Lovoltech, Incorporated

Qspeed Semiconductor Inc.

Other

Power Integrations, Inc.

Champion Microelectronic Corporation

Yutechnix, Inc.

Vlsi Technology, Inc.

Mobius Green Energy, Inc.

Ho-Yuan Yu

Valentino Liva

Jian Li

Daniel Chang

Haiping Dun

Hung-Chen Lin

Pete Pegler

Chong-Ming Lin

Chung S Wang

Ying-Tsong Loh

Eric Earl Johnson

Muzahid Bin Huda

Apparatus and other embodiments associated with high speed and high breakdown voltage rectifier are disclosed. A Junction All Around structure, where a deep trench structure surrounds and encloses a P-N junction or a MOS structure, is created and applied in various rectifiers. In one embodiment, multiple deep trenches in ring shape enclosed a vertical P-N junction. For each deep trench, a corresponding wider ring-shape P+ region is created on top of a N&#x2212; epi layer. This enclosed deep trench surrounding a vertical P-N junction and a thinner N&#x2212; epitaxial layer allow higher reverse bias voltage and low leakage current. In another embodiment, an enclosed deep trench in ring shape surrounds a horizontal P-N junction, which results in a planar N-channel MOS during forward bias. The structure can be extended to multiple deep trenches with associated horizontal P-N junctions. In a further embodiment, an enclosed deep trench in ring shape surrounds a vertical MOS structure plus a shallow trench gate in the center to create yet another device with very high breakdown voltage and very low leakage current. This structure can be extended to multiple deep trenches and shallow trenches as well.

Deep trench MOS barrier junction all around rectifier and MOSFET

Apparatus, methods and other embodiments associated with a high speed and high breakdown voltage Schottky rectifier are disclosed. In one embodiment, the Schottky rectifier has three layers of N-type semiconductor, a first layer of highly doped N-type substrate at the bottom, a second layer of lightly doped epitaxial N-type material above the first layer, and a third layer of very low doping concentration N-type material created by converting the top shallow portion of the second layer without turning into P-type. The Schottky device further includes an enclosed deep trench structure close to the bottom of the second layer and can sustain high reverse bias voltage up to 2,000 volt.

High speed Schottky rectifier

A field effect transistor, in accordance with one embodiment, includes a metal-oxide-semiconductor field effect transistor (MOSFET) having a junction field effect transistor (JFET) embedded as a body diode.

MOSFET having a JFET embedded as a body diode

Various stress relief structures are provided for effectively reducing thermal stress on a semiconductor chip in a chip package. Trenches on a metal substrate are created in groups in two-dimension, where each trench is opened from top or bottom surface of the metal substrate and in various shapes. The metal substrate is partitioned into many smaller substrates depending on the number of trench groups and partitions, and is attached to a semiconductor chip for stress relief. In an alternative embodiment, a plurality of cylindrical metal structures are used together with a metal substrate in a chip package for the purpose of heat removal and thermal stress relief on a semiconductor chip. In another alternative embodiment, a metal foam is used together with a semiconductor chip to create a chip package. In another alternative embodiment, a semiconductor chip is sandwiched between a heat sink and a circuit board by solder bumps directly with underfill on the circuit board.

Apparatus for chip thermal stress relief

A fast recovery rectifier structure with the combination of Schottky structure to relieve the minority carriers during the forward bias condition for the further reduction of the reverse recovery time during switching in addition to the lifetime killer such as Pt, Au, and/or irradiation. This fast recovery rectifier uses unpolished substrates and thick impurity diffusion for low cost production. A reduced p-n junction structure with a heavily p-type doped thin film is provided to terminate and shorten the p-n junction space charge region. This reduced p-n junction with less total charge in the p-n junction to further improve the reverse recovery time. This reduced p-n junction can be used alone, with the traditional lifetime killer method, with the Schottky structure and/or with the epitaxial substrate.

Fast recovery reduced p-n junction rectifier

Circuits and methods of dynamic modulation are disclosed. A dynamic modulator is used to reduce measurable conducted and/or radiated electromagnetic interference (EMI). The dynamic modulator is configured to generate either a set of optimal frequency modulation depths or discrete frequencies or both, and dynamically selects them to use over a series of programmable time durations (dwell time). Together with the utilization of Peak, Average or Quasi-Peak (QP) method of measurement, the dynamic modulator can reduce the spectral amplitude of EMI components, in particular the lower harmonics, to effectively pass regulatory requirements. In alternative embodiments, the dynamic modulator is used in a closed loop system to continuously adjust the frequency and the duty cycle of a PWM signal to reduce conducted and/or radiated EMI.

Method and apparatus for dynamic modulation

This invention discloses a novel apparatus of fully depleted emitter so that the built-in potential between emitter and the base becomes lower and the charge storage between the emitter and base becomes small. This concept also applies to the diodes or rectifiers. With depleted junction, this results in very fast switching of the diodes and transistors. Another novel structure utilizes the strip base structure to achieve lower on resistance of the bipolar transistor. The emitter region of the strip base can be a normal emitter or depleted emitter.

Bipolar transistor with depleted emitter

A fast recovery rectifier structure with the combination of Schottky structure to relieve the minority carriers during the forward bias condition for the further reduction of the reverse recovery time during switching in addition to the lifetime killer such as Pt, Au, and/or irradiation. This fast recovery rectifier uses unpolished substrates and thick impurity diffusion for low cost production. A reduced p-n junction structure with a heavily doped film is provided to terminate and shorten the p-n junction space charge region. This reduced p-n junction with less total charge in the p-n junction to further improve the reverse recovery time. This reduced p-n junction can be used alone, with the traditional lifetime killer method, with the Schottky structure and/or with the epitaxial substrate.

This invention disclosed a novel method of fully depleted emitter so that the built-in potential between emitter and the base becomes lower and the charge storage between the emitter and base becomes small. This concept also applies to the diodes or rectifiers. With depleted junction, this result in very fast switching of the diodes and transistors. Another novel structure utilizes the strip base structure to achieve lower on resistance of the bipolar transistor. The emitter region of the strip base can be a normal emitter or depleted emitter.

Bipolar transistors with depleted emitter

A field effect transistor (FET), in accordance with one embodiment, includes a first semiconductor layer, a first dielectric layer, a second semiconductor layer, a second dielectric layer and a third semiconductor layer. The first dielectric layer may be disposed upon the first semiconductor layer, wherein the first semiconductor layer has a first conductivity type. The second semiconductor layer, having a second conductivity type, may be disposed upon the first dielectric layer. The second dielectric layer may be disposed upon the second semiconductor layer. The third semiconductor layer, having a first conductivity type, may be disposed upon the first semiconductor layer between a first and second portion of the first dielectric layer, a first and second portion of the second semiconductor layer and a first and second portion of the second dielectric layer. The FET may also include a third dielectric layer disposed between the third semiconductor layer and the first and second portions of the second semiconductor layer.

Field effect transistor

A method for fabricating a dual gate structure for JFETs and MESFETs and the associated devices. Trenches are etched in a semiconductor substrate for fabrication of a gate structure for a JFET or MESFET. A sidewall spacer may be formed on the walls of the trenches to adjust the lateral dimension for a first gate. Following the formation of the first gate by implantation or deposition, a buffer region is implanted below the first gate using a complementary dopant and a second sidewall spacer with a thickness that may be the same or greater than the thickness of the first sidewall spacer. Subsequent to the buffer implant, a second gate is implanted beneath the buffer layer using a third sidewall spacer with a greater thickness than the first sidewall spacer.

Method for a junction field effect transistor with reduced gate capacitance

A junction field effect transistor (JFET) with a reduced gate capacitance. A gate definition spacer is formed on the wall of an etched trench to establish the lateral extent of an implanted gate region for a JFET. After implant, the gate is annealed. In addition to controlling the final junction geometry and thereby reducing the junction capacitance by establishing the lateral extent of the implanted gate region, the gate definition spacer also limits the available diffusion paths for the implanted dopant species during anneal. Also, the gate definition spacer defines the walls of a second etched trench that is used to remove a portion of the p-n junction, thereby further reducing the junction capacitance.

Structure for reduced gate capacitance in a JFET

A method and structure for a composite trench fill for silicon electronic devices. On a planar silicon substrate having a first deposited layer of oxide and a second deposited layer of polysilicon, a trench is etched. Deposition and etch processes using a combination of oxide and polysilicon are used to fabricate a composite trench fill. The trench bottom and a lower portion of the walls are covered with oxide. The remaining portion of the trench volume is filled with polysilicon. The method may be used for junction field effect transistors (JFETs) and metal oxide semiconductor field effect transistors (MOSFETs).

Growing community of inventors

Saratoga, CA, United States of America

Ho-Yuan Yu