Apparatus and Method for Non-Destructively Measuring Local Carrier Concentration and Gap Energy in a Semiconductor.
Patent Application, Filed 25 Mar 88,
DEPARTMENT OF THE NAVY WASHINGTON DC
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An apparatus and method for non-destructive measuring of local carrier concentration and bandgap in a semiconductor such as gallium arsenide or gallium aluminum arsenide. A high energy source of photons, e.g. a laser, photo injects carriers on the surface of the semiconductor causing a change in the semiconductors surface photo reflectance. The fractional change in photo reflectance is measured for a plurality of the photon energies sufficient to identify several Franz-Keldysh peaks, and the photon energies corresponding to these peaks. This information is used to infer the local electric field strength and carrier concentration of the semiconductor as well as semiconductors bandgap. By noting variations in these parameters throughout the bulk semiconductor, one can identify fatal fabrication flaws in the semiconductor crystal before time and money is expended to fabricate complicated semiconductor architectures in the crystal. Patent applications. mgm
- Inorganic Chemistry
- Fluidics and Fluerics
- Test Facilities, Equipment and Methods