Superjunction has arguably been the most creative and important concept in the power device field since the introduction of the insulated gate bipolar transistor (IGBT) in the 1980s. It is the only concept known today that has challenged and ultimately proved wrong the well-known theoretical study on the limit of silicon in high-voltage devices. This paper deals with the history, device and process development, and the future prospects of Superjunction technologies. It covers fundamental physics, technological challenges as well as aspects of design and modeling of unipolar devices, such as CoolMOS. The superjunction concept is compared to other methods of enhancing the conductivity of power devices (from bipolar to employment of wide-bandgap materials) to derive its set of benefits and limitations. This paper closes with the application of the superjunction concept to other structures or materials, such as terminations, superjunction IGBTs, or silicon carbide Field Effect Transistors (FETs).

Superjunction Power Devices, History, Development, and Future Prospects

The present disclosure describes a methodology for wireless power transmission based on pocket-forming. This methodology may include one transmitter and at least one or more receivers, being the transmitter the source of energy and the receiver the device that is desired to charge or power. The transmitter may identify and locate the device to which the receiver is connected and thereafter aim pockets of energy to the device in order to power it. Pockets of energy may be generated through constructive and destructive interferences, which may create null-spaces and spots of pockets of energy ranged into one or more radii from transmitter. Such feature may enable wireless power transmission through a selective range, which may limit operation area of electronic devices and/or may avoid formation of pockets of energy near and/or over certain areas, objects and people.

Wireless power transmission with selective range

Configurations and methods of wireless power transmission for charging or powering one or more electronic devices inside a vehicle are disclosed. A transmitter capable of single or multiple pocket-forming may be connected to a car lighter, where this transmitter may include a circuitry module and an antenna array integrated within the transmitter, or operatively connected through a cable. This cable may allow the positioning of the antenna array in different locations inside the vehicle suitable for directing RF waves or pockets of energy towards one or more electronic devices. Transmitter's configuration can be accessed by one or more electronic devices through Bluetooth communication in order to set up charging or powering priorities.

Wireless charging and powering of electronic devices in a vehicle

The present disclosure may provide a wireless power system which may be used to provide wireless power transmission (WPT) while using suitable WPT techniques such as pocket-forming. Wireless power system may be used in a wireless powered house for providing power and charge to a plurality of mobile and non-mobile devices. Wireless powered house may include a single base station which may be connected to several transmitters. Base station may manage operation of every transmitter in an independently manner or may operate them as a single transmitter. Connection between base station and transmitters may be achieved through a plurality of techniques including wired connections and wireless connections.

Wireless powered house

Embodiments directed to providing health safety in a wireless power transmission systems are disclosed herein. One embodiment includes a processing apparatus with a processor; a data storage; and one or more wireless power transmitters each including at least two antennas. The one or more wireless power transmitters receive instructions from the processing apparatus that cause the transmitters to transmit RF waves that constructively interfere to provide wirelessly delivered power to one or more receivers. The processing apparatus receives and processes wireless power proscribing data for each respective receiver, respective wireless power proscribing data including at least one user-specified circumstance that a user inputs as to when a respective electronic device coupled with the respective receiver is in use; and the processing apparatus causes transmission of the RF waves by the transmitters in accordance with determining that the at least one user-specified circumstance is not present at the respective electronic device.

System and method for providing health safety in a wireless power transmission system

A transverse ultra-thin insulated gate bipolar transistor having current density includes: a P substrate, where the P substrate is provided with a buried oxide layer thereon, the buried oxide layer is provided with an N epitaxial layer thereon, the N epitaxial layer is provided with an N well region and P base region therein, the P base region is provided with a first P contact region and an N source region therein, the N well region is provided with an N buffer region therein, the N well region is provided with a field oxide layer thereon, the N buffer region is provided with a P drain region therein, the N epitaxial layer is provided therein with a P base region array including a P annular base region, the P base region array is located between the N well region and the P base region, the P annular base region is provided with a second P contact region and an N annular source region therein, and the second P contact region is located in the N annular source region. The present invention greatly increases current density of a transverse ultra-thin insulated gate bipolar transistor, thus significantly improving the performance of an intelligent power module.

Transverse ultra-thin insulated gate bipolar transistor having high current density

This paper presents the electrical characteristic of a 500 V silicon-on-insulator (SOI) lateral insulated-gate bipolar transistor (LIGBT) with segmented trenches in the anode (STA) region. The STA-LIGBT features segmented n+ anodes and segmented trenches. The segmented n+ anodes are shorted to the p+ anode, which accelerates the extraction of stored electrons during the device turn-OFF. The segmented trenches are arranged between the p+ anode and the shorted n+ anode. The resistors between the adjacent segmented trenches and the adjacent segmented n+ anodes contribute to low snapback voltage ( $V_{S}$ ) while maintain high current density. In addition, an internal diode is formed by introducing the shorted n+ anode. The 3-D simulations and the experiments are carried out to characterize the electrical performances of the STA-LIGBT and its internal diode. Compared with the conventional SOI-LIGBT, the STA device achieves a 73% improvement in turn-OFF time ( $t_{\mathrm{\scriptscriptstyle OFF}}$ ) at the same current density. Correspondingly, the internal diode of the STA-LIGBT achieves a forward voltage drop ( $V_{F}$ ) of 1.32 V and a reverse recovery time ( $t_{\mathrm {rr}}$ ) of 321 ns, which are superior to those of a conventional p-i-n SOI diode.

Electrical Characteristic Study of an SOI-LIGBT With Segmented Trenches in the Anode Region

A high-voltage silicon-on-insulator lateral insulated-gate bipolar transistor (SOI-LIGBT) with U-shaped channels, which are composed of parallel channels and orthogonal channels for improving the current density ( $J_{C}$ ) and latch-up immunity, is proposed and studied intensively in this paper. By using the U-shaped channels, the electron injection from the emitter into the $n$ -drift region is significantly enhanced, and the current density is improved. In addition, an analytical model is proposed, and it is indicated that $J_{C}$ can be improved as $\alpha $ (the angle between the parallel channel and the orthogonal channel) increases in a certain range. The hole current density distribution in the ON-state and the lattice temperature distribution in the short-circuit state of the proposed structure are also investigated. Increasing $\alpha $ is beneficial to alleviate the holes crowding beneath the n+ emitter and suppress the temperature rise in the JFET region, which is favorable for increasing the latch-up voltage ( $V_{\textrm {LP}}$ ) and short-circuit withstand time ( $t_{\textrm {SC}}$ ). The experiments demonstrate that the U-shaped channel SOI-LIGBT fabricated with 0.5- $\mu \text{m}$ SOI technology exhibits a high current density ( $J_{C}$ ) of 305 A/cm2 at $V_{\textrm {CE}}=3$ V and $V_{\textrm {GE}}=5$ V, and a low specific ON-resistance ( $R_{{\mathrm{\scriptscriptstyle ON}}\,\cdot \,\textrm {sp}}$ ) of 0.984 $\Omega \cdot \textrm {mm}^{2}$ with breakdown voltage of 590 V. The improved latch-up voltage ( $V_{\textrm {LP}}$ ) of 560 V and the short-circuit withstand time ( $t_{\textrm {SC}}$ ) of 5.1 $\mu \text{s}$ are obtained.

Further Study of the U-Shaped Channel SOI-LIGBT With Enhanced Current Density for High-Voltage Monolithic ICs

A silicon-on-insulator lateral insulated gate bipolar transistor with dual trenches located under the high voltage interconnection (HVI), which can be used in 500 V three-phase single chip inverter ICs, is proposed in this letter for the first time. Using the dual trenches to sustain the electric potential from the collector region, the electric field crowding induced by HVI at the silicon surface can be alleviated. The influence of HVI can be shielded completely by adjusting the position and spacing of the trenches. The experimental results show that the breakdown voltage of the proposed structure is 550 V and its latch-up voltage ( $\text{V}_{\mathrm {\mathbf {LP}}})\vphantom {\big ({}}$ at gate-emitter voltage of 15 V ( $\text{V}_{\mathrm {\mathbf {GE}}} = 15$ V) is higher than 500 V. The current density ( $\text{J}_{\mathrm {\mathbf {C}}})$ is 129 A/cm $^{\mathrm {\mathbf {2}}}$ when $\text{V}_{\mathrm {\mathbf {GE}}} = 5$ V and collector-emitter voltage ( $\text{V}_{\mathrm {\mathbf {CE}}})$ is 3 V. The turn OFF time ( $\text{t}_{\mathrm {\mathbf {OFF}}})$ is 132 ns at turn OFF current density of 84 A/cm $^{\mathrm {\mathbf {2}}}$ .

A Novel Silicon-on-Insulator Lateral Insulated-Gate Bipolar Transistor With Dual Trenches for Three-Phase Single Chip Inverter ICs

A SOI-LIGBT with Segmented Trenches in the Anode region (STA-LIGBT) is proposed and compared with the separated shorted-anode LIGBT (SSA-LIGBT) for the first time. The proposed STA-LIGBT structure features that there are segmented trenches located between the P+ anode and the segmented N+ anodes. By employing the segmented trenches, the resistance between the P+ anode and the shorted N+ anode is significantly increased, which effectively suppresses the negative differential resistance (NDR). The experiments show that the STA-LIGBT with its blocking voltage of 540V can achieve a current density (J C ) of 247 A/cm2 when the gate voltage is 10V and the anode voltage is 3V. With the same the NDR regime (the snapback voltage is 1.3V), the current density (J C ) of the STA-LIGBT is about 170% of that of the SSA-LIGBT. The fabrication of the segmented trenches is compatible with the trench isolation process and no extra or complicated processes are needed.

Jing Zhu

Papers

Transverse ultra-thin insulated gate bipolar transistor having high current density

Electrical Characteristic Study of an SOI-LIGBT With Segmented Trenches in the Anode Region

Further Study of the U-Shaped Channel SOI-LIGBT With Enhanced Current Density for High-Voltage Monolithic ICs

A Novel Silicon-on-Insulator Lateral Insulated-Gate Bipolar Transistor With Dual Trenches for Three-Phase Single Chip Inverter ICs

A high current density SOI-LIGBT with Segmented Trenches in the Anode region for suppressing negative differential resistance regime