Abstract: Systems and methods for substrate wafer back side and edge cross section seals. In accordance with a first method embodiment, a silicon wafer of a first conductivity type is accessed. An epitaxial layer of the first conductivity type is grown on a front surface of the silicon wafer. The epitaxial layer is implanted to form a region of an opposite conductivity type. The growing and implanting are repeated to form a vertical column of the opposite conductivity type. The wafer may also be implanted to form a region of the opposite conductivity type vertically aligned with the vertical column.

Abstract: Vertical sense devices in vertical trench MOSFET. In accordance with an embodiment of the present invention, an electronic circuit includes a vertical trench metal oxide semiconductor field effect transistor configured for switching currents of at least one amp and a current sensing field effect transistor configured to provide an indication of drain to source current of the MOSFET. A current sense ratio of the current sensing FET is at least 15 thousand and may be greater than 29 thousand.

Abstract: First polysilicon (poly-1) is deposited into deep trenches that have been formed in a substrate. A first polysilicon polishing process is performed to planarize the exposed surfaces of the poly-1 so that the surfaces are flush with adjacent surfaces. Then, shallow trenches are formed in the substrate between the deep trenches, and second polysilicon (poly-2) is deposited into the shallow trenches. A second polysilicon polishing process is performed to planarize the exposed surface of the poly-2 so that the surface is flush with adjacent surfaces. Metal contacts to the poly-1 and the poly-2 are then formed.

Abstract: Vertical sense devices in vertical trench MOSFET. In accordance with an embodiment of the present invention, a semiconductor device includes a main vertical trench metal oxide semiconductor field effect transistor (main-MOSFET). The main-MOSFET includes a plurality of parallel main trenches, wherein the main trenches comprise a first electrode coupled to a gate of the main-MOSFET, and a plurality of main mesas between the main trenches, wherein the main mesas comprise a main source and a main body of the main-MOSFET. The semiconductor device also includes a sense-diode. The sense-diode includes a plurality of sense-diode trenches, wherein each of the sense-diode trenches comprises a portion of one of the main trenches, and a plurality of sense-diode mesas between the source-FET trenches, wherein the sense-diode mesas comprise a sense-diode anode that is electrically isolated from the main source of the main-MOSFET.

Abstract: A method for fabricating a dual trench structure. The method includes providing a wafer comprising a semiconductor layer including a top surface. The method includes providing charge compensation trenches and termination trenches open to the top surface that are formed in a single etch step but with different final shield oxide thicknesses. A first shield oxide layer of a first thickness is formed on the plurality of charge compensation surfaces and the termination trench surface, wherein the first thickness of the first shield oxide layer is sufficient to allow formation of voids through the charge compensation trenches. Poly-silicon is deposited to form the electrodes in the charge compensation trenches. An isolated poly-silicon etch and clean etch is performed in the termination trenches to expose the first shield oxide layer. A second shield oxide layer is deposited on the first shield oxide layer in the termination trenches.

Abstract: A high-electron-mobility transistor (HEMT) includes a substrate layer of silicon, a first contact disposed on a first surface of the substrate layer, and a number of layers disposed on a second surface of the substrate layer opposite the first surface. A second contact and a gate contact are disposed on those layers. A trench containing conducting material extends completely through the layers and into the substrate layer. In an embodiment of the HEMT, the first contact is a drain contact and the second contact is a source contact. In another embodiment of the HEMT, the first contact is a source contact and the second contact is a drain contact.

Abstract: Edge termination for MOSFETs. In accordance with an embodiment of the present invention, a metal oxide semiconductor field effect transistor (MOSFET) includes a core region including a plurality of parallel core plates coupled to a source terminal of the MOSFET. The MOSFET also includes a termination region surrounding the core region comprising a plurality of separated floating termination segments configured to force breakdown into the core region and not in the termination region. Each termination segment has a length dimension less than a length dimension of the core plates.

Abstract: A semiconductor device—e.g., a super junction power MOSFET—includes a number of columns of one type of dopant formed in a region of another type of dopant. Generally speaking, the columns are modulated in some manner. For example, the widths (e.g., diameters) of some columns are greater than the widths of other columns.

Abstract: Disclosed are semiconductor devices that include additional gate pads, and methods of fabricating and testing such devices. A device may include a first gate pad, a second gate pad, and a third gate pad. The first gate pad is connected to a gate including a gate oxide layer. The second and third gate pads are part of an electro-static discharge (ESD) protection network for the device. The ESD protection network is initially isolated from the first gate pad and hence from the gate and gate oxide layer. Accordingly, gate oxide integrity (GOI) testing can be effectively performed and the reliability and quality of the gate oxide layer can be checked. The second gate pad can be subsequently connected to the first gate pad to enable the ESD protection network, and the third gate pad can be subsequently connected to an external terminal when the device is packaged.

Abstract: Vertical sense devices in vertical trench MOSFET. In accordance with an embodiment of the present invention, an electronic circuit includes a vertical trench metal oxide semiconductor field effect transistor configured for switching currents of at least one amp and a current sensing field effect transistor configured to provide an indication of drain to source current of the MOSFET. A current sense ratio of the current sensing FET is at least 15 thousand and may be greater than 29 thousand.

Abstract: In one embodiment, a semiconductor device can include a substrate including a first type dopant. The semiconductor device can also include an epitaxial layer located above the substrate and including a lower concentration of the first type dopant than the substrate. In addition, the semiconductor device can include a junction extension region located within the epitaxial layer and including a second type dopant. Furthermore, the semiconductor device can include a set of field rings in physical contact with the junction extension region and including a higher concentration of the second type dopant than the junction extension region. Moreover, the semiconductor device can include an edge termination structure in physical contact with the set of field rings.

Abstract: A semiconductor package and a method for making the same are provided. In the method, a clip is used to conduct a lead frame and at least one chip. The clip has at least one second connection segment, at least one third connection segment, and at least one intermediate connection segment. The second connection segment is electrically connected to a second conduction region of the chip and a second pin of the lead frame respectively, and the third connection segment is electrically connected to a third conduction region of the chip and a third pin of the lead frame respectively. The intermediate connection segment connects the at least one second connection segment and the at least one third connection segment, and is removed in a subsequent process. Thereby, the present invention does not need to use any gold wire, which effectively saves the material cost and the processing time.

Abstract: A device includes a first high electronic mobility transistor (HEMT) and a second HEMT. The first HEMT includes a first gate, a source coupled to the first gate, and a drain coupled to the first gate. The second HEMT includes a second gate coupled to the source and to the drain. The second HEMT has a lower threshold voltage than the first HEMT.

Abstract: A laterally diffused metal oxide semiconductor (LDMOS) transistor structure with improved unclamped inductive switching immunity. The LDMOS includes a substrate and an adjacent epitaxial layer both of a first conductivity type. A gate structure is above the epitaxial layer. A drain region and a source region, both of a second conductivity type, are within the epitaxial layer. A channel is formed between the source and drain region and arranged below the gate structure. A body structure of the first conductivity type is at least partially formed under the gate structure and extends laterally under the source region, wherein the epitaxial layer is less doped than the body structure. A conductive trench-like feed-through element passes through the epitaxial layer and contacts the substrate and the source region. The LDMOS includes a tub region of the first conductivity type formed under the source region, and adjacent laterally to and in contact with said body structure and said trench-like feed-through element.

Abstract: A method for fabricating a MOSFET having an active area and an edge termination area is disclosed. The method includes forming a first plurality of implants at the bottom of trenches located in the active area and in the edge termination area. A second plurality of implants is formed at the bottom of the trenches located in the active area. The second plurality of implants formed at the bottom of the trenches located in the active area causes the implants formed at the bottom of the trenches located in the active area to reach a predetermined concentration. In so doing, the breakdown voltage of both the active and edge termination areas can be made similar and thereby optimized while maintaining advantageous RDson.

Abstract: A semiconductor device (e.g., a flip chip) includes a substrate layer that is separated from a drain contact by an intervening layer. Trench-like feed-through elements that pass through the intervening layer are used to electrically connect the drain contact and the substrate layer when the device is operated.

Abstract: A trench metal-oxide-semiconductor field effect transistor (TMOSFET) includes a plurality of mesas disposed between a plurality of gate regions. Each mesa includes a drift region and a body region. The width of the mesa is in the order of quantum well dimension at the interface between the gate insulator regions and the body regions The TMOSFET also includes a plurality of gate insulator regions disposed between the gate regions and the body regions, drift regions, and drain region. The thickness of the gate insulator regions between the gate regions and the drain region results in a gate-to-drain electric field in an OFF-state that is substantially lateral aiding to deplete the charge in the drift regions.

Abstract: A semiconductor device includes a trench formed in an epitaxial layer and an oxide layer that lines the sidewalls of the trench. The thickness of the oxide layer is non-uniform, so that the thickness of the oxide layer toward the top of the trench is thinner than it is toward the bottom of the trench. The epitaxial layer can have a non-uniform dopant concentration, where the dopant concentration varies according to the thickness of the oxide layer.

Abstract: In one embodiment, a stack die package can include a lead frame and a first die including a gate and a source that are located on a first surface of the first die and a drain that is located on a second surface of the first die that is opposite the first surface. The gate and source are flip chip coupled to the lead frame. The stack die package can include a second die including a gate and a drain that are located on a first surface of the second die and a source that is located on a second surface of the second die that is opposite the first surface. The source of the second die is facing the drain of the first die.

Abstract: A trench metal-oxide-semiconductor field effect transistor (MOSFET), in accordance with one embodiment, includes a drain region, a plurality of gate regions disposed above the drain region, a plurality of gate insulator regions each disposed about a periphery of a respective one of the plurality of gate regions, a plurality of source regions disposed in recessed mesas between the plurality of gate insulator regions, a plurality of body regions disposed in recessed mesas between the plurality of gate insulator regions and between the plurality of source regions and the drain region.