摘要:
A heterojunction device including a first semiconductive layer on a substrate, a barrier layer on the first layer, a second semiconductive layer on the barrier layer and a multi-layer cap, on the second semiconductive layer. First and second gates positioned on layers of the cap to define first and second transistors, with the cap layers being selected and etched to pin the Fermi level in a first transistor conduction channel in the second semiconductive layer such that the number of carriers in the first conduction channel are substantially less than the number of carriers in surrounding portions of the second semiconductive layer and the Fermi level in a second transistor conduction channel in the first semiconductive layer such that the number of carriers in the second conduction channel are substantially less than the number of carriers in surrounding portions of the first semiconductive layer.
摘要:
A field effect semiconductor device having multiple vertically stacked channels (12, 14, 16) separated by barrier layers comprising wide bandgap material (18) is provided. The channels (12, 14, 16) are formed on a wide bandgap buffer layer (11) and each channel is coupled a P-type drain region (22b). Each channel is also coupled to an N-type source region (25b). With appropriate gate bias on a gate electrode (17), quantized energy levels in the channels (12, 14, 16) are aligned providing peak current flow by electrons tunneling from the conduction band of one or more N-channels (12, 16) to the valence band of the P-channel (14).
摘要:
A high transconductance HFET (21) utilizes nonalloy semiconductor materials (26) to form a strained channel layer (26) that has a deep quantum well (38). The materials utilized for layers adjacent to the channel layer (26) apply strain to the channel layer (26) and create an excess of high mobility carriers in the channel layer (26). The materials also form a deep quantum well (38) that confines the high mobility carriers to the channel (26). The high mobility carriers and the high confinement provide an HFET (21) that has high transconductance, high frequency response, and sharp pinch-off characteristics.
摘要:
A semiconductor structure that provides both N-type and P-type doping from a single dopant source is provided. A first doping region (13) comprising a first material composition includes holes and electrons in a doping energy level (E.sub.D)- A first undoped spacer region (12) comprising the first material composition covers the doping region (13). An undoped channel (11,14) comprising a second material composition covers the first spacer region (12) and a second undoped spacer region (12) comprising the first material composition covers the undoped channel (11,14). The first material composition has a wider bandgap than the second material composition and the doping energy level (E.sub.D) is selected to provide electrons to the undoped channel (11,14) when the second material composition has a conduction band minimum less than the doping energy level (E.sub.D) and to provide holes to the first undoped channel (11,14) when the second material composition has a valence band maximum greater than the doping energy level (E.sub.D).
摘要:
A resonant tunneling diode having a quantum well sandwiched between first and second tunnel barrier layers and the quantum well and tunnel barrier layers sandwiched between an injection layer and a collector layer. The improvement includes a relatively thin layer of semiconductor material sandwiched between either the first tunnel barrier layer and the injection layer or the first tunnel barrier layer and the quantum well. The thin semiconductor layer has a valence band with an energy level lower than the valence band of the first tunnel barrier layer so as to prevent minority carriers from travelling toward the injection layer.
摘要:
A logic circuit including a pair of FETs connected in parallel and including first and second common current terminals, each of the FETs further having a control terminal connected to receive a logic signal thereon. A negative differential resistance device affixed to one of the first and second common current terminals and having a conductance characteristic such that the device operates at a peak current when one of the FETs is turned ON and at a valley current when both of the FETs are simultaneously turned ON. A load resistance coupled to the other of the first and second common current terminals and providing an output for the logic circuit.
摘要:
A resonant tunneling FET including a heterostructure FET with a channel layer having a first current contact and a control contact operatively coupled thereto and a resonant tunneling device, including a quantum well layer sandwiched between barrier layers with a resonant tunneling layer affixed to an opposite side of one barrier layer, operably affixed to the heterostructure FET to form a second current contact. The resonant tunneling FET being constructed from a material system which allows the fabrication of additional devices on the same substrate.
摘要:
A band-to-band resonant tunneling transistor including GaSb and InAs resonant tunneling layers separated by a thin barrier layer and a second InAs layer separated from the GaSb layer by another thin barrier layer. A terminal on the InAs resonant tunneling layer and a terminal on the second InAs layer. Leakage current reduction layers are positioned on the second InAs layer with a bias terminal positioned thereon. The InAs resonant tunneling layer has a plurality of quantized states which are misaligned with the ground state of the GaSb layer in a quiescent state, each of the quantized states of the InAs resonant tunneling layer are movable into alignment with the ground state of the GaSb layer to provide current flow through the transistor with the application of a specific potential to the terminal on the second InAs layer.
摘要:
A heterojunction device including a first semiconductive layer on a substrate, a barrier layer on the first layer, a second semiconductive layer on the barrier layer and a multi-layer cap, on the second semiconductive layer. First and second gates positioned on layers of the cap to define first and second transistors, with the cap layers being selected and etched to pin the Fermi level in a first transistor conduction channel in the second semiconductive layer such that the number of carriers in the first conduction channel are substantially less than the number of carriers in surrounding portions of the second semiconductive layer and the Fermi level in a second transistor conduction channel in the first semiconductive layer such that the number of carriers in the second conduction channel are substantially less than the number of carriers in surrounding portions of the first semiconductive layer.
摘要:
An SRAM including first and second RITDs each formed with a heterostructure including a GaSb active layer sandwiched between AlSb barrier layers, which are sandwiched between InAs layers with each RITD having a contact connected to a first of the InAs layers. A TD including an AlSb layer sandwiched between InAS layers. A second InAs layer for each of the RITDs being integrally formed with a first InAs layer of the TD and a read/write terminal connected to a second InAs layer of the TD.