Fracture of hard thin films using nanoindentation and nanoscratch techniques: A materials and mechanics approach
- Sandia National Labs., Livermore, CA (United States)
- Applied Materials, Santa Clara, CA (United States)
- Univ. of Minnesota, Minneapolis, MN (United States)
Thin films are used in many applications where special properties are needed to insure performance and reliability. Of particular interest are thin tantalum nitride films. They are used extensively in microelectronic applications because of their long term stability and low thermal coefficient of resistance. They are sputter deposited which produces films with a high structural defect content and high compressive residual stresses both of which can alter the physical and mechanical properties of microelectronic thin films. Although these films are strong heat generators, they exhibit no changes in structure or composition of the interface with aluminum oxide substrates that degrade performance or reliability. However, the use of high power density components is driving a move to replace aluminum oxide with aluminum nitride for greater heat transfer. 6 This replacement substrate creates concern as residual stresses and long-term operation could induce detrimental changes along the thin film interface not observed in aluminum oxide devices. As a result, the authors employed nanoindentation and continuous nanoscratch testing to determine the effects of the intrinsic compressive residual stresses on the properties and fracture resistance of the thin tantalum nitride films. These techniques sample small volumes of material while preserving the production configuration of a free surface. Although nanoscratch tests lack a rigorous derivation of stress distributions and strain energy release rates, good approximations for strain energy release rates can be obtained using mechanics-based models for blister formation where residual stresses dominate interfacial fracture behavior. When combined with scanning and transmission electron microscopy, the results define structure-property relationships and resistance to fracture of these hard films.
- Research Organization:
- Sandia National Lab. (SNL-CA), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 654125
- Report Number(s):
- SAND-98-8504C; CONF-980627-; ON: DE98052525; TRN: AHC2DT05%%210
- Resource Relation:
- Conference: 1998 SEM spring conference on experimental and applied mechanics, Houston, TX (United States), 1-3 Jun 1998; Other Information: PBD: 19 Mar 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Aging effects on the durability of tantalum nitride films
Fracture of thin tantalum nitride films on AlN substrates