hall effect measurement

**Hall Effect Measurement** is a **semiconductor characterization technique that determines carrier type, concentration, and mobility** — by measuring the transverse voltage (Hall voltage) developed when a current-carrying sample is placed in a perpendicular magnetic field. **How Does It Work?** - **Setup**: Current $I$ flows through the sample in the $x$-direction. Magnetic field $B$ is applied in the $z$-direction. - **Hall Voltage**: $V_H = IB / (nqt)$ develops in the $y$-direction (Lorentz force on carriers). - **Carrier Type**: Sign of $V_H$ indicates $n$-type (electrons) or $p$-type (holes). - **Mobility**: $mu = V_H / (R_s cdot I cdot B)$ combined with sheet resistance measurement. **Why It Matters** - **Non-Destructive**: Determines carrier type, concentration, and mobility without damaging the sample. - **Process Monitoring**: Monitors implant dose and activation in production. - **Material Qualification**: Standard measurement for qualifying epitaxial wafers and substrates. **Hall Effect Measurement** is **the carrier census** — counting charge carriers and measuring their speed using the transverse force from a magnetic field.