Lateral bipolar structures for evaluating the effectiveness of surface doping techniques

A lateral bipolar test structure is presented for evaluating the effectiveness of surface doping techniques used to fabricate ultrashallow diodes and ohmic contacts. The test structure requires very limited processing and simple I-V measurements provide a separation of the hole and electron currents across the junction under investigation. The ability to discern between Schottky-like and pn-junction diodes is demonstrated by the measurement of a series of junctions fabricated by arsenic dopant deposition plus laser annealing. The activation and drive-in of the deposited arsenic is tuned by the laser energy.