Abstract: Compact trench-gate semiconductor devices, for example a cellular power MOSFET with sub-micron pitch (Yc), are manufactured with self-aligned techniques that use sidewall spacers (52) in different ways. Thereby, the source region (13) and a contact window (18a) for a source electrode (33) can be self-aligned to a narrow trench (20) containing the trench-gate (11). Thereby, the channel-accommodating region (15) can also be provided after forming the trench-gate (11), and with very good control of its doping concentration (Na; p) adjacent to the trench (20). To achieve this control, its dopant is provided after removing the spacers (52) from the mask (51) so as to form a doping window (51b), which may also be used for the source dopant, adjacent to the trench-gate (11). A high energy dopant implant (61) or other doping process provides this channel dopant adjacent to the trench (20) and extending laterally below the mask (51, 51n).

Abstract: A two-terminal self-powered synchronous rectifier (ASR) is provided, together with two-terminal or three-terminal packaged devices that can replace an output diode rectifier (D) in a switched mode power supply. The synchronous rectifier comprises a field-effect transistor (M) having its source-drain path in a first arm (11) between the two rectifier terminals (A,K), normally a parallel diode (BD) in a second arm (12), a gate-control circuit (GC) connected to a gate electrode (g) of the transistor (M) for switching the transistor (M) synchronously on and off in accordance with voltage reversal at the two rectifier terminals (A,K), and a charge pump (C,R; C,R,C2,R2) in a third parallel arm for powering the control circuit from the power signal being rectified by the rectifier.

Abstract: A field effect transistor structure is formed with a body semiconductor layer (5) having source (9), body (7), drift region and drain (11). An upper semiconductor layer (21) is separated from the body by an oxide layer (17). The upper semiconductor layer (21) is doped to have a gate region (23) arranged over the body (7), a field plate region (25) arranged over the drift region 13 and at least one p-n junction (26) forming at least one diode between the field plate region (25) and the gate region (23). A source contact (39) is connected to both the source (9) and the field plate region (25).

Abstract: A switch circuit for battery-powered equipment, for example a mobile telephone or a portable computer, comprises a 4-terminal bi-directional semiconductor switch (M1) and a protection diode (Dbg). The switch (M1) has a control-gate terminal (g) for applying a control signal (Vg) to form a conduction channel (12) in a body region (11) of the switch, for turning the switch (M1) on and off between a battery (B) and a power line (2) of the equipment. The switch (M1) also has a back-gate terminal (b; bg) in a bias path that serves for applying a bias potential (Vmin) to the body region (11). The protection diode (Dbg) has a diode path in series with the back-gate terminal (b; bg) so as to provide in the bias path a rectifying barrier (25; 25′) that blocks current flow between the body region (11) and the gate-bias terminal (b, bg) in the event of a reverse voltage polarity across the switch (M1), for example when recharging the battery (B).

Abstract: A semiconductor device assembly comprises within an envelope (100) one or more upper component bodies (102, 103) mounted on a lower component body (101) to provide a low-cost, yet reliable half-bridge or full-bridge driver or rectifier circuit or a solenoid driver circuit or the like. Each component body (101, 102, 103) comprises a power MOSFET, IGBT, Schottky diode and/or other semiconductor component. A bottom main electrode (29a) of the lower body (101) is bonded to a mounting pad (130) in the envelope (100). Electrical connections (150) are bonded from conductor leads (140) of the envelope lead frame (130, 140) to respective bonding pads (124a/b/c, and 121a/b/c) of the top electrodes (24a/b/c; (21a/b/c) of the bodies (101, 102, 103). The lead-frame connection (150) to the bottom electrode (29b/d) of the upper body (102, 103) is via the top main electrode (24a/c) of the lower body (101), to which it is bonded without covering the electrode bonding pads (124a/c, 121a/c) of the lower body (101).