AVS 46th International Symposium
    Electronic Materials and Processing Division Thursday Sessions
       Session EM2-ThA

Paper EM2-ThA3
Characterization of PECVD SiC and its Application in Advanced Reticle Technology-SCALPEL Membrane

Thursday, October 28, 1999, 2:40 pm, Room 611

Session: Silicon Carbide and Dielectrics on Si
Presenter: S. Han, Motorola, Inc.
Authors: S. Han, Motorola, Inc.
W.J. Dauksher, Motorola, Inc.
P.J.S. Mangat, Motorola, Inc.
K.D. Cummings, Motorola, Inc.
S.M. Smith, Motorola, Inc.
Correspondent: Click to Email
The material which forms thin membrane layer (1000@Ao@) in Scattering with Angular Limitation Projection Electron Beam Lithography (SCALPEL) mask technology should satisfy a handful of rigid requirements such as stress controllability, high mechanical stiffness and good chemical etch resistance for wet processing. We have demonstrated that amorphous PECVD SiC can be an excellent choice of material that satisfies the criteria above. SiC potentially could be a better candidate for the membrane layer than silicon nitride, which is currently recommended. Furthermore, it has the possibility of better membrane yield and improved image placement because the elastic modulus for SiC is almost twice that for silicon nitride. Amorphous SiC films were prepared by PECVD using SiH4 and CH4 chemistries. The as-deposited intrinsic stress can be varied from mid-compressive to weak tensile depending on the deposition conditions. Furthermore, we have shown that the magnitude and sign of the as-deposited stress in the film can be modulated by RTA anneal cycle. Stress level in the films can be modified to our level of interest (about 1e9 dynes/cm2 tensile.) In addition, the etch resistance in KOH etchant, an important criteria, is improved after the post annealing cycle. This is associated with hydrogen evolution during the annealing, which reduces the density of hydrogen bonds with C and Si. Results will include the yield impact of controlling stress on the membrane by deposition conditions or by post annealing. In addition, characterization results of films using FTIR and RBS for hydrogen bonding and atomic ratio, respectively will be included. In summary, this paper addresses comprehensive information on a uniform, low stress PECVD SiC that can be used as a membrane material for SCALPEL mask technology.