Nondestructive and Noncontact Observation of Microdefects in GaAs Wafers with a New Photo-Thermal-Radiation Microscope
Abstract
A nondestructive and noncontact method for observation of microdefects in GaAs wafers has been developed with a new photo-thermal-radiation (PTR) microscope. We measured the PTR signal as a function of excitation energy (PTR spectrum) and the spatial distribution of PTR intensity (PTR image) of n-GaAs wafers at room temperature. We found that the PTR spectra have a peak due to a nonradiative state of microdefects at wavelengths ranging from 895 to 903 nm. The present PTR image shows inhomogeneities of microdefect density in GaAs wafers which cannot be observed by X-ray topography.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- November 1985
- DOI:
- 10.1143/JJAP.24.L876
- Bibcode:
- 1985JaJAP..24L.876N
- Keywords:
-
- Crystal Defects;
- Gallium Arsenides;
- N-Type Semiconductors;
- Nondestructive Tests;
- Inhomogeneity;
- Laser Applications;
- Microscopes;
- Thermal Radiation;
- Wafers;
- Solid-State Physics