Title :
Resistivity and adhesive strength of thin film metallizations on single crystal quartz
Author :
Vianco, Paul T. ; Sifford, Catherine H. ; Romero, Juan A.
Author_Institution :
Sandia Nat. Labs., Albuquerque, NM, USA
fDate :
3/1/1997 12:00:00 AM
Abstract :
Resistivity and adhesive strength were measured for the thin films 450 /spl Aring/ Cr-1800 /spl Aring/ Au, 450 /spl Aring/ Cr-1000 /spl Aring/ Mo-1800 /spl Aring/ Au, 450 /spl Aring/ Cr-1000 /spl Aring/ Ni-1800 /spl Aring/ Au, 450 /spl Aring/ Mo-1800 /spl Aring/ Au, 1800 /spl Aring/ Au, and 2000 /spl Aring/ Al on z-and AT-oriented single crystal quartz substrates in the as-deposited condition as well as after thermal annealing at 380/spl deg/C and 450/spl deg/C for 30 min in air or vacuum. The Cr-Au films exhibited significant resistivity increases after thermal annealing which were caused by the interdiffusion of Cr and Au. Barrier layers of Mo or Ni limited such increases after heat treatment. The Mo-Au, Au, and Al films exhibited resistivity decreases following thermal annealing. The mean adhesive strengths of the Cr-Au, Cr-Mo-Au, and Cr-Ni-Au films were excellent in the as-deposited and annealed conditions, ranging from 41 MPa to 70 MPa. The Mo-Au and Au films maintained relatively poor adhesion under all circumstances. Heat treatment improved the poor adhesive strength of the as-deposited Al films to values exceeding 63 MPa. Resistivity and adhesive strengths did not differ significantly between the z- and AT-oriented substrates.
Keywords :
adhesion; annealing; electrical resistivity; metallic thin films; metallisation; piezoelectric materials; quartz; 380 C; 450 C; AT-oriented substrate; Al; Au; Cr-Au; Cr-Mo-Au; Cr-Ni-Au; Mo-Au; SiO/sub 2/; adhesive strength; barrier layer; heat treatment; interdiffusion; resistivity; single crystal quartz; thermal annealing; thin film metallization; z-oriented substrate; Adhesive strength; Annealing; Chromium; Conductivity; Gold; Heat treatment; Metallization; Substrates; Thermal resistance; Transistors;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on