Abstract: A bi-directional ESD protection device for an RF circuit that utilizes two pre-driver FETs to reliably maintain the gate voltage of a ggNMOS-type main transistor the lowest applied voltage (e.g., 0V) in order to maximize the main transistor's drain-to-source breakdown voltage, which determines the trigger voltage of the ESD protection device. One pre-driver FET couples the main transistor's gate to ground during positive voltage input signal phases, and the other pre-driver FET couples the main transistor's gate to the input signal path during negative voltage input signal phases. While the amplitude of the input signals remains below the main transistor's trigger voltage, the main transistor remains completely turned off, whereby the input signals are passed to I/O circuitry with minimal interference. Whenever the input signal exceeds the trigger voltage, the main transistor turns on to shunt the over-voltage/current to ground, thereby protecting the I/O circuitry.

Abstract: An RF switch includes series-connected transistors having different threshold voltages, breakdown voltages and on-resistances, without relying on different channel lengths to provide these differences. A first set of transistors located near a power amplifier output are fabricated to have first channel regions with relatively high dopant concentrations. A second set of transistors located near an antenna input, are fabricated to have second channel regions with relatively low dopant concentrations. The first set of transistors can also include halo implants to increase the dopant concentrations in the first channel regions. Lightly doped drain (LDD) regions of the first set of transistors can have a lower dopant concentration (and be shallower) than LDD regions of the second set of transistors. Transistors in the first set have a relatively high on-resistance, a relatively high breakdown voltage and a relatively high threshold voltage, when compared with transistors in the second set.

Abstract: A radio frequency (RF) switch includes a plurality of series-connected silicon-on-insulator (SOI) CMOS transistors fabricated in accordance with a semiconductor process having a first minimum line width (e.g., 0.18 microns). While the semiconductor process conventionally implements a polysilicon gate layer having a first thickness (e.g., 2000 Angstroms), each of the plurality of SOI CMOS transistors is fabricated with a polysilicon gate electrode having a second thickness, which is less than the first thickness. The reduced thickness of the polysilicon gate electrodes of the SOI CMOS transistors reduces the on-resistance and the off-capacitance of the associated RF switch.

Abstract: An RF switch includes series-connected transistors having different threshold voltages, breakdown voltages and on-resistances, without relying on different channel lengths to provide these differences. A first set of transistors located near a power amplifier output are fabricated to have first channel regions with relatively high dopant concentrations. A second set of transistors located near an antenna input, are fabricated to have second channel regions with relatively low dopant concentrations. The first set of transistors can also include halo implants to increase the dopant concentrations in the first channel regions. Lightly doped drain (LDD) regions of the first set of transistors can have a lower dopant concentration (and be shallower) than LDD regions of the second set of transistors. Transistors in the first set have a relatively high on-resistance, a relatively high breakdown voltage and a relatively high threshold voltage, when compared with transistors in the second set.

Abstract: A radio frequency (RF) switch includes a plurality of series-connected silicon-on-insulator (SOI) CMOS transistors, including a plurality of parallel source/drain regions, a plurality of channel regions located between the plurality of source/drain regions, and a polysilicon gate structure located over the plurality of channel regions. The polysilicon gate structure includes a plurality of polysilicon gate fingers, wherein each polysilicon gate finger extends over a corresponding one of the channel regions. The polysilicon gate structure also includes a polysilicon base region that connects first ends of the polysilicon gate fingers. The polysilicon gate structure also includes triangular polysilicon extension regions coupled to the polysilicon gate fingers. The triangular extension regions can be located at the first ends of the polysilicon gate fingers (abutting the polysilicon base region), or at second (opposing ends) of the polysilicon gate fingers.

Abstract: A semiconductor device includes a source finger electrode coupled to a source region in a semiconductor die, a drain finger electrode coupled to a drain region in the semiconductor die, where the source finger electrode includes at least one isolated segment and a main segment having a first portion and a second portion narrower than the first portion, whereby the source finger electrode reduces a drain-to-source capacitance of the semiconductor device. A common source rail is electrically coupled to the at least one isolated segment and the main segment of the source finger electrode. The drain finger electrode includes at least one isolated segment and a main segment having a first portion and a second portion narrower than the first portion. A common drain rail is electrically coupled to the at least one isolated segment and the main segment of the drain finger electrode.

Abstract: An RF switch includes series-connected transistors having different threshold voltages, breakdown voltages and on-resistances, without relying on different channel lengths to provide these differences. A first set of transistors located near a power amplifier output are fabricated to have first channel regions with relatively high dopant concentrations. A second set of transistors located near an antenna input, are fabricated to have second channel regions with relatively low dopant concentrations. The first set of transistors can also include halo implants to increase the dopant concentrations in the first channel regions. Lightly doped drain (LDD) regions of the first set of transistors can have a lower dopant concentration (and be shallower) than LDD regions of the second set of transistors. Transistors in the first set have a relatively high on-resistance, a relatively high breakdown voltage and a relatively high threshold voltage, when compared with transistors in the second set.

Abstract: A semiconductor device includes a source finger electrode coupled to a source region in a semiconductor die, a drain finger electrode coupled to a drain region in the semiconductor die, where the source finger electrode includes at least one isolated segment and a main segment having a first portion and a second portion narrower than the first portion, whereby the source finger electrode reduces a drain-to-source capacitance of the semiconductor device. A common source rail is electrically coupled to the at least one isolated segment and the main segment of the source finger electrode. The drain fmger electrode includes at least one isolated segment and a main segment having a first portion and a second portion narrower than the first portion. A common drain rail is electrically coupled to the at least one isolated segment and the main segment of the drain finger electrode.