Effect of Chemicals on Chemical Mechanical Polishing of Glass Substrates

We investigate the effect of chemicals on chemical mechanical polishing （CMP） of glass substrates. Ceria slurry in an ultra-low concentration of 0.25 wt. % is used and characterized by scanning electron microscopy. Three typical molecules, i.e. acetic acid, citric acid and sodium acrylic polymer, are adopted to investigate the effect on CMP performance in terms of material removal rate （MRR） and surface quality. The addition of sodium acrylic polymer shows the highest MRR as well as the best surface by atomic force microscopy after CMP, while the addition of citric acid shows the worst performance. These results reveal a mechanism that a long-chain molecule without any branches rather than small molecules and common molecules with ramose abundant-electron groups is better for the dispersion of the slurry and thus better for the CMP process.     

In0.49Ga0.51P中缺陷的俘获行为

利用深能级瞬态谱（ＤＬＴＳ）和瞬态光电阻率谱（ＴＰＲＳ）研究了利用金属有机物化学汽相沉淀（ＭＯＣＶＤ）生长的未有意掺杂的Ｉｎ０．４９Ｇａ０．５１Ｐ中缺陷对载流子的俘获过程和发射过程．利用ＤＬＴＳ测量观测到了一个激活能为０．３７ｅＶ的缺陷,该缺陷的俘获势垒值介于１８０ｍｅＶ到２４０ｍｅＶ之间．该缺陷的俘获势垒值的大的分布被解释为缺陷周围原子重组的微观波动．在研究中发现研究这些缺陷的俘获过程比发射过程更有效,俘获势垒为０．０６ｅＶ和０．４０ｅＶ的两个缺陷在俘获过程中被观测到,而在发射过程中并没有观测到     

B2C3簇的结构和振动光谱的理论研究

用量子化学从头计算方法研究了Ｂ２Ｃ３簇各种可能的空间结构，计算了相应的振动光谱和结合能。对Ｂ２Ｃ３最稳定构型的电子结构进行了深入的分析和讨论。     

聚芳醚酮在溶液中分子构象与分子极化

经从头计算，得到４，４′－二氟苯酮二面角为４４°，ＭＥＳ３二面角为５１°；用ＵＶ光谱法研究了单分散齐聚物在Ｈ２ＳＯ４中的分子构象与极化，结果表明：Ｈ２ＳＯ４使羰基质子化是产生极化的主要因素之一，由此产生的新吸收峰在λ＝４００ｎｍ左右；极化作用产生的平面构象经重叠后在λ＝５００ｎｍ左右产生另一新的吸收峰，由质子化模型并考虑组太和相互作用的计算结果与文献一致，证明了聚芳醚酮高聚物在Ｈ２ＳＯ４中，于４０     

超临界CO2在高分子合成与制备中的应用

介绍超临界二氧化碳流体作为介质在高分子合成与制备中的研究进展。文中表明，可在超临界二氧化碳中实施氟代单体的自由基溶液聚合、甲基丙烯酸甲酯的分散聚合、丙烯酸的沉淀聚合、丙烯酰胺的反相乳液聚合以及异丁基乙烯基醚的阳离子聚合等多种聚合反应，可用超临界二氧化碳溶胀聚合法制备梯度共混物。此外，超临界二氧化碳还可用于聚合物分级和聚合物微孔、微纤与微球材料的制备等，显示出超临界二氧化碳是一种对环境无污染且价廉的     

中间体C60（CH3）^—和产物C60（CH3）2的结构及产物光谱性…

用ＩＮＤＯ系列方法对Ｃ＾２－６０与ＣＨ３反应的中间体Ｃ６０（ＣＨ３）＾－进行理论研究。得到具有Ｃ，对称性的构型，结果表明，ＣＨ３加成到Ｃ１５上，将使与共相邻的双键碳（Ｃ３０）的电荷密度和自旋密度达极大值，故加成反应部位在Ｃ３０处；另外，Ｃ１５的对位Ｃ１２也较其它部位易于反应，且有两个反应场所，因而产物Ｃ６０（ＣＨ３）２可能为六元环上的１，２－加成和１，４－加成两种异构体的混合物，同时对两种加成产物     

吗啡和海洛因等生物碱的高效液相色谱化学发光测定

研究了吗啡、可待因、Ｏ＾３单乙酰吗啡和海洛因等生物碱在多聚磷酸介质中与高锰酸钾的发光行为和光谱现象。建立了反相 高效液相色谱化学发光检测吸毒者尿液和雅片中吗啡、可待因等物质的方法。     

氧化铜转化法制备氢氧化钡

以硫化钡为原料,在水溶液中与氧化铜反应,生成氢氧化钡。副产物硫化铜经氧化焙烧生成氧化铜,循环使用于下一次合成中。放出的二氧化硫经石灰乳吸收用来制备亚硫酸氢钙。     

Heterogeneous integration of InP HEMTs on quartz wafer using BCB bonding technology

Heterogeneous integrated InP high electron mobility transistors(HEMTs)on quartz wafers are fabricated successfully by using a reverse-grown InP epitaxial structure and benzocyclobutene(BCB)bonding technology.The channel of the new device is In_0.7Ga_0.3As,and the gate length is 100 nm.A maximum extrinsic transconductance gm,max of 855.5 mS/mm and a maximum drain current of 536.5 mA/mm are obtained.The current gain cutoff frequency is as high as 262 GHz and the maximum oscillation frequency reaches 288 GHz.In addition,a small signal equivalent circuit model of heterogeneous integration of InP HEMTs on quartz wafer is built to characterize device performance.     

Impact of symmetric gate-recess length on the DC and RF characteristics of InP HEMTs

We fabricated a set of symmetric gate-recess devices with gate length of 70 nm.We kept the source-to-drain spacing(L_SD)unchanged,and obtained a group of devices with gate-recess length(L_recess)from 0.4μm to 0.8μm through process improvement.In order to suppress the influence of the kink effect,we have done SiN_X passivation treatment.The maximum saturation current density(ID_max)and maximum transconductance(g_m,max)increase as L_recess decreases to 0.4μm.At this time,the device shows ID_max=749.6 mA/mm at V_GS=0.2 V,V_DS=1.5 V,and g_m,max=1111 mS/mm at V_GS=?0.35 V,V_DS=1.5 V.Meanwhile,as L_recess increases,it causes parasitic capacitance C_gd and g_d to decrease,making f_max drastically increases.When L_recess=0.8μm,the device shows f_T=188 GHz and f_max=1112 GHz.