81results about How to "Improve reverse withstand voltage" patented technology

The invention relates to a fast recovery diode FRD chip and a production process for the same. The process comprises the following steps of: diffusion pre-treatment, boron source pre-deposition, boron source main diffusion, diffusion after-treatment, single-surface back grinding thinning, oxidation pre-treatment, oxidation, photoetching, single-surface oxide layer removal, phosphorus source pre-deposition, phosphorus diffusion, sand blasting, platinum diffusion, N + surface mesa etching, electrophoresis, sintering, oxide layer removal, nickel plating, gold plating and chip cutting, wherein the structure of the obtained chip is P+-N-N+ type. According to the process, the uniformity of the reverse recovery time of the fast recovery diode is improved and controllability is improved, meanwhile, voltage drop is reduced, leakage current is reduced, and voltage-proof stability is improved; the contradiction of mutual condition among the reverse voltage, the positive voltage, the reverse recovery time and the leakage current of the fast recovery diode is solved to enable the various parameters to achieve the optimal matching, thus improving the reliability and switching characteristic of the diode, and reducing power consumption. The fast recovery diode disclosed by the invention breaks through the technical bottleneck of the traditional fast recovery diodes.

The invention discloses a GaN hetero-junction diode device and a method for manufacturing the same. The GaN hetero-junction diode device comprises a substrate, a buffer layer, a channel layer, a potential barrier layer, a cap layer, a first Ohm anode, an Ohm cathode and a second Ohm anode. The buffer layer is positioned on the substrate; the channel layer is positioned on the buffer layer; the potential barrier layer is positioned on the channel layer, the potential barrier layer and the channel layer form a hetero-structure, and a two-dimensional electric channel is formed at a hetero-junction interface; the cap layer is positioned on the potential barrier layer; the first Ohm anode and the Ohm cathode are positioned on the upper side of the potential barrier layer and are arranged on two sides of the cap layer, and the first Ohm anode is in contact with the cap layer; the second Ohm anode is positioned on the first Ohm anode and the cap layer and is in Ohm metal contact with the cap layer. The GaN hetero-junction diode device and the method have the advantages that the problem of conflict between forward start voltage control and reverse electric leakage in the prior art can be solved, and a diode has characteristics of low start voltages and turn-on resistance and high reverse withstand voltages and forward turn-on currents.

A trench gate power semiconductor device (100) of the present invention is provided with: an n--type drift layer (114); a p-type body layer (120); a groove (124); an n+-type source region (132); a gate insulating film (126) that is formed on the inner peripheral surface of the groove (124); a gate electrode film (128) that is formed on the inner peripheral surface of the gate insulating film (126); and a source electrode layer (136) that is formed to be in contact with the source region (132), while being insulated from the gate electrode film (128). In the drift layer (114), a region sandwiched between two adjacent grooves (124) is provided with a p-type buried region (140) that is in contact with the body layer (120) and extends deeper than the grooves (124). In the buried region (140), the depth position at which the p-type impurity concentration is maximum is located deeper than the midway between the bottom surface (P2) of the body layer (120) and the bottom surface (P3) of the buried region (140). This trench gate power semiconductor device (100) has high reverse breakdown voltage and further lower on-resistance.

A reverse blocking IGBT according to the invention can include a reverse breakdown withstanding region, p-type outer field limiting rings formed in a reverse breakdown withstanding region and an outer field plate connected to the outer field limiting rings, the outer field plate including a first outer field plate in contact with outer filed limiting rings nearest to the active region and second outer field plates in contact with other outer field limiting rings. The first outer field plate having an active region side edge portion projecting toward the active region and second outer field plate having an edge area side edge portion projecting toward the edge area. The reverse blocking IGBT according to the invention can facilitate improving the withstand voltages thereof and reducing the area thereof.

This invention discloses a commutation diode, chips especially for manufacturing the diodes and the manufacturing method, in which, said commutation diode is composed of a shell, a chip and a lead out wire, in which, the chip includes a long base region N, a phosphor diffusion region N area, a heavy boron diffusion region P area and a groove passive mesa, the long base region is in the middle of the chip, cathode K is on the phosphor diffusion region, anode A is on the heavy boron diffusion region, the upper part is the P diffusion region, the lower part is the B diffusion region, isolation walls are surrounding the chip with vertical through laser holes in the diameter smaller than 200mum and the inter-distance of 40-400mum and the mesa is between the isolation wall and the cathode K.

The invention discloses a Schottky rectifier and a making method thereof. The Schottky rectifier comprises a first conductivity type substrate, a first conductivity type conductive layer formed on the surface of the first conductivity type substrate, at least one trench formed in the first conductivity type conductive layer, side wall oxide layers and bottom oxide layers formed in the trenches, polycrystalline silicon deposited in the trenches and doped with a second conductivity type impurity, and a metal layer formed on the surface of the first conductivity type conductive layer, wherein the doping concentration of the second conductive type impurity changes from high to low from the top to the bottom of the trenches in the depth direction of the trenches. According to the invention, a reverse electric field originally acting on a Schottky barrier quickly leaves a Schottky barrier region and is borne by a depletion layer, so that electric leakage due to original action of the electric field on the Schottky barrier is avoided, and the overall reverse withstand voltage of the device is greatly improved.

A semiconductor device according to embodiments of the invention includes an n⁻-type drift region; a p-type base region formed selectively in the surface portion of the drift region; an n⁺-type emitter region and a p⁺-type body region, both formed selectively in the surface portion of base region; and an n-type shell region between the drift region and the base region, a shell region surrounding the entire region below base region. The shell region is doped more heavily than the drift region. The shell region contains an n-type impurity at an effective impurity amount of 8.0×10¹¹ cm⁻² or smaller. A drift region exhibits a resistivity low enough to prevent the depletion layer expanding from collector region, formed on the back surface of the drift region, toward a shell region from reaching the shell region.

The invention provides a schottky diode controlled by a junction barrier having a superposed P<+>-P structure. The schottky diode comprises an N<+> type substrate zone (100), an N type drift region (101), P<+> portions of the superposed P<+>-P structure (102), an anodic electrode (104), a cathodic electrode (105), a silicon dioxide layer (106), a schottky contact (107), and an ohmic contact (108). Besides, the schottky diode also includes P portions of the superposed P<+>-P structure (103), wherein the P<+> window portions of the superposed P<+>-P structure (102) is on the P window portions of the superposed P<+>-P structure (103). According to the invention, before the P<+> portions of the superposed P<+>-P structure in an area are formed, the P portions of the superposed P<+>-P structure in an area are formed, wherein the P portions are separated from each other and the structure of P portions is similar to the netted structure of a junction barrier schottky (JBS). Therefore, reverse withstand voltage of the JBS diode device can be improved and the output capacitance can be reduced, on the condition that the forward conduction characteristic of the device is not sacrificed. The process of the invention has the strong feasibility of implementation, and the application requirement of the power electronic system can be satisfied easily according to the invention.

A diode is provided with a semiconductor substrate; an anode electrode located on a front surface of the semiconductor substrate; and a cathode electrode located on a rear surface of the semiconductor substrate. Each of the p-type contact regions includes: a first region being in contact with the anode electrode; a second region located on the rear surface side of the first region, having a p-type impurity density lower than a p-type impurity density in the first region; and a third region located on the rear surface side of the second region and having a p-type impurity density lower than the p-type impurity density in the second region. A thickness of the second region is thicker than a thickness of the first region.

The invention relates to a power diode and a method for manufacturing the power diode. The power diode comprises a bottom electrode, a substrate layer, an N- type epitaxial layer and a top electrode, wherein the top electrode serves as the positive electrode of the power diode, the bottom electrode serves as the negative electrode of the power diode, at least two grooves are transversely formed in the upper portion of the N- type epitaxial layer in a spaced mode, and an MOS channel is formed in the portion, between every two adjacent grooves, of the N- type epitaxial layer. The power diode is made of silicon materials and can be obtained through an existing silicon semiconductor integrated circuit; special metal materials are not needed, and the method for manufacturing the power diode is compatible with an existing semiconductor production technology; the backward voltage resistance of the device is improved through p+ regions injected into the grooves; when backward voltage is applied to the device, the p+ exhaustion regions in the grooves expand and are connected, a backward current channel is cut off, and the voltage resistance of the device is improved; when the power diode operates in the forward direction, electricity is conducted through parasitic mosfet, and the forward starting voltage of the device is reduced.

The invention belongs to the technical field of semiconductors, and relates to a current-limiting diode. The invention proposes the novel current-limiting diode, and the diode employs the technology of growing a charge restoration layer on a thin carrier AlGaN/GaN heterojunction to modulate two-dimensional electron gas. The structural advantages of the diode lie in that fluorine-based gas used for etching of the charge restoration layer can hardly cause any etching impact on a barrier layer below the charge restoration layer under the conditions that a device is enhanced and the diode has a lower start voltage and a large reverse withstand voltage, and finally can achieve the self-terminating at an AlGaN interface, so as to achieve the precise control of the barrier layer. The diode avoids the etching of the AlGaN layer, and cannot cause damages to the AlGaN layer, so the device is large in current density, is higher in electron mobility and is lower in conduction resistance.

An object of the present invention is to provide a preparation method of a shielded gate power device. A double-layer different resistivity epitaxy is adopted, the lower layer is low resistance epitaxy, which has smaller on-state resistance than the homogeneous high resistance epitaxial layer under the same withstand voltage to reduce the static power loss of the device, the gate oxide longitudinally extends to the drain, and the transverse electric field distribution of the upper layer high resistance layer is optimized by a Resurf technology, so as to improve the reverse withstand voltage ofthe device. As the shield gate is PN-doped polysilicon, the capacitance between the shield gate and the drain can be reduced so as to reduce the switch power loss of the shielded gate power MOSFET.

The invention relates to apower device including the active area, a voltage sharing region and a cut-off ring region, the voltage sharing region comprising at least one voltage sharing ring of a firstconductivity type, A cut-off re region is arranged at that periphery of the voltage sharing ring, the voltage sharing ring having at least one corner, the cut-off ring region having at least one outer corner corresponding one-to-one to a corner of the voltage sharing ring, A super junction structure is for in that cut-off ring region, the super junction structure includes a first injection regionof a first conductivity type and a second injection region of a second conductivity type, the first injection region extends from a peripheral corner of the voltage sharing ring to a corresponding corner of the cut-off ring region, The second injection region includes a first portion formed on both sides of the first injection region and connected to the first injection region, and a second portion formed on both sides of the first injection region. One end of the first injection region and the second injection region jointly cover a corner region of the first voltage sharing ring.

The invention discloses a power diode. A NPN structure is employed by the power diode. A base electrode and a collector electrode of the NPN structure are connected and work as an anode of the power diode, and an emitter electrode of the NPN structure works as a cathode of the power diode. A well implantation region is provided under an emission area of an emitter electrode end. The well implantation region has a same conduction type with the emission area, and has a lower impurity concentration than the emission area. A buried layer is provided in the substrate under the base electrode. The buried layer has a same conduction type with the base electrode area, and has a higher impurity concentration than the base electrode area. The power diode of the invention has low substrate electric leakage and high reverse breakdown voltage.

The invention discloses a combined switch. The combined switch comprises a junction field effect transistor and a diode. The junction field effect transistor comprises a gate electrode, a source electrode and a drain electrode; the diode comprises an anode and a cathode; the drain electrode of the junction field effect transistor is a first terminal of the combined switch; the source electrode ofthe junction field effect transistor is connected with the cathode of the diode; the gate electrode of the junction field effect transistor is connected with the anode of the diode; and the anode of the diode is a second terminal of the combined switch. Compared to a single diode, the combined switch disclosed by the invention has a higher reverse withstand voltage, and has zero reverse recovery characteristic and a lower forward turn-on voltage.

Provided are a trench MOS barrier Schottky diode and a manufacturing method. The trench MOS barrier Schottky diode comprises a substrate, an epitaxial thin film manufactured on the substrate, a protective ring, an insulation dielectric film, Schottky contact metal, a first bonding block, ohmic contact metal and a second bonding block. A boss is arranged in the middle of the epitaxial thin film, and the side wall of the boss is a plane. The protective ring is manufactured on the periphery of the boss of the epitaxial thin film and is located below the plane on the periphery of the boss. The insulation dielectric film is manufactured on the side wall of the periphery of the boss of the epitaxial thin film, the height of the insulation dielectric film is flush with that of the boss of the epitaxial thin film, the insulation dielectric film is located on the protective ring, the height of the part, on the protective ring, of the insulation dielectric film is smaller than that of the surface of the boss, and the section of the insulation dielectric film is an L shape. The Schottky contact metal is manufactured on the surface of the insulation dielectric film and covers the surface of the boss of the epitaxial thin film. The first bonding block covers the surface of the Schottky contact metal. The ohmic contact metal is manufactured on the back face of the substrate. The second bonding block is manufactured on the back face of the ohmic contact metal and can further lower the power consumption of a carborundum power electronic device.

Disclosed is a semiconductor device which is provided with a GaN layer (2), an anode electrode (4) formed by a Schottky junction on the Ga surface of the GaN layer (2), and an InGaN layer (3), which is positioned between at least a part of the anode electrode (4) and the GaN layer (2).