Temperature-dependent carrier mobility variations in commercially available silicon diodes

How reliably do commercial silicon diodes perform across the temperature ranges encountered in practical electronic applications? This research presents systematic measurements of carrier mobility variations in commercially available silicon diodes spanning temperatures from 250K to 375K, addressing a knowledge gap between idealized theoretical predictions and actual device behavior. The investigation examined 127 diode samples from five major semiconductor manufacturers, representing both general-purpose rectifier and signal diode categories commonly deployed in industrial and consumer electronics. Measurements were conducted at the Stockholm Institute of Applied Sciences semiconductor characterization facility between January and August 2024, employing Hall Effect measurements combined with current-voltage characterization techniques calibrated against national metrology standards. The experimental approach isolated mobility contributions from various scattering mechanisms by analyzing temperature-dependent behavior across devices with different doping concentrations ranging from 10^14 to 10^18 cm^-3. Results demonstrated that lattice scattering dominated mobility reduction at elevated temperatures, accounting for approximately 48.3% of total mobility degradation at 350K. Ionized impurity scattering contributed 23.7%, while carrier-carrier interactions and surface effects accounted for 12.4% and 9.8% respectively. These proportions showed remarkable consistency across manufacturer sources, suggesting that fundamental physical mechanisms overshadow manufacturing process variations for this parameter. Quantitative mobility measurements revealed values ranging from 1420 cm^2/V.s at 250K for lightly doped samples to 650 cm^2/V.s at 375K for heavily doped specimens. The temperature coefficient of mobility averaged -0.42% per kelvin across all samples, though individual devices showed coefficients ranging from -0.31% to -0.58% depending on doping level and manufacturing source. Heavily doped devices exhibited less temperature sensitivity due to the already-dominant role of impurity scattering at room temperature. Statistical analysis across manufacturers revealed that while mean mobility values differed by up to 8.3% between sources, the temperature dependence patterns remained highly consistent. This finding carries practical implications for circuit designers who may substitute equivalent devices from different manufacturers without significantly altering temperature compensation requirements. However, tighter tolerances in precision analog applications may still necessitate manufacturer-specific characterization. The research establishes empirical relationships enabling mobility prediction across the tested temperature and doping ranges with uncertainty below 4.2%. These relationships employ modified power-law formulations incorporating both lattice and impurity scattering terms, providing superior accuracy compared to simplified single-mechanism models commonly found in undergraduate textbooks and simulation libraries. Circuit designers can apply these refined models to improve temperature compensation accuracy in applications ranging from power electronics to precision instrumentation where silicon diode characteristics influence overall system performance.