Electronic Characterization of CVD Diamond

Sammanfattning: Diamond is a promising material for high-power, high-frequency and hightemperatureelectronics applications, where its outstanding physical propertiescan be fully exploited. It exhibits an extremely high energy gap, veryhigh carrier mobilities, high breakdown field strength, and the highest thermalconductivity of any wide bandgap material. It could therefore producethe fastest switching, the highest power density, and the most efficient electronicdevices obtainable, with applications in the RF power, automotive andaerospace industries. Lightweight diamond devices, capable of high temperatureoperation in harsh environments, could also be used in radiationdetectors and particle physics applications where no other semiconductordevices would survive.The high defect and impurity concentration in natural diamond or polycrystallinehigh-pressure-high-temperature (HPHT) diamond substrates hasmade it difficult to establish reliable results when studying the electronicproperties of diamond. However, recent progress in the growth of high puritySingle-Crystal Chemical Vapor Deposited Diamond (SC-CVD) has openedthe perspective of applications under such extreme conditions based on thistype of artificial diamond.Despite the improvements, there are still many questions which must beanswered. This work will focus on electrical characterization of (SC-CVD)diamond by different measurements techniques such as internal photoemission,I-V, C-V, Hall and in particular, time-of-flight (TOF) carrier driftvelocity measurements. With the mentioned techniques, some importantproperties of diamond such as drift mobilities, lateral carrier transit velocities,compensation ratio and Schottky barrier heights have been investigated.Low compensation ratios (ND/NA) < 10-4 have been achieved in boron-dopeddiamond and a drift mobility of about 860 cm2 / V for the hole transit nearthe surface in a lateral TOF configuration could be measured.