(Color) Schematic of polysilicon doped microheater measuring wide.
Stokes-shifted peak position under the effects of both temperature (top) and stress (bottom). The dual linear dependence of the Stokes-shifted peak position makes the measurement of either parameter impossible when both effects are present.
Stokes linewidth under the effects of both temperature (top) and stress (bottom). The linewidth varies parabolically with temperature while showing no correlation with respect to mechanical loading, thus allowing for accurate temperature measurement even in the presence of stress.
Relationship between temperature and relative linewidth for single crystalline and several polycrystalline silicon samples. Data show that the temperature vs relative linewidth change is very similar regardless of the microstructural aspects of the silicon sample. The relative linewidth is defined as from Eq. (15).
(Color) Temperature (°C) maps of the beam at 240 (top) and (bottom).
Temperature distribution across the length of the microheater when dissipating 240 (top) and of power (bottom). The peak-based method significantly underpredicts the temperature indicating, as expected, that the beam is under a compressive stress.
The inherent variation in the stress measurements was determined to be for the temperature range of interest in this study. The variation is primarily controlled by the scatter from the Stokes linewidth measurement.
Data comparison of biaxial stress calculated using finite-element analysis (FEA) and Raman spectroscopy for power dissipation levels of 240 (top) and (bottom). At the higher power level, the Raman data show a lower stress level than that calculated by FEA which is close to the inherent uncertainty of the system . This may be due to the use of a temperature independent modulus in the analysis.
Calibration constants calculating biaxial stress and temperature.
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