Hints, Tips and Solutions – February 2005
Q: Can ATHENA get the STRESS in Compound Advanced material?
A: The ATHENA STRESS command has been augmented to allow the 2 Dimensional stress distribution. To get the STRESS, the simple SiO2/GaAs/AlGaAs Optical waveguide was considered.
When the temperature difference is -400 C, then the command is
STRESS TEMP1=430 TEMP2=30
And to get the stress, the material parameters need for the SiO2, GaAs, AlGaAs as Table 1.
| GaAs | AlxGa1-xAs | SiO2 | |
| Young.m dynes/cm2 | 8.538e11 | (8.53-0.18x)e11 | 7.679e11 |
| Poission Raio | 0.31 | 0.31+0.1x | 0.186 |
| Linear Coefficient ofThermal Expansion /K | 5.73e-6 | (5.73-0.53x)e-6 | class=”table-cells”5.4e-7 |
As the all material parameter of the AlxGa1-xAs depends on the mole fraction, in Deckbuild, the SET command is useful for the definition of the material parameters as like,
# for AlxGa1-xAs
set xcomp=0.3
material algaas Young.m=((8.53- 0.18*$xcomp)*1e11)
material algaas Poiss.r=(0.31+0.1*$xcomp)
material algaas lcte=((5.73- 0.53*$xcomp)*1e-6
Then the stress distribution shows in Figure 1. Figure 1 (a) shows the Stress X and (b) shows the Stress Y. And the magnitude of positive is the compressive strss and the negative is the tensile stress.
