A novel SiC high-k superjunction power MOSFET integrated Schottky barrier diode with improved forward and reverse performance

A new SiC superjunction power MOSFET device using high-k insulator and p-type pillar with an integrated Schottky barrier diode(Hk-SJ-SBD MOSFET)is proposed,and has been compared with the SiC high-k MOSFET(Hk MOSFET),SiC superjuction MOSFET(SJ MOSFET)and the conventional SiC MOSFET in this article.In the proposed SiC Hk-SJ-SBD MOSFET,under the combined action of the p-type region and the Hk dielectric layer in the drift region,the concentration of the N-drift region and the current spreading layer can be increased to achieve an ultra-low specific on-resistance(Ron,sp).The integrated Schottky barrier diode(SBD)also greatly improves the reverse recovery performance of the device.TCAD simulation results indicate that the Ron,sp of the proposed SiC Hk-SJ-SBD MOSFET is 0.67 mΩ·cm^(2)with a 2240 V breakdown voltage(BV),which is more than 72.4%,23%,5.6%lower than that of the conventional SiC MOSFET,Hk SiC MOSFET and SJ SiC MOSFET with the 1950,2220,and 2220V BV,respectively.The reverse recovery time and reverse recovery charge of the proposed MOSFET is 16 ns and18 nC,which are greatly reduced by more than 74%and 94%in comparison with those of all the conventional SiC MOSFET,Hk SiC MOSFET and SJ SiC MOSFET,due to the integrated SBD in the proposed MOSFET.And the trade-off relationship between the Ron,sp and the BV is also significantly improved compared with that of the conventional MOSFET,Hk MOSFET and SJ MOSFET as well as the MOSFETs in other previous literature,respectively.In addition,compared with conventional SJ SiC MOSFET,the proposed SiC MOSFET has better immunity to charge imbalance,which may bring great application prospects.

A review of the etched terminal structure of a 4H-SiC PiN diode

The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power devices.However,achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon.Many previously reported studies adopted many new structures to solve this problem.Additionally,the JTE structure is strongly sensitive to the ion implantation dose.Thus,GA-JTE,double-zone etched JTE structures,and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage.They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes.This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad.Presently,the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.

Highly efficient 1D p-Te/2D n-Bi_(2)Te_(3) heterojunction self-driven broadband photodetector

Broadband photodetectors with self-driven functions have attracted intensive scientific interest due to their low energy consumption and high optical gain.However,high-performance broadband self-driven photodetectors are still a significant challenge due to the complex fabrication processes,environmental toxicity,high production costs of traditional 3D semiconductor materials and sharply raised contact resistance,severe interfacial recombination of 2D materials and 2D/3D mixed dimension heterojunction.Here,1D p-Te/2D n-Bi_(2)Te_(3) heterojunctions are constructed by the simple and low-cost hydrothermal method.1D p-Te/2D n-Bi_(2)Te_(3) devices are applied in photoelectrochemical(PEC)photodetectors,with their high performance attributed to the good interfacial contacts reducing interface recombination.The device demonstrated a broad wavelength range(365–850 nm)with an Iph/Idark as high as 377.45.The R_(i),D^(*),and external quantum efficiency(EQE)values of the device were as high as 12.07 mA/W,5.87×10^(10) Jones,and 41.05%,respectively,which were significantly better than the performance of the prepared Bi_(2)Te_(3) and Te devices.A comparison of the freshly fabricated device and the device after 30 days showed that 1D p-Te/2D n-Bi_(2)Te_(3) had excellent stability with only 18.08%decay of photocurrent.It is anticipated that this work will provide new emerging material for future design and preparation of a high-performance self-driven broadband photodetector.

基于磁控溅射法制备的大面积高质量硒化铂薄膜及其在红外探测中的应用

PtSe_(2)因其可调的带隙、高载流子迁移率和较高的光吸收率在红外探测领域受到广泛的研究和关注.然而,传统的制备方法存在生长条件复杂、生长时间长、铂源和硒源的选择性较低、晶体质量不高、成本昂贵以及大规模制造困难等缺点,限制了其实际应用.在此,我们采用了一种便捷、低成本的磁控共溅射法来制备大面积、高质量的PtSe_(2)薄膜.在不同温度下生长的薄膜的表面形貌和微观结构表征结果表明,我们制备的PtSe_(2)薄膜具有良好的结晶性、可控性、均匀性、较窄带隙和优异的红外波段吸收特性,同时我们还研究了最合适的衬底和生长温度.基于PtSe_(2)的光电探测器展示出良好的红外探测能力和较快的响应速度.尤其值得注意的是,相比于传统制备方法,本研究提出的制备方法的制备时间非常短,为PtSe_(2)大规模应用于下一代红外探测,并与现有的硅技术兼容提供了有益的指导.

Endoscopy-assisted purely total outer wall excision for pediatric Sylvian arachnoid cysts

Background To present a novel endoscopy-assisted surgical strategy of Sylvian arachnoid cysts(ACs).Case presentation Endoscopy-assisted surgery was performed on 9 children(May 2019-December 2021).All patients were evaluated with CT and/or MRI and had regular follow-up examinations.The procedure consisted of performing a small temporal craniotomy(2 cm)behind the hairline.After dural opening,the surgery was performed with the assistance of a rigid 30-degree transcranial endoscope,self-irrigating bipolar forceps,and other standard endoscopic instruments.Steps included total excision of the AC outer wall and dissection of arachnoid adhesion around the cystic edge to communicate the residual cyst cavity with subdural space.Compared with the microscopical procedure,a 30-degree transcranial endoscope provides a wider view,especially for the lateral part exposure of the outer wall.The average age of the patients was 27.7 months(range 13-44 months).The Sylvian AC was in the right hemisphere in three patients and six in the left,respectively.1 patient suffered transient postoperative epilepsy.There was no mortality or additional postoperative neurological deficit in this series.All of the patients achieved significant clinical improvement after surgery.Radiological examination after the operation showed a significant reduction in all cases(100%,9/9)and disappearance in one case(11.1%,1/9).Postoperative subdural fluid collection occurred in six cases and completely resolved spontaneously in 9 months.Conclusion The study demonstrated the minimally invasive,safety,and effectivity of the endoscopy-assisted purely total outer wall excision.