Abstract: Some exemplary embodiments of a direct contact leadless package and related structure and method, especially suitable for packaging high current semiconductor devices, have been disclosed. One exemplary structure comprises a first contact lead frame portion, a paddle portion, and an extended contact lead frame portion held together by a mold compound. A first semiconductor device is attached to a top side of the paddle portion and is enclosed by said mold compound, while a second semiconductor device is attached to a bottom side of said paddle portion and is in electrical contact with said the first semiconductor device. The extended contact lead frame portion is in direct electrical contact with the second semiconductor device without using a bond wire. Alternative exemplary embodiments may include additional extended lead frame portions, paddle portions, and semiconductor devices in various configurations.

Abstract: According to an exemplary embodiment, a stacked half-bridge package includes a control transistor having a control drain for connection to a high voltage input, a control source coupled to a common conductive clip, and a control gate for being driven by a driver IC. The stacked half-bridge package also includes a sync transistor having a sync drain for connection to the common conductive clip, a sync source coupled to a low voltage input, and a sync gate for being driven by the driver IC. The control and sync transistors are stacked on opposite sides of the common conductive clip with the common conductive clip electrically and mechanically coupling the control source with the sync drain, where the common conductive clip has a conductive leg for providing electrical and mechanical connection to an output terminal leadframe.

Abstract: A III-nitride based field effect transistor obtains improved performance characteristics through manipulation of the relationship between the in-plane lattice constant of the interface of material layers. A high mobility two dimensional electron gas generated at the interface of the III-nitride materials permits high current conduction with low ON resistance, and is controllable through the manipulation of spontaneous polarization fields obtained according to the characteristics of the III-nitride material. The field effect transistor produced can be made to be a nominally on device where the in-plane lattice constants of the material forming the interface match. A nominally off device may be produced where one of the material layers has an in-plane lattice constant that is larger than that of the other layer material. The layer materials are preferably InAlGaN/GaN layers that are particularly tailored to the characteristics of the present invention.

Abstract: A wire bond free power module assembly consists of a plurality of individual thin packages each consisting of two DBC wafers which sandwich one or more semiconductor die. The die electrodes and terminals extend through one insulation covered end of the wafer sandwich and the outer sides of the sandwiches are the outer copper plates of the DBC wafers which are in good thermal communication with the semiconductor die but are electrically insulated therefrom. The plural packages may be connected in parallel by lead frames on the terminals and the packages are stacked with a space between them to expose both sides of all packages to a cooling medium, either the fingers of a conductive comb or a fluid heat exchange medium.

Abstract: The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.

Abstract: Disclosed is a buck converter for converting a high voltage at the input of the buck converter to a low voltage at the output of the buck converter. The buck converter includes a control circuitry configured to control a duty cycle of a control switch, the control switch being interposed between the input and the output of the buck converter. A synchronous switch is interposed between the output and ground. The control switch and the synchronous switch comprise depletion-mode III-nitride transistors. In one embodiment, at least one of the control switch and the synchronous switches comprises a depletion-mode GaN HEMT. The buck converter further includes protection circuitry configured to disable current conduction through the control switch while the control circuitry is not powered up.

Abstract: In an exemplary implementation, a III-nitride semiconductor device includes a III-nitride heterojunction including a first III-nitride body situated over a second III-nitride body to form a two-dimensional electron gas. The III-nitride semiconductor device further includes a gate well formed in a dielectric body, the dielectric body situated over the III-nitride heterojunction. A gate arrangement is situated in the gate well and includes a gate electrode, a source-side field plate, and a drain-side field plate. The source-side field plate and the drain-side field plate each include one or more steps, where the drain-side field plate has a different number of the one or more steps than the source-side field plate.

Abstract: In an exemplary implementation, a III-nitride semiconductor device includes a III-nitride heterojunction including a first III-nitride body situated over a second III-nitride body to form a two-dimensional electron gas. The III-nitride semiconductor device further includes a gate well formed in a dielectric body, the dielectric body situated over the III-nitride heterojunction. A gate arrangement is situated in the gate well and includes a gate electrode, a source-side field plate, and a drain-side field plate. The source-side field plate and the drain-side field plate each include steps, and the drain-side field plate is wider than the source-side field plate.

Abstract: In one implementation, an integrated group III-V power stage includes a control switch including a first group III-V transistor coupled to a sync switch including a second group III-V transistor. The integrated group III-V power stage may also include one or more driver stages, which may be fabricated in a group die or dies. The driver stage or driver stages, the control switch, and the sync switch may all be situated in a single semiconductor package.

Abstract: In an exemplary implementation, a III-nitride semiconductor device includes a III-nitride heterojunction including a first III-nitride body situated over a second III-nitride body to form a two-dimensional electron gas. The III-nitride semiconductor device further includes a dielectric body situated over the III-nitride heterojunction and including a first dielectric layer of a first dielectric material and a second dielectric layer of a second dielectric material different than the first dielectric material. A gate well of a first width is defined by the first dielectric layer, and is of a second width defined by the second dielectric layer, where the second width is greater than the first width. The III-nitride semiconductor device further includes a gate arrangement situated in the gate well and including a gate electrode integrated with a field plate.

Abstract: In one implementation, a power converter includes an output stage integrated circuit (IC) in a group III-V die including a depletion mode group III-V transistor, and a driver IC in a group IV die. The driver IC is configured to drive the output stage IC. In addition, a group IV control switch in the group IV die is cascoded with the depletion mode group III-V transistor. The power converter further includes an overcurrent protection circuit for the depletion mode group III-V transistor, the overcurrent protection circuit monolithically integrated in the group IV die.

Abstract: Some exemplary embodiments of a multi-chip module (MCM) power quad flat no-lead (PQFN) semiconductor package utilizing a leadframe for electrical interconnections have been disclosed. One exemplary embodiment comprises a PQFN semiconductor package comprising a leadframe, a driver integrated circuit (IC) coupled to the leadframe, a plurality of vertical conduction power devices coupled to the leadframe, and a plurality of wirebonds providing electrical interconnects, including at least one wirebond from a top surface electrode of one of the plurality of vertical conduction power devices to a portion of the leadframe, wherein the portion of the leadframe is electrically connected to a bottom surface electrode of another of the plurality of vertical conduction power devices. In this manner, efficient multi-chip circuit interconnections can be provided in a PQFN package using low cost leadframes.

Abstract: One exemplary disclosed embodiment comprises a high power semiconductor package configured as a buck converter having a control transistor and a sync transistor disposed on a common leadframe pad, a driver integrated circuit (IC) for driving the control and sync transistors, and conductive clips electrically coupling the top surfaces of the transistors to substrate pads such as leadframe pads. In this manner, the leadframe and the conductive clips provide efficient grounding or current conduction by direct mechanical connection and large surface area conduction, thereby enabling a package with significantly reduced electrical resistance, form factor, complexity, and cost when compared to conventional packaging methods using wirebonds for transistor interconnections.

Abstract: In one implementation, a power converter includes an output stage integrated circuit (IC) on a group III-V die, and a driver IC for driving the output stage IC, the driver IC fabricated on a group IV die. The power converter also includes a composite power switch split between the group III-V die and the group IV die, wherein a depletion mode group III-V transistor of the composite power switch is monolithically integrated in the group III-V die, and a group IV control switch of the composite power switch is monolithically integrated in the group IV die. As a result, the depletion mode group III-V transistor may be operated as an enhancement mode transistor.

Abstract: According to one exemplary embodiment, a group III-V semiconductor device includes at least one transition layer situated over a substrate. The group III-V semiconductor device further includes a first strain-relieving interlayer situated over the at least one transition layer and a second strain-relieving interlayer situated over the first strain-relieving interlayer. The group III-V semiconductor device further includes a first group III-V semiconductor body situated over the second strain-relieving interlayer. The first and second strain-relieving interlayers comprise different semiconductor materials so as to reduce a strain in the first group III-V semiconductor body. The second strain-relieving interlayer can be substantially thinner than the first strain-relieving interlayer.

Abstract: In accordance with one implementation of the present disclosure, a III-Nitride heterojunction device includes a III-Nitride channel layer, a III-Nitride multilayer spacer situated over the III-Nitride channel layer, and a III-Nitride barrier layer situated over the III-Nitride multilayer spacer. A two-dimensional electron gas (2DEG) is formed near an interface of said III-Nitride Channel layer and said III-Nitride multilayer spacer. The III-Nitride multilayer spacer includes a III-Nitride interlayer. In one implementation, the III-Nitride multilayer spacer includes a III-Nitride polarization layer that is situated over the III-Nitride interlayer. The III-Nitride polarization layer has a higher total polarization than the III-Nitride interlayer, the III-Nitride channel layer, and the III-Nitride barrier layer.

Abstract: According to an exemplary embodiment, a III-nitride power conversion circuit includes a gate driver having a plurality of cascaded inverters, each of the plurality of cascaded inverters including at least one III-nitride transistor. At least one of the plurality of cascaded inverters has a cutoff switch and a III-nitride depletion mode load where the cutoff switch is configured to disconnect the III-nitride depletion mode load so as to prevent current from flowing from a supply voltage of the at least one of the plurality of cascaded inverters. The cutoff switch of the at least one of the plurality of cascaded inverters can be driven by one of the plurality of cascaded inverters. The III-nitride power conversion circuit can also include an output driver driven by the gate driver where the output driver has a segmented III-nitride transistor. Furthermore, a selector circuit can be configured to selectively disable at least one segment of the segmented III-nitride transistor.

Abstract: A semiconductor device package is formed of DBC in which thinned MOSgated and/or diode die are soldered to the bottom of an etched depression in the upper conductive layer. A via in the insulation layer of the DBC is filled with a conductive material to form a resistive shunt. Plural packages may be formed in a DBC card and may be separated individually or in clusters. The individual packages are mounted in various arrays on a support DBC board and heat sink. Integrated circuits may be mounted on the assembly and connected to the die for control of the die conduction.

Abstract: According to example configurations herein, a leadframe includes a connection interface. The connection interface can be configured for attaching an electrical circuit to the leadframe. The leadframe also can include a conductive path. The conductive path in the leadframe provides an electrical connection between a first electrical node of the electrical circuit and a second electrical node of the electrical circuit. Prior to making the connection between the electrical circuit and the leadframe, the first electrical node and the second electrical node can be electrically isolated from each other. Subsequent to making connection of the electrical circuit with the leadframe, the conductive path of the leadframe electrically connects the first electrical node and the second electrical node together. Accordingly, the leadframe provides connectivity between nodes of an electrical circuit in lieu of having to provide such connectivity at, for example, a metal interconnect layer of an integrated circuit device.

Abstract: According to one disclosed embodiment, a monolithic vertically integrated composite device comprises a double sided semiconductor substrate having first and second sides, a group IV semiconductor layer formed over the first side and comprising at least one group IV semiconductor device, and a group III-V semiconductor body formed over the second side and comprising at least one group III-V semiconductor device electrically coupled to the at least one group IV semiconductor device. The composite device may further comprise a substrate via and/or a through-wafer via providing electric coupling. In one embodiment, the group IV semiconductor layer may comprise an epitaxial silicon layer, and the at least one group IV semiconductor device may be a combined FET and Schottky diode (FETKY) fabricated on the epitaxial silicon layer. In one embodiment, the at least one group semiconductor device may be a III-nitride high electron mobility transistor (HEMT).