AVS 47th International Symposium
    Manufacturing Science and Technology Wednesday Sessions
       Session MS-WeA

Paper MS-WeA6
FSG Film Characterization and Process Development for Copper/Damascene Technology

Wednesday, October 4, 2000, 3:40 pm, Room 304

Session: Process Integration (Cu/Low-k/300mm)
Presenter: J.S. Martin, Texas Instruments, Inc.
Authors: J.S. Martin, Texas Instruments, Inc.
K.J. Taylor, Texas Instruments, Inc.
J.D. Luttmer, Texas Instruments, Inc.
A.R.K. Ralston, Texas Instruments, Inc.
T.D. Bonifield, Texas Instruments, Inc.
J.A. West, Texas Instruments, Inc.
C.T. Adams, Novellus Systems, Inc.
K.-H. Chew, Novellus Systems, Inc.
A. Bayman, Novellus Systems, Inc.
B. van Schravendijk, Novellus Systems, Inc.
Correspondent: Click to Email
The microelectronics industry is transitioning from wiring devices with aluminum and oxide-based interconnect structures to damascene-based integration, with both copper and low-k materials. Toward this end, we outline the process technology and material characterization for a fluorosilicate glass (FSG) developed specifically for copper/damascene technology, where both the via and metal line are embedded in FSG at six levels. We compare FSG deposited in both high density plasma (HDP) and standard PECVD reactors, for K values within the range 3.50 - 3.70. Fluorine loss and water absorption are appreciably less for HDP-FSG films. We note two additional issues for FSG processes and films. First, adhesion to subsequently deposited PECVD silicon nitride is problematic and delamination increases with thicker FSG films. Second, deposition temperature strongly influences in-film [F], but for systems without active wafer temperature control, wafer temperature, and hence in-film [F] depends on the substrate dopant concentration. We briefly outline our methods for actively controlling wafer temperature to ± 5°C during deposition and monitoring [F] in-line via X-ray fluorescence (XRF). HDP-FSG thin films are thus deposited with active temperature control, and in-film [F] is controlled to within ± 0.2 atomic percent, as measured by XRF. Most important, by systematically decreasing in-film [F] over a 25% range, we observe that K-value increases by 0.10 and adhesion to silicon nitride significantly improves. We view this as a viable FSG process, applicable at the 0.18 µm and 0.13 µm nodes.