Status of Non-contact Electrical Measurements

Non‐contact electrical metrology includes a variety of characterization techniques used to determine a number of material/device electrical parameters. These powerful methods, used on full wafers at various processing stages, complement the traditional device‐based contact electrical (capacitance‐voltage and current‐voltage) measurements of MOS‐based structures. The non‐contact electrical techniques are usually built around measurements of surface photovoltage and surface voltage in combination with illumination and corona charge deposited on a sample. In principle this allows recombination lifetime, minority carrier diffusion length, and iron contamination density to be determined for bulk silicon; generation lifetime, doping density and doping profile to be measured for near‐surface silicon; and equivalent oxide thickness, oxide charge density, mobile charge density, total charge density, flat band voltage, dielectric integrity and other parameters to be obtained for dielectric films. Interface trap den...