Index of content:
Volume 89, Issue 6, 15 March 2001
- DEVICE PHYSICS (PACS 85)
89(2001); http://dx.doi.org/10.1063/1.1347405View Description Hide Description
High-k cobalt–titanium oxide and nickel–titanium oxide were formed by directly oxidizing sputtered Co/Ti and Ni/Ti film. and capacitor structures were fabricated and measured. The effective dielectric constant with buffer layer for is larger than that of In addition, depicts excellent electrical properties at the same time. This metal oxide thus appears to be a very promising high-k gate dielectric for future ultralarge scale integrated devices.
89(2001); http://dx.doi.org/10.1063/1.1344584View Description Hide Description
We analyze the potential performance of quantum point contact (QPC) devices in charge detection applications. For the standard QPC structure we show that the charge sensitivity is strongly dependent on gate geometry and can be close to the quantum limit, and that the gain parameter is less than one under bias conditions where the charge sensitivity is optimized. We propose a novel QPC device consisting of two split gates for defining the QPC and a third gate which can be used to filter out hot electrons that are emitted from the QPC. We show that this proposed device can have a high gain and a charge sensitivity close to that of single electron transistors. The device can be realized using high quality GaAs/AlGaAs with a two-dimensional electron gas and standard nanofabrication techniques. Unlike single electron transistors, the gain of the proposed device does not depend on the charge configuration near the active region of the device. Therefore the device can be used as an electrometer without a feedback charged locked loop and multiple devices can easily be integrated.
A model for the segregation and pileup of boron at the interface during the formation of ultrashallow junctions89(2001); http://dx.doi.org/10.1063/1.1338990View Description Hide Description
We have quantitatively investigated how boron segregates to regions close to the surface, and what controls this phenomenon, using x-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy and backside secondary ion mass spectrometrymeasurement techniques. We found that, contrary to the equilibrium segregation, the pileup of boron is mainly on and within 0.6 nm of the Si side of the interface, and that there is no difference between the kind of encapsulation. This also suggests that the pileup of boron is mainly on the Si side, and implies that the main factor in this segregation is the existence of the Si surface. From the viewpoint of device fabrication, this result seems to be useful in terms of the fabrication of sidewalls. The possibility of boron pileup to occurring in the interstitial state was also shown. Our results suggested a way of looking at dopant profiles by predictive computer modeling.
89(2001); http://dx.doi.org/10.1063/1.1343888View Description Hide Description
The current–voltage characteristics of an InGaP/GaAs/InGaP double heterojunctionbipolar transistor (DHBT) are modeled where the tunneling effect at the base–collector (B–C) junction and base–emitter (B–E) junction is taken into account. Therefore, this model can be applied to both conventional DHBT and composite collector heterojunctionbipolar transistor. The role of the layer and layer are discussed and the effects of variation in the doping level and thickness of these layers are considered in the model. Good agreement between our predictions of the model and reported experimental results is achieved.