Characterization of electron‐beam deposited tungsten films on sapphire and silicon
| Autor: | J. Angillelo, J. H. Souk, J. F. O’Hanlon |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Materials science
chemistry.chemical_element Surfaces and Interfaces Substrate (electronics) Tungsten Condensed Matter Physics Epitaxy Electron beam physical vapor deposition Surfaces Coatings and Films Crystallography Surface coating chemistry Electrical resistivity and conductivity Sapphire Kikuchi line |
| Zdroj: | Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 3:2289-2292 |
| ISSN: | 1520-8559 0734-2101 |
| DOI: | 10.1116/1.572866 |
| Popis: | In this work, the electrical and structural properties of e-beam deposited tungsten films on sapphire are described. Tungsten thin films (200--400 nm) were evaporated on sapphire substrates at different substrate temperature T/sub s/. Film resistivity varied from 95 ..mu cap omega.. cm deposited at room temperature to 5.5 ..mu cap omega.. cm deposited at T/sub s/ between 440 and 500 /sup 0/C. The resistivity value of 5.5 ..mu cap omega.. cm is comparable to the bulk resistivity value of 5.50--5.65 ..mu cap omega.. cm. The crystalline structure of these films was characterized by x-ray diffraction and scanning transmission electron microscopy (STEM) (Kikuchi lines). The films show a distinct increase in the degree of crystal orientation as T/sub s/ approaches 400 /sup 0/C. The films deposited at 400 /sup 0/C and above shows (100) epitaxial growth on the (1102)= plane or r plane of sapphire, which has a distorted fourfold symmetry. Film stresses which vary from tensile (7.3 x 10/sup 9/ dyn/cm/sup 2/) to compressive (-4.4 x 10/sup 9/ dyn/cm/sup 2/) between 100 and 500 /sup 0/C were measured by the interference fringe technique. The intrinsic stress was determined to vary from 8.3 x 10/sup 9/ dyn/cm/sup 2/ at T/sub s/more » = 100 /sup 0/C to 2.4 x 10/sup 9/ dyn/cm/sup 2/ at T/sub s/ = 500 /sup 0/C. The observed intrinsic stresses (tensile) in epitaxial films are regarded as produced by the lattice misfit at the film--substrate interface. The minimum total film stress was obtained between T/sub s/ = 350 and 400 /sup 0/C, where tensile intrinsic stress was compensated by the compressive thermal stress.« less |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|