Abstract:
Each of a pair of like-polarity IGFETs (40 or 42 and 240 or 242) has a channel zone (64 or 84) situated in body material (50). Short-channel effects are alleviated by arranging for the net dopant concentration in the channel zone to longitudinally reach a local surface minimum at a location between the IGFET's source/drain zones (60 and 62 or 80 and 82) and by arranging for the net dopant concentration in the body material to reach a local subsurface maximum more than 0.1 μm deep into the body material but not more than 0.4 μm deep into the body material. A pocket portion (100/102 or 104) extends along both source drain zones of one of the IGFETs. A pocket portion (244 or 246) extends largely along only one of the source/drain zones of the other IGFET so that it is an asymmetrical device.
Abstract:
A semiconductor technology combines a normally off n-channel channel-junction insulated-gate field-effect transistor (“IGFET”) (104) and an n-channel surface-channel IGFET (100 or 160) to reduce low-frequency 1/f noise. The channel-junction IGFET is normally fabricated to be of materially greater gate dielectric thickness than the surface-channel IGFET so as to operate across a greater voltage range than the surface-channel IGFET. A p-channel surface-channel IGFET (102 or 162), which is typically fabricated to be of approximately the same gate-dielectric thickness as the n-channel surface-channel IGFET, is preferably combined with the two n-channel IGFETs to produce a complementary-IGFET structure. A further p-channel IGFET (106, 180, 184, or 192), which is typically fabricated to be of approximately the same gate dielectric thickness as the n-channel channel-junction IGFET, is also preferably included. The further p-channel IGFET can be a surface-channel or channel-junction device.
Abstract translation:半导体技术结合了正常n沟道沟道结绝缘栅场效应晶体管(“IGFET”)(104)和n沟道表面沟道IGFET(100或160),以降低低频1 / f 噪声。 沟道结IGFET通常被制造为具有比表面沟道IGFET大得多的栅介质厚度,以便在比表面沟道IGFET更大的电压范围内工作。 典型地制造为与n沟道表面沟道IGFET大致相同的栅介质厚度的p沟道表面沟道IGFET(102或162)优选地与两个n沟道IGFET组合以产生 互补IGFET结构。 还优选包括通常被制造为具有与n沟道沟道结IGFET大致相同的栅介质厚度的另外的p沟道IGFET(106,180,184或192)。 另外的p沟道IGFET可以是表面沟道或沟道结器件。
Abstract:
A semiconductor junction varactor utilizes gate enhancement for enabling the varactor to achieve a high ratio of maximum capacitance to minimum capacitance. The varactor has a gate region (131 or 181) divided into multiple portions of differing zero-point threshold voltages for enabling the varactor capacitance to vary relatively gradually with a control voltage applied to the varactor.
Abstract:
An insulated-gate field-effect transistor utilizes local threshold-adjust doping to control the voltage at which the transistor turns on. The local threshold-adjust doping is present along part, but not all, of the lateral extent of the channel. In the transistor structure, a channel zone laterally separates a pair of source/drain zones. The channel zone is formed with a main channel portion and a more heavily doped threshold channel portion that contains the local threshold-adjust doping. Gate dielectric material vertically separates the channel zone from an overlying gate electrode. The transistor is a long device in that the gate electrode is longer, preferably at least 50% longer, than the gate electrode of a minimum-sized transistor whose gate length is approximately the minimum feature size. The long-gate transistor is suitable for use in analog and high-voltage digital portions of a VLSI circuit.
Abstract:
An insulated gate semiconductor device contains a common drain and a plurality of cells, each having a body region and a source. In each cell, the body region contains a channel region extending between the common drain and the source. The body region further includes a special portion spaced apart from the channel region, more heavily doped than the portion of the body region below the source, extending no more than an electrically insignificant amount below the source, and not extending significantly deeper below the upper semiconductor surface than the portion of the body region underlying the source. The special portion of each body region provides improved ruggedness under drain avalanche conditions. The special portion of each body region normally reaches a peak net dopant concentration below the upper semiconductor surface. Instead of, or in addition to, having the special portion of each body region be subsurface-peaked, the portion of each body region below the source can extend deeper below the upper semiconductor surface than the portion of the body region underlying the special portion.
Abstract:
Power MOSFET apparatus, and method for its production, that suppresses voltage breakdown near the gate, using a polygon-shaped trench in which the gate is positioned, using a shaped deep body junction that partly lies below the trench bottom, and using special procedures for growth of gate oxide at various trench corners.
Abstract:
Power MOSFET apparatus, and method for its production, that suppresses voltage breakdown near the gate, using a polygon-shaped trench in which the gate is positioned in order to suppress oxide dielectric breakdown, using a shaped deep body junction that partly lies below the trench bottom to force voltage breakdown away from the trench surfaces and into the bulk of the semiconductor material, and using special procedures for growth of gate oxide at various trench corners.
Abstract:
An IGFET (40 or 42) has a channel zone (64 or 84) situated in body material (50). Short-channel threshold voltage roll-off and punchthrough are alleviated by arranging for the net dopant concentration in the channel zone to longitudinally reach a local surface minimum at a location between the IGFET's source/drain zones (60 and 62 or 80 and 82) and by arranging for the net dopant concentration in the body material to reach a local subsurface maximum more than 0.1 μm deep into the body material but not more than 0.1 μm deep into the body material. The source/drain zones (140 and 142 or 160 and 162) of a p-channel IGFET (120 or 122) are provided with graded-junction characteristics to reduce junction capacitance, thereby increasing switching speed.
Abstract:
A static induction transistor comprising: a region of semiconductor material having a first conductivity type; at least two spaced-apart gate regions formed in the region of semiconductor material, the gate regions having a second conductivity type that is opposite to the first conductivity type; at least one source region having the first conductivity type formed in the region of semiconductor material between the spaced-apart gate regions; a drain region having the first conductivity type formed in the region of semiconductor and spaced-apart from the source region to define a channel region therebetween; and a dielectric carrier separation layer formed at the periphery of the gate regions.
Abstract:
An asymmetric insulated-gate field effect transistor (100U or 102U) is provided along an upper surface of a semiconductor body so as to have first and second source/drain zones (240 and 242 or 280 and 282) laterally separated by a channel zone (244 or 284) of the transistor's body material. A gate electrode (262 or 302) overlies a gate dielectric layer (260 or 300) above the channel zone. A pocket portion (250 or 290) of the body material more heavily doped than laterally adjacent material of the body material extends along largely only the first of the S/D zones and into the channel zone. The vertical dopant profile of the pocket portion is tailored to reach a plurality of local maxima at respective locations (PH-1-PH-3-NH-3) spaced apart from one another. This typically enables the transistor to have reduced current leakage.