Measuring the stress tensor in nitrogen-doped CVD diamond using solid-state quantum sensor

Area of Science:

• Materials Science
• Solid State Physics
• Diamond Technology

Background:

• Residual stress significantly impacts the properties and performance of diamond films.
• Nitrogen doping is a common technique to modify diamond's electronic and optical characteristics.
• Understanding stress in diamond films is crucial for applications in electronics and photonics.

Purpose of the Study:

• To quantify the residual stress tensor in nitrogen-doped (001) chemical vapor deposition (CVD) diamond films.
• To investigate the spatial variation of stress distribution within the diamond film.
• To determine the influence of nitrogen doping on the stress state and volume of the diamond film.

Main Methods:

• Utilized optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers to measure the stress tensor components.
• Employed a confocal microscopy setup for spatially resolved stress mapping.
• Analyzed shifts in ODMR spectra to deduce stress values.

Main Results:

• The residual stress tensor components (σxy, σyz, σzx, σxx+σyy+σzz) were determined to be approximately 0.077, -0.39, -0.67, and 1.52 GPa, respectively.
• Identified significant shear stress in the growth direction (z-direction) of the CVD diamond film.
• Observed compressive axial stress (σxx+σyy+σzz) leading to a 0.073% volume reduction.

Conclusions:

• Nitrogen doping in CVD diamond films results in a compressive stress state.
• The observed compressive stress and subsequent volume decrease are attributed to the presence of nitrogen.
• These findings provide critical insights into the mechanical behavior of doped diamond films for advanced applications.