Abstract: A silicon carbide semiconductor device having a JFET or a MOSFET includes a semiconductor substrate and a trench. The semiconductor substrate has a silicon carbide substrate, a drift layer on the silicon carbide substrate, a first gate region on the drift layer, and a source region on the first gate region. The trench has a strip shape with a longitudinal direction and reaches the drift layer by penetrating the source region and the first gate region. The trench is filled with a channel layer and a second gate region on the channel layer. The source region is not located at an end portion of the trench in the longitudinal direction.

Abstract: A semiconductor device with reduced defect density is fabricated by forming localized metal silicides instead of full area silicidation. Embodiments include forming a transistor having a gate electrode and source/drain regions on a substrate, forming a masking layer with openings exposing portions of both the gate electrode and source/drain regions over the substrate, depositing metal in the openings on the exposed portions, forming silicides in the openings, and removing unreacted metal and the masking layer.

Abstract: A semiconductor structure and method for manufacturing the same are provided. The semiconductor structure includes a substrate having a first conductive type; a deep well having a second conductive type formed in the substrate and extending down from a surface of the substrate; a first well having the first conductive type formed in the deep well and extending down from the surface of the substrate; and a second well having the second conductive type formed in the deep well and extending down from the surface of the substrate, and the second well adjacent to the first well. The first well includes a block region and plural finger regions joined to one side of the block region, while the second well includes plural channel regions interlaced with the finger regions to separate the finger regions.

Abstract: A method for fabricating a semiconductor device includes: forming a first film on a nitride semiconductor layer so as to contact the nitride semiconductor layer and have a thickness equal to or larger than 1 nm and equal to or smaller than 5 nm, the first film being made of silicon nitride having a composition ratio of silicon to nitrogen larger than 0.75, silicon oxide having a composition ratio of silicon to oxygen larger than 0.5, or aluminum; and forming a source electrode, a gate electrode and a drain electrode on the nitride semiconductor layer.

Abstract: According to one embodiment, a junction type field effect transistor includes a first conductive type semiconductor substrate, a first conductive type drift layer, a second conductive type gate region, a first conductive type channel layer, a first conductive type source region, a source electrode, a drain electrode, a second conductive type gate contact layer, and a gate electrode. The drift layer is provided on a first main surface of the semiconductor substrate. The gate region is provided on a surface of the drift layer. The channel layer is provided on the drift layer and the gate region. The source region is provided on a surface of the channel layer to face the gate region, and has an impurity concentration higher than the channel layer. The source electrode is provided on the channel layer with Schottky contact and on the source region with ohmic contact.

Abstract: In general, in a semiconductor active element such as a normally-off JFET based on SiC in which an impurity diffusion speed is significantly lower than in silicon, gate regions are formed through ion implantation into the side walls of trenches formed in source regions. However, to ensure the performance of the JFET, it is necessary to control the area between the gate regions thereof with high precision. Besides, there is such a problem that, since a heavily doped PN junction is formed by forming the gate regions in the source regions, an increase in junction current cannot be avoided. The present invention provides a normally-off power JFET and a manufacturing method thereof and forms the gate regions according to a multi-epitaxial method which repeats a process including epitaxial growth, ion implantation, and activation annealing a plurality of times.

Abstract: A semiconductor device with a JFET is disclosed. The semiconductor device includes a trench and a contact embedded layer formed in the trench. A gate wire is connected to the contact embedded layer, so that the gate wire is connected to an embedded gate layer via the contact embedded layer. In this configuration, it is possible to downsize a contact structure between the embedded gate layer and the gate wire.

Abstract: An electrostatic discharge (ESD) protection circuit is disclosed. The circuit includes a first terminal (200), a first power supply terminal (Vdd), and a second power supply terminal (Vss). The circuit further includes a junction field effect transistor (JFET) having a current path coupled between the first terminal and the second power supply terminal. The JFET has a control terminal (202) coupled to the first power supply terminal.

Abstract: An integrated circuit containing a field controlled diode which includes a p-type channel region between an upper gate and a lower n-type depletion gate, a p-type anode in a p-type anode well abutting the channel region, and an n-type cathode in a p-type anode well abutting the channel region opposite from the anode well. An n-type lower gate link connects the lower gate to the surface of the substrate. A surface control element is located at the surface of the channel region between the cathode and the upper gate. A process of forming the integrated circuit containing the field controlled diode is described.

Abstract: An embodiment is a method for forming a static random access memory (SRAM) cell. The method comprises forming transistors on a semiconductor substrate and forming a first linear intra-cell connection and a second linear intra-cell connection. Longitudinal axes of the active areas of the transistors are parallel. A first pull-down transistor and a first pull-up transistor share a first common gate structure, and a second pull-down transistor and a second pull-up transistor share a second common gate structure. The first linear intra-cell connection electrically couples active areas of the first pull-down transistor and the first pull-up transistor to the second common gate structure. The second linear intra-cell connection electrically couples active areas of the second pull-down transistor and the second pull-up transistor to the first common gate structure.

Abstract: A semiconductor structure is fabricated with reduced gate capacitance by thinning of a gate electrode to provide a reduced thickness gate electrode. The gate electrode is thinned after forming a spacer layer adjoining the gate electrode. In addition, the height of the spacer layer may also be reduced. The spacer layer thus has an enhanced horizontal width desired for locating an intrinsic source/drain with respect to an extension region and in particular, an enhanced horizontal width relative to the spacer height. The reduced thickness gate electrode may be fully silicided to provide decreased gate resistance. A raised source/drain layer may be located upon the intrinsic source/drain region. The raised source/drain layer may have a top surface higher than the reduced thickness gate electrode. In addition, the raised source/drain layer may have a top surface higher than the reduced height spacer layer.

Abstract: In accordance with the present techniques, there is provided a JFET device structures and methods for fabricating the same. Specifically, there is provided a transistor including a semiconductor substrate having a source and a drain. The transistor also includes a doped channel formed in the semiconductor substrate between the source and the drain, the channel configured to pass current between the source and the drain. Additionally, the transistor has a gate comprising a semiconductor material formed over the channel and dielectric spacers on each side of the gate. The source and the drain are spatially separated from the gate so that the gate is not over the drain and source.

Abstract: The disclosure relates to a complementary junction field effect transistor (c-JFET) and its gate-last fabrication method. The method of fabricating a semiconductor device includes: forming a dummy gate on a first conductivity type wafer, forming sidewall spacers on opposite sides of the dummy gate, forming a source and a drain regions on the opposite sides of the dummy gate, removing the dummy gate, forming a first semiconductor region of a second conductivity type in an opening exposed through the removing the dummy gate, and forming a gate electrode in the opening.

Abstract: First, third, and fourth regions have a first conductivity type, and a second region has a second conductivity type. The second region is provided with a plurality of through holes exposing the first region. The third region includes a contact portion, a connecting portion, and a filling portion. The contact portion is in contact with a first portion of the second region. The connecting portion extends from the contact portion to each of the plurality of through holes in the second region. The filling portion fills each of the plurality of through holes in the second region. The fourth region, is provided on the first portion of the second region.

Abstract: A method of fabricating a semiconductor device that includes forming a replacement gate structure on a portion of a semiconductor substrate, wherein source regions and drain regions are formed in opposing sides of the replacement gate structure. A dielectric is formed on the semiconductor substrate having an upper surface that is coplanar with an upper surface of the replacement gate structure. The replacement gate structure is removed to provide an opening to an exposed portion of the semiconductor substrate. A functional gate conductor is epitaxially grown within the opening in direct contact with the exposed portion of the semiconductor substrate. The method is applicable to planar metal oxide semiconductor field effect transistors (MOSFETs) and fin field effect transistors (finFETs).

Abstract: A semiconductor device and a method for fabricating the same are described. The semiconductor device includes a well of a first conductive type, first doped regions of a second conductive type, gates of the second conductive type, second doped regions of the first conductive type, and isolation structures. The well is disposed in a substrate. The first doped regions are disposed in the well. The first doped regions are arranged in parallel and extend along a first direction. The gates are disposed on the substrate. The gates are arranged in parallel and extend along a second direction different from the first direction. One of the first doped regions is electrically connected to one of the gates. Each of the second doped regions is disposed in the first doped regions between two adjacent gates. Each of the isolation structures is disposed in the substrate between two adjacent first doped regions.

Abstract: A semiconductor device includes a substrate, a compound semiconductor layer formed over the substrate, and a protective insulating film composed of silicon nitride, which is formed over a surface of the compound semiconductor layer and whose film density in an intermediate portion is lower than that in a lower portion.

Abstract: The present invention discloses a power device with integrated power transistor and Schottky diode and a method for making the same. The power device comprises a power transistor having a drain region, a Schottky diode in the drain region of the power transistor, and a trench-barrier near the Schottky diode. The trench-barrier is provided to reduce a reverse leakage current of the Schottky diode and minimizes the possibility of introducing undesired parasitic bipolar junction transistor in the power device.

Abstract: A semiconductor device includes: a rectifying element; an electrode pad electrically connected to the rectifying element; and a resistance and a depletion transistor arranged between the rectifying element and the electrode pad, and electrically connected to each other. The semiconductor device has a configuration in which the rectifying element, the resistance, the depletion transistor, and the electrode pad are serially connected. The semiconductor device is configured to generate a gate potential of the depletion transistor based on a difference in potential across the resistance and to produce a depletion layer in a channel of the depletion transistor based on the gate potential. As a result, a semiconductor device having reasonably large current at low voltage and small current at high voltage can be obtained.

Abstract: A semiconductor device with reduced defect density is fabricated by forming localized metal silicides instead of full area silicidation. Embodiments include forming a transistor having a gate electrode and source/drain regions on a substrate, forming a masking layer with openings exposing portions of both the gate electrode and source/drain regions over the substrate, depositing metal in the openings on the exposed portions, forming silicides in the openings, and removing unreacted metal and the masking layer.

Abstract: A double-gate semiconductor device includes a MOS gate and a junction gate, in which the bias of the junction gate is a function of the gate voltage of the MOS gate. The breakdown voltage of the double-gate semiconductor device is the sum of the breakdown voltages of the MOS gate and the junction gate. The double-gate semiconductor device provides improved RF capability in addition to operability at higher power levels as compared to conventional transistor devices. The double-gate semiconductor device may also be fabricated in a higher spatial density configuration such that a common implantation between the MOS gate and the junction gate is eliminated.

Abstract: A drift layer has a thickness direction throughout which a current flows and has an impurity concentration N1d for a first conductivity type. A body region is provided on a portion of the drift layer, has a channel to be switched by a gate electrode, has an impurity concentration N1b for the first conductivity type, and has an impurity concentration N2b for the second conductivity type greater than the impurity concentration N1b. A JFET region is disposed adjacent to the body region on the drift layer, has an impurity concentration N1j for the first conductivity type, and has an impurity concentration N2j for the second conductivity type smaller than the impurity concentration N1j. N1j?N2j>N1d and N2j<N2b are satisfied.

Abstract: The present disclosure provides a method of fabricating a semiconductor device. The method includes forming a buffer layer over a substrate, the buffer layer containing a first compound semiconductor that includes elements from one of: III-V families of a periodic table; and II-VI families of the periodic table. The method includes forming a channel layer over the buffer layer. The channel layer contains a second compound semiconductor that includes elements from the III-V families of the periodic table. The method includes forming a gate over the channel layer. The method includes depositing impurities on regions of the channel layer on either side of the gate. The method includes performing an annealing process to activate the impurities in the channel layer.

Abstract: A method of fabricating a semiconductor device that includes forming a replacement gate structure on a portion of a semiconductor substrate, wherein source regions and drain regions are formed in opposing sides of the replacement gate structure. A dielectric is formed on the semiconductor substrate having an upper surface that is coplanar with an upper surface of the replacement gate structure. The replacement gate structure is removed to provide an opening to an exposed portion of the semiconductor substrate. A functional gate conductor is epitaxially grown within the opening in direct contact with the exposed portion of the semiconductor substrate. The method is applicable to planar metal oxide semiconductor field effect transistors (MOSFETs) and fin field effect transistors (finFETs).

Abstract: A chip bump structure is formed on a substrate. The substrate includes at least one contact pad and a dielectric layer. The dielectric layer has at least one opening. The at least one opening exposes the at least one contact pad. The chip bump structure includes at least one elastic bump, at least one first metal layer, at least one second metal layer, and at least one solder ball. The at least one elastic bump covers a central portion of the at least one contact pad. The at least one first metal layer covers the at least one elastic bump. The at least one first metal layer has a portion of the at least one contact pad. The portion of the at least one contact pad is not overlaid by the at least one elastic bump. The at least one second metal layer is formed on a portion of the at least one first metal layer. The portion of the at least one first metal layer is located on the top of the at least one elastic bump. The at least one solder ball is formed on the at least one second metal layer.

Abstract: A MOSFET driver compatible JFET device is disclosed. The JFET device can include a gate contact, a drain contact, and a source contact. The JFET device can further include a first gate region of semiconductor material adjacent the gate contact and a second region of semiconductor material adjacent the first gate region. The first gate region and the second gate region can form a first p-n junction between the first gate region and the second gate region. The JFET device can further include a channel region of semiconductor material adjacent the source contact. The channel region and the second gate region can form a second p-n junction between the second gate region and the channel region.

Abstract: A high voltage JFET has a deep well of a first type of conductivity made in a semiconductor substrate, a further well of an opposite second type of conductivity arranged in the deep well, a shallow well of a first type of conductivity arranged in the further well, a first contact region for source and a second contact region for drain arranged in the further well, a third contact region for gate arranged between the first contact region and the second contact region in the shallow well, a first distance between the first contact region and the third contact region being smaller than a second distance between the second contact region and the third contact region, and an electrical connection between the first contact region and the second contact region via at least one channel region present between the deep well and the shallow well in the further well.

Abstract: A junction field effect transistor includes a lower P-type substrate layer of a semiconductor substrate; an N-type channel layer which may be formed on and/or over the P-type substrate layer within an active area; an upper P-type diffusion layer which may be formed on and/or over the N-type channel layer at a prescribed depth over the entire active area; an additional P-type diffusion layer which may be formed in a ripple pattern in the upper P-type diffusion layer; a gate electrode which may be formed on and/or over the upper P-type diffusion layer; and a source electrode and a drain electrode which may be formed on and/or over both sides of the upper P-type diffusion layer within the active area on the semiconductor substrate. The additional P-type diffusion layer in the ripple pattern may be formed of a plurality of P-type diffusion layers which are formed to be separated from each other in the upper P-type diffusion layer.

Abstract: A junction field effect transistor having a drain and a source, each defined by regions of a first type of semiconductor interconnected by a channel, and in which a dopant profile at a side of the drain facing the channel is modified so as to provide a region of reduced doping compared to a body region of the drain. The region of reduced doping and the body region can be defined by the same mask and doping step, but the mask is shaped to provide a lesser amount and thus less depth of doping for the region of reduced doping.

Abstract: Fabricating high voltage transistors includes forming a buried p-type implant on a p-substrate for each transistor, the transistor having a source side and a drain side, wherein the p-type implant is positioned adjacent the source and is configured to extend under a gate region; depositing a low doping epitaxial layer on the p-substrate and the p-type implant for each high voltage transistor, the low doping epitaxial layer extending from the source to the drain; forming an N-Well in the low doping epitaxial layer for each transistor, wherein the N-Well corresponds to a low voltage transistor N-Well fabricated using a low voltage transistor fabrication process; and forming a p-top diffusion region in or on the N-Well for each transistor, wherein the p-top diffusion region is configured to compensate for a dopant concentration of the N-Well at or near a surface of the N-Well opposing the substrate.

Abstract: According to one embodiment, a self-aligned trench structure junction gate field-effect transistor (JFET) includes a silicon substrate, two or more trenches having a P-type polysilicon gate region near a bottom portion of the trench and an interlayer dielectric layer (ILDL) above the P-type polysilicon gate region, a channel region separating each trench including epitaxial silicon, an N+ source region above the channel region extending between a top of each trench, and a source metal above the N+ source region. In another embodiment, a self-aligned trench structure JFET includes a silicon substrate, two or more trenches having an N-type polysilicon gate region near a bottom portion of the trench and an ILDL above the N-type polysilicon gate region, a channel region separating each trench including epitaxial silicon, a P+ source region above the channel region extending between a top of each trench, and a source metal above the P+ source region.

Abstract: Semiconductor devices and methods of making the devices are described. The devices can be junction field-effect transistors (JFETs) or diodes such as junction barrier Schottky (JBS) diodes or PiN diodes. The devices have graded p-type semiconductor layers and/or regions formed by epitaxial growth. The methods do not require ion implantation. The devices can be made from a wide-bandgap semiconductor material such as silicon carbide (SiC) and can be used in high temperature and high power applications.

Abstract: A semiconductor device includes a substrate, a compound semiconductor layer formed over the substrate, and a protective insulating film composed of silicon nitride, which is formed over a surface of the compound semiconductor layer and whose film density in an intermediate portion is lower than that in a lower portion.

Abstract: A semiconductor device with a JFET is disclosed. The semiconductor device includes a trench and a contact embedded layer formed in the trench. A gate wire is connected to the contact embedded layer, so that the gate wire is connected to an embedded gate layer via the contact embedded layer. In this configuration, it is possible to downsize a contact structure between the embedded gate layer and the gate wire.

Abstract: A semiconductor die with integrated MOSFET and diode-connected enhancement mode JFET is disclosed. The MOSFET-JFET die includes common semiconductor substrate region (CSSR) of type-1 conductivity. A MOSFET device and a diode-connected enhancement mode JFET (DCE-JFET) device are located upon CSSR. The DCE-JFET device has the CSSR as its DCE-JFET drain. At least two DCE-JFET gate regions of type-2 conductivity located upon the DCE-JFET drain and laterally separated from each other with a DCE-JFET gate spacing. At least a DCE-JFET source of type-1 conductivity located upon the CSSR and between the DCE-JFET gates. A top DCE-JFET electrode, located atop and in contact with the DCE-JFET gate regions and DCE-JFET source regions. When properly configured, the DCE-JFET simultaneously exhibits a forward voltage Vf substantially lower than that of a PN junction diode while the reverse leakage current can be made comparable to that of a PN junction diode.

Abstract: A semiconductor device having a CMOS structure, wherein, in manufacturing a CMOS circuit, an impurity element which imparts p-type conductivity to the active layer of the p-channel type semiconductor device is added before forming the gate insulating film. Then, by applying thermal oxidation treatment to the active layer, the impurity element is subjected to redistribution, and the concentration of the impurity element in the principal surface of the active layer is minimized. The precise control of threshold voltage is enabled by the impurity element that is present in a trace quantity.

Abstract: Devices and methods for providing JFET transistors with improved operating characteristics are provided. Specifically, one or more embodiments of the present invention relate to JFET transistors with a higher diode turn-on voltage. For example, one or more embodiments include a JFET with a doped silicon-carbide gate, while other embodiments include a JFET with a metal gate. One or more embodiments also relate to systems and devices in which the improved JFET may be employed, as well as methods of manufacturing the improved JFET.

Abstract: A method for fabricating a semiconductor device includes forming ohmic electrodes on a source region and a drain region of a nitride semiconductor layer, forming a low-resistance layer between an uppermost surface of the nitride semiconductor layer and the ohmic electrodes by annealing the nitride semiconductor layer, removing the ohmic electrodes from at least one of the source region and the drain region after forming the low-resistance layer, and forming at least one of a source electrode and a drain electrode on the low-resistance layer, the at least one of a source electrode and a drain electrode having an edge, a distance between the edge and a gate electrode is longer than a distance between an edge of the low-resistance layer and the gate electrode.

Abstract: A cascoded junction field transistor (JFET) device comprises a first stage high voltage JFET cascoded to a second stage low voltage JFET wherein one of the first and second stages JFET is connected to a drain electrode of another JFET stage.

Abstract: This invention discloses an improved semiconductor power device includes a plurality of power transistor cells wherein each cell further includes a planar gate padded by a gate oxide layer disposed on top of a drift layer constituting an upper layer of a semiconductor substrate wherein the planar gate further constituting a split gate including a gap opened in a gate layer whereby the a total surface area of the gate is reduced. The transistor cell further includes a JFET (junction field effect transistor) diffusion region disposed in the drift layer below the gap of the gate layer wherein the JFET diffusion region having a higher dopant concentration than the drift region for reducing a channel resistance of the semiconductor power device.

Abstract: An embodiment is a method for forming a static random access memory (SRAM) cell. The method comprises forming transistors on a semiconductor substrate and forming a first linear intra-cell connection and a second linear intra-cell connection. Longitudinal axes of the active areas of the transistors are parallel. A first pull-down transistor and a first pull-up transistor share a first common gate structure, and a second pull-down transistor and a second pull-up transistor share a second common gate structure. The first linear intra-cell connection electrically couples active areas of the first pull-down transistor and the first pull-up transistor to the second common gate structure. The second linear intra-cell connection electrically couples active areas of the second pull-down transistor and the second pull-up transistor to the first common gate structure.

Abstract: A method for reducing low frequency noise of a transistor operable at cryogenic temperatures includes a first step in which the transistor is illuminated with a light in a state that the transistor is activated and flowed current by supplying a power at a predetermined temperature, and a second step in which the transistor is operated at the predetermined temperature after the illumination of the light.

Abstract: A system and method for ion implantation during semiconductor fabrication. An integrated circuit may be designed with proximately located one-directional transistor gates. A two-way halo ion implantation is performed perpendicularly to the transistor gates in order to embed the dopant into the silicon body on the surface of the semiconductor wafer. The two-way halo both reduces the channeling effect by allowing ion implantation beneath the transistor gate, and reduces the halo shadowing effect resulting from halo implanting which is done parallel to the transistor gates.

Abstract: A semiconductor device includes an active region defined in a semiconductor substrate, and gate electrodes crossing over the active region. Source/drain regions are defined in the active region on two sides of the gate electrode. At least one of the source/drain regions is a field effect source/drain region generated by a fringe field of the gate. The other source/drain region is a PN-junction source/drain region having different impurity fields and different conductivity than the substrate. At least one of the source/drain regions is a field effect source/drain region. Accordingly, a short channel effect is reduced or eliminated in the device.

Abstract: The present invention has an object to provide an FET and a method of manufacturing the FET that are capable of increasing the threshold voltage as well as decreasing the on-resistance. The FET of the present invention includes a first undoped GaN layer; a first undoped AlGaN layer formed on the first undoped GaN layer, having a band gap energy greater than that of the first undoped GaN layer; a second undoped GaN layer formed on the first undoped AlGaN layer; a second undoped AlGaN layer formed on the second undoped GaN layer, having a band gap energy greater than that of the second undoped GaN layer; a p-type GaN layer formed in the recess of the second undoped AlGaN layer; a gate electrode formed on the p-type GaN layer; and a source electrode and a drain electrode which are formed in both lateral regions of the gate electrode, wherein a channel is formed at the heterojunction interface between the first undoped GaN layer and the first undoped AlGaN layer.

Abstract: A method is disclosed that provides a self-aligned nitrogen-implant particularly suited for a Junction Field Effect Transistor (JFET) semiconductor device preferably comprised of a silicon carbide (SiC). This self-aligned nitrogen-implant allows for the realization of durable and stable electrical functionality of high temperature transistors such as JFETs. The method implements the self-aligned nitrogen-implant having predetermined dimensions, at a particular step in the fabrication process, so that the SiC junction field effect transistors are capable of being electrically operating continuously at 500° C. for over 10,000 hours in an air ambient with less than a 10% change in operational transistor parameters.

Abstract: A semiconductor device includes a substrate, a compound semiconductor layer formed over the substrate, and a protective insulating film composed of silicon nitride, which is formed over a surface of the compound semiconductor layer and whose film density in an intermediate portion is lower than that in a lower portion.

Abstract: The invention provides a transistor having a leak current between a source and drain in a nitride compound semiconductor formed on a substrate that is reduced. A gate electrode, a source electrode and a drain electrode are formed respectively on the surface of the nitride compound semiconductor formed on the silicon substrate in the transistor. At least one of the source electrode and the drain electrode is surrounded by an auxiliary electrode connected with the gate electrode. Because a depletion layer is formed in the nitride compound semiconductor under the auxiliary electrode, a route of the leak current is shut off and the leak current between the source and drain may be effectively reduced.

Abstract: A method for forming a memory device. The method provides a protective layer overlying a surface region of a substrate before threshold voltage implant. The method then includes depositing a photo resist layer and patterning the photo resist by selectively removing a portion of the photo resist to expose the protective layer overlying a first region while maintaining the photo resist overlying a second region. The method includes implanting impurities for threshold voltage adjustment into the first region while the second region is substantially free of the impurities for threshold voltage adjustment. The method also includes forming a source region and a drain region. The method further includes providing a conductive structure over the source region. A junction between the conductive structure and the source region is substantially within the second region. The method then provides a storage capacitor in electrical contact with the source region via the conductive structure.

Abstract: A semiconductor device includes a buried insulator layer formed on a bulk substrate; a first type semiconductor material formed on the buried insulator layer, and corresponding to a body region of a field effect transistor (FET); a second type of semiconductor material formed over the buried insulator layer, adjacent opposing sides of the body region, and corresponding to source and drain regions of the FET; the second type of semiconductor material having a different bandgap than the first type of semiconductor material; wherein a source side p/n junction of the FET is located substantially within whichever of the first and the second type of semiconductor material having a lower bandgap, and a drain side p/n junction of the FET is located substantially entirely within whichever of the first and the second type of semiconductor material having a higher bandgap.