关键词： Cross-scale mechanical manipulation   Flexoelectricity   Piezoelectricity   Semiconductor  

摘要： Flexoelectricity, an electromechanical coupling between strain gradient and electrical polarization in dielectrics or semiconductors, has attracted significant scientific interest. It is reported that large flexoelectric behaviors can be obtained at the nanoscale because of the size effect. However, the flexoelectric responses of centrosymmetric semiconductors (CSs) are extremely weak under a conventional beam-bending approach, owing to weak flexoelectric coefficients and small strain gradients. The flexoelectric-like effect is an enhanced electromechanical effect coupling the flexoelectricity and piezoelectricity. In this paper, a composite structure consisting of piezoelectric dielectric layers and a CS layer is proposed. The electromechanical response of the CS is significantly enhanced via antisymmetric piezoelectric polarization. Consequently, the cross-scale mechanically tuned carrier distribution in the semiconductor is realized. Meanwhile, the significant size dependence of the electromechanical fields in the semiconductor is demonstrated. The flexoelectronics suppression is found when the semiconductor thickness reaches a critical size (0.8 mu m). In addition, the first-order carrier density of the composite structure under local loads is illustrated. Our results can suggest the structural design for flexoelectric semiconductor devices. (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic), (sic)(sic)(sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic). (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(s

关键词： 半导体产业战略   产业转型   社会网络分析   供应链   友岸外包  

摘要： 日本半导体产业在二战结束后开始崛起并经历了鼎盛期、衰退期、转型期等发展阶段,当前进入了全面复兴期。在产业结构变化和全球供应链复杂化的背景下,日本政府通过“尖端化”“本土化”和“友岸化”策略提升影响力;日本企业则专注于关键技术创新和加强优势领域发展,以提升竞争力。社会网络分析结果显示,日本在全球半导体供应链中定位为上游核心供应国并发挥全球供应链稳定器的作用,日本半导体产业的转型发展取得了一定成效。在科技产业发展浪潮和新的国际发展局势下,日本政府制定全面的半导体产业战略,试图通过多种措施实现建设半导体强国的宏大目标。

关键词： 痔   激光疗法   消融技术   微创治疗   门诊外科手术  

摘要： 痔病是世界范围内最常见的肛肠疾病之一,严重影响病人的生活质量。为了最大限度地减少解剖切除的疼痛和各种传统手术带来的并发症,痔病的各种微创技术应运而生。努力寻找侵入性更小、对病人更人性化的技术来治疗痔疮,更符合现代痔病的治疗理念。随着新的激光波段和激光导丝半导体的出现,新型半导体激光技术被应用于痔病的治疗,包括激光痔固定术(LHP)和痔动脉激光疗法(HeLP)。更好地把握激光技术的适应证和深入探讨其优缺点是值得研究的方向。该研究就激光技术治疗痔病的历史与原理、优势、LHP和HeLP的研究进展、现存争议与缺点进行综述,以供临床医师参考。

关键词： 晶圆键合   加压   精度控制  

摘要： 为解决晶圆键合加压精度控制问题,提高键合质量水平,以伺服电机驱动电动缸加压系统为例进行研究。重点对压力传感器实时反馈与ARM控制器闭环控制技术进行分析,阐述在晶圆键合过程中的应用效果,并以此为基础提出柔性力自平行加压结构设计建议,通过系统化试验的方式进行研究。结果表明:该控制方法具有优异的加压精度控制能力,位移控制精度可达±1%,键合力控制精度达到±0.5%,研究结果具有较强的实用性,能够为半导体器件制造工艺提供参考。

关键词： CW ultraviolet laser   275 nm laser   Pr:YLF   frequency doubling  

摘要： This paper describes what is thought to be the first generation of a continuous wave deep ultraviolet laser at 275 nm by efficient frequency doubling of a blue-diode-pumped Pr:YLF laser at 550 *** employing a novel fast-axis collimated blue semiconductor laser as the pump source,combined with a folded cavity and innovation coating technology,and utilizing a Brewster-cut BBO crystal for intracavity frequency doubling,TEM00 mode deep UV laser radiation at 275 nm with an output power of 351 mW is *** marks the first report of achieving 275 nm laser generation based on Pr:LiYF4 to date.

关键词： 日本经济   半导体产业   人才短缺   人才培养   人才引进  

摘要： 以1995年日本劳动年龄人口数达峰为始,历经近30年的复杂演进之后,日本半导体产业人才短缺问题日趋严峻,堪称该产业发展的最大瓶颈。这一问题的形成,既有全球半导体产业竞争加剧等外因推动,也源于日本的少子老龄化、半导体产业衰退以及劳动力流动性弱等内因。当前,日本正从人才培养与人才引进两方面展开应对措施。其中,人才培养是重点,是以构建官产学一体化的半导体人才培养体系为目标;人才引进为补充,推出了优化签证政策、推动项目引才、打破就业壁垒等举措,急于扩充半导体人才库。当前,日本劳动市场整体流动性显著提高,半导体产业人才储量出现增长趋势,这将是扭转其半导体产业长期颓势的关键。不过,由于全球半导体人才竞争愈演愈烈,且日本相关政策也存在一些隐患,导致其半导体产业振兴前景仍面临不确定性。

关键词： 苝二酰亚胺   D-A结构   电子效应   有机半导体  

摘要： 为了改变由于苝二酰亚胺(PDI)共轭面较大、分子自聚集而造成的电子传输途径受限问题,本研究以PDI基团为母体材料,通过连接不同给受体基团,成功地合成了多种电子传输材料小分子。利用循环伏安法(CV)测定了合成化合物的能级,并探讨了共轭体系结构的变化对分子的光学吸收特性和能级、电化学性质以及分子热性能的影响。同时,研究了在两个PDI单元之间插入缺电子单元吡咯并吡咯二酮(DPP)基团时,分子在有机场效应晶体管器件的性能,实验测得目标分子表现为n型半导体特性和较好的电子迁移率。实验表明,通过连接不同给受体基团,化合物具有良好的热稳定性、溶液加工性和合适的能级,在柔性材料和印刷电子方面具有潜在的应用价值。

关键词： 半导体   CVD   温度控制   微环境   颗粒污染   二氧化硅  

摘要： 二氧化硅(SiO_(2))薄膜制备作为集成电路制造工艺中重要的一个步骤,在芯片的制造过程中具有多种用途,但易受颗粒污染造成产品不良。对采用TEOS源LPCVD法沉积SiO_(2)膜颗粒污染的方法进行了探索,设计了一种用于防颗粒污染的机构,该机构主要包括微环境系统和温度控制系统,重点介绍了立式LPCVD设备工艺颗粒来源、微环境系统和温度控制系统结构组成,以及微环境系统和温度控制系统的应用效果。

关键词： van der Waals layered semiconductor   lead iodide   anti-Stokes photoluminescence   exciton-phonon coupling   two-step photon absorption  

摘要： Anti-Stokes photoluminescence (ASPL) in low-dimensional van der Waals (vdW) layered materials is becoming increasingly attractive for its potential in advanced applications such as optical cooling, sub-energy band detection and optoelectronic devices. While transition metal dichalcogenides (TMDCs), among the most studied vdW semiconductors for ASPL, exhibit a direct bandgap exclusively in their monolayer form. This characteristic results in a short light-matter interaction distance and thus low ASPL emission efficiency, which seriously impedes the advancement of ASPL in vdW layered materials. In contrast, transition metal halide lead iodide (PbI2), a vdW semiconductor with a direct bandgap in a wide range of thicknesses (>= 3 layers) superior to TMDCs, has shown promise for ASPL. However, the reported ASPL emission efficiency of PbI2 is notably low. Moreover, scant research has focused on the rich ASPL emission states in PbI2, particularly concerning the assignment of these emission states. Here, through a designed thickness selection, we observed more detailed ASPL emissions in submicrometer-thick PbI2 at room temperature, in addition to a series of previously unreported ASPL emission peaks that emerge at low temperatures. Importantly, the low-temperature ASPL of PbI2 exhibits an approximate 1000-fold enhancement compared to that observed at room temperature. This significant enhancement is attributed to the transition from phonon-assisted one-photon absorption to two-step photon absorption induced by resonance absorption effect, as well as substantially reduced nonradiative decays at low temperatures. Our findings enhance the comprehensive understanding of ASPL in PbI2, holding great significance for the development of ASPL applications.