched-off,” and the substrate current exiting the MOSFET structure independently and controllably tuned, by applying a potential bias to the electrically conductive trench fill layer. Also, a process for manufacturing the semiconductor device that is compatible with conventional IC manufacturing techniques.