超低介电常数纳米多孔SiO2薄膜制备技术进展

纳米多孔SiO2薄膜具有超低的介电常数，作为绝缘介质在超大规模集成电路互连系统有着巨大的应用潜力。文中概述了纳米多孔SiO2薄膜的孔隙度与介电常数的关系，指出所有模型均位于串联和并联模型之间，介电常数均随孔隙度的增加而下降。说明了多孔SiO2薄膜按孔隙度不同主要分气凝胶和干凝胶两类。介绍了从溶液前驱物中合成的原理，绘出了制备纳米多孔SiO2薄膜的一般流程。详细总结了用气凝胶／干凝胶法和模板法制备纳米多孔SiO2薄膜的技术进展。探讨了旋转涂覆制备多孔SiO2薄膜的弱点及改进办法，指明了超低介电常数纳米多孔SiO2薄膜制备技术的发展方向。

TECHNOLOGICAL PROGRESSES IN SYNTHESIS OF ULTRALOW DIELECTRIC CONSTANT NANOPOROUS SILICA FILMS

Nanoporous silica film with ultralow dielectric constant has a great potential usage as interconnection dielectrics in ul-tralarge integration circuits. The relationship between the porosity and the dielectric constant of nanoporous silica film were re-viewed. The curves representing the dielectric constant as a function of the porosity predicted by all the models should lie be-tween the curves for the parallel and serial models. With the porosity increasing, the dielectric constant decreases. It indicates that nanoporous silica film is subdivided into two classes according to resulting porosity. The principle to form silica sol - gel from solution precursors is introduced, and the general procedure in the sol - gel synthesis of porous silica is given. The tech-nological progresses in synthesis of porous silica using an "aerogel or xerogel" process and rnolecular!y template process are summarized in details. The weakness of the porous silica film prepared by spin-on , and the method to improving are also ex-plored. The prospects of synthesis of porous silica are presented.