44results about How to "Improve vertical pressure resistance" patented technology

The invention relates to a super junction lateral double-diffused metal-oxide semiconductor (LDMOS) device and belongs to the field of semiconductor power devices. By means of the super junction LDMOS device, evenly distributed N+ islands are embedded in a P type substrate of a traditional super junction LDMOS device, and a P type electric field screening buried layer is added between an active area and the substrate. An N+ island (2) can improve longitudinal withstand voltage of the device by enhancing internal electric field, simultaneously generates extra electric charge to eliminate substrate auxiliary depletion effect, and further improves breakdown voltage of the device. The P type electric field screening buried layer (3) can screen high electric fields generated by an N+ island near an active end, lower electric field peak value near the active area, and form super junction with an N type cushion layer; and a super junction drift area is provided, the device is enabled to have multiple super junction structures, accordingly electric field distribution inside the device can be effectively improved, breakdown voltage of the device is improved, conduction ratio resistance of the device is simultaneously lowered by improving dosage concentration of the drift area, and finally the aim of effectively reducing device area and lower device cost can be achieved.

The disclosed SOI power device with VLk SOI, Lk SOI, VLk PSOI and Lk PSOI four structures apples the low-k (dielectric coefficient) material to increase longitudinal electric field strength of the buried layer and modulate Si active electric field by the additional field on variable-k layer interface, while decrease the capacitor between drift region and substrate to improve on-off speed. This invention can be used to lots of new high pressure-resistant devices, such as lateral dual-diffusion FET, PN diode, etc.

The invention provides a nitride high-voltage device on silicon substrate and a manufacturing method thereof. According to the nitride high-voltage device on the silicon substrate, a high-voltage tolerance layer is led into a drain electrode region, and the thickness of a partial epitaxial layer is thickened to bear higher voltage reduction, so that high punch through voltage resistant device is achieved. Via the method of partial generation, the high punch through voltage resistant device is achieved, the problems of warping and chap of nitride epitaxial layer, which are caused by a whole material with over thickness, are avoided, therefore, material generation quality is ensured, material generation efficiency is improved, and the cost is lowered.

A high-voltage lateral double-diffused metal oxide semiconductor (LDMOS) device comprises a P-type channel region, an N-type drift region, a voltage-resistance layer, and a P-type substrate located at the bottom, the voltage-resistance layer being provided between the P-type substrate and the N-type drift region. For the high-voltage LDMOS device, the trapping time in the process is shortened by adding a voltage-resistance layer, thereby increasing a sectional area of a current channel, improving the on resistance, and further enhancing lateral voltage resistance by enhancing longitudinal voltage resistance.

The invention discloses an ultra-large dual-layer steel plate concrete silo prestressed technology and a structure of an ultra-large dual-layer steel plate concrete silo. The technology comprises the steps of firstly digging a foundation pit, hitting a pile foundation, making a foundation plate, mounting a silo assembly, and sealing the bottom of a silo; after the silo assembly and foundation water in the silo are prestressed for a certain time, pouring concrete into the silo assembly to form a dual-layer steel plate concrete silo wall and removing the water pressure after consolidation; prestressing the foundation in the silo for a certain time by the rest prestressed water filling body, removing the prestressed water, and finally performing secondary pouring on the foundation plate in the silo. The structure of the ultra-large dual-layer steel plate concrete silo comprises the foundation, a belt corridor, the silo assembly, a belt trestle, a central blanking drum, a rainshed and a bottom sealing film. The characteristics of strong pulling resistant performance of the steel plate and the strong crushing resistance of the concrete are utilized, so the soil is prestressed by the actual load of loaded materials; in the structure, a steel pipe support pouring concrete is adopted to replace a steel plate or concrete support, and a steel structure cone is used for replacing a reinforced concrete cone, so the problems that after the silo is put into use, the use of the foundation is influenced caused by unevenness and deformation due to unbalanced loading of the materials and the like are avoided.

The invention relates to semiconductor technology, in particular to a partial SOI (silicon on insulator) super junction high-voltage power semiconductor device. The partial SOI super junction high-voltage power semiconductor device is characterized by comprising a plurality of N+ pads and a P-type electric field shielding layer, the N+ pads are uniformly embedded into a P-type substrate, the P-type electric field shielding layer is arranged in the P-type substrate, the upper surface of the P-type electric field shielding layer is connected with a P-type body area and the lower surface of an N-type buffer area close to a source end, and the lower surface of the P-type electric field shielding layer is connected with the upper surface of a buried oxide layer. The partial SOI super junction high-voltage power semiconductor device has the advantages that the doping concentration of a drift region is increased by changing electric field distribution, the voltage resistance of the device is improved, on resistance is reduced, the area of the device is decreased, and cost is reduced. The invention is particularly applicable to the partial SOI super junction high-voltage power semiconductor device.

The invention discloses a fiber-enhanced cellulose triacetate reverse osmosis membrane and a preparation method thereof. The reverse osmosis membrane comprises a cellulose triacetate separating layeron an outer layer and an S-twist yarn or Z-twist yarn enhancing layer on an inner layer. The thickness of the cellulose triacetate separating layer is 20-200 microns, and the thickness of the S-twistyarn or Z-twist yarn enhancing layer is 100-500 microns. A permeation flux of the reverse osmosis membrane is 10-100 Lm<-2>h<-1>MPa, and a salt removing rate is 90-99%. The method comprises the following steps: A, preparing twisting fibers: twisting a fiber filament to be an S-twist yarn or a Z-twist yarn; B, preparing a membrane forming system: blending cellulose triacetate, a plasticizer and anadditive to obtain the membrane forming system; and C, preparing the reverse osmosis membrane: extruding the membrane forming system through a screw extruder and uniformly coating the outer surface ofthe S-twist yarn or the Z-twist yarn by melt through an annular spinning nozzle, and drafting to a coagulating bath for cooling and forming, to obtain the fiber-enhanced cellulose triacetate reverseosmosis membrane.

The invention discloses a preparation method of a deep trench isolation structure and a semiconductor device. The device comprises the deep trench isolation structure. According to the invention, in the preparation process of the LDMOS device, after a first trench corresponding to the deep trench isolation structure is formed by etching, phosphorus ion implantation is carried out on the first groove; an N-type heavily doped layer is forme on on the side wall and the bottom of the first trench, the N-type heavily-doped layer can lead out the N-type buried region in contact with the N-type heavily-doped layer, so that the deep N-type well does not need to be diffused to be in contact with the N-type buried layer to facilitate lead-out by consuming long time to carry out high-temperature thermal propulsion when the deep N-type well is formed, the processing time of high-temperature thermal propulsion is shortened, and the manufacturing cost is reduced; meanwhile, due to the fact that thehigh-temperature thermal propulsion time is shortened, upward further diffusion of the N-type buried layer is prevented, the withstand voltage length in the longitudinal structure of the device is increased, and the longitudinal withstand voltage is improved.

The invention relates to the technology of semiconductors, and particularly relates to a high-voltage heterojunction transistor. An N-type structure is doped in partial intervals of a device epitaxial layer and a P-type exhaust structure is doped in partial intervals of a silicon-based substrate layer based on a conventional transverse heterojunction transistor device structure. The substrate and a buffer layer are enabled to be completely exhausted by introduction of a P-type doping region and an N-type doping region so that the substrate is enabled to bear longitudinal withstanding voltage, and thus voltage withstanding capacity of the device can be improved. Meanwhile, height of a barrier layer is increased and a leakage current channel is blocked by introduction of P-type impurities in the epitaxial layer, and finally leakage current is reduced.

The invention relates to a method for manufacturing an SOI (silicon on insulator) LIGBT (lateral insulated gate bipolar transistor) device unit with a p buried layer and a longitudinal channel. The SOI LIGBT device manufactured by the existing method abruptly degrades and even becomes invalid under a high temperature and large current. In the method, SOI materials with p-type buried layers are adopted to manufacture the SOI LIGBT device with the longitudinal channel; the longitudinal withstand voltage is mainly borne by a reversely biased pn junction depletion layer formed by a p-type buried layer with backward impurity concentration distribution and an n-type top layer semiconductor with forward impurity concentration distribution; and the SOI LIGBT device unit is manufactured through ten-time etching and seven-time oxidizing. The method has the beneficial effects of effectively reducing the on-state resistance, on-state voltage drop and on-state power consumption of the device, improving the on-state current and working efficiency of the device, obviously improving the performance of the SOI LIGBT device and improving the reliability of the device.

The invention discloses an SOI power device with medium layer fixed charges. The SOI power device comprises a substrate layer, an active layer and an insulating medium buried layer located between the substrate layer and the active layer. A high-concentration fixed charge area is disposed in the edge area of the contact surface of the insulating medium buried layer and the active layer. The area of the high-concentration fixed charge area accounts for 50-75% of the area of the contact surface of the insulating medium buried layer and the active layer. The concentration of the high-concentration fixed charge area is 1*10<17>-1*10<18>/cm<2>. The SOI power device is simple in process, large in fixed charge doping concentration process allowance, small in influence by high-temperature processes, and completely compatible with a conventional CMOS/SOI process. In addition, the voltage resistance of the power device is increased greatly by an enhanced medium buried layer electric field.

The invention relates to a manufacturing method of a silicon-on-insulator lateral insulated-gate bipolar transistor (SOI LIGBT) device unit of a lateral channel with a positive (p) buried layer. An SOI LIGBT device which is manufactured by the conventional method is abruptly degraded or even invalid in a high-temperature and large-current environment. In the method provided by the invention, the SOI LIGBT device is manufactured by using an SOI material with a p-buried layer; a reverse bias pn junction which is formed by the p-buried layer with reverse impurity concentration distribution and anegative (n) top-layer semiconductor with forward impurity concentration distribution is used for longitudinal voltage resistance; and the SOI LIGBT device unit of the lateral channel with the p buried layer is manufactured by etching for nine times and oxidation twice. The device unit which is manufactured by the method improves the longitudinal voltage resistance of the device under the condition of reducing the thickness of a buried oxidation layer, reduces a self-heating effect, improves the thermal property of the device and improves the reliability of the device.

The invention relates to a manufacturing method of an SOI (Silicon On Insulator) nLDMOS (n Laterally Diffused Metal Oxide Semiconductor) device unit with a P buried layer. An SOI nLDMOS device manufactured by the traditional method seriously influences the voltage withstanding property of the SOI nLDMOS device and influences the heat radiation of the SOI nLDMOS device. The SOI nLDMOS device with the P buried layer is manufactured by carrying out photoetching on an SOI thick film material with the P buried layer for nine times. The manufactured SOI nLDMOS device bears the vast majority of withstand voltages through a depletion layer formed by a reverse biased PN junction positioned between an N type top silicon film and a P type buried layer when the voltages of a blocking-state drain electrode are increased, thereby enhancing the longitudinal voltage withstanding property of the SOI nLDMOS device and breaking the bottleneck of limiting the improvement of horizontal withstand voltages due to over-low longitudinal withstand voltages; and in addition, the thin buried oxide layer is beneficial to the heat radiation of the SOI nLDMOS device, thereby effectively reducing the self-heating effect. The manufacturing method ensures that electrical and thermal properties of the SOI nLDMOS device integrating power and radio frequency are remarkably improved, and is beneficial to saving of the resources and the energy and protecting of the environment.

The invention discloses an SOI-LDMOS (silicon-on-insulator laterally diffused metal oxide semiconductor) high-tension power device with a triangular trench and aims to solve the problems that voltage of a drain of the prior SOI-LDMOS device is induced out of an electronic inversion layer from beneath a buried oxide layer, an equipotential line is prevented from penetrating the buried oxide layer, and early breakdown occurs to a silicon layer, and breakdown voltage withstanding is difficult to increase. The SOI-LDMOS high-tension power device is mainly characterized in that the triangular trench is etched in a buried oxide layer under a drift area; a buried oxide slope exists under the drift area and is capable of constraining positively charged holes, high-density positive charge is produced, and breakdown voltage withstanding of the device is greatly increased through the high-density positive charge; thickness of the drift area linearly increases from a source to a drain, according to the principle of RESURF (reduced surface field), a transverse electric field is uniformized owing to modulation, lateral voltage withstanding can be improved, and rejection ratio on resistance can be increased fast.

The invention discloses a super-junction device. A groove of the super-junction structure is of a side face inclined structure; the doping concentration of an N-type epitaxial layer is of a step distribution structure; a P-type column is composed of a P-type ion implantation region formed at the bottom of the groove, and a P-type epitaxial layer which are arranged in a stacked mode; a protective ring oxide film surrounds the peripheral side of a current flow region; and the N-type epitaxial layer at the oxide film epitaxial layer interface of the N-type epitaxial layer in the protective ring oxide film and a terminal region comprises a top region with lowered N type doping concentration, so that the transverse depletion capability of the N-type column at the interface of the epitaxial layer of the oxidation film can be enhanced. The invention further discloses a manufacturing method of the super-junction device. According to the invention, the charge balance between the P-type column and the N-type column of the super-junction structure with the inclined groove can be improved, the longitudinal voltage withstand capability of the device is improved, and the source and drain breakdown voltage of the device is improved; and the capacity of bearing transverse voltage of the device terminal can be improved, and the reliability of the device can be improved.

The invention provides a silicon-on-insulator (SOI) low-resistance lateral high-voltage device and a manufacturing method thereof. The manufacturing method comprises the following steps of taking an SOI as a substrate, forming an N-type linear variable doping thick SOI layer and a thin silicon layer drift region, forming a thin silicon layer region, namely a thick dielectric layer, and forming a Pwell region; and forming an Nwell region, forming a gate oxide layer, forming a poly-silicon gate electrode, forming an N strips, forming a P strip, performing injection of a first P-type heavy-doping region, a first N-type heavy-doping region and a second N-type heavy-doping region to form ohmic contact, etching a first-layer contact hole of a leading-out electrode, depositing aluminum metal, and forming a source contact electrode and a drain contact electrode. The manufacturing method is highly compatible with a traditional process and has universality; with the manufactured device, the device area can be effectively reduced, and the device cost is reduced; and in the SOI low-resistance lateral high-voltage device fabricated by the method, the formulas of BV=950V and R<on, sp>=153 ohms.cm<2> can be achieved.

The invention relates to a manufacturing method of a VC SOI nLDMOS (Vertical Channel Silicon-on-insulator n Lateral Double-diffused Metal Oxide Semiconductor) device unit with a p-type buried layer. The SOI nLDMOS device manufactured by the prior art seriously limits vertical voltage resistance and lateral voltage resistance, and has serious self-heating effect and poor high temperature resistance and thermal stability. Through the manufacturing method disclosed by the invention, ten times of photoetching are carried out on an SOI thick film material with the p-type buried layer to manufacture the VC SOI nLDMOS device with the p-type buried layer, and a formed depletion layer bears the vast majority of vertical withstand voltage when the VC SOI nLDMOS device applies a high voltage between a drain electrode and a source electrode in the blocking state, thus the vertical voltage resistance of the VC SOI nLDMOS device is improved, the self-heating effect of the device is remarkably reduced, and the high temperature resistance and the thermal stability are improved; furthermore, the volume and the weight of a system are reduced, the resource is saved, the energy consumption is reduced and the environment is protected.