Contactless method for electrical characterization of silicon-on-insulatormaterials

The Kelvin-probe method, in combination with surface photovoltage (SPV) mea surements, is applied to the nondestructive electrical characterization of silicon-on-insulator (SOI) materials. It is shown that a simple sandwich-ty pe electrode configuration can be used for the contactless characterization of the SOI layer, when the capacitance between the vibrating electrode and the SOI surface is much smaller than the buried-oxide (BOX) and depletion- layer series capacitances. The light-intensity dependence of the SPV gives data equivalent to common cuurent-voltage (I-V) characteristics of diodes. Thus, we call the proposed method the contactless I-V method. Lastly, we de monstrate that UV illumination is effective for applying the contactless I- V method to ultrathin SOI layers such as fully depleted SOI material.