Abstract: Semiconductor power devices, and related methods, wherein a recessed contact makes lateral ohmic contact to the source diffusion, but is insulated from the underlying recessed field plate (RFP). Such an insulated RFP is here referred to as an embedded recessed field plate (ERFP).

Abstract: An edge termination structure includes a final dielectric trench containing permanent charge. The final dielectric trench is surrounded by first conductivity type semiconductor material (doped by lateral outdiffusion from the trenches), which in turn is laterally surrounded by second conductivity type semiconductor material.

Abstract: Devices, structures, and related methods for IGBTs and the like which include a self-aligned series resistance at the source-body junction to avoid latchup. The series resistance is achieved by using a charged dielectric, and/or by using a dielectric which provides a source of dopant atoms of the same conductivity type as the source region, at a sidewall adjacent to the source region.

Abstract: N-channel power semiconductor devices in which an insulated field plate is coupled to the drift region, and immobile electrostatic charge is also present at the interface between the drift region and the insulation around the field plate. The electrostatic charge permits OFF-state voltage drop to occur near the source region, in addition to the voltage drop which occurs near the drain region (due to the presence of the field plate).

Abstract: A semiconductor device includes a semiconductor layer of a first conductivity type and a semiconductor layer of a second conductivity type formed thereon. The semiconductor layer of the second conductivity type is characterized by a first thickness. The semiconductor device includes a set of trenches having a predetermined depth and extending into the semiconductor layer of the second conductivity type, thereby defining interfacial regions disposed between the semiconductor layer of the second conductivity type and each of the trenches. The trenches comprises a distal portion consisting essentially of a dielectric material disposed therein and a proximal portion comprising the dielectric material and a gate material disposed interior to the dielectric material in the proximal portion of the trench. The semiconductor device further includes a source region coupled to the semiconductor layer of the second conductivity type.

Abstract: A MOSFET switch which has a low surface electric field at an edge termination area, and also has increased breakdown voltage. The MOSFET switch has a new edge termination structure employing an N-P-N sandwich structure. The MOSFET switch also has a polysilicon field plate configuration operative to enhance any spreading of any depletion layer located at an edge of a main PN junction of the N-P-N sandwich structure.

Abstract: Power devices using refilled trenches with permanent charge at or near their sidewalls. These trenches extend vertically into a drift region.

Abstract: A high-voltage termination structure includes a peripheral voltage-spreading network. One or more trench structures are connected at least partly in series between first and second power supply voltages. The trench structures include first and second current-limiting structures connected in series with a semiconductor material, and also includes permanent charge in a trench-wall dielectric. The current-limiting structures in the trench structures are jointly connected in a series-parallel ladder configuration. The current-limiting structures, in combination with the semiconductor material, provide a voltage distribution between the core portion and the edge portion.

Abstract: A manufacturing process and design structure for a super self-aligned trench power MOSFET. A plurality of super self-aligned trenches of different depths are formed into the body layer and epitaxial layers, preferably by using a multilayer stack of dielectric material etched to form spacers. Respective trenches contain gate conductors, body-contact conductors, and preferably a third trench containing a recessed field plate. This results in a MOSFET structure having high cell density and low gate charges and gate-drain charges.

Abstract: A trench MOSFET contains a recessed field plate (RFP) trench adjacent the gate trench. The RFP trench contains an RFP electrode insulated from the die by a dielectric layer along the walls of the RFP trench. The gate trench has a thick bottom oxide layer, and the gate and RFP trenches are preferably formed in the same processing step and are of substantially the same depth. When the MOSFET operates in the third quadrant (with the source/body-to-drain junction forward-biased), the combined effect of the RFP and gate electrodes significantly reduces in the minority carrier diffusion current and reverse-recovery charge. The RFP electrode also functions as a recessed field plates to reduce the electric field in the channel regions when the MOSFET source/body to-drain junction reverse-biased.

Abstract: The present application discloses new approaches to integrated power. Two new classes of structures each provide an integrated phase leg, in a process which can easily be integrated with low-voltage and/or peripheral circuits: in one class of disclosed structures, a lateral PMOS device is combined with an NMOS device which has predominantly vertical current flow. In another class of embodiments, a predominantly vertical n-channel device is used for the low-side switch, in combination with a lateral n-channel device. In either case, the common output node is preferably brought out at a backside contact. This device structure is advantageously used to construct complete power supply and/or voltage conversions circuits on a single chip (perhaps connected to external passive reactances).

Abstract: The present inventors have realized that manufacturability plays into optimization of power semiconductor devices in some surprising new ways. If the process window is too narrow, the maximum breakdown voltage will not be achieved due to doping variations and the like normally seen in device fabrication. Thus, among other teachings, the present application describes some ways to improve the process margin, for a given breakdown voltage specification, by actually reducing the maximum breakdown voltage. In one class of embodiments, this is done by introducing a vertical gradation in the density of fixed electrostatic charge, or in the background doping of the drift region, or both. Several techniques are disclosed for achieving this.

Abstract: A method of fabricating a trench device includes forming a first trench and forming a hardmask layer on sidewalls of the trench. A second trench may be etched narrower than the first trench, into the bottom of the first trench. A dielectric material may be grown to substantially fill the second trench, using a reaction process to which the hardmask material is substantially inert. The growing action also grows tapered portions of the dielectric material upwardly under part of the hardmask. A conductive layer may be formed over said dielectric material. The dielectric material in the second trench, in combination with the tapered portions which extend upward from the dielectric material may provide smooth gradation of voltage differences within the semiconductor material. The gradation may be caused by potential differences between the gate and various portions of the semiconductor material.

Abstract: A trench MOSFET contains a recessed field plate (RFP) trench adjacent the gate trench. The RFP trench contains an RFP electrode insulated from the die by a dielectric layer along the walls of the RFP trench. The gate trench has a thick bottom oxide layer, and the gate and RFP trenches are preferably formed in the same processing step and are of substantially the same depth. When the MOSFET operates in the third quadrant (with the source/body-to-drain junction forward-biased), the combined effect of the RFP and gate electrodes significantly reduces in the minority carrier diffusion current and reverse-recovery charge. The RFP electrode also functions as a recessed field plates to reduce the electric field in the channel regions when the MOSFET source/body to-drain junction reverse-biased.

Abstract: A trench MIS device is formed in a P-epitaxial layer that overlies an N-epitaxial layer and an N+ substrate. In one embodiment, the device includes an N-type drain-drift region that extends from the bottom of the trench to the N-epitaxial layer. Preferably, the drain-drift region is formed at least in part by fabricating spacers on the sidewalls of the trench and implanting an N-type dopant between the sidewall spacers and through the bottom of the trench. The drain-drift region can be doped more heavily than the conventional “drift region” that is formed in an N-epitaxial layer. Thus, the device has a low on-resistance. The device can be terminated by a plurality of polysilicon-filled termination trenches located near the edge of the die, with the polysilicon in each termination trench being connected to the mesa adjacent the termination trench.

Abstract: MOS-gated devices, related methods, and systems for vertical power and RF devices including an insulated trench and a gate electrode. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. Permanent electrostatic charges are included in said insulation material. A conductive shield layer is positioned above the insulated trench, to reduce parasitic capacitances.

Abstract: Vertical power devices which include an insulated trench containing insulating material and a gate electrode, and related methods. A body region is positioned so that a voltage bias on the gate electrode will cause an inversion layer in the body region. A layer of permanent charge, at or near the sidewall of the trench, provides charge balancing for the space charge in the depleted semiconductor material during the OFF state. A conductive shield layer is positioned below the gate electrode in the insulating material, and reduces capacitive coupling between the gate and the lower part of the trench. This reduces switching losses. In other embodiments, a planar gate electrode controls horizontal carrier injection into the vertical conduction pathway along the trench, while a shield plate lies over the trench itself to reduce capacitive coupling.

Abstract: A lateral device includes a gate region connected to a drain region by a drift layer. An insulation region adjoins the drift layer between the gate region and the drain region. Permanent charges are embedded in the insulation region, sufficient to cause inversion in the insulation region.

Abstract: A lateral SOI device may include a semiconductor channel region connected to a drain region by a drift region. An insulation region on the drift layer is positioned between the channel region and the drain region. Permanent charges may be embedded in the insulation region sufficient to cause inversion in the insulation region. The semiconductor layer also overlies a global insulation layer, and permanent charges are preferably embedded in at least selected areas of this insulation layer too.

Abstract: A vertical device structure includes a volume of semiconductor material, laterally adjoining a trench having insulating material on sidewalls thereof. A gate electrode within the trench is capacitively coupled through the insulating material to a first portion of the semiconducting material. Some portions of the insulating material contain fixed electrostatic charge in a density high enough to invert a second portion of the semiconductor material when no voltage is applied. The inverted portions can be used as induced source or drain extensions, to assure that parasitic are reduced without increasing on-resistance.