Stress in evaporated films used in GaAs processing

Abstract

A simple and practical method is described for determining the residual stress in vapor deposited thin films that are less than 1000 Å in thickness. The method relies on the evaporation of thin films onto prefabricated micro-cantilever beams of SiO2. The vertical deflection at the end of the beam is measured using an optical microscope to determine the average film stress with a resolution of 25 MPa. Calculations show that the vapor deposition of metal films onto these beams does not induce significant heating, so the thermal component of residual film stress is minimal. The micro-cantilever technique is used to measure the film stress in 500 Å films of Al, Ti, Pt, Au, Ni, and Ge. These measured values are compared to similar measurements reported in the literature.

Laser machined ultrathin microscale platinum thermometers on transparent oxide substrates

“…Further, the overall value of TCRs increases, agreeing with the literature [49]. Insufficient annealing time means larger residual stress [52] inside Pt and between layers, which contribute to the stronger hysteresis manifested in Fig. 3fii.…”

Electro-thermal resistance of GaAs interconnects

“…Each metal within the combination exhibits a different tensile film stress. 17 Trapped during deposition are vacancies on the Au surface and at grain boundaries, [18][19][20] which increase R over its bulk value. 18 The thermal conductivity κ in Eq.…”