| 摘要 |
An apparatus (30) for determining the minority carrier lifetime of a semiconductor sample (32) includes a positioner for moving the sample relative to a coil (44). The coil (44) is connected to a bridge circuit (42) such that the impedance of one arm of the bridge circuit (42) is varied as sample is positioned relative to the coil (44). The sample (32) is positioned relative to the coil (44) such that any change in the photoconductance of the sample (32) created by illumination of the sample (32) creates a linearly related change in the input impedance of the bridge circuit (42). In addition, the apparatus (30) is calibrated to work at a fixed frequency so that the apparatus (30) maintains a consistently high sensitivity and high linearly for samples of different sizes, shapes, and material properties. When a light source (34) illuminates the sample (32), the impedance of the bridge circuit (42) is altered as excess carriers are generated in the sample (32), thereby producing a measurable signal indicative of the minority carrier lifetimes or recombination rates of the sample (32). |
