J. Phys. IV France 03 (1993) C3-433-C3-440
Adhesion and leakage current characteristics of selective CVD tungsten films on the silicon substrateC. LEE1, Y.J. IM2 and J.G. LEE2
1 Department of Metallurgical Engineering, Inha University, 253 Yonghyun-dong, Inchon 402-751, Korea
2 Samsung Electronics, P.O. Box 37, Suwon, Korea
In this study we investigated the effects of SF6 and CF4 plasma pretreatments on the adhesion and junction leakage characteristics of the selective CVD W films by SiH4 reduction of WF6 on the Si substrate. The SF6 plasma pretreatment performed in situ prior to W deposition to remove the polymer films in contact holes results in enhancement of the adhesion of W films to the Si substrate but degradation of junction leakages due to vertical and lateral Si consumptions. The CF4 plasma pretreatment performed as the last step of the reactive ion etching for contact window opening produced the W/Si contacts of good adhesion, low contact resistances and low junction leakages for thin W films, while it produced the W/Si contacts of poor adhesion and high contact resistances for thick W films. The selective CVD W films deposited by the three step process of SiH4 reduction/ in situ annealing / SiH4 reduction was found to have both good adhesion and low junction leakage characteristics.
© EDP Sciences 1993