掺CH4的SiCOH低介电常数薄膜结构与介电性能研究

以十甲基环五硅氧烷和甲烷作为反应气体，采用电子回旋共振等离子体化学气相沉积(ECR-C VD)方法制备了k = 2.45，485℃下的热稳定性优良的SiCOH低介电常数薄膜.通过薄膜结构的 FTIR谱分析，比较了十甲基环五硅氧烷(D5)液态源和不同甲烷流量下制备的薄膜的键结构差 异，发现在沉积过程中甲烷含量的增大，一方面有利于D5源环结构的保留，另一方面有利于 薄膜中形成高密度的CH_n基团.高密度碳氢大分子基团的存在降低了薄膜密度， 结合薄膜中形成的本构孔隙、低极化率Si—C键以及—OH键减少的共同作用，导致薄膜介电 常数的降低. 关键词： 低介电常数 SiCOH薄膜 碳氢掺杂     

CHx掺杂SiCOH低介电常数薄膜的物性热稳定性分析

研究了真空热处理对掺CH.的SiCOH低介电常数薄膜的电流.电压(I-V)特性、电容.电压(C-V)特性、疏水性能以及微结构的影响.结果表明:在热处理过程中,热稳定性较差的碳氢基团发生了热解吸,使薄膜的漏电流减小、绝缘性能改善,并使薄膜的导电行为更趋于空间电荷限流过程.碳氢基团的热解吸使SiCOH/Si界面的界面态发生改变,导致SiCOH薄膜MIS结构的平带电压VFB发生漂移.封端的碳氢基团热解吸使薄膜表面的开口孔结构减少,薄膜表面变得更平整.但是碳氢基团为疏水基团,其热解吸导致薄膜的疏水性能降低.     

CHx掺杂SiCOH 低介电常数薄膜的物性热稳定性分析

研究了真空热处理对掺CH₄的SiCOH低介电常数薄膜的电流-电压(I-V)特性、电容-电压(C-V)特性、疏水性能以及微结构的影响. 结果表明：在热处理过程中,热稳定性较差的碳氢基团发生了热解吸,使薄膜的漏电流减小、绝缘性能改善,并使薄膜的导电行为更趋于空间电荷限流过程. 碳氢基团的热解吸使SiCOH/Si界面的界面态发生改变,导致SiCOH薄膜MIS结构的平带电压V_FB发生漂移. 封端的碳氢 关键词： SiCOH薄膜 热处理 结构与性能     

Si—OH基团对SiCOH低k薄膜性能的影响与控制

研究了十甲基环五硅氧烷(D5)的电子回旋共振等离子体沉积的SiCOH薄膜中Si—OH基团对介电性能和漏电流的影响.结果表明Si—OH含量的增大会导致介电常数k的增大、漏电流的降低和介电色散的增强.由于Si—OH结构的强极化补偿了薄膜密度减小带来的介电常数降低，导致总的介电常数k增大.高Si—OH含量下漏电流的降低是由于封端的Si—OH基团降低了薄膜中Si—O网络的连通概率p而导致网络电导下降的缘故.介电色散的增强与Si—OH封端结构的快极化过程有关.改变放电参数以提高电子能量，从而提高源的电离程度，使更多的Si—OH基团断裂并通过缩合反应形成Si—O—Si网络，可以进一步降低薄膜的介电常数. 关键词： SiCOH薄膜 Si—OH结构 介电性能 ECR放电等离子体     

Broadband acoustic focusing by symmetric Airy beams with phased arrays comprised of different numbers of cavity structures

We realize broadband acoustic focusing effect by employing two symmetric Airy beams generated from phased arrays,in which the units of the phased arrays consist of different numbers of cavity structures, each of which is composed of a square cavity and two inclined channels in air. The exotic phenomenon arises from the energy overlapping of the two symmetric Airy beams. Besides, we demonstrate the focusing performance with high self-healing property, and discuss the effects of structure parameters on focusing performance, and present the characteristics of the cavity structure with straight channels. Compared with other acoustic lenses, the proposed acoustic lens has advantages of broad bandwidth(about 1.4 kHz), high self-healing property of focusing performance, and free adjustment of focal length. Our finding should have great potential applications in ultrasound imaging and medical diagnosis.     

Effect of F- and CH-Doped on Dielectric Properties of SiCOH Films Deposited by Decamethylcyclopentasiloxane Electron Cyclotron Resonance Plasma

We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by de- camethylcyclopentasiloxane （DMCPS） electron cyclotron resonance plasma. The dielectric constant k is closely related to the configurations of films. For the films deposited only using DMCPS, the minimum k is as low as 2.88. By adding CH4 in the precursor, the k value can be reduced to 2.45 due to the film density decreasing by incorporating large size CHx groups. By adding CHF3 in the precursor, the k value can also be reduced to 2.48 due to the incorporation of the weak-polarization F atom. Thus the dielectric constant for SiCOH films depends on not only the film density but also the polarization of atoms. By increasing the film density or by reducing the polarization of atoms under the condition of a lower film density, the low dielectric constant SiCOH films can be obtained.     

O2掺杂对SiCOH低k薄膜结构与电学性能的影响

以十甲基环五硅氧烷(D5)和氧气(O₂)作为反应气体，采用电子回旋共振等离子体化学气相沉积(ECR-CVD)方法制备了k＝2.62的SiCOH薄膜.研究了O₂掺杂对薄膜结构与电学性能的影响.结果表明，采用O₂掺杂可以在保持较低介电常数的前提下极大地降低薄膜的漏电流，提高薄膜的绝缘性能，这与薄膜中Si-O立体鼠笼、Si-OH结构含量的提高有关. 关键词： SiCOH薄膜 2掺杂')" href="#">O₂掺杂 介电性能 键结构     

Do we need to use regularization for the thermal part in the NJL model?

The Nambu–Jona-Lasinio(NJL)model is one of the most useful tools for studying non-perturbative strong interactions in matter.Because it is a nonrenormalizable model,the choice of regularization is a subtle issue.In this paper,we discuss one of the general issues regarding regularization in the NJL model,which is whether we need to use regularization for the thermal part by evaluating the quark chiral condensate and thermal properties in the two-flavor NJL model.The calculations in this work include three regularization schemes that contain both gauge covariant and invariant schemes.We found that,regardless of the regularization scheme we choose,it is necessary to use regularization for the thermal part when calculating physical quantities related to the chiral condensate and to not use regularization for the thermal part when calculating physical quantities related to the grand potential.     

掺CH4的SiCOH低介电常数薄膜结构与介电性能研究

以十甲基环五硅氧烷和甲烷作为反应气体,采用电子回旋共振等离子体化学气相沉积(ECR-CVD)方法制备了k=2.45,485℃下的热稳定性优良的SiCOH低介电常数薄膜.通过薄膜结构的FTIR谱分析,比较了十甲基环五硅氧烷(D5)液态源和不同甲烷流量下制备的薄膜的键结构差异,发现在沉积过程中甲烷含量的增大,一方面有利于D5源环结构的保留,另一方面有利于薄膜中形成高密度的CHn基团.高密度碳氢大分子基团的存在降低了薄膜密度,结合薄膜中形成的本构孔隙、低极化率Si-C键以及-OH键减少的共同作用,导致薄膜介电常数的降低.     

improvement of electrical properties of Cu/SiCOH low-k film integrated system by O2 plasma treatment

This paper investigates the effect of O2 plasma treatment on the electric property of Cu/SiCOH low dielectric constant （low-k） film integrated structure. The results show that the leakage current of Cu/SiCOH low-k integrated structure can be reduced obviously at the expense of a slight increase in dielectric constant k of SiCOH films. Bythe Fourier transform infrared （FTIR） analysis on the bonding configurations of SiCOH films treated by O2 plasmar it is found that the decrease of leakage current is related to the increase of Si-O cages originating from the linkage of Si dangling bonds through O, which makes the open pores sealed and reduces the diffusion of Cu to pores.