Abstract
In order to achieve better performance of devices, the interconnects RC delay time, the limiting factor of the device speed today, must be reduced. This calls for a new interconnect stack: lower resistivity Copper and low k materials (k<3) as dielectrics. Fluorinated amorphous carbon (a-F:C) prepared by HDP- CVD is an attractive candidate as a low-k material. In this work we have studied the film, its stability and its interface with Copper metallization. The high density plasma CVD process resulted in a film which contains C and F at a ratio of 1:0.6 as determined by Nuclear Reactions Analysis. XPS analysis of the C1s transition indicated four types of bonds: C-C, C-CF, CF, and CF2. X-ray diffraction as well as high resolution TEM analyses proved that the film was amorphous at least up to 500°C anneal. For various applications, the advantage of adding a thin bi-layer of a-SiC/SiOx for adhesion promotion purposes was demonstrated. In addition, the interface of a-F:C and the adhesion promoter layer with Ta, TaN and Cu was studied. No interdiffusion was observed by SIMS after 400°C annealing. 500°C annealing caused F outdiffusion from the film and Cu diffusion into the adhesion promoter layer.
Original language | English |
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Pages (from-to) | 565-570 |
Number of pages | 6 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 564 |
DOIs | |
State | Published - 1999 |
Externally published | Yes |
Event | Proceedings of the 1999 MRS Spring Meeting - Symposium N: 'Advanced Interconnects and Contacts' - San Francisco, CA, United States Duration: 5 Apr 1999 → 7 Apr 1999 |