Si—OH基团对SiCOH低k薄膜性能的影响与控制  

Influence of Si—OH groups on properties and avoidance for SiCOH films prepared by decamethylcyclopentasiloxane electron cyclotron resonance plasma

作　　者：叶超[1] 宁兆元[1] 辛煜[1] 王婷婷[1] 俞笑竹[1] 

机构地区：[1]苏州大学物理科学与技术学院

出　　处：《物理学报》2006年第5期2606-2612,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10575074);苏州大学薄膜材料江苏省重点实验室资助的课题~~

摘　　要：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.This paper investigates the effect of Si-OH groups on dielectric property and leakage current of the SiCOH low dielectric constant films deposited by decamethylcyclopentasioxane （DS） electron cyclotron resonance plasma. The results show that the increasing of Si-OH content in the films can lead to the increasing of dielectric constant k, decreasing of leakage current and rise in dielectric dispersion. The increasing of k value is the result of compensation of the decreasing of k value originated from cage by the strong polarization of Si-OH groups. The decreasing of leakage current at high Si-OH content is due to the low connecting probability p of networks because the networks break at the terminal Si-OH groups. In the case of high ionization degree of D5 plasma, more Si-OH groups break and form Si-O-Si linkages by chemical condensation occurring between proximal Si-OH groups. As a result, the k value of SiCOH films can be further reduced.

关 键 词：SiCOH薄膜 Si-OH结构 介电性能 ECR放电等离子体 

分 类 号：O484.4[理学—固体物理]