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.

A semiconductor high-voltage device includes a semiconductor substrate; a high-voltage well in the semiconductor substrate; a drift region in the high-voltage well; a recessed channel region adjacent to the drift region; a heavily doped drain region in the drift region and spaced apart from the recessed channel; an isolation structure between the recessed channel region and the heavily doped drain region in the drift region; a buried gate dielectric layer on the recessed channel region, wherein the top surface of the buried gate dielectric layer is lower than the top surface of the heavily doped drain region; and a gate on the buried gate dielectric layer.

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.

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.

The present disclosure generally to semiconductor devices, and more particularly to semiconductor devices having high-voltage transistors integrated on a semiconductor-on-insulator substrate and methods of forming the same. The present disclosure provides a semiconductor device including a semiconductor-on-insulator (SOI) substrate having a semiconductor layer, a bulk substrate and an insulating layer between the semiconductor layer and the bulk substrate, a source region and a drain region disposed on the bulk substrate, an isolation structure extending through the insulating layer and the semiconductor layer and terminates in the bulk substrate, and a gate structure between the source region and the drain region, the gate structure is disposed on the semiconductor layer.

A network device includes one or more circuit components. The one or more circuit components include a semiconductor substrate, a first device terminal and a second device terminal, a drift region, and a mobility modulator. Both device terminals are coupled to the semiconductor substrate, the second device terminal being spatially separated from the first device terminal. The drift region is disposed on the semiconductor substrate between the first device terminal and the second device terminal, the drift region being configured to allow a flow of charge-carriers between the first device terminal and the second device terminal. The mobility modulator is coupled to the drift region, the mobility modulator being configured to selectively apply a field across the drift region responsive to one or more modulation signals, so as to modulate a mobility of charge-carriers as a function of longitudinal position along the drift region.

A semiconductor device includes: a chip having a main surface; a first conductive type first region formed on a surface layer portion of the main surface; a second conductive type second region formed on a surface layer portion of the first region; a drain region formed on a surface layer portion of the second region; a source region formed on the surface layer portion of the first region at a distance from the second region; and a second conductive type floating region formed in the first region at a thickness position between a bottom portion of the first region and a bottom portion of the second region and being spaced apart from the bottom portion of the second region, wherein the floating region faces the second region with a portion of the first region interposed between the floating region and the second region.

A voltage tracking circuit is provided and includes first and second P-type transistors and a voltage reducing circuit. The drain of the first P-type transistor is coupled to a first voltage terminal. The voltage reducing circuit is coupled between the first voltage terminal and the gate of the first P-type transistor. The voltage reducing circuit reduces a first voltage at the first voltage terminal by a modulation voltage to generate a control voltage and provides the control voltage to the gate of the first P-type transistor. The gate of the second P-type transistor is coupled to the first voltage terminal, and the drain thereof is coupled to a second voltage terminal. The source of the first P-type transistor and the source of the second P-type transistor are coupled to the output terminal of the voltage tracking circuit. The output voltage is generated at the output terminal.

A semiconductor device includes a semiconductor substrate, a gate dielectric, a gate electrode, and a pair of source/drain regions. The gate dielectric is disposed in the semiconductor substrate having an upper boundary lower than an upper surface of the semiconductor substrate, and an upper surface flush with the upper surface of the semiconductor substrate. The gate electrode is disposed over the gate dielectric having a first section over the upper boundary of the gate dielectric and a second section over the upper surface of the gate dielectric. The second section partially covers and partially exposes the upper surface of the gate dielectric. The pair of source/drain regions are disposed on opposing sides of the gate dielectric.

An integrated circuit (IC) device comprises a high voltage semiconductor device (HVSD) on a frontside of a semiconductor body and further comprises an electrode on a backside of the semiconductor body opposite the frontside. The HVSD may, for example, be a transistor or some other suitable type of semiconductor device. The electrode has one or more gaps directly beneath the HVSD. The one or more gaps enhance the effectiveness of the electrode for improving the breakdown voltage of the HVSD.