氮化硼薄膜的制备和离子注入掺杂

通常人们对氮化硼薄膜的S掺杂,采用的是在氮化硼制备过程中就地掺杂的方法,文中则采用S离子注入方法.氮化硼薄膜用射频溅射法制得.实验结果表明,在氮化硼薄膜中注入S,可以实现氮化硼薄膜的n型掺杂;随着注入剂量的增加,氮化硼薄膜的电阻率降低.真空退火有利于氮化硼薄膜S离子注入掺杂效果的提高.在离子注入剂量为1×1016cm-2时,在600℃的温度下退火60min后,氮化硼薄膜的电阻率为2.20×105 Ω·cm,比离子注入前下降了6个数量级.     

氮化硼薄膜的制备和离子注入掺杂

通常人们对氮化硼薄膜的S掺杂,采用的是在氮化硼制备过程中就地掺杂的方法,文中则采用S离子注入方法.氮化硼薄膜用射频溅射法制得.实验结果表明,在氮化硼薄膜中注入S,可以实现氮化硼薄膜的n型掺杂;随着注入剂量的增加,氮化硼薄膜的电阻率降低.真空退火有利于氮化硼薄膜S离子注入掺杂效果的提高.在离子注入剂量为1×1016cm-2时,在600℃的温度下退火60min后,氮化硼薄膜的电阻率为2.20×105 Ω·cm,比离子注入前下降了6个数量级.     

氮生长掺杂和离子注入掺杂CVD金刚石薄膜的场电子发射

本文研究了氮生长掺杂和离子注入掺杂金刚石薄膜的场电子发射性能．测试结果表明,两类样品均显示良好的发射性能,即开启电压低（５０～１５０Ｖ）、发射电流大（６～３０ｍＡ）,但它们有不同的发射行为：注入掺杂样品存在发射电流的饱和与滞后、开启电压的前移现象,而生长掺杂样品的发射符合Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ理论．实验还得到了用于生长场发射阴极薄膜的最佳掺杂氮碳流量比为～４２％．     

C掺杂对离子注入合成β-FeSi2薄膜的影响

采用离子注入方法制备β-FeSi2薄膜，选择C作为掺杂元素，得到了β-FeSi2硅化物层与基体间的界面平直、厚度均一的高质量薄膜。经透射电镜分析可知，引入C离子后硅化物层的微结构向有利于薄膜质量的方向发展，晶粒得到细化，β-FeSi2层稳定性提高。从微结构角度考虑，引入C离子对于提高β-FeSi2薄膜的质量是很有益处的。进一步进行光这吸收表征，发现C离子的引入对β-FeSi2层的E^dg值没有产生不良影响，讨论了E^dg值的影响因素，如制备方法、工艺参数、基体取向、掺杂离子种类、掺杂离子数量、退炎温度等等，解释了文献报道的不同E^dg值。     

宽带隙立方氮化硼薄膜制备

报道了用偏压调制射频溅射方法制备宽带隙立方氮化硼(c-BN)薄膜的实验结果.研究了衬底负偏压对制备c-BN薄膜的影响.c-BN薄膜沉积在p型Si(100)衬底上,溅射靶为六角氮化硼（h-BN）,工作气体为Ar气和N2气混合而成,薄膜的成分由傅里叶变换红外谱标识.结果表明,在射频功率和衬底温度一定时,衬底负偏压是影响c-BN薄膜生长的重要参数.在衬底负偏压为-200V时得到了立方相含量在90%以上的c-BN薄膜.还给出了薄膜中的立方相含量随衬底负偏压的变化,并对c-BN薄膜的生长机制进行了讨论.     

宽带隙立方氮化硼薄膜制备

报道了用偏压调制射频溅射方法制备宽带隙立方氮化硼 ( c- BN)薄膜的实验结果 .研究了衬底负偏压对制备c- BN薄膜的影响 .c- BN薄膜沉积在 p型 Si( 10 0 )衬底上 ,溅射靶为六角氮化硼 ( h- BN) ,工作气体为 Ar气和 N2 气混合而成 ,薄膜的成分由傅里叶变换红外谱标识 .结果表明 ,在射频功率和衬底温度一定时 ,衬底负偏压是影响 c-BN薄膜生长的重要参数 .在衬底负偏压为 - 2 0 0 V时得到了立方相含量在 90 %以上的 c- BN薄膜 .还给出了薄膜中的立方相含量随衬底负偏压的变化 ,并对 c- BN薄膜的生长机制进行了讨论     

GaN的离子注入掺杂和隔离

在ＧａＮ中注入Ｓｉ＾－和Ｍｇ＾＋／Ｐ＾＋之后，在约１１００℃下退火，分别形成ｎ区和ｐ区。每种元素的注入剂量为５×１０＾１４ｃｍ＾－２时，Ｓｉ的截流子激活率为９３％，Ｍｇ的是６２％。相反，在原ｎ型或ｐ型ＧａＮ中注入Ｎ＾＋，然后在约７５０℃下退火，能形成高阻区（＞５×１０＾９Ω／□）。控制这些注入隔离材料电阻率的深能态激活能在０．８－０．９ｅＶ范围内，这些工艺参数适用于各种不同的ＧａＮ基电子和光器件。     

多晶硅膜离子注入和扩散掺杂制备浅结的研究

本文对多晶硅膜离子注入掺杂和扩散掺杂制备浅发射结进行了实验研究。针对新型薄发射极晶闸管特性改善对薄发射极参数的要求,重点研究了采用不同方法时退火条件对薄发射区掺杂剖面、结深以及杂质总量的影响。管芯研究结果表明,在适当的退火条件下,离子注入掺杂制备浅结是改善器件特性较为理想的方法。     

用离子注入方法实现P型掺杂

讨论用B^ 离子注入实现P型掺杂的原理及方法。     

立方氮化硼薄膜的研制

研究了热灯丝射频等离子体化学气相沉积法立方氮化硼薄膜。实验结果表明，沉积条件对膜的质量及结构的重要影响。在合适的条件下，可制备出优质的立方氮化硼薄膜材料。     

氮化硼薄膜的脉冲激光沉积

用Ｑ开关ＹＡＧ激光器的１．０６μｍ的脉冲激光在硅及玻璃衬底上沉积了氮化硼薄膜。做了ＳＥＭ，ＸＲＤ，红外透射谱和紫外一可见透射谱等测试。确认为六方氮化硼（ｈ－ＢＮ）薄膜．并测出其禁带宽度、晶格常数等。     

非晶氮化硼薄膜的场致电子发射研究

利用脉冲激光沉积 (PLD)技术在镀钛的陶瓷衬底上制备出了非晶态氮化硼薄膜 ,借助于X射线衍射(XRD)、扫描电子显微镜 (SEM )及Raman光谱分析了该薄膜的结构 ,并研究了薄膜场致电子发射特性 ,阈值电场为4 6V μm ,当电场为 9V μm时 ,电流密度为 5 0 μA cm2 。     

硼离子选择注入制备多孔硅微阵列

根据 p型硅和 n型硅不同的制备多孔硅的工艺条件 ,利用硼离子选择注入 ,在 n型硅片上的局部微区域 ,形成易于腐蚀的 p型硅 ,用电化学腐蚀方法制备出图形化的多孔硅阵列 .省去了传统掩膜腐蚀工艺的掩膜材料的选取与制备以及后道工艺中掩膜材料的清除等工艺 ,克服了掩膜材料掩蔽效果较差以及存在横向钻蚀等缺点 .通过 AFM,SEM测试 ,证明该方法的效果很好     

Chemical Sharpening,Shortening, and Unzipping of Boron Nitride Nanotubes

Boron nitride nanotubes (BNNTs), the one‐dimensional member of the boron nitride nanostructure family, are generally accepted to be highly inert to oxidative treatments and can only be covalently modified by highly reactive species. Conversely, it is discovered that the BNNTs can be chemically dispersed and their morphology modified by a relatively mild method: simply sonicating the nanotubes in aqueous ammonia solution. The dispersed nanotubes are significantly corroded, with end‐caps removed, tips sharpened, and walls thinned. The sonication treatment in aqueous ammonia solution also removes amorphous BN impurities and shortened BNNTs, resembling various oxidative treatments of carbon nanotubes. Importantly, the majority of BNNTs are at least partially longitudinally cut, or “unzipped”. Entangled and freestanding BN nanoribbons (BNNRs), resulting from the unzipping, are found to be ～5–20 nm in width and up to a few hundred nanometers in length. This is the first chemical method to obtain BNNRs from BNNT unzipping. This method is not derived from known carbon nanotube unzipping strategies, but is unique to BNNTs because the use of aqueous ammonia solutions specifically targets the B‐N bond network. This study may pave the way for convenient processing of BNNTs, previously thought to be highly inert, toward controlling their dispersion, purity, lengths, and electronic properties.     

Hexagonal Boron Nitride Thin Film for Flexible Resistive Memory Applications

Hexagonal boron nitride (hBN), which is a 2D layered dielectric material, sometimes referred as “white graphene” due to its structural similarity with graphene, has attracted much attention due to its fascinating physical properties. Here, for the first time the use of chemical vapor deposition ‐grown hBN films to fabricate ultrathin (≈3 nm) flexible hBN‐based resistive switching memory device is reported, and the switching mechanism through conductive atomic force microscopy and ex situ transmission electron microscopy is studied. The hBN‐based resistive memory exhibits reproducible switching endurance, long retention time, and the capability to operate under extreme bending conditions. Contrary to the conventional electrochemical metallization theory, the conductive filament is found to commence its growth from the anode to cathode. This work provides an important step for broadening and deepening the understanding on the switching mechanism in filament‐based resistive memories and propels the 2D material application in the resistive memory in future computing systems.     

六方氮化硼忆阻器的研究进展

六方氮化硼是一种与石墨烯结构相似的材料,以六方氮化硼作为阻变介质层的忆阻器,具有良好的散热性能,不易发生介电击穿,能够实现小尺寸、低功耗和大的开关比;在计算机运算存储研究、人工神经网络和神经形态(即类脑)计算领域有极大的应用前景。文章主要介绍了忆阻器的分类,分析了六方氮化硼忆阻器的阻变机制,综述了六方氮化硼忆阻器的研究现状。最后,指出了六方氮化硼忆阻器当前面临的挑战,并展望了未来的发展方向。     

Carbon‐Doped Boron Nitride Nanosheets with Ferromagnetism above Room Temperature

The possibility to induce magnetism in light‐element materials that contain only s and p electrons is of fundamental and practical importance. Here, weak high‐temperature ferromagnetism is observed in carbon‐doped boron nitride (B‐C‐N) nanosheets. The bulk‐quantities of B‐C‐N nanosheets that are free of metallic impurities are prepared through a multi‐step process. These B‐C‐N samples exhibit ferromagnetic hysteresis stable at room temperature and above, with saturation magnetization and coercivity comparable to the previously reported results of defective graphite samples. The ferromagnetic response disappears upon the removal of carbon dopants from the BN lattice, indicating that the observed magnetism originates from substitutional carbon‐doping rather than from extrinsic magnetic impurities. On the basis of first‐principle calculations it is shown that not only substitutional carbon doping in a honeycomb BN lattice favors spontaneous spin polarization and local moment formation, but also that the spin moments can exhibit long‐range magnetic ordering.     

Surface Growth of Boron Nitride Nanotubes through Boron Source Design

Boron nitride nanotubes (BNNTs) are promising materials due to their unique physical and chemical properties. Fabrication technologies based on gas-phase reactions reduce the control and collection efficiency of BNNTs due to reactant and product dispersion within the reaction vessel. A surface growth method that allows for controllable growth of BNNTs in certain regions using a preburied boron source is introduced. This work leverages the high solubility of boron in metals to create a boronized layer on the surface which serves as the boron source to confine the growth of BNNTs. Dense and uniform BNNTs are obtained after loading catalysts onto the boronized substrate and annealing under ammonia. Confirmatory experiments demonstrate that the boride layer provides boron for BNNTs growth. Furthermore, the patterned growth of BNNTs is realized by patterning the boronizing region, demonstrating the controllability of this method. In addition, the Ni substrate with BNNTs growth exhibits better performance in corrosion resistance and thermal conductivity than pure Ni. This study introduces an alternative strategy for the surface growth of BNNTs based on boron source design, which offers new possibilities for the controllable preparation of BNNTs for various applications.