A shielded gate MOSFET device and a manufacturing method thereof is provided. In the method, the shielded gate thick dielectric layers are formed with the thick oxide layer process at the bottoms in the trenches, poly is deposited in each trench and is back etched to leave gate poly on the side wall of each trench, whereas the portion, right in the center of each trench, of the thin poly layer is removed to be filled with the contact hole dielectric layer, which achieves the effect of streamlining the process flow.

A semiconductor device includes a semiconductor substrate, a gate structure, a source region, a drain region, a first oxide layer, a field plate, and a second oxide layer. The gate structure is disposed on the semiconductor substrate. The source region and the drain region are disposed in the semiconductor substrate and located at two opposite sides of the gate structure respectively. The first oxide layer includes a first portion disposed between the gate structure and the semiconductor substrate and a second portion disposed between the gate structure and the drain region. The field plate is partly disposed above the gate structure and partly disposed above the second portion of the first oxide layer. The second oxide layer includes a first portion disposed between the field plate and the gate structure and a second portion disposed between the field plate and the second portion of the first oxide layer.

The present invention introduces a new shielded gate trench SBR (Super Barrier Rectifier) wherein an epitaxial layer having special MSE (multiple stepped epitaxial) layers with different doping concentrations decreasing in a direction from a substrate to a top surface of the epitaxial layer, wherein each of the MSE layers has an uniform doping concentration as grown. Forward voltage V.sub.f is significantly reduced with the special MSE layers. An integrated circuit comprising a SGT MOSFET and a SBR formed on a single chip obtains benefits of low on-resistance, low reverse recovery time and high avalanche capability from the special MSE layers.

A semiconductor device comprises: a substrate; a well region provided in the substrate, having a second conductivity type; source regions having a first conductivity type; body tile regions having the second conductivity type, the source regions and the body tie regions being alternately arranged in a conductive channel width direction so as to form a first region extending along the conductive channel width direction, and a boundary where the edges of the source regions and the edges of the body tie regions are alternately arranged being formed on two sides of the first region; and a conductive auxiliary region having the first conductivity type, provided on at least one side of the first region, and directly contacting the boundary, a contact part comprising the edge of at least one source region on the boundary and the edge of at least one body tie region on the boundary.

A modified structure of an n-channel lateral double-diffused metal oxide semiconductor (LDMOS) transistor is provided to suppress the rupturing of the gate-oxide which can occur during the operation of the LDMOS transistor. The LDMOS transistor comprises a dielectric isolation structure which physically isolates the region comprising a parasitic NPN transistor from the region generating a hole current due to weak-impact ionization, e.g., the extended drain region of the LDMOS transistor. According to an embodiment of the disclosure, this can be achieved using a vertical trench between the two regions. Further embodiments are also proposed to enable a reduction in the gain of the parasitic NPN transistor and in the backgate resistance in order to further improve the robustness of the LDMOS transistor.

Existing semiconductor transistor processes may be leveraged to form lateral extensions adjacent to a conventional gate structure. The dielectric thickness under these lateral gate extensions can be varied to optimize device channel resistance and enable resistance to breakdown at high operating voltages. These extensions may be patterned with dimensions that are not limited by lithographic resolution and overlay capabilities and are compatible with conventional processing for ease of integration with other devices. The lateral extensions and dielectric spacers may be used to form self-aligned source, drain, and channel regions. A thin dielectric layer may be formed under an extension gate to reduce channel resistance. A thick dielectric layer may be formed under an extension gate to improve operation voltage range. The present invention provides an innovative structure with lateral gate extensions which may be referred to as EGMOS (extended gate metal oxide semiconductor).

An EEPROM memory integrated circuit includes memory cells arranged in a memory plane. Each memory cell includes an access transistor in series with a state transistor. Each access transistor is coupled, via its source region, to the corresponding source line and each state transistor is coupled, via its drain region, to the corresponding bit line. The floating gate of each state transistor rests on a dielectric layer having a first part with a first thickness, and a second part with a second thickness that is less than the first thickness. The second part is located on the source side of the state transistor.

Embodiments herein describe techniques for a semiconductor device including a substrate and a FinFET transistor on the substrate. The FinFET transistor includes a fin structure having a channel area, a source area, and a drain area. The FinFET transistor further includes a gate dielectric area between spacers above the channel area of the fin structure and below a top surface of the spacers; spacers above the fin structure and around the gate dielectric area; and a metal gate conformally covering and in direct contact with sidewalls of the spacers. The gate dielectric area has a curved surface. The metal gate is in direct contact with the curved surface of the gate dielectric area. Other embodiments may be described and/or claimed.

Methods of forming a self-aligned gate (SAG) and self-aligned source (SAD) device for high E.sub.crit semiconductors are presented. A dielectric layer is deposited on a high E.sub.crit substrate. The dielectric layer is etched to form a drift region. A refractory material is deposited on the substrate and dielectric layer. The refractory material is etched to form a gate length. Implant ionization is applied to form high-conductivity and high-critical field strength source with SAG and SAD features. The device is annealed to activate the contact regions. Alternately, a refractory material may be deposited on a high E.sub.crit substrate. The refractory material is etched to form a channel region. Implant ionization is applied to form high-conductivity and high E.sub.crit source and drain contact regions with SAG and SAD features. The refractory material is selectively removed to form the gate length and drift regions. The device is annealed to activate the contact regions.

Disclosed herein are methods for forming MOSFETs. In some embodiments, a method may include providing a device structure including a plurality of trenches, and forming a mask over the device structure including within each of the plurality of trenches and over a top surface of the device structure. The method may further include removing the mask from within the trenches, wherein the mask remains along the top surface of the device structure, and implanting the device structure to form a treated layer along a bottom of the trenches. In some embodiments, the method may further include forming a gate oxide layer along a sidewall of each of the trenches and along the bottom of the trenches, wherein a thickness of the oxide along the bottom of the trenches is greater than a thickness of the oxide along the sidewall of each of the trenches.