Abstract: In one general aspect, an apparatus can include a semiconductor region, and a trench defined within the semiconductor region. The trench can have a depth aligned along a vertical axis and have a length aligned along a longitudinal axis orthogonal to the vertical axis. The trench can have a first portion of the length included in a termination region of the semiconductor region and can have a second portion of the length included in an active region of the semiconductor region.

Abstract: Methods for fabricating MOSFET devices with superjunction having high breakdown voltages (>600 volts) with competitively low specific resistance include growing an epitaxial layer of a second conductivity type on a substrate of a first conductivity type, forming a trench in the epitaxial layer, and growing a second epitaxial layer along the sidewalls and bottom of the trench. The second epitaxial layer is doped with a dopant of first conductivity type. MOSFET devices with superjunction having high breakdown voltages include a first epitaxial layer of a second conductivity type disposed over a substrate of a first conductivity type and a trench formed in the epitaxial layer. The trench includes a second epitaxial layer grown along the sidewalls and bottom of the trench.

Abstract: Methods for localized thinning of wafers used in semiconductor devices and the structures formed from such methods are described. The methods thin localized areas of the backside of the semiconductor wafer to form recesses with a bi-directional channel design that is repeated within the wafer (or die) so that no straight channel line crosses the wafer (or die). The bi-directional pattern design keeps the channels from being aligned with the crystal orientation of the wafer. The recesses are then filled by a solder ball drop process by dropping proper size solder balls into the recesses and then annealing the wafer to reflow the solder balls and flatten them out. The reflow process begins to fill in the recesses from the bottom up, thereby avoiding void formation and the resulting air traps in the reflowed solder material. Other embodiments are also described.

Abstract: Disclosed are semiconductor dice with backside trenches filled with elastic conductive material. The trenches reduce the on-state resistances of the devices incorporated on the dice. The elastic conductive material provides a conductive path to the backsides of the die with little induced stress on the semiconductor die caused by thermal cycling. Also disclosed are packages using the dice, and methods of making the dice.

Abstract: Edge termination structures for power semiconductor devices and methods for making such structures are described. The power semiconductor devices (or power devices) contain a substrate with an epitaxial layer thereon, an array of substantially-parallel, active trenches formed in the epitaxial layer, with the active trenches containing a transistor structure with an insulated gate conducting layer, a superjunction or shielded region adjacent the active trenches; a peripheral trench surrounding the active trenches, and a source contact area within an upper surface of the epitaxial layer, where the gate conducting layer extends over the superjunction or shielded region and over the surrounding peripheral trench. Such a configuration allows the edge termination structure to be used with a wide range of breakdown voltages in power MOSFET devices containing PN superjunction structures. Other embodiments are described.

Abstract: A method for obtaining individual dies from a semiconductor structure is disclosed. The semiconductor structure includes a device layer, and the device layer in turn includes active regions separated by predefined spacings. Thick metal is selectively formed on backside of the device layer such that thick metal is formed on backside of active regions but not on backside of the predefined spacings. The semiconductor structure is then cut along the predefined spacings to separate the active regions with thick metal on their backside into individual dies.

Abstract: A semiconductor structure comprises a semiconductor layer of a first conductivity type, trenches extending into the semiconductor layer, and a conductive layer of a second conductivity type lining sidewalls and bottom of each trench and forming PN junctions with the semiconductor layer. A first plurality of the trenches are disposed in a field effect transistor region that comprises a body region of the first conductivity type, source regions of the second conductivity type in the body region, and gate electrodes isolated from the body region and the source regions by a gate dielectric. A second plurality of the trenches are disposed in a Schottky region that comprises a conductive material contacting mesa surfaces of the semiconductor layer between adjacent ones of the second plurality of the trenches to form Schottky contacts. The conductive material also contacts the conductive layer proximate an upper portion of the second plurality of the trenches.

Abstract: Methods for localized thinning of wafers used in semiconductor devices and the structures formed from such methods are described. The methods thin localized areas of the backside of the semiconductor wafer to form recesses with a bi-directional channel design that is repeated within the wafer (or die) so that no straight channel line crosses the wafer (or die). The bi-directional pattern design keeps the channels from being aligned with the crystal orientation of the wafer. The recesses are then filled by a solder ball drop process by dropping proper size solder balls into the recesses and then annealing the wafer to reflow the solder balls and flatten them out. The reflow process begins to fill in the recesses from the bottom up, thereby avoiding void formation and the resulting air traps in the reflowed solder material. Other embodiments are also described.

Abstract: Methods for localized thinning of wafers used in semiconductor devices and the structures formed from such methods are described. The methods thin localized areas of the backside of the semiconductor wafer to form recesses with a bi-directional channel design that is repeated within the wafer (or die) so that no straight channel line crosses the wafer (or die). The bi-directional pattern design keeps the channels from being aligned with the crystal orientation of the wafer. The recesses are then filled by a solder ball drop process by dropping proper size solder balls into the recesses and then annealing the wafer to reflow the solder balls and flatten them out. The reflow process begins to fill in the recesses from the bottom up, thereby avoiding void formation and the resulting air traps in the reflowed solder material. Other embodiments are also described.

Abstract: Semiconductor devices and methods for making such devices that are especially suited for high-frequency applications are described. The semiconductor devices combine a SIT (or a junction field-effect transistor [JFET]) architecture with a PN super-junction structure. The SIT architecture can be made using a trench formation containing a gate that is sandwiched between thick dielectric layers. While the gate is vertically sandwiched between the two isolating regions in the trench, it is also connected to a region of one conductivity type of the super-junction structure, thereby allowing control of the current path of the semiconductor device. Such semiconductor devices have a lower specific resistance and capacitance relative to conventional planar gate and recessed gate SIT semiconductor devices. Other embodiments are described.

Abstract: Methods for fabricating MOSFET devices with superjunction having high breakdown voltages (>600 volts) with competitively low specific resistance include growing an epitaxial layer of a second conductivity type on a substrate of a first conductivity type, forming a trench in the epitaxial layer, and growing a second epitaxial layer along the sidewalls and bottom of the trench. The second epitaxial layer is doped with a dopant of first conductivity type. MOSFET devices with superjunction having high breakdown voltages include a first epitaxial layer of a second conductivity type disposed over a substrate of a first conductivity type and a trench formed in the epitaxial layer. The trench includes a second epitaxial layer grown along the sidewalls and bottom of the trench.

Abstract: Semiconductor devices and methods for making such devices that contain a 3D channel architecture are described. The 3D channel architecture is formed using a dual trench structure containing with a plurality of lower trenches extending in an x and y directional channels and separated by a mesa and an upper trench extending in a y direction and located in an upper portion of the substrate proximate a source region. Thus, smaller pillar trenches are formed within the main line-shaped trench. Such an architecture generates additional channel regions which are aligned substantially perpendicular to the conventional line-shaped channels. The channel regions, both conventional and perpendicular, are electrically connected by their corner and top regions to produce higher current flow in all three dimensions. With such a configuration, higher channel density, a stronger inversion layer, and a more uniform threshold distribution can be obtained for the semiconductor device. Other embodiments are described.

Abstract: Disclosed are semiconductor die structures that enable a die having a vertical power device to be packaged in a wafer-level chip scale package where the current-conducting terminals are present at one surface of the die, and where the device has very low on-state resistance. In an exemplary embodiment, a trench and an aperture are formed in a backside of a die, with the aperture contacting a conductive region at the top surface of the die. A conductive layer and/or a conductive body may be disposed on the trench and aperture to electrically couple the backside current-conducting electrode of the device to the conductive region. Also disclosed are packages and systems using a die with a die structure according to the invention, and methods of making dice with a die structure according to the invention.

Abstract: Disclosed are semiconductor dice with backside trenches filled with elastic conductive material. The trenches reduce the on-state resistances of the devices incorporated on the dice. The elastic conductive material provides a conductive path to the backsides of the die with little induced stress on the semiconductor die caused by thermal cycling. Also disclosed are packages using the dice, and methods of making the dice.

Abstract: A method for obtaining individual dies from a semiconductor structure is disclosed. The semiconductor structure includes a device layer, and the device layer in turn includes active regions separated by predefined spacings. Thick metal is selectively formed on backside of the device layer such that thick metal is formed on backside of active regions but not on backside of the predefined spacings. The semiconductor structure is then cut along the predefined spacings to separate the active regions with thick metal on their backside into individual dies.

Abstract: Semiconductor devices combining a MOSFET architecture with a PN super-junction structure and methods for making such devices are described. The MOSFET architecture can be made using a trench configuration containing a gate that is sandwiched between thick dielectric layers in the top and the bottom of the trench. The PN junction of the super-junction structure is formed between n-type dopant regions in the sidewalls of the trench and a p-type epitaxial layer. The gate of the trench MOSFET is separated from the super-junction structure using a gate insulating layer. Such semiconductor devices can have a lower capacitance and a higher breakdown voltage relative to shield-based trench MOSFET devices and can replace such devices in medium to high voltage ranges. Other embodiments are described.

Abstract: Disclosed are semiconductor dice with backside trenches filled with elastic conductive material. The trenches reduce the on-state resistances of the devices incorporated on the dice. The elastic conductive material provides a conductive path to the backsides of the die with little induced stress on the semiconductor die caused by thermal cycling. Also disclosed are packages using the dice, and methods of making the dice.

Abstract: Semiconductor devices and methods for making such devices that are especially suited for high-frequency applications are described. The semiconductor devices combine a SIT (or a junction field-effect transistor [JFET]) architecture with a PN super-junction structure. The SIT architecture can be made using a trench formation containing a gate that is sandwiched between thick dielectric layers. While the gate is vertically sandwiched between the two isolating regions in the trench, it is also connected to a region of one conductivity type of the super-junction structure, thereby allowing control of the current path of the semiconductor device. Such semiconductor devices have a lower specific resistance and capacitance relative to conventional planar gate and recessed gate SIT semiconductor devices. Other embodiments are described.

Abstract: A method for obtaining individual dies from a semiconductor structure is disclosed. The semiconductor structure includes a device layer, and the device layer in turn includes active regions separated by predefined spacings. Thick metal is selectively formed on backside of the device layer such that thick metal is formed on backside of active regions but not on backside of the predefined spacings. The semiconductor structure is then cut along the predefined spacings to separate the active regions with thick metal on their backside into individual dies.

Abstract: Semiconductor devices containing nickel-titanium (NiTi or TiNi) compounds or alloys and methods for making such devices are described. The devices contain a silicon substrate with an integrated circuit, a contact layer contacting the substrate, a TiNi-containing soldering layer on the contact layer, an oxidation prevention layer on the soldering layer, a solder bump on the soldering layer, and a lead frame or PCB attached to the solder bump. The combination of the Ti and Ni materials in the soldering layer exhibits many features not found in the Ti and Ni materials alone, such as reduced wafer warpage, increased ductility for improved elasticity, decreased consumption of the Ni in the soldering layer, and decreased manufacturing costs. Other embodiments are described.