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: 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 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.

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: A semiconductor structure includes a number of semiconductor regions, a pair of dielectric regions and a pair of terminals. The first and second regions of the structure are respectively coupled to the first and second terminals. The third region of the structure is disposed between the first and second regions. The dielectric regions extend into the third region. A concentration of doping impurities present in the third region and a distance between the dielectric regions define an electrical characteristic of the structure. The electrical characteristic of the structure is independent of the width of the dielectric regions width. The first and second regions are of opposite conductivity types. The structure optionally includes a fourth region that extends into the third region, and surrounds a portion of the pair of dielectric regions. The interface region between the dielectric regions and the fourth region includes intentionally introduced charges.

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 device also includes a body layer extending a first predetermined distance into the semiconductor layer of the second conductivity type and a pair of trenches extending a second predetermined distance into the semiconductor layer of the second conductivity type. Each of the pair of trenches consists essentially of a dielectric material disposed therein and a concentration of doping impurities present in the semiconductor layer of the second conductivity type and a distance between the pair of trenches define an electrical characteristic of the semiconductor device. The semiconductor device further includes a control gate coupled to the semiconductor layer of the second conductivity type and a source region coupled to the semiconductor layer of the second conductivity type.

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 semiconductor device includes a semiconductor layer of a first conductivity type having a first surface and a second surface, a source region disposed on the first surface, a gate region disposed on the first surface adjacent the source region, and a drain region disposed on the first surface. The semiconductor device also includes a pair of charge control trenches disposed between the gate region and the drain region. Each of the pair of charge control trenches is characterized by a width and includes a first dielectric material disposed therein and a second material disposed internal to the first dielectric material. Additionally, a concentration of doping impurities present in the semiconductor layer of the first conductivity type and a distance between the pair of charge control trenches define an electrical characteristic of the semiconductor device that is independent of the width of each of the pair of charge control trenches.

Abstract: A method of manufacturing a semiconductor device includes providing a semiconductor layer of a first conductivity type and forming a semiconductor layer of a second conductivity type thereon. The method also includes forming an insulator layer on the semiconductor layer of the second conductivity type, etching a trench into at least the semiconductor layer of the second conductivity type, and forming a thermal oxide layer in the trench and on the semiconductor layer of the second conductivity type. The method further includes implanting ions into the thermal oxide layer, forming a second insulator layer, removing the second insulator layer from a portion of the trench, and forming an oxide layer in the trench and on the epitaxial layer. Moreover, the method includes forming a material in the trench, forming a second gate oxide layer over the material, and patterning the second gate oxide layer.