Novel method of producing ultrasmall platinum silicide gate electrodes

\u3cp\u3eA novel method has been developed for producing platinum silicide gate electrodes with submicron width. A lateral chemical reaction of platinum with polycrystalline silicon at a step edge was used. The width of the wire is determined by the thickness of a sputtered metal layer. Wires with width between 35 and 300 nm have been produced. The method has been used for making long-channel field-effect transistors with good device properties. Some preliminary results of the study of the low-temperature electrical transport properties of inversion layers with width of 0.12 μm are reported.\u3c/p\u3

Impact of donor traps on the 2DEG and electrical behavior of AlGaN/GaN MISFETs

As an important step in understanding trap-related mechanisms in AlGaN/GaN transistors, the physical properties of surface states have been analyzed through the study of the transfer characteristics of a MISFET. This letter focused initially on the relationship between donor parameters (concentration and energy level) and electron density in the channel in AlGaN/GaN heterostructures. This analysis was then correlated to dc and pulsed measurements of the transfer characteristics of a MISFET, where the gate bias was found to modulate either the channel density or the donor states. Traps-free and traps-frozen TCAD simulations were performed on an equivalent device to capture the donor behavior. A donor concentration of 1.14× 1013 ∼ cm-2 with an energy level located 0.2 eV below the conduction band edge gave the best fit to measurements. With the approach described here, we were able to analyze the region of the MISFET that corresponds to the drift region of a conventional HEMT. © 1980-2012 IEEE

Semiconductor device comprising a pn-heterojunction

An electric device is disclosed comprising a pn-heterojunction ( 4 ) formed by a nanowire ( 3 ) of 111 -V semiconductor material and a semiconductor body ( 1 ) comprising a group IV semiconductor material. The nanowire ( 3 ) is positioned in direct contact with the surface ( 2 ) of the semiconductor body ( 1 ) and has a first conductivity type, the semiconductor body ( 1 ) has a second conductivity type opposite to the first conductivity type, the nanowire ( 3 ) forming with the semiconductor body ( 1 ) a pn-heterojunction ( 4 ). The nanowire of III-V semiconductor material can be used as a diffusion source ( 5 ) of dopant atoms into the semiconductor body. The diffused group III atoms and/or the group V atoms from the III-V material are the dopant atoms forming a region ( 6 ) in the semiconductor body in direct contact with the nanowire ( 3 )

Observation of anomalous electrical transport properties in MoSi \u3csub\u3e2\u3c/sub\u3e films

\u3cp\u3eWe measured the temperature dependence of the electrical resistivity and of the Hall constant for MoSi\u3csub\u3e2\u3c/sub\u3e films between 3.5 and 350 K. A behavior quite unusual for a metal was observed. The most striking effect is the proportionality of the resistivity with T \u3csup\u3e2\u3c/sup\u3e for temperatures between 70 and 220 K. Further, we find the Hall constant, which is positive at room temperature, to change sign around 170 K. The bulk resistivity of the MoSi \u3csub\u3e2\u3c/sub\u3e at 295 K is deduced to be approximately 18 μΩ cm. We suggest that the observed anomalies and the high resistivity are due to strong s-d scattering.\u3c/p\u3

Semiconductor device and method of manufacturing the same

The invention relates to a semiconductor device (10) with a semiconductor body (12) comprising a bipolar transistor with an emitter region, a base region and a collector region (1, 2, 3) of, respectively, a first conductivity type, a second conductivity type opposite to the first conductivity type, and the first conductivity type. One of the emitter or collector regions (1, 3) comprises a nanowire (30). The base region (2) has been formed from a layer (20) at the surface of the semiconductor body (12); the other one (3, 1) of the emitter or collector regions (1, 3) has been formed in the semiconductor body (12) below the base region (2). The emitter or collector region (1, 3) comprising the nanowire (30) has been provided on the surface of the semiconductor body (12) such that its longitudinal axis extends perpendicularly to the surface

Correlative transmission electron microscopy and electrical properties study of switchable phase-change random access memory line cells

Phase-change memory line cells, where the active material has a thickness of 15 nm, were prepared for transmission electron microscopy (TEM) observation such that they still could be switched and characterized electrically after the preparation. The result of these observations in comparison with detailed electrical characterization showed (i) normal behavior for relatively long amorphous marks, resulting in a hyperbolic dependence between SET resistance and SET current, indicating a switching mechanism based on initially long and thin nanoscale crystalline filaments which thicken gradually, and (ii) anomalous behavior, which holds for relatively short amorphous marks, where initially directly a massive crystalline filament is formed that consumes most of the width of the amorphous mark only leaving minor residual amorphous regions at its edges. The present results demonstrate that even in (purposely) thick TEM samples, the TEM sample preparation hampers the probability to observe normal behavior and it can be debated whether it is possible to produce electrically switchable TEM specimen in which the memory cells behave the same as in their original bulk embedded state

Evidence of the thermo-electric Thomson effect and influence on the program conditions and cell optimization in phase-change memory cells

\u3cp\u3eWe present physical and electrical evidence of the Thomson thermo-electric effect in line-type phase-change memory cells. This causes a shift of the molten zone during RESET programming towards the anode contact, and as a consequence the phase change material (PCM) design at the contact area has a significant influence on the program conditions. First statistical studies showed a reduction of minimum Reset currents by ∼55% and Set voltages by ∼28% when PCM extensions around the anode are used instead of fine line contacts. This Thomson effect remains important with further cell scaling.\u3c/p\u3